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Annotation of OpenXM_contrib2/asir2000/gc/os_dep.c, Revision 1.8

1.1       noro        1: /*
1.2       noro        2:  * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
1.1       noro        3:  * Copyright (c) 1991-1995 by Xerox Corporation.  All rights reserved.
1.2       noro        4:  * Copyright (c) 1996-1999 by Silicon Graphics.  All rights reserved.
                      5:  * Copyright (c) 1999 by Hewlett-Packard Company.  All rights reserved.
1.1       noro        6:  *
                      7:  * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
                      8:  * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
                      9:  *
                     10:  * Permission is hereby granted to use or copy this program
                     11:  * for any purpose,  provided the above notices are retained on all copies.
                     12:  * Permission to modify the code and to distribute modified code is granted,
                     13:  * provided the above notices are retained, and a notice that the code was
                     14:  * modified is included with the above copyright notice.
                     15:  */
                     16:
1.4       noro       17: # include "private/gc_priv.h"
1.1       noro       18:
                     19: # if defined(LINUX) && !defined(POWERPC)
                     20: #   include <linux/version.h>
                     21: #   if (LINUX_VERSION_CODE <= 0x10400)
                     22:       /* Ugly hack to get struct sigcontext_struct definition.  Required      */
                     23:       /* for some early 1.3.X releases.  Will hopefully go away soon. */
                     24:       /* in some later Linux releases, asm/sigcontext.h may have to   */
                     25:       /* be included instead.                                         */
                     26: #     define __KERNEL__
                     27: #     include <asm/signal.h>
                     28: #     undef __KERNEL__
                     29: #   else
                     30:       /* Kernels prior to 2.1.1 defined struct sigcontext_struct instead of */
                     31:       /* struct sigcontext.  libc6 (glibc2) uses "struct sigcontext" in     */
                     32:       /* prototypes, so we have to include the top-level sigcontext.h to    */
                     33:       /* make sure the former gets defined to be the latter if appropriate. */
                     34: #     include <features.h>
                     35: #     if 2 <= __GLIBC__
1.2       noro       36: #       if 2 == __GLIBC__ && 0 == __GLIBC_MINOR__
1.1       noro       37:          /* glibc 2.1 no longer has sigcontext.h.  But signal.h        */
                     38:          /* has the right declaration for glibc 2.1.                   */
                     39: #         include <sigcontext.h>
                     40: #       endif /* 0 == __GLIBC_MINOR__ */
                     41: #     else /* not 2 <= __GLIBC__ */
                     42:         /* libc5 doesn't have <sigcontext.h>: go directly with the kernel   */
                     43:         /* one.  Check LINUX_VERSION_CODE to see which we should reference. */
                     44: #       include <asm/sigcontext.h>
                     45: #     endif /* 2 <= __GLIBC__ */
                     46: #   endif
                     47: # endif
1.4       noro       48: # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) && !defined(MACOS) \
                     49:     && !defined(MSWINCE)
1.1       noro       50: #   include <sys/types.h>
                     51: #   if !defined(MSWIN32) && !defined(SUNOS4)
                     52: #      include <unistd.h>
                     53: #   endif
                     54: # endif
                     55:
                     56: # include <stdio.h>
1.4       noro       57: # if defined(MSWINCE)
                     58: #   define SIGSEGV 0 /* value is irrelevant */
                     59: # else
                     60: #   include <signal.h>
                     61: # endif
1.1       noro       62:
                     63: /* Blatantly OS dependent routines, except for those that are related  */
1.2       noro       64: /* to dynamic loading.                                                 */
1.1       noro       65:
1.6       noro       66: # if defined(HEURISTIC2) || defined(SEARCH_FOR_DATA_START)
1.1       noro       67: #   define NEED_FIND_LIMIT
                     68: # endif
                     69:
1.6       noro       70: # if !defined(STACKBOTTOM) && defined(HEURISTIC2)
1.1       noro       71: #   define NEED_FIND_LIMIT
                     72: # endif
                     73:
1.3       noro       74: # if (defined(SUNOS4) && defined(DYNAMIC_LOADING)) && !defined(PCR)
1.1       noro       75: #   define NEED_FIND_LIMIT
                     76: # endif
                     77:
1.6       noro       78: # if (defined(SVR4) || defined(AUX) || defined(DGUX) \
                     79:       || (defined(LINUX) && defined(SPARC))) && !defined(PCR)
1.1       noro       80: #   define NEED_FIND_LIMIT
                     81: # endif
                     82:
1.7       noro       83: #if defined(FREEBSD) && defined(I386)
                     84: #  include <machine/trap.h>
                     85: #  if !defined(PCR)
                     86: #    define NEED_FIND_LIMIT
                     87: #  endif
                     88: #endif
                     89:
1.1       noro       90: #ifdef NEED_FIND_LIMIT
                     91: #   include <setjmp.h>
                     92: #endif
                     93:
                     94: #ifdef AMIGA
1.4       noro       95: # define GC_AMIGA_DEF
                     96: # include "AmigaOS.c"
                     97: # undef GC_AMIGA_DEF
1.1       noro       98: #endif
                     99:
1.4       noro      100: #if defined(MSWIN32) || defined(MSWINCE)
1.1       noro      101: # define WIN32_LEAN_AND_MEAN
                    102: # define NOSERVICE
                    103: # include <windows.h>
                    104: #endif
                    105:
                    106: #ifdef MACOS
                    107: # include <Processes.h>
                    108: #endif
                    109:
                    110: #ifdef IRIX5
                    111: # include <sys/uio.h>
                    112: # include <malloc.h>   /* for locking */
                    113: #endif
                    114: #ifdef USE_MMAP
                    115: # include <sys/types.h>
                    116: # include <sys/mman.h>
                    117: # include <sys/stat.h>
1.4       noro      118: #endif
                    119:
                    120: #ifdef UNIX_LIKE
1.1       noro      121: # include <fcntl.h>
                    122: #endif
                    123:
1.6       noro      124: #if defined(SUNOS5SIGS) || defined (HURD) || defined(LINUX)
                    125: # ifdef SUNOS5SIGS
                    126: #  include <sys/siginfo.h>
                    127: # endif
1.1       noro      128: # undef setjmp
                    129: # undef longjmp
                    130: # define setjmp(env) sigsetjmp(env, 1)
                    131: # define longjmp(env, val) siglongjmp(env, val)
                    132: # define jmp_buf sigjmp_buf
                    133: #endif
                    134:
1.7       noro      135: #ifdef DARWIN
                    136: /* for get_etext and friends */
                    137: #include <mach-o/getsect.h>
                    138: #endif
                    139:
1.1       noro      140: #ifdef DJGPP
1.4       noro      141:   /* Apparently necessary for djgpp 2.01.  May cause problems with     */
1.1       noro      142:   /* other versions.                                                   */
                    143:   typedef long unsigned int caddr_t;
                    144: #endif
                    145:
                    146: #ifdef PCR
                    147: # include "il/PCR_IL.h"
                    148: # include "th/PCR_ThCtl.h"
                    149: # include "mm/PCR_MM.h"
                    150: #endif
                    151:
                    152: #if !defined(NO_EXECUTE_PERMISSION)
                    153: # define OPT_PROT_EXEC PROT_EXEC
                    154: #else
                    155: # define OPT_PROT_EXEC 0
                    156: #endif
                    157:
1.7       noro      158: #if defined(LINUX) && \
                    159:     (defined(USE_PROC_FOR_LIBRARIES) || defined(IA64) || !defined(SMALL_CONFIG))
                    160:
                    161: /* We need to parse /proc/self/maps, either to find dynamic libraries, */
                    162: /* and/or to find the register backing store base (IA64).  Do it once  */
                    163: /* here.                                                               */
                    164:
                    165: #define READ read
                    166:
                    167: /* Repeatedly perform a read call until the buffer is filled or        */
                    168: /* we encounter EOF.                                           */
                    169: ssize_t GC_repeat_read(int fd, char *buf, size_t count)
                    170: {
                    171:     ssize_t num_read = 0;
                    172:     ssize_t result;
                    173:
                    174:     while (num_read < count) {
                    175:        result = READ(fd, buf + num_read, count - num_read);
                    176:        if (result < 0) return result;
                    177:        if (result == 0) break;
                    178:        num_read += result;
                    179:     }
                    180:     return num_read;
                    181: }
                    182:
                    183: /*
                    184:  * Apply fn to a buffer containing the contents of /proc/self/maps.
                    185:  * Return the result of fn or, if we failed, 0.
                    186:  */
                    187:
                    188: word GC_apply_to_maps(word (*fn)(char *))
                    189: {
                    190:     int f;
                    191:     int result;
                    192:     int maps_size;
                    193:     char maps_temp[32768];
                    194:     char *maps_buf;
                    195:
                    196:     /* Read /proc/self/maps    */
                    197:         /* Note that we may not allocate, and thus can't use stdio.    */
                    198:         f = open("/proc/self/maps", O_RDONLY);
                    199:         if (-1 == f) return 0;
                    200:        /* stat() doesn't work for /proc/self/maps, so we have to
                    201:           read it to find out how large it is... */
                    202:        maps_size = 0;
                    203:        do {
                    204:            result = GC_repeat_read(f, maps_temp, sizeof(maps_temp));
                    205:            if (result <= 0) return 0;
                    206:            maps_size += result;
                    207:        } while (result == sizeof(maps_temp));
                    208:
                    209:        if (maps_size > sizeof(maps_temp)) {
                    210:            /* If larger than our buffer, close and re-read it. */
                    211:            close(f);
                    212:            f = open("/proc/self/maps", O_RDONLY);
                    213:            if (-1 == f) return 0;
                    214:            maps_buf = alloca(maps_size);
                    215:            if (NULL == maps_buf) return 0;
                    216:            result = GC_repeat_read(f, maps_buf, maps_size);
                    217:            if (result <= 0) return 0;
                    218:        } else {
                    219:            /* Otherwise use the fixed size buffer */
                    220:            maps_buf = maps_temp;
                    221:        }
                    222:
                    223:        close(f);
                    224:         maps_buf[result] = '\0';
                    225:
                    226:     /* Apply fn to result. */
                    227:        return fn(maps_buf);
                    228: }
                    229:
                    230: #endif /* Need GC_apply_to_maps */
                    231:
                    232: #if defined(LINUX) && (defined(USE_PROC_FOR_LIBRARIES) || defined(IA64))
                    233: //
                    234: //  GC_parse_map_entry parses an entry from /proc/self/maps so we can
                    235: //  locate all writable data segments that belong to shared libraries.
                    236: //  The format of one of these entries and the fields we care about
                    237: //  is as follows:
                    238: //  XXXXXXXX-XXXXXXXX r-xp 00000000 30:05 260537     name of mapping...\n
                    239: //  ^^^^^^^^ ^^^^^^^^ ^^^^          ^^
                    240: //  start    end      prot          maj_dev
                    241: //  0        9        18            32
                    242: //
                    243: //  For 64 bit ABIs:
                    244: //  0       17       34            56
                    245: //
                    246: //  The parser is called with a pointer to the entry and the return value
                    247: //  is either NULL or is advanced to the next entry(the byte after the
                    248: //  trailing '\n'.)
                    249: //
                    250: #if CPP_WORDSZ == 32
                    251: # define OFFSET_MAP_START   0
                    252: # define OFFSET_MAP_END     9
                    253: # define OFFSET_MAP_PROT   18
                    254: # define OFFSET_MAP_MAJDEV 32
                    255: # define ADDR_WIDTH        8
                    256: #endif
                    257:
                    258: #if CPP_WORDSZ == 64
                    259: # define OFFSET_MAP_START   0
                    260: # define OFFSET_MAP_END    17
                    261: # define OFFSET_MAP_PROT   34
                    262: # define OFFSET_MAP_MAJDEV 56
                    263: # define ADDR_WIDTH       16
                    264: #endif
                    265:
                    266: /*
                    267:  * Assign various fields of the first line in buf_ptr to *start, *end,
                    268:  * *prot_buf and *maj_dev.  Only *prot_buf may be set for unwritable maps.
                    269:  */
                    270: char *GC_parse_map_entry(char *buf_ptr, word *start, word *end,
                    271:                                 char *prot_buf, unsigned int *maj_dev)
                    272: {
                    273:     int i;
                    274:     char *tok;
                    275:
                    276:     if (buf_ptr == NULL || *buf_ptr == '\0') {
                    277:         return NULL;
                    278:     }
                    279:
                    280:     memcpy(prot_buf, buf_ptr+OFFSET_MAP_PROT, 4);
                    281:                                /* do the protections first. */
                    282:     prot_buf[4] = '\0';
                    283:
                    284:     if (prot_buf[1] == 'w') {/* we can skip all of this if it's not writable. */
                    285:
                    286:         tok = buf_ptr;
                    287:         buf_ptr[OFFSET_MAP_START+ADDR_WIDTH] = '\0';
                    288:         *start = strtoul(tok, NULL, 16);
                    289:
                    290:         tok = buf_ptr+OFFSET_MAP_END;
                    291:         buf_ptr[OFFSET_MAP_END+ADDR_WIDTH] = '\0';
                    292:         *end = strtoul(tok, NULL, 16);
                    293:
                    294:         buf_ptr += OFFSET_MAP_MAJDEV;
                    295:         tok = buf_ptr;
                    296:         while (*buf_ptr != ':') buf_ptr++;
                    297:         *buf_ptr++ = '\0';
                    298:         *maj_dev = strtoul(tok, NULL, 16);
                    299:     }
                    300:
                    301:     while (*buf_ptr && *buf_ptr++ != '\n');
                    302:
                    303:     return buf_ptr;
                    304: }
                    305:
                    306: #endif /* Need to parse /proc/self/maps. */
                    307:
1.3       noro      308: #if defined(SEARCH_FOR_DATA_START)
1.1       noro      309:   /* The I386 case can be handled without a search.  The Alpha case    */
                    310:   /* used to be handled differently as well, but the rules changed     */
                    311:   /* for recent Linux versions.  This seems to be the easiest way to   */
                    312:   /* cover all versions.                                               */
1.4       noro      313:
                    314: # ifdef LINUX
1.7       noro      315:     /* Some Linux distributions arrange to define __data_start.  Some  */
                    316:     /* define data_start as a weak symbol.  The latter is technically  */
                    317:     /* broken, since the user program may define data_start, in which  */
                    318:     /* case we lose.  Nonetheless, we try both, prefering __data_start.        */
                    319:     /* We assume gcc-compatible pragmas.       */
1.4       noro      320: #   pragma weak __data_start
1.6       noro      321:     extern int __data_start[];
1.4       noro      322: #   pragma weak data_start
1.6       noro      323:     extern int data_start[];
1.4       noro      324: # endif /* LINUX */
1.6       noro      325:   extern int _end[];
1.4       noro      326:
1.1       noro      327:   ptr_t GC_data_start;
                    328:
                    329:   void GC_init_linux_data_start()
                    330:   {
                    331:     extern ptr_t GC_find_limit();
                    332:
1.4       noro      333: #   ifdef LINUX
                    334:       /* Try the easy approaches first:        */
1.6       noro      335:       if ((ptr_t)__data_start != 0) {
                    336:          GC_data_start = (ptr_t)(__data_start);
1.4       noro      337:          return;
                    338:       }
1.6       noro      339:       if ((ptr_t)data_start != 0) {
                    340:          GC_data_start = (ptr_t)(data_start);
1.4       noro      341:          return;
                    342:       }
                    343: #   endif /* LINUX */
1.6       noro      344:     GC_data_start = GC_find_limit((ptr_t)(_end), FALSE);
1.4       noro      345:   }
                    346: #endif
                    347:
1.6       noro      348: # ifdef ECOS
                    349:
                    350: # ifndef ECOS_GC_MEMORY_SIZE
                    351: # define ECOS_GC_MEMORY_SIZE (448 * 1024)
                    352: # endif /* ECOS_GC_MEMORY_SIZE */
                    353:
                    354: // setjmp() function, as described in ANSI para 7.6.1.1
                    355: #define setjmp( __env__ )  hal_setjmp( __env__ )
                    356:
                    357: // FIXME: This is a simple way of allocating memory which is
                    358: // compatible with ECOS early releases.  Later releases use a more
                    359: // sophisticated means of allocating memory than this simple static
                    360: // allocator, but this method is at least bound to work.
                    361: static char memory[ECOS_GC_MEMORY_SIZE];
                    362: static char *brk = memory;
                    363:
                    364: static void *tiny_sbrk(ptrdiff_t increment)
                    365: {
                    366:   void *p = brk;
                    367:
                    368:   brk += increment;
                    369:
                    370:   if (brk >  memory + sizeof memory)
                    371:     {
                    372:       brk -= increment;
                    373:       return NULL;
                    374:     }
                    375:
                    376:   return p;
                    377: }
                    378: #define sbrk tiny_sbrk
                    379: # endif /* ECOS */
                    380:
                    381: #if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__)
1.4       noro      382:   ptr_t GC_data_start;
                    383:
                    384:   void GC_init_netbsd_elf()
                    385:   {
                    386:     extern ptr_t GC_find_limit();
                    387:     extern char **environ;
                    388:        /* This may need to be environ, without the underscore, for     */
                    389:        /* some versions.                                               */
                    390:     GC_data_start = GC_find_limit((ptr_t)&environ, FALSE);
1.1       noro      391:   }
                    392: #endif
                    393:
                    394: # ifdef OS2
                    395:
                    396: # include <stddef.h>
                    397:
                    398: # if !defined(__IBMC__) && !defined(__WATCOMC__) /* e.g. EMX */
                    399:
                    400: struct exe_hdr {
                    401:     unsigned short      magic_number;
                    402:     unsigned short      padding[29];
                    403:     long                new_exe_offset;
                    404: };
                    405:
                    406: #define E_MAGIC(x)      (x).magic_number
                    407: #define EMAGIC          0x5A4D
                    408: #define E_LFANEW(x)     (x).new_exe_offset
                    409:
                    410: struct e32_exe {
                    411:     unsigned char       magic_number[2];
                    412:     unsigned char       byte_order;
                    413:     unsigned char       word_order;
                    414:     unsigned long       exe_format_level;
                    415:     unsigned short      cpu;
                    416:     unsigned short      os;
                    417:     unsigned long       padding1[13];
                    418:     unsigned long       object_table_offset;
                    419:     unsigned long       object_count;
                    420:     unsigned long       padding2[31];
                    421: };
                    422:
                    423: #define E32_MAGIC1(x)   (x).magic_number[0]
                    424: #define E32MAGIC1       'L'
                    425: #define E32_MAGIC2(x)   (x).magic_number[1]
                    426: #define E32MAGIC2       'X'
                    427: #define E32_BORDER(x)   (x).byte_order
                    428: #define E32LEBO         0
                    429: #define E32_WORDER(x)   (x).word_order
                    430: #define E32LEWO         0
                    431: #define E32_CPU(x)      (x).cpu
                    432: #define E32CPU286       1
                    433: #define E32_OBJTAB(x)   (x).object_table_offset
                    434: #define E32_OBJCNT(x)   (x).object_count
                    435:
                    436: struct o32_obj {
                    437:     unsigned long       size;
                    438:     unsigned long       base;
                    439:     unsigned long       flags;
                    440:     unsigned long       pagemap;
                    441:     unsigned long       mapsize;
                    442:     unsigned long       reserved;
                    443: };
                    444:
                    445: #define O32_FLAGS(x)    (x).flags
                    446: #define OBJREAD         0x0001L
                    447: #define OBJWRITE        0x0002L
                    448: #define OBJINVALID      0x0080L
                    449: #define O32_SIZE(x)     (x).size
                    450: #define O32_BASE(x)     (x).base
                    451:
                    452: # else  /* IBM's compiler */
                    453:
                    454: /* A kludge to get around what appears to be a header file bug */
                    455: # ifndef WORD
                    456: #   define WORD unsigned short
                    457: # endif
                    458: # ifndef DWORD
                    459: #   define DWORD unsigned long
                    460: # endif
                    461:
                    462: # define EXE386 1
                    463: # include <newexe.h>
                    464: # include <exe386.h>
                    465:
                    466: # endif  /* __IBMC__ */
                    467:
                    468: # define INCL_DOSEXCEPTIONS
                    469: # define INCL_DOSPROCESS
                    470: # define INCL_DOSERRORS
                    471: # define INCL_DOSMODULEMGR
                    472: # define INCL_DOSMEMMGR
                    473: # include <os2.h>
                    474:
                    475:
                    476: /* Disable and enable signals during nontrivial allocations    */
                    477:
                    478: void GC_disable_signals(void)
                    479: {
                    480:     ULONG nest;
                    481:
                    482:     DosEnterMustComplete(&nest);
                    483:     if (nest != 1) ABORT("nested GC_disable_signals");
                    484: }
                    485:
                    486: void GC_enable_signals(void)
                    487: {
                    488:     ULONG nest;
                    489:
                    490:     DosExitMustComplete(&nest);
                    491:     if (nest != 0) ABORT("GC_enable_signals");
                    492: }
                    493:
                    494:
                    495: # else
                    496:
                    497: #  if !defined(PCR) && !defined(AMIGA) && !defined(MSWIN32) \
1.4       noro      498:       && !defined(MSWINCE) \
1.6       noro      499:       && !defined(MACOS) && !defined(DJGPP) && !defined(DOS4GW) \
                    500:       && !defined(NOSYS) && !defined(ECOS)
1.1       noro      501:
1.6       noro      502: #   if defined(sigmask) && !defined(UTS4) && !defined(HURD)
1.1       noro      503:        /* Use the traditional BSD interface */
                    504: #      define SIGSET_T int
                    505: #      define SIG_DEL(set, signal) (set) &= ~(sigmask(signal))
                    506: #      define SIG_FILL(set)  (set) = 0x7fffffff
                    507:          /* Setting the leading bit appears to provoke a bug in some   */
                    508:          /* longjmp implementations.  Most systems appear not to have  */
                    509:          /* a signal 32.                                               */
                    510: #      define SIGSETMASK(old, new) (old) = sigsetmask(new)
                    511: #   else
                    512:        /* Use POSIX/SYSV interface     */
                    513: #      define SIGSET_T sigset_t
                    514: #      define SIG_DEL(set, signal) sigdelset(&(set), (signal))
                    515: #      define SIG_FILL(set) sigfillset(&set)
                    516: #      define SIGSETMASK(old, new) sigprocmask(SIG_SETMASK, &(new), &(old))
                    517: #   endif
                    518:
                    519: static GC_bool mask_initialized = FALSE;
                    520:
                    521: static SIGSET_T new_mask;
                    522:
                    523: static SIGSET_T old_mask;
                    524:
                    525: static SIGSET_T dummy;
                    526:
                    527: #if defined(PRINTSTATS) && !defined(THREADS)
                    528: # define CHECK_SIGNALS
                    529:   int GC_sig_disabled = 0;
                    530: #endif
                    531:
                    532: void GC_disable_signals()
                    533: {
                    534:     if (!mask_initialized) {
                    535:        SIG_FILL(new_mask);
                    536:
                    537:        SIG_DEL(new_mask, SIGSEGV);
                    538:        SIG_DEL(new_mask, SIGILL);
                    539:        SIG_DEL(new_mask, SIGQUIT);
                    540: #      ifdef SIGBUS
                    541:            SIG_DEL(new_mask, SIGBUS);
                    542: #      endif
                    543: #      ifdef SIGIOT
                    544:            SIG_DEL(new_mask, SIGIOT);
                    545: #      endif
                    546: #      ifdef SIGEMT
                    547:            SIG_DEL(new_mask, SIGEMT);
                    548: #      endif
                    549: #      ifdef SIGTRAP
                    550:            SIG_DEL(new_mask, SIGTRAP);
                    551: #      endif
                    552:        mask_initialized = TRUE;
                    553:     }
                    554: #   ifdef CHECK_SIGNALS
                    555:        if (GC_sig_disabled != 0) ABORT("Nested disables");
                    556:        GC_sig_disabled++;
                    557: #   endif
                    558:     SIGSETMASK(old_mask,new_mask);
                    559: }
                    560:
                    561: void GC_enable_signals()
                    562: {
                    563: #   ifdef CHECK_SIGNALS
                    564:        if (GC_sig_disabled != 1) ABORT("Unmatched enable");
                    565:        GC_sig_disabled--;
                    566: #   endif
                    567:     SIGSETMASK(dummy,old_mask);
                    568: }
                    569:
                    570: #  endif  /* !PCR */
                    571:
                    572: # endif /*!OS/2 */
                    573:
                    574: /* Ivan Demakov: simplest way (to me) */
1.6       noro      575: #if defined (DOS4GW)
1.1       noro      576:   void GC_disable_signals() { }
                    577:   void GC_enable_signals() { }
                    578: #endif
                    579:
                    580: /* Find the page size */
                    581: word GC_page_size;
                    582:
1.4       noro      583: # if defined(MSWIN32) || defined(MSWINCE)
1.1       noro      584:   void GC_setpagesize()
                    585:   {
1.4       noro      586:     GetSystemInfo(&GC_sysinfo);
                    587:     GC_page_size = GC_sysinfo.dwPageSize;
1.1       noro      588:   }
                    589:
                    590: # else
                    591: #   if defined(MPROTECT_VDB) || defined(PROC_VDB) || defined(USE_MMAP) \
                    592:        || defined(USE_MUNMAP)
                    593:        void GC_setpagesize()
                    594:        {
                    595:            GC_page_size = GETPAGESIZE();
                    596:        }
                    597: #   else
                    598:        /* It's acceptable to fake it. */
                    599:        void GC_setpagesize()
                    600:        {
                    601:            GC_page_size = HBLKSIZE;
                    602:        }
                    603: #   endif
                    604: # endif
                    605:
                    606: /*
                    607:  * Find the base of the stack.
                    608:  * Used only in single-threaded environment.
                    609:  * With threads, GC_mark_roots needs to know how to do this.
                    610:  * Called with allocator lock held.
                    611:  */
1.4       noro      612: # if defined(MSWIN32) || defined(MSWINCE)
1.1       noro      613: # define is_writable(prot) ((prot) == PAGE_READWRITE \
                    614:                            || (prot) == PAGE_WRITECOPY \
                    615:                            || (prot) == PAGE_EXECUTE_READWRITE \
                    616:                            || (prot) == PAGE_EXECUTE_WRITECOPY)
                    617: /* Return the number of bytes that are writable starting at p. */
                    618: /* The pointer p is assumed to be page aligned.                        */
                    619: /* If base is not 0, *base becomes the beginning of the        */
                    620: /* allocation region containing p.                             */
                    621: word GC_get_writable_length(ptr_t p, ptr_t *base)
                    622: {
                    623:     MEMORY_BASIC_INFORMATION buf;
                    624:     word result;
                    625:     word protect;
                    626:
                    627:     result = VirtualQuery(p, &buf, sizeof(buf));
                    628:     if (result != sizeof(buf)) ABORT("Weird VirtualQuery result");
                    629:     if (base != 0) *base = (ptr_t)(buf.AllocationBase);
                    630:     protect = (buf.Protect & ~(PAGE_GUARD | PAGE_NOCACHE));
                    631:     if (!is_writable(protect)) {
                    632:         return(0);
                    633:     }
                    634:     if (buf.State != MEM_COMMIT) return(0);
                    635:     return(buf.RegionSize);
                    636: }
                    637:
                    638: ptr_t GC_get_stack_base()
                    639: {
                    640:     int dummy;
                    641:     ptr_t sp = (ptr_t)(&dummy);
                    642:     ptr_t trunc_sp = (ptr_t)((word)sp & ~(GC_page_size - 1));
                    643:     word size = GC_get_writable_length(trunc_sp, 0);
                    644:
                    645:     return(trunc_sp + size);
                    646: }
                    647:
                    648:
1.4       noro      649: # endif /* MS Windows */
                    650:
                    651: # ifdef BEOS
                    652: # include <kernel/OS.h>
                    653: ptr_t GC_get_stack_base(){
                    654:        thread_info th;
                    655:        get_thread_info(find_thread(NULL),&th);
                    656:        return th.stack_end;
                    657: }
                    658: # endif /* BEOS */
                    659:
1.1       noro      660:
                    661: # ifdef OS2
                    662:
                    663: ptr_t GC_get_stack_base()
                    664: {
                    665:     PTIB ptib;
                    666:     PPIB ppib;
                    667:
                    668:     if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
                    669:        GC_err_printf0("DosGetInfoBlocks failed\n");
                    670:        ABORT("DosGetInfoBlocks failed\n");
                    671:     }
                    672:     return((ptr_t)(ptib -> tib_pstacklimit));
                    673: }
                    674:
1.4       noro      675: # endif /* OS2 */
1.1       noro      676:
                    677: # ifdef AMIGA
1.4       noro      678: #   define GC_AMIGA_SB
                    679: #   include "AmigaOS.c"
                    680: #   undef GC_AMIGA_SB
                    681: # endif /* AMIGA */
1.1       noro      682:
1.4       noro      683: # if defined(NEED_FIND_LIMIT) || defined(UNIX_LIKE)
1.1       noro      684:
                    685: #   ifdef __STDC__
                    686:        typedef void (*handler)(int);
                    687: #   else
                    688:        typedef void (*handler)();
                    689: #   endif
                    690:
1.6       noro      691: #   if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) || defined(HURD)
1.1       noro      692:        static struct sigaction old_segv_act;
1.6       noro      693: #      if defined(_sigargs) /* !Irix6.x */ || defined(HPUX) || defined(HURD)
1.1       noro      694:            static struct sigaction old_bus_act;
                    695: #      endif
                    696: #   else
                    697:         static handler old_segv_handler, old_bus_handler;
                    698: #   endif
                    699:
1.4       noro      700: #   ifdef __STDC__
                    701:       void GC_set_and_save_fault_handler(handler h)
                    702: #   else
                    703:       void GC_set_and_save_fault_handler(h)
                    704:       handler h;
                    705: #   endif
1.1       noro      706:     {
1.6       noro      707: #      if defined(SUNOS5SIGS) || defined(IRIX5)  \
                    708:         || defined(OSF1) || defined(HURD)
1.1       noro      709:          struct sigaction      act;
                    710:
1.4       noro      711:          act.sa_handler        = h;
1.6       noro      712: #        ifdef SUNOS5SIGS
                    713:             act.sa_flags          = SA_RESTART | SA_NODEFER;
                    714: #         else
                    715:             act.sa_flags          = SA_RESTART;
                    716: #        endif
1.1       noro      717:           /* The presence of SA_NODEFER represents yet another gross    */
                    718:           /* hack.  Under Solaris 2.3, siglongjmp doesn't appear to     */
                    719:           /* interact correctly with -lthread.  We hide the confusion   */
                    720:           /* by making sure that signal handling doesn't affect the     */
                    721:           /* signal mask.                                               */
                    722:
                    723:          (void) sigemptyset(&act.sa_mask);
1.6       noro      724: #        ifdef GC_IRIX_THREADS
1.1       noro      725:                /* Older versions have a bug related to retrieving and  */
                    726:                /* and setting a handler at the same time.              */
                    727:                (void) sigaction(SIGSEGV, 0, &old_segv_act);
                    728:                (void) sigaction(SIGSEGV, &act, 0);
                    729: #        else
                    730:                (void) sigaction(SIGSEGV, &act, &old_segv_act);
1.2       noro      731: #              if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \
1.6       noro      732:                   || defined(HPUX) || defined(HURD)
1.2       noro      733:                    /* Under Irix 5.x or HP/UX, we may get SIGBUS.      */
                    734:                    /* Pthreads doesn't exist under Irix 5.x, so we     */
                    735:                    /* don't have to worry in the threads case.         */
1.1       noro      736:                    (void) sigaction(SIGBUS, &act, &old_bus_act);
                    737: #              endif
1.6       noro      738: #        endif /* GC_IRIX_THREADS */
1.1       noro      739: #      else
1.4       noro      740:          old_segv_handler = signal(SIGSEGV, h);
1.1       noro      741: #        ifdef SIGBUS
1.4       noro      742:            old_bus_handler = signal(SIGBUS, h);
1.1       noro      743: #        endif
                    744: #      endif
                    745:     }
1.4       noro      746: # endif /* NEED_FIND_LIMIT || UNIX_LIKE */
                    747:
                    748: # ifdef NEED_FIND_LIMIT
                    749:   /* Some tools to implement HEURISTIC2        */
                    750: #   define MIN_PAGE_SIZE 256   /* Smallest conceivable page size, bytes */
                    751:     /* static */ jmp_buf GC_jmp_buf;
                    752:
                    753:     /*ARGSUSED*/
                    754:     void GC_fault_handler(sig)
                    755:     int sig;
                    756:     {
                    757:         longjmp(GC_jmp_buf, 1);
                    758:     }
                    759:
                    760:     void GC_setup_temporary_fault_handler()
                    761:     {
                    762:        GC_set_and_save_fault_handler(GC_fault_handler);
                    763:     }
1.1       noro      764:
                    765:     void GC_reset_fault_handler()
                    766:     {
1.6       noro      767: #       if defined(SUNOS5SIGS) || defined(IRIX5) \
                    768:           || defined(OSF1) || defined(HURD)
1.1       noro      769:          (void) sigaction(SIGSEGV, &old_segv_act, 0);
1.2       noro      770: #        if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \
1.6       noro      771:             || defined(HPUX) || defined(HURD)
1.1       noro      772:              (void) sigaction(SIGBUS, &old_bus_act, 0);
                    773: #        endif
                    774: #       else
                    775:          (void) signal(SIGSEGV, old_segv_handler);
                    776: #        ifdef SIGBUS
                    777:            (void) signal(SIGBUS, old_bus_handler);
                    778: #        endif
                    779: #       endif
                    780:     }
                    781:
                    782:     /* Return the first nonaddressible location > p (up) or    */
1.7       noro      783:     /* the smallest location q s.t. [q,p) is addressable (!up).        */
                    784:     /* We assume that p (up) or p-1 (!up) is addressable.      */
1.1       noro      785:     ptr_t GC_find_limit(p, up)
                    786:     ptr_t p;
                    787:     GC_bool up;
                    788:     {
                    789:         static VOLATILE ptr_t result;
                    790:                /* Needs to be static, since otherwise it may not be    */
                    791:                /* preserved across the longjmp.  Can safely be         */
                    792:                /* static since it's only called once, with the         */
                    793:                /* allocation lock held.                                */
                    794:
                    795:
                    796:        GC_setup_temporary_fault_handler();
                    797:        if (setjmp(GC_jmp_buf) == 0) {
                    798:            result = (ptr_t)(((word)(p))
                    799:                              & ~(MIN_PAGE_SIZE-1));
                    800:            for (;;) {
                    801:                if (up) {
                    802:                    result += MIN_PAGE_SIZE;
                    803:                } else {
                    804:                    result -= MIN_PAGE_SIZE;
                    805:                }
                    806:                GC_noop1((word)(*result));
                    807:            }
                    808:        }
                    809:        GC_reset_fault_handler();
                    810:        if (!up) {
                    811:            result += MIN_PAGE_SIZE;
                    812:        }
                    813:        return(result);
                    814:     }
                    815: # endif
                    816:
1.6       noro      817: #if defined(ECOS) || defined(NOSYS)
                    818:   ptr_t GC_get_stack_base()
                    819:   {
                    820:     return STACKBOTTOM;
                    821:   }
                    822: #endif
                    823:
1.2       noro      824: #ifdef LINUX_STACKBOTTOM
                    825:
1.3       noro      826: #include <sys/types.h>
                    827: #include <sys/stat.h>
1.7       noro      828: #include <ctype.h>
1.3       noro      829:
1.2       noro      830: # define STAT_SKIP 27   /* Number of fields preceding startstack       */
1.3       noro      831:                        /* field in /proc/self/stat                     */
1.2       noro      832:
1.4       noro      833: # pragma weak __libc_stack_end
                    834:   extern ptr_t __libc_stack_end;
                    835:
                    836: # ifdef IA64
1.7       noro      837:     /* Try to read the backing store base from /proc/self/maps.        */
                    838:     /* We look for the writable mapping with a 0 major device,  */
                    839:     /* which is        as close to our frame as possible, but below it.*/
                    840:     static word backing_store_base_from_maps(char *maps)
                    841:     {
                    842:       char prot_buf[5];
                    843:       char *buf_ptr = maps;
                    844:       word start, end;
                    845:       unsigned int maj_dev;
                    846:       word current_best = 0;
                    847:       word dummy;
                    848:
                    849:       for (;;) {
                    850:         buf_ptr = GC_parse_map_entry(buf_ptr, &start, &end, prot_buf, &maj_dev);
                    851:        if (buf_ptr == NULL) return current_best;
                    852:        if (prot_buf[1] == 'w' && maj_dev == 0) {
                    853:            if (end < (word)(&dummy) && start > current_best) current_best = start;
                    854:        }
                    855:       }
                    856:       return current_best;
                    857:     }
                    858:
                    859:     static word backing_store_base_from_proc(void)
                    860:     {
                    861:         return GC_apply_to_maps(backing_store_base_from_maps);
                    862:     }
                    863:
1.4       noro      864: #   pragma weak __libc_ia64_register_backing_store_base
                    865:     extern ptr_t __libc_ia64_register_backing_store_base;
                    866:
                    867:     ptr_t GC_get_register_stack_base(void)
                    868:     {
1.6       noro      869:       if (0 != &__libc_ia64_register_backing_store_base
                    870:          && 0 != __libc_ia64_register_backing_store_base) {
                    871:        /* Glibc 2.2.4 has a bug such that for dynamically linked       */
                    872:        /* executables __libc_ia64_register_backing_store_base is       */
1.7       noro      873:        /* defined but uninitialized during constructor calls.          */
1.6       noro      874:        /* Hence we check for both nonzero address and value.           */
1.4       noro      875:        return __libc_ia64_register_backing_store_base;
                    876:       } else {
1.7       noro      877:        word result = backing_store_base_from_proc();
                    878:        if (0 == result) {
                    879:          /* Use dumb heuristics.  Works only for default configuration. */
                    880:          result = (word)GC_stackbottom - BACKING_STORE_DISPLACEMENT;
                    881:          result += BACKING_STORE_ALIGNMENT - 1;
                    882:          result &= ~(BACKING_STORE_ALIGNMENT - 1);
                    883:          /* Verify that it's at least readable.  If not, we goofed. */
                    884:          GC_noop1(*(word *)result);
                    885:        }
1.4       noro      886:        return (ptr_t)result;
                    887:       }
                    888:     }
                    889: # endif
                    890:
1.2       noro      891:   ptr_t GC_linux_stack_base(void)
                    892:   {
1.3       noro      893:     /* We read the stack base value from /proc/self/stat.  We do this  */
                    894:     /* using direct I/O system calls in order to avoid calling malloc   */
                    895:     /* in case REDIRECT_MALLOC is defined.                             */
                    896: #   define STAT_BUF_SIZE 4096
1.7       noro      897: #   define STAT_READ read
                    898:          /* Should probably call the real read, if read is wrapped.    */
1.3       noro      899:     char stat_buf[STAT_BUF_SIZE];
                    900:     int f;
1.2       noro      901:     char c;
                    902:     word result = 0;
1.3       noro      903:     size_t i, buf_offset = 0;
1.2       noro      904:
1.4       noro      905:     /* First try the easy way.  This should work for glibc 2.2 */
                    906:       if (0 != &__libc_stack_end) {
1.6       noro      907: #       ifdef IA64
                    908:          /* Some versions of glibc set the address 16 bytes too        */
                    909:          /* low while the initialization code is running.              */
                    910:          if (((word)__libc_stack_end & 0xfff) + 0x10 < 0x1000) {
                    911:            return __libc_stack_end + 0x10;
                    912:          } /* Otherwise it's not safe to add 16 bytes and we fall      */
                    913:            /* back to using /proc.                                     */
                    914: #      else
                    915:          return __libc_stack_end;
                    916: #      endif
1.4       noro      917:       }
1.3       noro      918:     f = open("/proc/self/stat", O_RDONLY);
                    919:     if (f < 0 || STAT_READ(f, stat_buf, STAT_BUF_SIZE) < 2 * STAT_SKIP) {
                    920:        ABORT("Couldn't read /proc/self/stat");
                    921:     }
                    922:     c = stat_buf[buf_offset++];
1.2       noro      923:     /* Skip the required number of fields.  This number is hopefully   */
                    924:     /* constant across all Linux implementations.                      */
                    925:       for (i = 0; i < STAT_SKIP; ++i) {
1.3       noro      926:        while (isspace(c)) c = stat_buf[buf_offset++];
                    927:        while (!isspace(c)) c = stat_buf[buf_offset++];
1.2       noro      928:       }
1.3       noro      929:     while (isspace(c)) c = stat_buf[buf_offset++];
1.2       noro      930:     while (isdigit(c)) {
                    931:       result *= 10;
                    932:       result += c - '0';
1.3       noro      933:       c = stat_buf[buf_offset++];
1.2       noro      934:     }
1.3       noro      935:     close(f);
1.2       noro      936:     if (result < 0x10000000) ABORT("Absurd stack bottom value");
                    937:     return (ptr_t)result;
                    938:   }
                    939:
                    940: #endif /* LINUX_STACKBOTTOM */
1.1       noro      941:
1.4       noro      942: #ifdef FREEBSD_STACKBOTTOM
                    943:
                    944: /* This uses an undocumented sysctl call, but at least one expert      */
                    945: /* believes it will stay.                                              */
                    946:
                    947: #include <unistd.h>
                    948: #include <sys/types.h>
                    949: #include <sys/sysctl.h>
                    950:
                    951:   ptr_t GC_freebsd_stack_base(void)
                    952:   {
1.6       noro      953:     int nm[2] = {CTL_KERN, KERN_USRSTACK};
                    954:     ptr_t base;
                    955:     size_t len = sizeof(ptr_t);
                    956:     int r = sysctl(nm, 2, &base, &len, NULL, 0);
1.4       noro      957:
                    958:     if (r) ABORT("Error getting stack base");
                    959:
1.6       noro      960:     return base;
1.4       noro      961:   }
                    962:
                    963: #endif /* FREEBSD_STACKBOTTOM */
                    964:
                    965: #if !defined(BEOS) && !defined(AMIGA) && !defined(MSWIN32) \
                    966:     && !defined(MSWINCE) && !defined(OS2)
                    967:
1.1       noro      968: ptr_t GC_get_stack_base()
                    969: {
1.7       noro      970: #   if defined(HEURISTIC1) || defined(HEURISTIC2) || \
                    971:        defined(LINUX_STACKBOTTOM) || defined(FREEBSD_STACKBOTTOM)
1.1       noro      972:     word dummy;
                    973:     ptr_t result;
1.7       noro      974: #   endif
1.1       noro      975:
                    976: #   define STACKBOTTOM_ALIGNMENT_M1 ((word)STACK_GRAN - 1)
                    977:
                    978: #   ifdef STACKBOTTOM
                    979:        return(STACKBOTTOM);
                    980: #   else
                    981: #      ifdef HEURISTIC1
                    982: #         ifdef STACK_GROWS_DOWN
                    983:             result = (ptr_t)((((word)(&dummy))
                    984:                               + STACKBOTTOM_ALIGNMENT_M1)
                    985:                              & ~STACKBOTTOM_ALIGNMENT_M1);
                    986: #         else
                    987:             result = (ptr_t)(((word)(&dummy))
                    988:                              & ~STACKBOTTOM_ALIGNMENT_M1);
                    989: #         endif
                    990: #      endif /* HEURISTIC1 */
1.2       noro      991: #      ifdef LINUX_STACKBOTTOM
                    992:           result = GC_linux_stack_base();
                    993: #      endif
1.4       noro      994: #      ifdef FREEBSD_STACKBOTTOM
                    995:           result = GC_freebsd_stack_base();
                    996: #      endif
1.1       noro      997: #      ifdef HEURISTIC2
                    998: #          ifdef STACK_GROWS_DOWN
                    999:                result = GC_find_limit((ptr_t)(&dummy), TRUE);
                   1000: #              ifdef HEURISTIC2_LIMIT
                   1001:                    if (result > HEURISTIC2_LIMIT
                   1002:                        && (ptr_t)(&dummy) < HEURISTIC2_LIMIT) {
                   1003:                            result = HEURISTIC2_LIMIT;
                   1004:                    }
                   1005: #              endif
                   1006: #          else
                   1007:                result = GC_find_limit((ptr_t)(&dummy), FALSE);
                   1008: #              ifdef HEURISTIC2_LIMIT
                   1009:                    if (result < HEURISTIC2_LIMIT
                   1010:                        && (ptr_t)(&dummy) > HEURISTIC2_LIMIT) {
                   1011:                            result = HEURISTIC2_LIMIT;
                   1012:                    }
                   1013: #              endif
                   1014: #          endif
                   1015:
                   1016: #      endif /* HEURISTIC2 */
                   1017: #      ifdef STACK_GROWS_DOWN
                   1018:            if (result == 0) result = (ptr_t)(signed_word)(-sizeof(ptr_t));
                   1019: #      endif
                   1020:        return(result);
                   1021: #   endif /* STACKBOTTOM */
                   1022: }
                   1023:
1.4       noro     1024: # endif /* ! AMIGA, !OS 2, ! MS Windows, !BEOS */
1.1       noro     1025:
                   1026: /*
                   1027:  * Register static data segment(s) as roots.
                   1028:  * If more data segments are added later then they need to be registered
                   1029:  * add that point (as we do with SunOS dynamic loading),
                   1030:  * or GC_mark_roots needs to check for them (as we do with PCR).
                   1031:  * Called with allocator lock held.
                   1032:  */
                   1033:
                   1034: # ifdef OS2
                   1035:
                   1036: void GC_register_data_segments()
                   1037: {
                   1038:     PTIB ptib;
                   1039:     PPIB ppib;
                   1040:     HMODULE module_handle;
                   1041: #   define PBUFSIZ 512
                   1042:     UCHAR path[PBUFSIZ];
                   1043:     FILE * myexefile;
                   1044:     struct exe_hdr hdrdos;     /* MSDOS header.        */
                   1045:     struct e32_exe hdr386;     /* Real header for my executable */
                   1046:     struct o32_obj seg;        /* Currrent segment */
                   1047:     int nsegs;
                   1048:
                   1049:
                   1050:     if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
                   1051:        GC_err_printf0("DosGetInfoBlocks failed\n");
                   1052:        ABORT("DosGetInfoBlocks failed\n");
                   1053:     }
                   1054:     module_handle = ppib -> pib_hmte;
                   1055:     if (DosQueryModuleName(module_handle, PBUFSIZ, path) != NO_ERROR) {
                   1056:        GC_err_printf0("DosQueryModuleName failed\n");
                   1057:        ABORT("DosGetInfoBlocks failed\n");
                   1058:     }
                   1059:     myexefile = fopen(path, "rb");
                   1060:     if (myexefile == 0) {
                   1061:         GC_err_puts("Couldn't open executable ");
                   1062:         GC_err_puts(path); GC_err_puts("\n");
                   1063:         ABORT("Failed to open executable\n");
                   1064:     }
                   1065:     if (fread((char *)(&hdrdos), 1, sizeof hdrdos, myexefile) < sizeof hdrdos) {
                   1066:         GC_err_puts("Couldn't read MSDOS header from ");
                   1067:         GC_err_puts(path); GC_err_puts("\n");
                   1068:         ABORT("Couldn't read MSDOS header");
                   1069:     }
                   1070:     if (E_MAGIC(hdrdos) != EMAGIC) {
                   1071:         GC_err_puts("Executable has wrong DOS magic number: ");
                   1072:         GC_err_puts(path); GC_err_puts("\n");
                   1073:         ABORT("Bad DOS magic number");
                   1074:     }
                   1075:     if (fseek(myexefile, E_LFANEW(hdrdos), SEEK_SET) != 0) {
                   1076:         GC_err_puts("Seek to new header failed in ");
                   1077:         GC_err_puts(path); GC_err_puts("\n");
                   1078:         ABORT("Bad DOS magic number");
                   1079:     }
                   1080:     if (fread((char *)(&hdr386), 1, sizeof hdr386, myexefile) < sizeof hdr386) {
                   1081:         GC_err_puts("Couldn't read MSDOS header from ");
                   1082:         GC_err_puts(path); GC_err_puts("\n");
                   1083:         ABORT("Couldn't read OS/2 header");
                   1084:     }
                   1085:     if (E32_MAGIC1(hdr386) != E32MAGIC1 || E32_MAGIC2(hdr386) != E32MAGIC2) {
                   1086:         GC_err_puts("Executable has wrong OS/2 magic number:");
                   1087:         GC_err_puts(path); GC_err_puts("\n");
                   1088:         ABORT("Bad OS/2 magic number");
                   1089:     }
                   1090:     if ( E32_BORDER(hdr386) != E32LEBO || E32_WORDER(hdr386) != E32LEWO) {
                   1091:         GC_err_puts("Executable %s has wrong byte order: ");
                   1092:         GC_err_puts(path); GC_err_puts("\n");
                   1093:         ABORT("Bad byte order");
                   1094:     }
                   1095:     if ( E32_CPU(hdr386) == E32CPU286) {
                   1096:         GC_err_puts("GC can't handle 80286 executables: ");
                   1097:         GC_err_puts(path); GC_err_puts("\n");
                   1098:         EXIT();
                   1099:     }
                   1100:     if (fseek(myexefile, E_LFANEW(hdrdos) + E32_OBJTAB(hdr386),
                   1101:              SEEK_SET) != 0) {
                   1102:         GC_err_puts("Seek to object table failed: ");
                   1103:         GC_err_puts(path); GC_err_puts("\n");
                   1104:         ABORT("Seek to object table failed");
                   1105:     }
                   1106:     for (nsegs = E32_OBJCNT(hdr386); nsegs > 0; nsegs--) {
                   1107:       int flags;
                   1108:       if (fread((char *)(&seg), 1, sizeof seg, myexefile) < sizeof seg) {
                   1109:         GC_err_puts("Couldn't read obj table entry from ");
                   1110:         GC_err_puts(path); GC_err_puts("\n");
                   1111:         ABORT("Couldn't read obj table entry");
                   1112:       }
                   1113:       flags = O32_FLAGS(seg);
                   1114:       if (!(flags & OBJWRITE)) continue;
                   1115:       if (!(flags & OBJREAD)) continue;
                   1116:       if (flags & OBJINVALID) {
                   1117:           GC_err_printf0("Object with invalid pages?\n");
                   1118:           continue;
                   1119:       }
                   1120:       GC_add_roots_inner(O32_BASE(seg), O32_BASE(seg)+O32_SIZE(seg), FALSE);
                   1121:     }
                   1122: }
                   1123:
1.4       noro     1124: # else /* !OS2 */
                   1125:
                   1126: # if defined(MSWIN32) || defined(MSWINCE)
1.1       noro     1127:
                   1128: # ifdef MSWIN32
                   1129:   /* Unfortunately, we have to handle win32s very differently from NT,         */
                   1130:   /* Since VirtualQuery has very different semantics.  In particular,  */
                   1131:   /* under win32s a VirtualQuery call on an unmapped page returns an   */
1.6       noro     1132:   /* invalid result.  Under NT, GC_register_data_segments is a noop and        */
1.1       noro     1133:   /* all real work is done by GC_register_dynamic_libraries.  Under    */
                   1134:   /* win32s, we cannot find the data segments associated with dll's.   */
1.7       noro     1135:   /* We register the main data segment here.                           */
1.6       noro     1136:   GC_bool GC_no_win32_dlls = FALSE;
1.7       noro     1137:        /* This used to be set for gcc, to avoid dealing with           */
                   1138:        /* the structured exception handling issues.  But we now have   */
                   1139:        /* assembly code to do that right.                              */
1.1       noro     1140:
                   1141:   void GC_init_win32()
                   1142:   {
1.6       noro     1143:     /* if we're running under win32s, assume that no DLLs will be loaded */
                   1144:     DWORD v = GetVersion();
                   1145:     GC_no_win32_dlls |= ((v & 0x80000000) && (v & 0xff) <= 3);
1.1       noro     1146:   }
1.4       noro     1147:
1.1       noro     1148:   /* Return the smallest address a such that VirtualQuery              */
                   1149:   /* returns correct results for all addresses between a and start.    */
                   1150:   /* Assumes VirtualQuery returns correct information for start.       */
                   1151:   ptr_t GC_least_described_address(ptr_t start)
                   1152:   {
                   1153:     MEMORY_BASIC_INFORMATION buf;
                   1154:     DWORD result;
                   1155:     LPVOID limit;
                   1156:     ptr_t p;
                   1157:     LPVOID q;
                   1158:
1.4       noro     1159:     limit = GC_sysinfo.lpMinimumApplicationAddress;
1.1       noro     1160:     p = (ptr_t)((word)start & ~(GC_page_size - 1));
                   1161:     for (;;) {
                   1162:        q = (LPVOID)(p - GC_page_size);
                   1163:        if ((ptr_t)q > (ptr_t)p /* underflow */ || q < limit) break;
                   1164:        result = VirtualQuery(q, &buf, sizeof(buf));
                   1165:        if (result != sizeof(buf) || buf.AllocationBase == 0) break;
                   1166:        p = (ptr_t)(buf.AllocationBase);
                   1167:     }
                   1168:     return(p);
                   1169:   }
1.4       noro     1170: # endif
1.7       noro     1171:
                   1172: # ifndef REDIRECT_MALLOC
                   1173:   /* We maintain a linked list of AllocationBase values that we know   */
                   1174:   /* correspond to malloc heap sections.  Currently this is only called */
                   1175:   /* during a GC.  But there is some hope that for long running                */
                   1176:   /* programs we will eventually see most heap sections.               */
                   1177:
                   1178:   /* In the long run, it would be more reliable to occasionally walk   */
                   1179:   /* the malloc heap with HeapWalk on the default heap.  But that      */
                   1180:   /* apparently works only for NT-based Windows.                       */
                   1181:
                   1182:   /* In the long run, a better data structure would also be nice ...   */
                   1183:   struct GC_malloc_heap_list {
                   1184:     void * allocation_base;
                   1185:     struct GC_malloc_heap_list *next;
                   1186:   } *GC_malloc_heap_l = 0;
                   1187:
                   1188:   /* Is p the base of one of the malloc heap sections we already know  */
                   1189:   /* about?                                                            */
                   1190:   GC_bool GC_is_malloc_heap_base(ptr_t p)
                   1191:   {
                   1192:     struct GC_malloc_heap_list *q = GC_malloc_heap_l;
                   1193:
                   1194:     while (0 != q) {
                   1195:       if (q -> allocation_base == p) return TRUE;
                   1196:       q = q -> next;
                   1197:     }
                   1198:     return FALSE;
                   1199:   }
                   1200:
                   1201:   void *GC_get_allocation_base(void *p)
                   1202:   {
                   1203:     MEMORY_BASIC_INFORMATION buf;
                   1204:     DWORD result = VirtualQuery(p, &buf, sizeof(buf));
                   1205:     if (result != sizeof(buf)) {
                   1206:       ABORT("Weird VirtualQuery result");
                   1207:     }
                   1208:     return buf.AllocationBase;
                   1209:   }
                   1210:
                   1211:   size_t GC_max_root_size = 100000;    /* Appr. largest root size.     */
                   1212:
                   1213:   void GC_add_current_malloc_heap()
                   1214:   {
                   1215:     struct GC_malloc_heap_list *new_l =
                   1216:                  malloc(sizeof(struct GC_malloc_heap_list));
                   1217:     void * candidate = GC_get_allocation_base(new_l);
                   1218:
                   1219:     if (new_l == 0) return;
                   1220:     if (GC_is_malloc_heap_base(candidate)) {
                   1221:       /* Try a little harder to find malloc heap.                      */
                   1222:        size_t req_size = 10000;
                   1223:        do {
                   1224:          void *p = malloc(req_size);
                   1225:          if (0 == p) { free(new_l); return; }
                   1226:          candidate = GC_get_allocation_base(p);
                   1227:          free(p);
                   1228:          req_size *= 2;
                   1229:        } while (GC_is_malloc_heap_base(candidate)
                   1230:                 && req_size < GC_max_root_size/10 && req_size < 500000);
                   1231:        if (GC_is_malloc_heap_base(candidate)) {
                   1232:          free(new_l); return;
                   1233:        }
                   1234:     }
                   1235: #   ifdef CONDPRINT
                   1236:       if (GC_print_stats)
                   1237:          GC_printf1("Found new system malloc AllocationBase at 0x%lx\n",
                   1238:                      candidate);
                   1239: #   endif
                   1240:     new_l -> allocation_base = candidate;
                   1241:     new_l -> next = GC_malloc_heap_l;
                   1242:     GC_malloc_heap_l = new_l;
                   1243:   }
                   1244: # endif /* REDIRECT_MALLOC */
1.1       noro     1245:
                   1246:   /* Is p the start of either the malloc heap, or of one of our */
                   1247:   /* heap sections?                                            */
                   1248:   GC_bool GC_is_heap_base (ptr_t p)
                   1249:   {
                   1250:
1.7       noro     1251:      unsigned i;
1.1       noro     1252:
                   1253: #    ifndef REDIRECT_MALLOC
1.7       noro     1254:        static word last_gc_no = -1;
1.1       noro     1255:
1.7       noro     1256:        if (last_gc_no != GC_gc_no) {
                   1257:         GC_add_current_malloc_heap();
                   1258:         last_gc_no = GC_gc_no;
1.1       noro     1259:        }
1.7       noro     1260:        if (GC_root_size > GC_max_root_size) GC_max_root_size = GC_root_size;
                   1261:        if (GC_is_malloc_heap_base(p)) return TRUE;
1.1       noro     1262: #    endif
                   1263:      for (i = 0; i < GC_n_heap_bases; i++) {
1.7       noro     1264:          if (GC_heap_bases[i] == p) return TRUE;
1.1       noro     1265:      }
1.7       noro     1266:      return FALSE ;
1.1       noro     1267:   }
1.4       noro     1268:
                   1269: # ifdef MSWIN32
1.1       noro     1270:   void GC_register_root_section(ptr_t static_root)
                   1271:   {
                   1272:       MEMORY_BASIC_INFORMATION buf;
                   1273:       DWORD result;
                   1274:       DWORD protect;
                   1275:       LPVOID p;
                   1276:       char * base;
                   1277:       char * limit, * new_limit;
                   1278:
1.6       noro     1279:       if (!GC_no_win32_dlls) return;
1.1       noro     1280:       p = base = limit = GC_least_described_address(static_root);
1.4       noro     1281:       while (p < GC_sysinfo.lpMaximumApplicationAddress) {
1.1       noro     1282:         result = VirtualQuery(p, &buf, sizeof(buf));
                   1283:         if (result != sizeof(buf) || buf.AllocationBase == 0
                   1284:             || GC_is_heap_base(buf.AllocationBase)) break;
                   1285:         new_limit = (char *)p + buf.RegionSize;
                   1286:         protect = buf.Protect;
                   1287:         if (buf.State == MEM_COMMIT
                   1288:             && is_writable(protect)) {
                   1289:             if ((char *)p == limit) {
                   1290:                 limit = new_limit;
                   1291:             } else {
                   1292:                 if (base != limit) GC_add_roots_inner(base, limit, FALSE);
                   1293:                 base = p;
                   1294:                 limit = new_limit;
                   1295:             }
                   1296:         }
                   1297:         if (p > (LPVOID)new_limit /* overflow */) break;
                   1298:         p = (LPVOID)new_limit;
                   1299:       }
                   1300:       if (base != limit) GC_add_roots_inner(base, limit, FALSE);
                   1301:   }
1.4       noro     1302: #endif
1.1       noro     1303:
                   1304:   void GC_register_data_segments()
                   1305:   {
1.4       noro     1306: #     ifdef MSWIN32
1.1       noro     1307:       static char dummy;
                   1308:       GC_register_root_section((ptr_t)(&dummy));
                   1309: #     endif
                   1310:   }
                   1311:
1.4       noro     1312: # else /* !OS2 && !Windows */
1.1       noro     1313:
1.4       noro     1314: # if (defined(SVR4) || defined(AUX) || defined(DGUX) \
                   1315:       || (defined(LINUX) && defined(SPARC))) && !defined(PCR)
1.7       noro     1316: ptr_t GC_SysVGetDataStart(max_page_size, etext_addr)
1.1       noro     1317: int max_page_size;
                   1318: int * etext_addr;
                   1319: {
                   1320:     word text_end = ((word)(etext_addr) + sizeof(word) - 1)
                   1321:                    & ~(sizeof(word) - 1);
                   1322:        /* etext rounded to word boundary       */
                   1323:     word next_page = ((text_end + (word)max_page_size - 1)
                   1324:                      & ~((word)max_page_size - 1));
                   1325:     word page_offset = (text_end & ((word)max_page_size - 1));
                   1326:     VOLATILE char * result = (char *)(next_page + page_offset);
                   1327:     /* Note that this isnt equivalent to just adding           */
                   1328:     /* max_page_size to &etext if &etext is at a page boundary */
                   1329:
                   1330:     GC_setup_temporary_fault_handler();
                   1331:     if (setjmp(GC_jmp_buf) == 0) {
                   1332:        /* Try writing to the address.  */
                   1333:        *result = *result;
                   1334:         GC_reset_fault_handler();
                   1335:     } else {
                   1336:         GC_reset_fault_handler();
                   1337:        /* We got here via a longjmp.  The address is not readable.     */
                   1338:        /* This is known to happen under Solaris 2.4 + gcc, which place */
                   1339:        /* string constants in the text segment, but after etext.       */
                   1340:        /* Use plan B.  Note that we now know there is a gap between    */
                   1341:        /* text and data segments, so plan A bought us something.       */
1.7       noro     1342:        result = (char *)GC_find_limit((ptr_t)(DATAEND), FALSE);
                   1343:     }
                   1344:     return((ptr_t)result);
                   1345: }
                   1346: # endif
                   1347:
1.8     ! saito    1348: // # if defined(FREEBSD) && defined(I386) && !defined(PCR)
        !          1349: # if defined(FREEBSD) && ( defined(I386) || defined(X86_64) ) && !defined(PCR)
1.7       noro     1350: /* Its unclear whether this should be identical to the above, or       */
                   1351: /* whether it should apply to non-X86 architectures.                   */
                   1352: /* For now we don't assume that there is always an empty page after    */
                   1353: /* etext.  But in some cases there actually seems to be slightly more.  */
                   1354: /* This also deals with holes between read-only data and writable data.        */
                   1355: ptr_t GC_FreeBSDGetDataStart(max_page_size, etext_addr)
                   1356: int max_page_size;
                   1357: int * etext_addr;
                   1358: {
                   1359:     word text_end = ((word)(etext_addr) + sizeof(word) - 1)
                   1360:                     & ~(sizeof(word) - 1);
                   1361:        /* etext rounded to word boundary       */
                   1362:     VOLATILE word next_page = (text_end + (word)max_page_size - 1)
                   1363:                              & ~((word)max_page_size - 1);
                   1364:     VOLATILE ptr_t result = (ptr_t)text_end;
                   1365:     GC_setup_temporary_fault_handler();
                   1366:     if (setjmp(GC_jmp_buf) == 0) {
                   1367:        /* Try reading at the address.                          */
                   1368:        /* This should happen before there is another thread.   */
                   1369:        for (; next_page < (word)(DATAEND); next_page += (word)max_page_size)
                   1370:            *(VOLATILE char *)next_page;
                   1371:        GC_reset_fault_handler();
                   1372:     } else {
                   1373:        GC_reset_fault_handler();
                   1374:        /* As above, we go to plan B    */
                   1375:        result = GC_find_limit((ptr_t)(DATAEND), FALSE);
1.1       noro     1376:     }
1.7       noro     1377:     return(result);
1.1       noro     1378: }
1.7       noro     1379:
1.1       noro     1380: # endif
                   1381:
                   1382:
1.4       noro     1383: #ifdef AMIGA
                   1384:
                   1385: #  define GC_AMIGA_DS
                   1386: #  include "AmigaOS.c"
                   1387: #  undef GC_AMIGA_DS
                   1388:
                   1389: #else /* !OS2 && !Windows && !AMIGA */
                   1390:
1.1       noro     1391: void GC_register_data_segments()
                   1392: {
1.7       noro     1393: #   if !defined(PCR) && !defined(SRC_M3) && !defined(MACOS)
1.6       noro     1394: #     if defined(REDIRECT_MALLOC) && defined(GC_SOLARIS_THREADS)
1.1       noro     1395:        /* As of Solaris 2.3, the Solaris threads implementation        */
                   1396:        /* allocates the data structure for the initial thread with     */
                   1397:        /* sbrk at process startup.  It needs to be scanned, so that    */
                   1398:        /* we don't lose some malloc allocated data structures          */
                   1399:        /* hanging from it.  We're on thin ice here ...                 */
                   1400:         extern caddr_t sbrk();
                   1401:
                   1402:        GC_add_roots_inner(DATASTART, (char *)sbrk(0), FALSE);
                   1403: #     else
                   1404:        GC_add_roots_inner(DATASTART, (char *)(DATAEND), FALSE);
1.6       noro     1405: #       if defined(DATASTART2)
                   1406:          GC_add_roots_inner(DATASTART2, (char *)(DATAEND2), FALSE);
                   1407: #       endif
1.1       noro     1408: #     endif
                   1409: #   endif
                   1410: #   if defined(MACOS)
                   1411:     {
                   1412: #   if defined(THINK_C)
                   1413:        extern void* GC_MacGetDataStart(void);
                   1414:        /* globals begin above stack and end at a5. */
                   1415:        GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
                   1416:                           (ptr_t)LMGetCurrentA5(), FALSE);
                   1417: #   else
                   1418: #     if defined(__MWERKS__)
                   1419: #       if !__POWERPC__
                   1420:          extern void* GC_MacGetDataStart(void);
                   1421:          /* MATTHEW: Function to handle Far Globals (CW Pro 3) */
                   1422: #         if __option(far_data)
                   1423:          extern void* GC_MacGetDataEnd(void);
                   1424: #         endif
                   1425:          /* globals begin above stack and end at a5. */
                   1426:          GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
                   1427:                             (ptr_t)LMGetCurrentA5(), FALSE);
                   1428:          /* MATTHEW: Handle Far Globals */
                   1429: #         if __option(far_data)
                   1430:       /* Far globals follow he QD globals: */
                   1431:          GC_add_roots_inner((ptr_t)LMGetCurrentA5(),
                   1432:                             (ptr_t)GC_MacGetDataEnd(), FALSE);
                   1433: #         endif
                   1434: #       else
                   1435:          extern char __data_start__[], __data_end__[];
                   1436:          GC_add_roots_inner((ptr_t)&__data_start__,
                   1437:                             (ptr_t)&__data_end__, FALSE);
                   1438: #       endif /* __POWERPC__ */
                   1439: #     endif /* __MWERKS__ */
                   1440: #   endif /* !THINK_C */
                   1441:     }
                   1442: #   endif /* MACOS */
                   1443:
                   1444:     /* Dynamic libraries are added at every collection, since they may  */
                   1445:     /* change.                                                         */
                   1446: }
                   1447:
                   1448: # endif  /* ! AMIGA */
1.4       noro     1449: # endif  /* ! MSWIN32 && ! MSWINCE*/
1.1       noro     1450: # endif  /* ! OS2 */
                   1451:
                   1452: /*
                   1453:  * Auxiliary routines for obtaining memory from OS.
                   1454:  */
1.4       noro     1455:
1.1       noro     1456: # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) \
1.4       noro     1457:        && !defined(MSWIN32) && !defined(MSWINCE) \
                   1458:        && !defined(MACOS) && !defined(DOS4GW)
1.1       noro     1459:
                   1460: # ifdef SUNOS4
                   1461:     extern caddr_t sbrk();
                   1462: # endif
                   1463: # ifdef __STDC__
                   1464: #   define SBRK_ARG_T ptrdiff_t
                   1465: # else
                   1466: #   define SBRK_ARG_T int
                   1467: # endif
                   1468:
1.4       noro     1469:
1.1       noro     1470: # ifdef RS6000
                   1471: /* The compiler seems to generate speculative reads one past the end of        */
                   1472: /* an allocated object.  Hence we need to make sure that the page      */
                   1473: /* following the last heap page is also mapped.                                */
                   1474: ptr_t GC_unix_get_mem(bytes)
                   1475: word bytes;
                   1476: {
                   1477:     caddr_t cur_brk = (caddr_t)sbrk(0);
                   1478:     caddr_t result;
                   1479:     SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1);
                   1480:     static caddr_t my_brk_val = 0;
                   1481:
                   1482:     if ((SBRK_ARG_T)bytes < 0) return(0); /* too big */
                   1483:     if (lsbs != 0) {
                   1484:         if((caddr_t)(sbrk(GC_page_size - lsbs)) == (caddr_t)(-1)) return(0);
                   1485:     }
                   1486:     if (cur_brk == my_brk_val) {
                   1487:        /* Use the extra block we allocated last time. */
                   1488:         result = (ptr_t)sbrk((SBRK_ARG_T)bytes);
                   1489:         if (result == (caddr_t)(-1)) return(0);
                   1490:         result -= GC_page_size;
                   1491:     } else {
                   1492:         result = (ptr_t)sbrk(GC_page_size + (SBRK_ARG_T)bytes);
                   1493:         if (result == (caddr_t)(-1)) return(0);
                   1494:     }
                   1495:     my_brk_val = result + bytes + GC_page_size;        /* Always page aligned */
                   1496:     return((ptr_t)result);
                   1497: }
                   1498:
                   1499: #else  /* Not RS6000 */
                   1500:
                   1501: #if defined(USE_MMAP)
1.4       noro     1502: /* Tested only under Linux, IRIX5 and Solaris 2 */
1.1       noro     1503:
                   1504: #ifdef USE_MMAP_FIXED
                   1505: #   define GC_MMAP_FLAGS MAP_FIXED | MAP_PRIVATE
                   1506:        /* Seems to yield better performance on Solaris 2, but can      */
                   1507:        /* be unreliable if something is already mapped at the address. */
                   1508: #else
                   1509: #   define GC_MMAP_FLAGS MAP_PRIVATE
                   1510: #endif
                   1511:
1.4       noro     1512: #ifndef HEAP_START
                   1513: #   define HEAP_START 0
                   1514: #endif
                   1515:
1.1       noro     1516: ptr_t GC_unix_get_mem(bytes)
                   1517: word bytes;
                   1518: {
                   1519:     void *result;
                   1520:     static ptr_t last_addr = HEAP_START;
                   1521:
1.7       noro     1522: #   ifndef USE_MMAP_ANON
                   1523:       static GC_bool initialized = FALSE;
                   1524:       static int fd;
                   1525:
                   1526:       if (!initialized) {
                   1527:          fd = open("/dev/zero", O_RDONLY);
                   1528:          fcntl(fd, F_SETFD, FD_CLOEXEC);
                   1529:          initialized = TRUE;
                   1530:       }
                   1531: #   endif
                   1532:
1.1       noro     1533:     if (bytes & (GC_page_size -1)) ABORT("Bad GET_MEM arg");
1.7       noro     1534: #   ifdef USE_MMAP_ANON
                   1535:       result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC,
                   1536:                    GC_MMAP_FLAGS | MAP_ANON, -1, 0/* offset */);
                   1537: #   else
                   1538:       result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC,
                   1539:                    GC_MMAP_FLAGS, fd, 0/* offset */);
                   1540: #   endif
1.1       noro     1541:     if (result == MAP_FAILED) return(0);
                   1542:     last_addr = (ptr_t)result + bytes + GC_page_size - 1;
                   1543:     last_addr = (ptr_t)((word)last_addr & ~(GC_page_size - 1));
1.4       noro     1544: #   if !defined(LINUX)
                   1545:       if (last_addr == 0) {
                   1546:         /* Oops.  We got the end of the address space.  This isn't     */
                   1547:        /* usable by arbitrary C code, since one-past-end pointers      */
                   1548:        /* don't work, so we discard it and try again.                  */
                   1549:        munmap(result, (size_t)(-GC_page_size) - (size_t)result);
                   1550:                        /* Leave last page mapped, so we can't repeat. */
                   1551:        return GC_unix_get_mem(bytes);
                   1552:       }
                   1553: #   else
                   1554:       GC_ASSERT(last_addr != 0);
                   1555: #   endif
1.1       noro     1556:     return((ptr_t)result);
                   1557: }
                   1558:
                   1559: #else /* Not RS6000, not USE_MMAP */
                   1560: ptr_t GC_unix_get_mem(bytes)
                   1561: word bytes;
                   1562: {
                   1563:   ptr_t result;
                   1564: # ifdef IRIX5
                   1565:     /* Bare sbrk isn't thread safe.  Play by malloc rules.     */
                   1566:     /* The equivalent may be needed on other systems as well.  */
                   1567:     __LOCK_MALLOC();
                   1568: # endif
                   1569:   {
                   1570:     ptr_t cur_brk = (ptr_t)sbrk(0);
                   1571:     SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1);
                   1572:
                   1573:     if ((SBRK_ARG_T)bytes < 0) return(0); /* too big */
                   1574:     if (lsbs != 0) {
                   1575:         if((ptr_t)sbrk(GC_page_size - lsbs) == (ptr_t)(-1)) return(0);
                   1576:     }
                   1577:     result = (ptr_t)sbrk((SBRK_ARG_T)bytes);
                   1578:     if (result == (ptr_t)(-1)) result = 0;
                   1579:   }
                   1580: # ifdef IRIX5
                   1581:     __UNLOCK_MALLOC();
                   1582: # endif
                   1583:   return(result);
                   1584: }
                   1585:
                   1586: #endif /* Not USE_MMAP */
                   1587: #endif /* Not RS6000 */
                   1588:
                   1589: # endif /* UN*X */
                   1590:
                   1591: # ifdef OS2
                   1592:
                   1593: void * os2_alloc(size_t bytes)
                   1594: {
                   1595:     void * result;
                   1596:
                   1597:     if (DosAllocMem(&result, bytes, PAG_EXECUTE | PAG_READ |
                   1598:                                    PAG_WRITE | PAG_COMMIT)
                   1599:                    != NO_ERROR) {
                   1600:        return(0);
                   1601:     }
                   1602:     if (result == 0) return(os2_alloc(bytes));
                   1603:     return(result);
                   1604: }
                   1605:
                   1606: # endif /* OS2 */
                   1607:
                   1608:
1.4       noro     1609: # if defined(MSWIN32) || defined(MSWINCE)
                   1610: SYSTEM_INFO GC_sysinfo;
                   1611: # endif
                   1612:
1.6       noro     1613: # ifdef MSWIN32
                   1614:
                   1615: # ifdef USE_GLOBAL_ALLOC
                   1616: #   define GLOBAL_ALLOC_TEST 1
                   1617: # else
                   1618: #   define GLOBAL_ALLOC_TEST GC_no_win32_dlls
                   1619: # endif
1.4       noro     1620:
1.1       noro     1621: word GC_n_heap_bases = 0;
                   1622:
                   1623: ptr_t GC_win32_get_mem(bytes)
                   1624: word bytes;
                   1625: {
                   1626:     ptr_t result;
1.4       noro     1627:
1.6       noro     1628:     if (GLOBAL_ALLOC_TEST) {
1.1       noro     1629:        /* VirtualAlloc doesn't like PAGE_EXECUTE_READWRITE.    */
                   1630:        /* There are also unconfirmed rumors of other           */
                   1631:        /* problems, so we dodge the issue.                     */
                   1632:         result = (ptr_t) GlobalAlloc(0, bytes + HBLKSIZE);
                   1633:         result = (ptr_t)(((word)result + HBLKSIZE) & ~(HBLKSIZE-1));
                   1634:     } else {
1.6       noro     1635:        /* VirtualProtect only works on regions returned by a   */
                   1636:        /* single VirtualAlloc call.  Thus we allocate one      */
                   1637:        /* extra page, which will prevent merging of blocks     */
                   1638:        /* in separate regions, and eliminate any temptation    */
                   1639:        /* to call VirtualProtect on a range spanning regions.  */
                   1640:        /* This wastes a small amount of memory, and risks      */
                   1641:        /* increased fragmentation.  But better alternatives    */
                   1642:        /* would require effort.                                */
                   1643:         result = (ptr_t) VirtualAlloc(NULL, bytes + 1,
1.1       noro     1644:                                      MEM_COMMIT | MEM_RESERVE,
                   1645:                                      PAGE_EXECUTE_READWRITE);
                   1646:     }
                   1647:     if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
                   1648:        /* If I read the documentation correctly, this can      */
                   1649:        /* only happen if HBLKSIZE > 64k or not a power of 2.   */
                   1650:     if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
                   1651:     GC_heap_bases[GC_n_heap_bases++] = result;
                   1652:     return(result);
                   1653: }
                   1654:
                   1655: void GC_win32_free_heap ()
                   1656: {
1.6       noro     1657:     if (GC_no_win32_dlls) {
1.1       noro     1658:        while (GC_n_heap_bases > 0) {
                   1659:            GlobalFree (GC_heap_bases[--GC_n_heap_bases]);
                   1660:            GC_heap_bases[GC_n_heap_bases] = 0;
                   1661:        }
                   1662:     }
                   1663: }
1.4       noro     1664: # endif
                   1665:
                   1666: #ifdef AMIGA
                   1667: # define GC_AMIGA_AM
                   1668: # include "AmigaOS.c"
                   1669: # undef GC_AMIGA_AM
                   1670: #endif
1.1       noro     1671:
                   1672:
1.4       noro     1673: # ifdef MSWINCE
                   1674: word GC_n_heap_bases = 0;
                   1675:
                   1676: ptr_t GC_wince_get_mem(bytes)
                   1677: word bytes;
                   1678: {
                   1679:     ptr_t result;
                   1680:     word i;
                   1681:
                   1682:     /* Round up allocation size to multiple of page size */
                   1683:     bytes = (bytes + GC_page_size-1) & ~(GC_page_size-1);
                   1684:
                   1685:     /* Try to find reserved, uncommitted pages */
                   1686:     for (i = 0; i < GC_n_heap_bases; i++) {
                   1687:        if (((word)(-(signed_word)GC_heap_lengths[i])
                   1688:             & (GC_sysinfo.dwAllocationGranularity-1))
                   1689:            >= bytes) {
                   1690:            result = GC_heap_bases[i] + GC_heap_lengths[i];
                   1691:            break;
                   1692:        }
                   1693:     }
                   1694:
                   1695:     if (i == GC_n_heap_bases) {
                   1696:        /* Reserve more pages */
                   1697:        word res_bytes = (bytes + GC_sysinfo.dwAllocationGranularity-1)
                   1698:                         & ~(GC_sysinfo.dwAllocationGranularity-1);
1.6       noro     1699:        /* If we ever support MPROTECT_VDB here, we will probably need to       */
                   1700:        /* ensure that res_bytes is strictly > bytes, so that VirtualProtect    */
                   1701:        /* never spans regions.  It seems to be OK for a VirtualFree argument   */
                   1702:        /* to span regions, so we should be OK for now.                         */
1.4       noro     1703:        result = (ptr_t) VirtualAlloc(NULL, res_bytes,
                   1704:                                      MEM_RESERVE | MEM_TOP_DOWN,
                   1705:                                      PAGE_EXECUTE_READWRITE);
                   1706:        if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
                   1707:            /* If I read the documentation correctly, this can  */
                   1708:            /* only happen if HBLKSIZE > 64k or not a power of 2.       */
                   1709:        if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
                   1710:        GC_heap_bases[GC_n_heap_bases] = result;
                   1711:        GC_heap_lengths[GC_n_heap_bases] = 0;
                   1712:        GC_n_heap_bases++;
                   1713:     }
                   1714:
                   1715:     /* Commit pages */
                   1716:     result = (ptr_t) VirtualAlloc(result, bytes,
                   1717:                                  MEM_COMMIT,
                   1718:                                  PAGE_EXECUTE_READWRITE);
                   1719:     if (result != NULL) {
                   1720:        if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
                   1721:        GC_heap_lengths[i] += bytes;
                   1722:     }
                   1723:
                   1724:     return(result);
                   1725: }
1.1       noro     1726: # endif
                   1727:
                   1728: #ifdef USE_MUNMAP
                   1729:
1.4       noro     1730: /* For now, this only works on Win32/WinCE and some Unix-like  */
                   1731: /* systems.  If you have something else, don't define          */
                   1732: /* USE_MUNMAP.                                                 */
1.1       noro     1733: /* We assume ANSI C to support this feature.                   */
1.4       noro     1734:
                   1735: #if !defined(MSWIN32) && !defined(MSWINCE)
                   1736:
1.1       noro     1737: #include <unistd.h>
                   1738: #include <sys/mman.h>
                   1739: #include <sys/stat.h>
                   1740: #include <sys/types.h>
1.4       noro     1741:
                   1742: #endif
1.1       noro     1743:
                   1744: /* Compute a page aligned starting address for the unmap       */
                   1745: /* operation on a block of size bytes starting at start.       */
                   1746: /* Return 0 if the block is too small to make this feasible.   */
                   1747: ptr_t GC_unmap_start(ptr_t start, word bytes)
                   1748: {
                   1749:     ptr_t result = start;
                   1750:     /* Round start to next page boundary.       */
                   1751:         result += GC_page_size - 1;
                   1752:         result = (ptr_t)((word)result & ~(GC_page_size - 1));
                   1753:     if (result + GC_page_size > start + bytes) return 0;
                   1754:     return result;
                   1755: }
                   1756:
                   1757: /* Compute end address for an unmap operation on the indicated */
                   1758: /* block.                                                      */
                   1759: ptr_t GC_unmap_end(ptr_t start, word bytes)
                   1760: {
                   1761:     ptr_t end_addr = start + bytes;
                   1762:     end_addr = (ptr_t)((word)end_addr & ~(GC_page_size - 1));
                   1763:     return end_addr;
                   1764: }
                   1765:
1.4       noro     1766: /* Under Win32/WinCE we commit (map) and decommit (unmap)      */
                   1767: /* memory using        VirtualAlloc and VirtualFree.  These functions  */
                   1768: /* work on individual allocations of virtual memory, made      */
                   1769: /* previously using VirtualAlloc with the MEM_RESERVE flag.    */
                   1770: /* The ranges we need to (de)commit may span several of these  */
                   1771: /* allocations; therefore we use VirtualQuery to check         */
                   1772: /* allocation lengths, and split up the range as necessary.    */
                   1773:
1.1       noro     1774: /* We assume that GC_remap is called on exactly the same range */
                   1775: /* as a previous call to GC_unmap.  It is safe to consistently */
                   1776: /* round the endpoints in both places.                         */
                   1777: void GC_unmap(ptr_t start, word bytes)
                   1778: {
                   1779:     ptr_t start_addr = GC_unmap_start(start, bytes);
                   1780:     ptr_t end_addr = GC_unmap_end(start, bytes);
                   1781:     word len = end_addr - start_addr;
                   1782:     if (0 == start_addr) return;
1.4       noro     1783: #   if defined(MSWIN32) || defined(MSWINCE)
                   1784:       while (len != 0) {
                   1785:           MEMORY_BASIC_INFORMATION mem_info;
                   1786:          GC_word free_len;
                   1787:          if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
                   1788:              != sizeof(mem_info))
                   1789:              ABORT("Weird VirtualQuery result");
                   1790:          free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
                   1791:          if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT))
                   1792:              ABORT("VirtualFree failed");
                   1793:          GC_unmapped_bytes += free_len;
                   1794:          start_addr += free_len;
                   1795:          len -= free_len;
                   1796:       }
                   1797: #   else
                   1798:       if (munmap(start_addr, len) != 0) ABORT("munmap failed");
                   1799:       GC_unmapped_bytes += len;
                   1800: #   endif
1.1       noro     1801: }
                   1802:
                   1803:
                   1804: void GC_remap(ptr_t start, word bytes)
                   1805: {
                   1806:     static int zero_descr = -1;
                   1807:     ptr_t start_addr = GC_unmap_start(start, bytes);
                   1808:     ptr_t end_addr = GC_unmap_end(start, bytes);
                   1809:     word len = end_addr - start_addr;
                   1810:     ptr_t result;
                   1811:
1.4       noro     1812: #   if defined(MSWIN32) || defined(MSWINCE)
                   1813:       if (0 == start_addr) return;
                   1814:       while (len != 0) {
                   1815:           MEMORY_BASIC_INFORMATION mem_info;
                   1816:          GC_word alloc_len;
                   1817:          if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
                   1818:              != sizeof(mem_info))
                   1819:              ABORT("Weird VirtualQuery result");
                   1820:          alloc_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
                   1821:          result = VirtualAlloc(start_addr, alloc_len,
                   1822:                                MEM_COMMIT,
                   1823:                                PAGE_EXECUTE_READWRITE);
                   1824:          if (result != start_addr) {
                   1825:              ABORT("VirtualAlloc remapping failed");
                   1826:          }
                   1827:          GC_unmapped_bytes -= alloc_len;
                   1828:          start_addr += alloc_len;
                   1829:          len -= alloc_len;
                   1830:       }
                   1831: #   else
                   1832:       if (-1 == zero_descr) zero_descr = open("/dev/zero", O_RDWR);
1.7       noro     1833:       fcntl(zero_descr, F_SETFD, FD_CLOEXEC);
1.4       noro     1834:       if (0 == start_addr) return;
                   1835:       result = mmap(start_addr, len, PROT_READ | PROT_WRITE | OPT_PROT_EXEC,
                   1836:                    MAP_FIXED | MAP_PRIVATE, zero_descr, 0);
                   1837:       if (result != start_addr) {
                   1838:          ABORT("mmap remapping failed");
                   1839:       }
                   1840:       GC_unmapped_bytes -= len;
                   1841: #   endif
1.1       noro     1842: }
                   1843:
                   1844: /* Two adjacent blocks have already been unmapped and are about to     */
                   1845: /* be merged.  Unmap the whole block.  This typically requires         */
                   1846: /* that we unmap a small section in the middle that was not previously */
                   1847: /* unmapped due to alignment constraints.                              */
                   1848: void GC_unmap_gap(ptr_t start1, word bytes1, ptr_t start2, word bytes2)
                   1849: {
                   1850:     ptr_t start1_addr = GC_unmap_start(start1, bytes1);
                   1851:     ptr_t end1_addr = GC_unmap_end(start1, bytes1);
                   1852:     ptr_t start2_addr = GC_unmap_start(start2, bytes2);
                   1853:     ptr_t end2_addr = GC_unmap_end(start2, bytes2);
                   1854:     ptr_t start_addr = end1_addr;
                   1855:     ptr_t end_addr = start2_addr;
                   1856:     word len;
                   1857:     GC_ASSERT(start1 + bytes1 == start2);
                   1858:     if (0 == start1_addr) start_addr = GC_unmap_start(start1, bytes1 + bytes2);
                   1859:     if (0 == start2_addr) end_addr = GC_unmap_end(start1, bytes1 + bytes2);
                   1860:     if (0 == start_addr) return;
                   1861:     len = end_addr - start_addr;
1.4       noro     1862: #   if defined(MSWIN32) || defined(MSWINCE)
                   1863:       while (len != 0) {
                   1864:           MEMORY_BASIC_INFORMATION mem_info;
                   1865:          GC_word free_len;
                   1866:          if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
                   1867:              != sizeof(mem_info))
                   1868:              ABORT("Weird VirtualQuery result");
                   1869:          free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
                   1870:          if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT))
                   1871:              ABORT("VirtualFree failed");
                   1872:          GC_unmapped_bytes += free_len;
                   1873:          start_addr += free_len;
                   1874:          len -= free_len;
                   1875:       }
                   1876: #   else
                   1877:       if (len != 0 && munmap(start_addr, len) != 0) ABORT("munmap failed");
                   1878:       GC_unmapped_bytes += len;
                   1879: #   endif
1.1       noro     1880: }
                   1881:
                   1882: #endif /* USE_MUNMAP */
                   1883:
                   1884: /* Routine for pushing any additional roots.  In THREADS       */
                   1885: /* environment, this is also responsible for marking from      */
1.4       noro     1886: /* thread stacks.                                              */
1.1       noro     1887: #ifndef THREADS
                   1888: void (*GC_push_other_roots)() = 0;
                   1889: #else /* THREADS */
                   1890:
                   1891: # ifdef PCR
                   1892: PCR_ERes GC_push_thread_stack(PCR_Th_T *t, PCR_Any dummy)
                   1893: {
                   1894:     struct PCR_ThCtl_TInfoRep info;
                   1895:     PCR_ERes result;
                   1896:
                   1897:     info.ti_stkLow = info.ti_stkHi = 0;
                   1898:     result = PCR_ThCtl_GetInfo(t, &info);
                   1899:     GC_push_all_stack((ptr_t)(info.ti_stkLow), (ptr_t)(info.ti_stkHi));
                   1900:     return(result);
                   1901: }
                   1902:
                   1903: /* Push the contents of an old object. We treat this as stack  */
                   1904: /* data only becasue that makes it robust against mark stack   */
                   1905: /* overflow.                                                   */
                   1906: PCR_ERes GC_push_old_obj(void *p, size_t size, PCR_Any data)
                   1907: {
                   1908:     GC_push_all_stack((ptr_t)p, (ptr_t)p + size);
                   1909:     return(PCR_ERes_okay);
                   1910: }
                   1911:
                   1912:
1.4       noro     1913: void GC_default_push_other_roots GC_PROTO((void))
1.1       noro     1914: {
                   1915:     /* Traverse data allocated by previous memory managers.            */
                   1916:        {
                   1917:          extern struct PCR_MM_ProcsRep * GC_old_allocator;
                   1918:
                   1919:          if ((*(GC_old_allocator->mmp_enumerate))(PCR_Bool_false,
                   1920:                                                   GC_push_old_obj, 0)
                   1921:              != PCR_ERes_okay) {
                   1922:              ABORT("Old object enumeration failed");
                   1923:          }
                   1924:        }
                   1925:     /* Traverse all thread stacks. */
                   1926:        if (PCR_ERes_IsErr(
                   1927:                 PCR_ThCtl_ApplyToAllOtherThreads(GC_push_thread_stack,0))
                   1928:               || PCR_ERes_IsErr(GC_push_thread_stack(PCR_Th_CurrThread(), 0))) {
                   1929:               ABORT("Thread stack marking failed\n");
                   1930:        }
                   1931: }
                   1932:
                   1933: # endif /* PCR */
                   1934:
                   1935: # ifdef SRC_M3
                   1936:
                   1937: # ifdef ALL_INTERIOR_POINTERS
                   1938:     --> misconfigured
                   1939: # endif
                   1940:
1.4       noro     1941: void GC_push_thread_structures GC_PROTO((void))
                   1942: {
                   1943:     /* Not our responsibibility. */
                   1944: }
1.1       noro     1945:
                   1946: extern void ThreadF__ProcessStacks();
                   1947:
                   1948: void GC_push_thread_stack(start, stop)
                   1949: word start, stop;
                   1950: {
                   1951:    GC_push_all_stack((ptr_t)start, (ptr_t)stop + sizeof(word));
                   1952: }
                   1953:
                   1954: /* Push routine with M3 specific calling convention. */
                   1955: GC_m3_push_root(dummy1, p, dummy2, dummy3)
                   1956: word *p;
                   1957: ptr_t dummy1, dummy2;
                   1958: int dummy3;
                   1959: {
                   1960:     word q = *p;
                   1961:
1.4       noro     1962:     GC_PUSH_ONE_STACK(q, p);
1.1       noro     1963: }
                   1964:
                   1965: /* M3 set equivalent to RTHeap.TracedRefTypes */
                   1966: typedef struct { int elts[1]; }  RefTypeSet;
                   1967: RefTypeSet GC_TracedRefTypes = {{0x1}};
                   1968:
1.4       noro     1969: void GC_default_push_other_roots GC_PROTO((void))
1.1       noro     1970: {
1.4       noro     1971:     /* Use the M3 provided routine for finding static roots.    */
                   1972:     /* This is a bit dubious, since it presumes no C roots.     */
                   1973:     /* We handle the collector roots explicitly in GC_push_roots */
                   1974:        RTMain__GlobalMapProc(GC_m3_push_root, 0, GC_TracedRefTypes);
1.1       noro     1975:        if (GC_words_allocd > 0) {
                   1976:            ThreadF__ProcessStacks(GC_push_thread_stack);
                   1977:        }
                   1978:        /* Otherwise this isn't absolutely necessary, and we have       */
                   1979:        /* startup ordering problems.                                   */
                   1980: }
                   1981:
                   1982: # endif /* SRC_M3 */
                   1983:
1.6       noro     1984: # if defined(GC_SOLARIS_THREADS) || defined(GC_PTHREADS) || \
                   1985:      defined(GC_WIN32_THREADS)
1.1       noro     1986:
                   1987: extern void GC_push_all_stacks();
                   1988:
1.4       noro     1989: void GC_default_push_other_roots GC_PROTO((void))
1.1       noro     1990: {
                   1991:     GC_push_all_stacks();
                   1992: }
                   1993:
1.6       noro     1994: # endif /* GC_SOLARIS_THREADS || GC_PTHREADS */
1.1       noro     1995:
1.4       noro     1996: void (*GC_push_other_roots) GC_PROTO((void)) = GC_default_push_other_roots;
1.1       noro     1997:
1.6       noro     1998: #endif /* THREADS */
1.1       noro     1999:
                   2000: /*
                   2001:  * Routines for accessing dirty  bits on virtual pages.
1.4       noro     2002:  * We plan to eventually implement four strategies for doing so:
1.1       noro     2003:  * DEFAULT_VDB:        A simple dummy implementation that treats every page
                   2004:  *             as possibly dirty.  This makes incremental collection
                   2005:  *             useless, but the implementation is still correct.
                   2006:  * PCR_VDB:    Use PPCRs virtual dirty bit facility.
                   2007:  * PROC_VDB:   Use the /proc facility for reading dirty bits.  Only
                   2008:  *             works under some SVR4 variants.  Even then, it may be
                   2009:  *             too slow to be entirely satisfactory.  Requires reading
                   2010:  *             dirty bits for entire address space.  Implementations tend
                   2011:  *             to assume that the client is a (slow) debugger.
                   2012:  * MPROTECT_VDB:Protect pages and then catch the faults to keep track of
                   2013:  *             dirtied pages.  The implementation (and implementability)
                   2014:  *             is highly system dependent.  This usually fails when system
                   2015:  *             calls write to a protected page.  We prevent the read system
                   2016:  *             call from doing so.  It is the clients responsibility to
                   2017:  *             make sure that other system calls are similarly protected
                   2018:  *             or write only to the stack.
                   2019:  */
                   2020: GC_bool GC_dirty_maintained = FALSE;
                   2021:
                   2022: # ifdef DEFAULT_VDB
                   2023:
                   2024: /* All of the following assume the allocation lock is held, and        */
                   2025: /* signals are disabled.                                       */
                   2026:
                   2027: /* The client asserts that unallocated pages in the heap are never     */
                   2028: /* written.                                                            */
                   2029:
                   2030: /* Initialize virtual dirty bit implementation.                        */
                   2031: void GC_dirty_init()
                   2032: {
1.7       noro     2033: #   ifdef PRINTSTATS
                   2034:       GC_printf0("Initializing DEFAULT_VDB...\n");
                   2035: #   endif
1.1       noro     2036:     GC_dirty_maintained = TRUE;
                   2037: }
                   2038:
                   2039: /* Retrieve system dirty bits for heap to a local buffer.      */
                   2040: /* Restore the systems notion of which pages are dirty.                */
                   2041: void GC_read_dirty()
                   2042: {}
                   2043:
                   2044: /* Is the HBLKSIZE sized page at h marked dirty in the local buffer?   */
                   2045: /* If the actual page size is different, this returns TRUE if any      */
                   2046: /* of the pages overlapping h are dirty.  This routine may err on the  */
                   2047: /* side of labelling pages as dirty (and this implementation does).    */
                   2048: /*ARGSUSED*/
                   2049: GC_bool GC_page_was_dirty(h)
                   2050: struct hblk *h;
                   2051: {
                   2052:     return(TRUE);
                   2053: }
                   2054:
                   2055: /*
                   2056:  * The following two routines are typically less crucial.  They matter
                   2057:  * most with large dynamic libraries, or if we can't accurately identify
                   2058:  * stacks, e.g. under Solaris 2.X.  Otherwise the following default
                   2059:  * versions are adequate.
                   2060:  */
                   2061:
                   2062: /* Could any valid GC heap pointer ever have been written to this page?        */
                   2063: /*ARGSUSED*/
                   2064: GC_bool GC_page_was_ever_dirty(h)
                   2065: struct hblk *h;
                   2066: {
                   2067:     return(TRUE);
                   2068: }
                   2069:
                   2070: /* Reset the n pages starting at h to "was never dirty" status.        */
                   2071: void GC_is_fresh(h, n)
                   2072: struct hblk *h;
                   2073: word n;
                   2074: {
                   2075: }
                   2076:
1.6       noro     2077: /* A call that:                                                */
                   2078: /* I) hints that [h, h+nblocks) is about to be written.        */
                   2079: /* II) guarantees that protection is removed.          */
                   2080: /* (I) may speed up some dirty bit implementations.    */
                   2081: /* (II) may be essential if we need to ensure that     */
                   2082: /* pointer-free system call buffers in the heap are    */
                   2083: /* not protected.                                      */
1.1       noro     2084: /*ARGSUSED*/
1.6       noro     2085: void GC_remove_protection(h, nblocks, is_ptrfree)
1.1       noro     2086: struct hblk *h;
1.6       noro     2087: word nblocks;
                   2088: GC_bool is_ptrfree;
1.1       noro     2089: {
                   2090: }
                   2091:
                   2092: # endif /* DEFAULT_VDB */
                   2093:
                   2094:
                   2095: # ifdef MPROTECT_VDB
                   2096:
                   2097: /*
                   2098:  * See DEFAULT_VDB for interface descriptions.
                   2099:  */
                   2100:
                   2101: /*
                   2102:  * This implementation maintains dirty bits itself by catching write
                   2103:  * faults and keeping track of them.  We assume nobody else catches
1.6       noro     2104:  * SIGBUS or SIGSEGV.  We assume no write faults occur in system calls.
                   2105:  * This means that clients must ensure that system calls don't write
                   2106:  * to the write-protected heap.  Probably the best way to do this is to
                   2107:  * ensure that system calls write at most to POINTERFREE objects in the
                   2108:  * heap, and do even that only if we are on a platform on which those
                   2109:  * are not protected.  Another alternative is to wrap system calls
                   2110:  * (see example for read below), but the current implementation holds
                   2111:  * a lock across blocking calls, making it problematic for multithreaded
                   2112:  * applications.
1.1       noro     2113:  * We assume the page size is a multiple of HBLKSIZE.
1.6       noro     2114:  * We prefer them to be the same.  We avoid protecting POINTERFREE
                   2115:  * objects only if they are the same.
1.1       noro     2116:  */
                   2117:
1.7       noro     2118: # if !defined(MSWIN32) && !defined(MSWINCE) && !defined(DARWIN)
1.1       noro     2119:
                   2120: #   include <sys/mman.h>
                   2121: #   include <signal.h>
                   2122: #   include <sys/syscall.h>
                   2123:
                   2124: #   define PROTECT(addr, len) \
1.2       noro     2125:          if (mprotect((caddr_t)(addr), (size_t)(len), \
1.1       noro     2126:                       PROT_READ | OPT_PROT_EXEC) < 0) { \
                   2127:            ABORT("mprotect failed"); \
                   2128:          }
                   2129: #   define UNPROTECT(addr, len) \
1.2       noro     2130:          if (mprotect((caddr_t)(addr), (size_t)(len), \
1.1       noro     2131:                       PROT_WRITE | PROT_READ | OPT_PROT_EXEC ) < 0) { \
                   2132:            ABORT("un-mprotect failed"); \
                   2133:          }
                   2134:
                   2135: # else
                   2136:
1.7       noro     2137: # ifdef DARWIN
                   2138:     /* Using vm_protect (mach syscall) over mprotect (BSD syscall) seems to
                   2139:        decrease the likelihood of some of the problems described below. */
                   2140:     #include <mach/vm_map.h>
                   2141:     extern mach_port_t GC_task_self;
                   2142:     #define PROTECT(addr,len) \
                   2143:         if(vm_protect(GC_task_self,(vm_address_t)(addr),(vm_size_t)(len), \
                   2144:                 FALSE,VM_PROT_READ) != KERN_SUCCESS) { \
                   2145:             ABORT("vm_portect failed"); \
                   2146:         }
                   2147:     #define UNPROTECT(addr,len) \
                   2148:         if(vm_protect(GC_task_self,(vm_address_t)(addr),(vm_size_t)(len), \
                   2149:                 FALSE,VM_PROT_READ|VM_PROT_WRITE) != KERN_SUCCESS) { \
                   2150:             ABORT("vm_portect failed"); \
                   2151:         }
                   2152: # else
                   2153:
1.4       noro     2154: #   ifndef MSWINCE
                   2155: #     include <signal.h>
                   2156: #   endif
1.1       noro     2157:
                   2158:     static DWORD protect_junk;
                   2159: #   define PROTECT(addr, len) \
                   2160:          if (!VirtualProtect((addr), (len), PAGE_EXECUTE_READ, \
                   2161:                              &protect_junk)) { \
                   2162:            DWORD last_error = GetLastError(); \
                   2163:            GC_printf1("Last error code: %lx\n", last_error); \
                   2164:            ABORT("VirtualProtect failed"); \
                   2165:          }
                   2166: #   define UNPROTECT(addr, len) \
                   2167:          if (!VirtualProtect((addr), (len), PAGE_EXECUTE_READWRITE, \
                   2168:                              &protect_junk)) { \
                   2169:            ABORT("un-VirtualProtect failed"); \
                   2170:          }
1.7       noro     2171: # endif /* !DARWIN */
                   2172: # endif /* MSWIN32 || MSWINCE || DARWIN */
1.1       noro     2173:
                   2174: #if defined(SUNOS4) || defined(FREEBSD)
                   2175:     typedef void (* SIG_PF)();
1.7       noro     2176: #endif /* SUNOS4 || FREEBSD */
                   2177:
1.6       noro     2178: #if defined(SUNOS5SIGS) || defined(OSF1) || defined(LINUX) \
1.7       noro     2179:     || defined(HURD)
1.2       noro     2180: # ifdef __STDC__
1.1       noro     2181:     typedef void (* SIG_PF)(int);
1.2       noro     2182: # else
                   2183:     typedef void (* SIG_PF)();
                   2184: # endif
1.7       noro     2185: #endif /* SUNOS5SIGS || OSF1 || LINUX || HURD */
                   2186:
1.1       noro     2187: #if defined(MSWIN32)
                   2188:     typedef LPTOP_LEVEL_EXCEPTION_FILTER SIG_PF;
                   2189: #   undef SIG_DFL
                   2190: #   define SIG_DFL (LPTOP_LEVEL_EXCEPTION_FILTER) (-1)
                   2191: #endif
1.4       noro     2192: #if defined(MSWINCE)
                   2193:     typedef LONG (WINAPI *SIG_PF)(struct _EXCEPTION_POINTERS *);
                   2194: #   undef SIG_DFL
                   2195: #   define SIG_DFL (SIG_PF) (-1)
                   2196: #endif
1.1       noro     2197:
1.6       noro     2198: #if defined(IRIX5) || defined(OSF1) || defined(HURD)
1.1       noro     2199:     typedef void (* REAL_SIG_PF)(int, int, struct sigcontext *);
1.7       noro     2200: #endif /* IRIX5 || OSF1 || HURD */
                   2201:
1.1       noro     2202: #if defined(SUNOS5SIGS)
1.2       noro     2203: # ifdef HPUX
                   2204: #   define SIGINFO __siginfo
                   2205: # else
                   2206: #   define SIGINFO siginfo
                   2207: # endif
                   2208: # ifdef __STDC__
                   2209:     typedef void (* REAL_SIG_PF)(int, struct SIGINFO *, void *);
                   2210: # else
                   2211:     typedef void (* REAL_SIG_PF)();
                   2212: # endif
1.7       noro     2213: #endif /* SUNOS5SIGS */
                   2214:
1.1       noro     2215: #if defined(LINUX)
1.6       noro     2216: #   if __GLIBC__ > 2 || __GLIBC__ == 2 && __GLIBC_MINOR__ >= 2
1.1       noro     2217:       typedef struct sigcontext s_c;
1.6       noro     2218: #   else  /* glibc < 2.2 */
                   2219: #     include <linux/version.h>
                   2220: #     if (LINUX_VERSION_CODE >= 0x20100) && !defined(M68K) || defined(ALPHA) || defined(ARM32)
                   2221:         typedef struct sigcontext s_c;
                   2222: #     else
                   2223:         typedef struct sigcontext_struct s_c;
                   2224: #     endif
                   2225: #   endif  /* glibc < 2.2 */
1.2       noro     2226: #   if defined(ALPHA) || defined(M68K)
                   2227:       typedef void (* REAL_SIG_PF)(int, int, s_c *);
                   2228: #   else
1.4       noro     2229: #     if defined(IA64) || defined(HP_PA)
1.2       noro     2230:         typedef void (* REAL_SIG_PF)(int, siginfo_t *, s_c *);
                   2231: #     else
                   2232:         typedef void (* REAL_SIG_PF)(int, s_c);
                   2233: #     endif
                   2234: #   endif
1.1       noro     2235: #   ifdef ALPHA
                   2236:     /* Retrieve fault address from sigcontext structure by decoding    */
                   2237:     /* instruction.                                                    */
                   2238:     char * get_fault_addr(s_c *sc) {
                   2239:         unsigned instr;
                   2240:        word faultaddr;
                   2241:
                   2242:        instr = *((unsigned *)(sc->sc_pc));
                   2243:        faultaddr = sc->sc_regs[(instr >> 16) & 0x1f];
                   2244:        faultaddr += (word) (((int)instr << 16) >> 16);
                   2245:        return (char *)faultaddr;
                   2246:     }
                   2247: #   endif /* !ALPHA */
1.7       noro     2248: # endif /* LINUX */
1.4       noro     2249:
1.7       noro     2250: #ifndef DARWIN
1.1       noro     2251: SIG_PF GC_old_bus_handler;
                   2252: SIG_PF GC_old_segv_handler;    /* Also old MSWIN32 ACCESS_VIOLATION filter */
1.7       noro     2253: #endif /* !DARWIN */
1.1       noro     2254:
1.7       noro     2255: #if defined(THREADS)
1.4       noro     2256: /* We need to lock around the bitmap update in the write fault handler */
                   2257: /* in order to avoid the risk of losing a bit.  We do this with a      */
                   2258: /* test-and-set spin lock if we know how to do that.  Otherwise we     */
                   2259: /* check whether we are already in the handler and use the dumb but    */
                   2260: /* safe fallback algorithm of setting all bits in the word.            */
                   2261: /* Contention should be very rare, so we do the minimum to handle it   */
                   2262: /* correctly.                                                          */
                   2263: #ifdef GC_TEST_AND_SET_DEFINED
                   2264:   static VOLATILE unsigned int fault_handler_lock = 0;
                   2265:   void async_set_pht_entry_from_index(VOLATILE page_hash_table db, int index) {
1.6       noro     2266:     while (GC_test_and_set(&fault_handler_lock)) {}
1.4       noro     2267:     /* Could also revert to set_pht_entry_from_index_safe if initial   */
                   2268:     /* GC_test_and_set fails.                                          */
                   2269:     set_pht_entry_from_index(db, index);
                   2270:     GC_clear(&fault_handler_lock);
                   2271:   }
                   2272: #else /* !GC_TEST_AND_SET_DEFINED */
                   2273:   /* THIS IS INCORRECT! The dirty bit vector may be temporarily wrong, */
                   2274:   /* just before we notice the conflict and correct it. We may end up   */
                   2275:   /* looking at it while it's wrong.  But this requires contention     */
                   2276:   /* exactly when a GC is triggered, which seems far less likely to    */
                   2277:   /* fail than the old code, which had no reported failures.  Thus we  */
                   2278:   /* leave it this way while we think of something better, or support  */
                   2279:   /* GC_test_and_set on the remaining platforms.                       */
                   2280:   static VOLATILE word currently_updating = 0;
                   2281:   void async_set_pht_entry_from_index(VOLATILE page_hash_table db, int index) {
                   2282:     unsigned int update_dummy;
                   2283:     currently_updating = (word)(&update_dummy);
                   2284:     set_pht_entry_from_index(db, index);
                   2285:     /* If we get contention in the 10 or so instruction window here,   */
                   2286:     /* and we get stopped by a GC between the two updates, we lose!    */
                   2287:     if (currently_updating != (word)(&update_dummy)) {
                   2288:        set_pht_entry_from_index_safe(db, index);
                   2289:        /* We claim that if two threads concurrently try to update the  */
                   2290:        /* dirty bit vector, the first one to execute UPDATE_START      */
                   2291:        /* will see it changed when UPDATE_END is executed.  (Note that */
                   2292:        /* &update_dummy must differ in two distinct threads.)  It      */
                   2293:        /* will then execute set_pht_entry_from_index_safe, thus        */
                   2294:        /* returning us to a safe state, though not soon enough.        */
                   2295:     }
                   2296:   }
                   2297: #endif /* !GC_TEST_AND_SET_DEFINED */
                   2298: #else /* !THREADS */
                   2299: # define async_set_pht_entry_from_index(db, index) \
                   2300:        set_pht_entry_from_index(db, index)
                   2301: #endif /* !THREADS */
                   2302:
1.1       noro     2303: /*ARGSUSED*/
1.7       noro     2304: #if !defined(DARWIN)
1.1       noro     2305: # if defined (SUNOS4) || defined(FREEBSD)
                   2306:     void GC_write_fault_handler(sig, code, scp, addr)
                   2307:     int sig, code;
                   2308:     struct sigcontext *scp;
                   2309:     char * addr;
                   2310: #   ifdef SUNOS4
                   2311: #     define SIG_OK (sig == SIGSEGV || sig == SIGBUS)
                   2312: #     define CODE_OK (FC_CODE(code) == FC_PROT \
                   2313:                    || (FC_CODE(code) == FC_OBJERR \
                   2314:                       && FC_ERRNO(code) == FC_PROT))
                   2315: #   endif
                   2316: #   ifdef FREEBSD
                   2317: #     define SIG_OK (sig == SIGBUS)
                   2318: #     define CODE_OK (code == BUS_PAGE_FAULT)
                   2319: #   endif
1.7       noro     2320: # endif /* SUNOS4 || FREEBSD */
                   2321:
1.6       noro     2322: # if defined(IRIX5) || defined(OSF1) || defined(HURD)
1.1       noro     2323: #   include <errno.h>
                   2324:     void GC_write_fault_handler(int sig, int code, struct sigcontext *scp)
                   2325: #   ifdef OSF1
1.6       noro     2326: #     define SIG_OK (sig == SIGSEGV)
1.1       noro     2327: #     define CODE_OK (code == 2 /* experimentally determined */)
                   2328: #   endif
                   2329: #   ifdef IRIX5
1.6       noro     2330: #     define SIG_OK (sig == SIGSEGV)
1.1       noro     2331: #     define CODE_OK (code == EACCES)
                   2332: #   endif
1.6       noro     2333: #   ifdef HURD
                   2334: #     define SIG_OK (sig == SIGBUS || sig == SIGSEGV)
                   2335: #     define CODE_OK  TRUE
                   2336: #   endif
1.7       noro     2337: # endif /* IRIX5 || OSF1 || HURD */
                   2338:
1.1       noro     2339: # if defined(LINUX)
1.2       noro     2340: #   if defined(ALPHA) || defined(M68K)
1.1       noro     2341:       void GC_write_fault_handler(int sig, int code, s_c * sc)
                   2342: #   else
1.4       noro     2343: #     if defined(IA64) || defined(HP_PA)
1.2       noro     2344:         void GC_write_fault_handler(int sig, siginfo_t * si, s_c * scp)
                   2345: #     else
1.6       noro     2346: #       if defined(ARM32)
                   2347:           void GC_write_fault_handler(int sig, int a2, int a3, int a4, s_c sc)
                   2348: #       else
                   2349:           void GC_write_fault_handler(int sig, s_c sc)
                   2350: #       endif
1.2       noro     2351: #     endif
1.1       noro     2352: #   endif
                   2353: #   define SIG_OK (sig == SIGSEGV)
                   2354: #   define CODE_OK TRUE
1.2       noro     2355:        /* Empirically c.trapno == 14, on IA32, but is that useful?     */
                   2356:        /* Should probably consider alignment issues on other           */
                   2357:        /* architectures.                                               */
1.7       noro     2358: # endif /* LINUX */
                   2359:
1.1       noro     2360: # if defined(SUNOS5SIGS)
1.2       noro     2361: #  ifdef __STDC__
                   2362:     void GC_write_fault_handler(int sig, struct SIGINFO *scp, void * context)
                   2363: #  else
                   2364:     void GC_write_fault_handler(sig, scp, context)
                   2365:     int sig;
                   2366:     struct SIGINFO *scp;
                   2367:     void * context;
                   2368: #  endif
                   2369: #   ifdef HPUX
                   2370: #     define SIG_OK (sig == SIGSEGV || sig == SIGBUS)
                   2371: #     define CODE_OK (scp -> si_code == SEGV_ACCERR) \
                   2372:                     || (scp -> si_code == BUS_ADRERR) \
                   2373:                     || (scp -> si_code == BUS_UNKNOWN) \
                   2374:                     || (scp -> si_code == SEGV_UNKNOWN) \
                   2375:                     || (scp -> si_code == BUS_OBJERR)
                   2376: #   else
                   2377: #     define SIG_OK (sig == SIGSEGV)
                   2378: #     define CODE_OK (scp -> si_code == SEGV_ACCERR)
                   2379: #   endif
1.7       noro     2380: # endif /* SUNOS5SIGS */
1.4       noro     2381:
                   2382: # if defined(MSWIN32) || defined(MSWINCE)
1.1       noro     2383:     LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info)
                   2384: #   define SIG_OK (exc_info -> ExceptionRecord -> ExceptionCode == \
1.4       noro     2385:                        STATUS_ACCESS_VIOLATION)
1.1       noro     2386: #   define CODE_OK (exc_info -> ExceptionRecord -> ExceptionInformation[0] == 1)
                   2387:                        /* Write fault */
1.7       noro     2388: # endif /* MSWIN32 || MSWINCE */
1.1       noro     2389: {
                   2390:     register unsigned i;
1.6       noro     2391: #   if defined(HURD)
                   2392:        char *addr = (char *) code;
                   2393: #   endif
1.1       noro     2394: #   ifdef IRIX5
                   2395:        char * addr = (char *) (size_t) (scp -> sc_badvaddr);
                   2396: #   endif
                   2397: #   if defined(OSF1) && defined(ALPHA)
                   2398:        char * addr = (char *) (scp -> sc_traparg_a0);
                   2399: #   endif
                   2400: #   ifdef SUNOS5SIGS
                   2401:        char * addr = (char *) (scp -> si_addr);
                   2402: #   endif
                   2403: #   ifdef LINUX
1.7       noro     2404: #     if defined(I386) || defined (X86_64)
1.1       noro     2405:        char * addr = (char *) (sc.cr2);
                   2406: #     else
                   2407: #      if defined(M68K)
                   2408:           char * addr = NULL;
                   2409:
1.4       noro     2410:          struct sigcontext *scp = (struct sigcontext *)(sc);
1.1       noro     2411:
                   2412:          int format = (scp->sc_formatvec >> 12) & 0xf;
                   2413:          unsigned long *framedata = (unsigned long *)(scp + 1);
                   2414:          unsigned long ea;
                   2415:
                   2416:          if (format == 0xa || format == 0xb) {
                   2417:                /* 68020/030 */
                   2418:                ea = framedata[2];
                   2419:          } else if (format == 7) {
                   2420:                /* 68040 */
                   2421:                ea = framedata[3];
1.4       noro     2422:                if (framedata[1] & 0x08000000) {
                   2423:                        /* correct addr on misaligned access */
                   2424:                        ea = (ea+4095)&(~4095);
                   2425:                }
1.1       noro     2426:          } else if (format == 4) {
                   2427:                /* 68060 */
                   2428:                ea = framedata[0];
                   2429:                if (framedata[1] & 0x08000000) {
                   2430:                        /* correct addr on misaligned access */
                   2431:                        ea = (ea+4095)&(~4095);
                   2432:                }
                   2433:          }
                   2434:          addr = (char *)ea;
                   2435: #      else
                   2436: #        ifdef ALPHA
                   2437:             char * addr = get_fault_addr(sc);
                   2438: #        else
1.4       noro     2439: #          if defined(IA64) || defined(HP_PA)
1.2       noro     2440:              char * addr = si -> si_addr;
1.3       noro     2441:              /* I believe this is claimed to work on all platforms for */
                   2442:              /* Linux 2.3.47 and later.  Hopefully we don't have to    */
                   2443:              /* worry about earlier kernels on IA64.                   */
1.2       noro     2444: #          else
                   2445: #             if defined(POWERPC)
                   2446:                 char * addr = (char *) (sc.regs->dar);
                   2447: #            else
1.6       noro     2448: #               if defined(ARM32)
                   2449:                   char * addr = (char *)sc.fault_address;
                   2450: #               else
                   2451:                  --> architecture not supported
                   2452: #               endif
1.2       noro     2453: #            endif
                   2454: #          endif
1.1       noro     2455: #        endif
                   2456: #      endif
                   2457: #     endif
                   2458: #   endif
1.4       noro     2459: #   if defined(MSWIN32) || defined(MSWINCE)
1.1       noro     2460:        char * addr = (char *) (exc_info -> ExceptionRecord
                   2461:                                -> ExceptionInformation[1]);
                   2462: #      define sig SIGSEGV
                   2463: #   endif
                   2464:
                   2465:     if (SIG_OK && CODE_OK) {
                   2466:         register struct hblk * h =
                   2467:                        (struct hblk *)((word)addr & ~(GC_page_size-1));
                   2468:         GC_bool in_allocd_block;
                   2469:
                   2470: #      ifdef SUNOS5SIGS
                   2471:            /* Address is only within the correct physical page.        */
                   2472:            in_allocd_block = FALSE;
                   2473:             for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
                   2474:               if (HDR(h+i) != 0) {
                   2475:                 in_allocd_block = TRUE;
                   2476:               }
                   2477:             }
                   2478: #      else
                   2479:            in_allocd_block = (HDR(addr) != 0);
                   2480: #      endif
                   2481:         if (!in_allocd_block) {
                   2482:            /* Heap blocks now begin and end on page boundaries */
                   2483:             SIG_PF old_handler;
                   2484:
                   2485:             if (sig == SIGSEGV) {
                   2486:                old_handler = GC_old_segv_handler;
                   2487:             } else {
                   2488:                 old_handler = GC_old_bus_handler;
                   2489:             }
                   2490:             if (old_handler == SIG_DFL) {
1.4       noro     2491: #              if !defined(MSWIN32) && !defined(MSWINCE)
1.1       noro     2492:                    GC_err_printf1("Segfault at 0x%lx\n", addr);
                   2493:                     ABORT("Unexpected bus error or segmentation fault");
                   2494: #              else
                   2495:                    return(EXCEPTION_CONTINUE_SEARCH);
                   2496: #              endif
                   2497:             } else {
                   2498: #              if defined (SUNOS4) || defined(FREEBSD)
                   2499:                    (*old_handler) (sig, code, scp, addr);
                   2500:                    return;
                   2501: #              endif
                   2502: #              if defined (SUNOS5SIGS)
                   2503:                    (*(REAL_SIG_PF)old_handler) (sig, scp, context);
                   2504:                    return;
                   2505: #              endif
                   2506: #              if defined (LINUX)
1.2       noro     2507: #                  if defined(ALPHA) || defined(M68K)
1.1       noro     2508:                        (*(REAL_SIG_PF)old_handler) (sig, code, sc);
                   2509: #                  else
1.4       noro     2510: #                    if defined(IA64) || defined(HP_PA)
1.2       noro     2511:                        (*(REAL_SIG_PF)old_handler) (sig, si, scp);
                   2512: #                    else
1.1       noro     2513:                        (*(REAL_SIG_PF)old_handler) (sig, sc);
1.2       noro     2514: #                    endif
1.1       noro     2515: #                  endif
                   2516:                    return;
                   2517: #              endif
1.6       noro     2518: #              if defined (IRIX5) || defined(OSF1) || defined(HURD)
1.1       noro     2519:                    (*(REAL_SIG_PF)old_handler) (sig, code, scp);
                   2520:                    return;
                   2521: #              endif
                   2522: #              ifdef MSWIN32
                   2523:                    return((*old_handler)(exc_info));
                   2524: #              endif
                   2525:             }
                   2526:         }
1.6       noro     2527:         UNPROTECT(h, GC_page_size);
                   2528:        /* We need to make sure that no collection occurs between       */
                   2529:        /* the UNPROTECT and the setting of the dirty bit.  Otherwise   */
                   2530:        /* a write by a third thread might go unnoticed.  Reversing     */
                   2531:        /* the order is just as bad, since we would end up unprotecting */
                   2532:        /* a page in a GC cycle during which it's not marked.           */
                   2533:        /* Currently we do this by disabling the thread stopping        */
                   2534:        /* signals while this handler is running.  An alternative might */
                   2535:        /* be to record the fact that we're about to unprotect, or      */
                   2536:        /* have just unprotected a page in the GC's thread structure,   */
                   2537:        /* and then to have the thread stopping code set the dirty      */
                   2538:        /* flag, if necessary.                                          */
1.1       noro     2539:         for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
                   2540:             register int index = PHT_HASH(h+i);
                   2541:
1.4       noro     2542:             async_set_pht_entry_from_index(GC_dirty_pages, index);
1.1       noro     2543:         }
1.6       noro     2544: #      if defined(OSF1)
1.1       noro     2545:            /* These reset the signal handler each time by default. */
                   2546:            signal(SIGSEGV, (SIG_PF) GC_write_fault_handler);
                   2547: #      endif
                   2548:        /* The write may not take place before dirty bits are read.     */
                   2549:        /* But then we'll fault again ...                               */
1.4       noro     2550: #      if defined(MSWIN32) || defined(MSWINCE)
1.1       noro     2551:            return(EXCEPTION_CONTINUE_EXECUTION);
                   2552: #      else
                   2553:            return;
                   2554: #      endif
                   2555:     }
1.4       noro     2556: #if defined(MSWIN32) || defined(MSWINCE)
1.1       noro     2557:     return EXCEPTION_CONTINUE_SEARCH;
                   2558: #else
                   2559:     GC_err_printf1("Segfault at 0x%lx\n", addr);
                   2560:     ABORT("Unexpected bus error or segmentation fault");
                   2561: #endif
                   2562: }
1.7       noro     2563: #endif /* !DARWIN */
1.1       noro     2564:
                   2565: /*
                   2566:  * We hold the allocation lock.  We expect block h to be written
1.6       noro     2567:  * shortly.  Ensure that all pages containing any part of the n hblks
                   2568:  * starting at h are no longer protected.  If is_ptrfree is false,
                   2569:  * also ensure that they will subsequently appear to be dirty.
1.1       noro     2570:  */
1.6       noro     2571: void GC_remove_protection(h, nblocks, is_ptrfree)
1.1       noro     2572: struct hblk *h;
1.6       noro     2573: word nblocks;
                   2574: GC_bool is_ptrfree;
1.1       noro     2575: {
1.6       noro     2576:     struct hblk * h_trunc;  /* Truncated to page boundary */
                   2577:     struct hblk * h_end;    /* Page boundary following block end */
                   2578:     struct hblk * current;
                   2579:     GC_bool found_clean;
1.1       noro     2580:
                   2581:     if (!GC_dirty_maintained) return;
                   2582:     h_trunc = (struct hblk *)((word)h & ~(GC_page_size-1));
1.6       noro     2583:     h_end = (struct hblk *)(((word)(h + nblocks) + GC_page_size-1)
                   2584:                            & ~(GC_page_size-1));
1.1       noro     2585:     found_clean = FALSE;
1.6       noro     2586:     for (current = h_trunc; current < h_end; ++current) {
                   2587:         int index = PHT_HASH(current);
1.1       noro     2588:
1.6       noro     2589:         if (!is_ptrfree || current < h || current >= h + nblocks) {
1.4       noro     2590:             async_set_pht_entry_from_index(GC_dirty_pages, index);
1.1       noro     2591:         }
                   2592:     }
1.6       noro     2593:     UNPROTECT(h_trunc, (ptr_t)h_end - (ptr_t)h_trunc);
1.1       noro     2594: }
                   2595:
1.7       noro     2596: #if !defined(DARWIN)
1.1       noro     2597: void GC_dirty_init()
                   2598: {
1.6       noro     2599: #   if defined(SUNOS5SIGS) || defined(IRIX5) || defined(LINUX) || \
                   2600:        defined(OSF1) || defined(HURD)
1.4       noro     2601:       struct sigaction act, oldact;
1.6       noro     2602:       /* We should probably specify SA_SIGINFO for Linux, and handle   */
                   2603:       /* the different architectures more uniformly.                   */
                   2604: #     if defined(IRIX5) || defined(LINUX) || defined(OSF1) || defined(HURD)
1.1       noro     2605:        act.sa_flags    = SA_RESTART;
1.6       noro     2606:         act.sa_handler  = (SIG_PF)GC_write_fault_handler;
1.4       noro     2607: #     else
1.1       noro     2608:        act.sa_flags    = SA_RESTART | SA_SIGINFO;
                   2609:         act.sa_sigaction = GC_write_fault_handler;
1.4       noro     2610: #     endif
                   2611:       (void)sigemptyset(&act.sa_mask);
1.6       noro     2612: #     ifdef SIG_SUSPEND
                   2613:         /* Arrange to postpone SIG_SUSPEND while we're in a write fault        */
                   2614:         /* handler.  This effectively makes the handler atomic w.r.t.  */
                   2615:         /* stopping the world for GC.                                  */
                   2616:         (void)sigaddset(&act.sa_mask, SIG_SUSPEND);
                   2617: #     endif /* SIG_SUSPEND */
1.4       noro     2618: #    endif
1.1       noro     2619: #   ifdef PRINTSTATS
                   2620:        GC_printf0("Inititalizing mprotect virtual dirty bit implementation\n");
                   2621: #   endif
                   2622:     GC_dirty_maintained = TRUE;
                   2623:     if (GC_page_size % HBLKSIZE != 0) {
                   2624:         GC_err_printf0("Page size not multiple of HBLKSIZE\n");
                   2625:         ABORT("Page size not multiple of HBLKSIZE");
                   2626:     }
                   2627: #   if defined(SUNOS4) || defined(FREEBSD)
                   2628:       GC_old_bus_handler = signal(SIGBUS, GC_write_fault_handler);
                   2629:       if (GC_old_bus_handler == SIG_IGN) {
                   2630:         GC_err_printf0("Previously ignored bus error!?");
                   2631:         GC_old_bus_handler = SIG_DFL;
                   2632:       }
                   2633:       if (GC_old_bus_handler != SIG_DFL) {
                   2634: #      ifdef PRINTSTATS
                   2635:           GC_err_printf0("Replaced other SIGBUS handler\n");
                   2636: #      endif
                   2637:       }
                   2638: #   endif
1.6       noro     2639: #   if defined(SUNOS4)
1.1       noro     2640:       GC_old_segv_handler = signal(SIGSEGV, (SIG_PF)GC_write_fault_handler);
                   2641:       if (GC_old_segv_handler == SIG_IGN) {
                   2642:         GC_err_printf0("Previously ignored segmentation violation!?");
                   2643:         GC_old_segv_handler = SIG_DFL;
                   2644:       }
                   2645:       if (GC_old_segv_handler != SIG_DFL) {
                   2646: #      ifdef PRINTSTATS
                   2647:           GC_err_printf0("Replaced other SIGSEGV handler\n");
                   2648: #      endif
                   2649:       }
                   2650: #   endif
1.6       noro     2651: #   if defined(SUNOS5SIGS) || defined(IRIX5) || defined(LINUX) \
                   2652:        || defined(OSF1) || defined(HURD)
                   2653:       /* SUNOS5SIGS includes HPUX */
                   2654: #     if defined(GC_IRIX_THREADS)
1.1       noro     2655:        sigaction(SIGSEGV, 0, &oldact);
                   2656:        sigaction(SIGSEGV, &act, 0);
                   2657: #     else
1.7       noro     2658:        {
                   2659:          int res = sigaction(SIGSEGV, &act, &oldact);
                   2660:          if (res != 0) ABORT("Sigaction failed");
                   2661:        }
1.1       noro     2662: #     endif
1.6       noro     2663: #     if defined(_sigargs) || defined(HURD) || !defined(SA_SIGINFO)
1.1       noro     2664:        /* This is Irix 5.x, not 6.x.  Irix 5.x does not have   */
                   2665:        /* sa_sigaction.                                        */
                   2666:        GC_old_segv_handler = oldact.sa_handler;
1.6       noro     2667: #     else /* Irix 6.x or SUNOS5SIGS or LINUX */
1.1       noro     2668:         if (oldact.sa_flags & SA_SIGINFO) {
                   2669:           GC_old_segv_handler = (SIG_PF)(oldact.sa_sigaction);
                   2670:         } else {
                   2671:           GC_old_segv_handler = oldact.sa_handler;
                   2672:         }
                   2673: #     endif
                   2674:       if (GC_old_segv_handler == SIG_IGN) {
                   2675:             GC_err_printf0("Previously ignored segmentation violation!?");
                   2676:             GC_old_segv_handler = SIG_DFL;
                   2677:       }
                   2678:       if (GC_old_segv_handler != SIG_DFL) {
                   2679: #       ifdef PRINTSTATS
                   2680:          GC_err_printf0("Replaced other SIGSEGV handler\n");
                   2681: #       endif
                   2682:       }
1.4       noro     2683: #   endif
1.7       noro     2684: #   if defined(HPUX) || defined(LINUX) || defined(HURD)
1.4       noro     2685:       sigaction(SIGBUS, &act, &oldact);
                   2686:       GC_old_bus_handler = oldact.sa_handler;
                   2687:       if (GC_old_bus_handler == SIG_IGN) {
                   2688:             GC_err_printf0("Previously ignored bus error!?");
                   2689:             GC_old_bus_handler = SIG_DFL;
                   2690:       }
                   2691:       if (GC_old_bus_handler != SIG_DFL) {
                   2692: #       ifdef PRINTSTATS
                   2693:          GC_err_printf0("Replaced other SIGBUS handler\n");
                   2694: #       endif
                   2695:       }
1.7       noro     2696: #   endif /* HPUX || LINUX || HURD */
1.1       noro     2697: #   if defined(MSWIN32)
                   2698:       GC_old_segv_handler = SetUnhandledExceptionFilter(GC_write_fault_handler);
                   2699:       if (GC_old_segv_handler != NULL) {
                   2700: #      ifdef PRINTSTATS
                   2701:           GC_err_printf0("Replaced other UnhandledExceptionFilter\n");
                   2702: #      endif
                   2703:       } else {
                   2704:           GC_old_segv_handler = SIG_DFL;
                   2705:       }
                   2706: #   endif
                   2707: }
1.7       noro     2708: #endif /* !DARWIN */
1.1       noro     2709:
1.6       noro     2710: int GC_incremental_protection_needs()
                   2711: {
                   2712:     if (GC_page_size == HBLKSIZE) {
                   2713:        return GC_PROTECTS_POINTER_HEAP;
                   2714:     } else {
                   2715:        return GC_PROTECTS_POINTER_HEAP | GC_PROTECTS_PTRFREE_HEAP;
                   2716:     }
                   2717: }
                   2718:
                   2719: #define HAVE_INCREMENTAL_PROTECTION_NEEDS
1.1       noro     2720:
1.6       noro     2721: #define IS_PTRFREE(hhdr) ((hhdr)->hb_descr == 0)
1.1       noro     2722:
1.6       noro     2723: #define PAGE_ALIGNED(x) !((word)(x) & (GC_page_size - 1))
1.1       noro     2724: void GC_protect_heap()
                   2725: {
                   2726:     ptr_t start;
                   2727:     word len;
1.6       noro     2728:     struct hblk * current;
                   2729:     struct hblk * current_start;  /* Start of block to be protected. */
                   2730:     struct hblk * limit;
1.1       noro     2731:     unsigned i;
1.6       noro     2732:     GC_bool protect_all =
                   2733:          (0 != (GC_incremental_protection_needs() & GC_PROTECTS_PTRFREE_HEAP));
1.1       noro     2734:     for (i = 0; i < GC_n_heap_sects; i++) {
                   2735:         start = GC_heap_sects[i].hs_start;
                   2736:         len = GC_heap_sects[i].hs_bytes;
1.6       noro     2737:        if (protect_all) {
                   2738:           PROTECT(start, len);
                   2739:        } else {
                   2740:          GC_ASSERT(PAGE_ALIGNED(len))
                   2741:          GC_ASSERT(PAGE_ALIGNED(start))
                   2742:          current_start = current = (struct hblk *)start;
                   2743:          limit = (struct hblk *)(start + len);
                   2744:          while (current < limit) {
                   2745:             hdr * hhdr;
                   2746:            word nhblks;
                   2747:            GC_bool is_ptrfree;
                   2748:
                   2749:            GC_ASSERT(PAGE_ALIGNED(current));
                   2750:            GET_HDR(current, hhdr);
                   2751:            if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
                   2752:              /* This can happen only if we're at the beginning of a    */
                   2753:              /* heap segment, and a block spans heap segments.         */
                   2754:              /* We will handle that block as part of the preceding     */
                   2755:              /* segment.                                               */
                   2756:              GC_ASSERT(current_start == current);
                   2757:              current_start = ++current;
                   2758:              continue;
                   2759:            }
                   2760:            if (HBLK_IS_FREE(hhdr)) {
                   2761:              GC_ASSERT(PAGE_ALIGNED(hhdr -> hb_sz));
                   2762:              nhblks = divHBLKSZ(hhdr -> hb_sz);
                   2763:              is_ptrfree = TRUE;        /* dirty on alloc */
                   2764:            } else {
                   2765:              nhblks = OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz);
                   2766:              is_ptrfree = IS_PTRFREE(hhdr);
                   2767:            }
                   2768:            if (is_ptrfree) {
                   2769:              if (current_start < current) {
                   2770:                PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
                   2771:              }
                   2772:              current_start = (current += nhblks);
                   2773:            } else {
                   2774:              current += nhblks;
                   2775:            }
                   2776:          }
                   2777:          if (current_start < current) {
                   2778:            PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
                   2779:          }
                   2780:        }
1.1       noro     2781:     }
                   2782: }
                   2783:
                   2784: /* We assume that either the world is stopped or its OK to lose dirty  */
                   2785: /* bits while this is happenning (as in GC_enable_incremental).                */
                   2786: void GC_read_dirty()
                   2787: {
                   2788:     BCOPY((word *)GC_dirty_pages, GC_grungy_pages,
                   2789:           (sizeof GC_dirty_pages));
                   2790:     BZERO((word *)GC_dirty_pages, (sizeof GC_dirty_pages));
                   2791:     GC_protect_heap();
                   2792: }
                   2793:
                   2794: GC_bool GC_page_was_dirty(h)
                   2795: struct hblk * h;
                   2796: {
                   2797:     register word index = PHT_HASH(h);
                   2798:
                   2799:     return(HDR(h) == 0 || get_pht_entry_from_index(GC_grungy_pages, index));
                   2800: }
                   2801:
                   2802: /*
                   2803:  * Acquiring the allocation lock here is dangerous, since this
                   2804:  * can be called from within GC_call_with_alloc_lock, and the cord
                   2805:  * package does so.  On systems that allow nested lock acquisition, this
                   2806:  * happens to work.
                   2807:  * On other systems, SET_LOCK_HOLDER and friends must be suitably defined.
                   2808:  */
1.4       noro     2809:
                   2810: static GC_bool syscall_acquired_lock = FALSE;  /* Protected by GC lock. */
1.1       noro     2811:
                   2812: void GC_begin_syscall()
                   2813: {
1.4       noro     2814:     if (!I_HOLD_LOCK()) {
                   2815:        LOCK();
                   2816:        syscall_acquired_lock = TRUE;
                   2817:     }
1.1       noro     2818: }
                   2819:
                   2820: void GC_end_syscall()
                   2821: {
1.4       noro     2822:     if (syscall_acquired_lock) {
                   2823:        syscall_acquired_lock = FALSE;
                   2824:        UNLOCK();
                   2825:     }
1.1       noro     2826: }
                   2827:
                   2828: void GC_unprotect_range(addr, len)
                   2829: ptr_t addr;
                   2830: word len;
                   2831: {
                   2832:     struct hblk * start_block;
                   2833:     struct hblk * end_block;
                   2834:     register struct hblk *h;
                   2835:     ptr_t obj_start;
                   2836:
1.6       noro     2837:     if (!GC_dirty_maintained) return;
1.1       noro     2838:     obj_start = GC_base(addr);
                   2839:     if (obj_start == 0) return;
                   2840:     if (GC_base(addr + len - 1) != obj_start) {
                   2841:         ABORT("GC_unprotect_range(range bigger than object)");
                   2842:     }
                   2843:     start_block = (struct hblk *)((word)addr & ~(GC_page_size - 1));
                   2844:     end_block = (struct hblk *)((word)(addr + len - 1) & ~(GC_page_size - 1));
                   2845:     end_block += GC_page_size/HBLKSIZE - 1;
                   2846:     for (h = start_block; h <= end_block; h++) {
                   2847:         register word index = PHT_HASH(h);
                   2848:
1.4       noro     2849:         async_set_pht_entry_from_index(GC_dirty_pages, index);
1.1       noro     2850:     }
                   2851:     UNPROTECT(start_block,
                   2852:              ((ptr_t)end_block - (ptr_t)start_block) + HBLKSIZE);
                   2853: }
                   2854:
1.6       noro     2855: #if 0
                   2856:
                   2857: /* We no longer wrap read by default, since that was causing too many  */
                   2858: /* problems.  It is preferred that the client instead avoids writing   */
                   2859: /* to the write-protected heap with a system call.                     */
                   2860: /* This still serves as sample code if you do want to wrap system calls.*/
                   2861:
                   2862: #if !defined(MSWIN32) && !defined(MSWINCE) && !defined(GC_USE_LD_WRAP)
                   2863: /* Replacement for UNIX system call.                                     */
                   2864: /* Other calls that write to the heap should be handled similarly.       */
                   2865: /* Note that this doesn't work well for blocking reads:  It will hold    */
                   2866: /* the allocation lock for the entire duration of the call. Multithreaded */
                   2867: /* clients should really ensure that it won't block, either by setting           */
                   2868: /* the descriptor nonblocking, or by calling select or poll first, to    */
                   2869: /* make sure that input is available.                                    */
                   2870: /* Another, preferred alternative is to ensure that system calls never           */
                   2871: /* write to the protected heap (see above).                              */
1.1       noro     2872: # if defined(__STDC__) && !defined(SUNOS4)
                   2873: #   include <unistd.h>
1.3       noro     2874: #   include <sys/uio.h>
1.1       noro     2875:     ssize_t read(int fd, void *buf, size_t nbyte)
                   2876: # else
                   2877: #   ifndef LINT
                   2878:       int read(fd, buf, nbyte)
                   2879: #   else
                   2880:       int GC_read(fd, buf, nbyte)
                   2881: #   endif
                   2882:     int fd;
                   2883:     char *buf;
                   2884:     int nbyte;
                   2885: # endif
                   2886: {
                   2887:     int result;
                   2888:
                   2889:     GC_begin_syscall();
                   2890:     GC_unprotect_range(buf, (word)nbyte);
1.6       noro     2891: #   if defined(IRIX5) || defined(GC_LINUX_THREADS)
1.1       noro     2892:        /* Indirect system call may not always be easily available.     */
                   2893:        /* We could call _read, but that would interfere with the       */
                   2894:        /* libpthread interception of read.                             */
1.3       noro     2895:        /* On Linux, we have to be careful with the linuxthreads        */
                   2896:        /* read interception.                                           */
1.1       noro     2897:        {
                   2898:            struct iovec iov;
                   2899:
                   2900:            iov.iov_base = buf;
                   2901:            iov.iov_len = nbyte;
                   2902:            result = readv(fd, &iov, 1);
                   2903:        }
                   2904: #   else
1.6       noro     2905: #     if defined(HURD)
                   2906:        result = __read(fd, buf, nbyte);
                   2907: #     else
1.4       noro     2908:        /* The two zero args at the end of this list are because one
                   2909:           IA-64 syscall() implementation actually requires six args
                   2910:           to be passed, even though they aren't always used. */
                   2911:        result = syscall(SYS_read, fd, buf, nbyte, 0, 0);
1.6       noro     2912: #     endif /* !HURD */
1.1       noro     2913: #   endif
                   2914:     GC_end_syscall();
                   2915:     return(result);
                   2916: }
1.6       noro     2917: #endif /* !MSWIN32 && !MSWINCE && !GC_LINUX_THREADS */
1.3       noro     2918:
1.6       noro     2919: #if defined(GC_USE_LD_WRAP) && !defined(THREADS)
1.3       noro     2920:     /* We use the GNU ld call wrapping facility.                       */
                   2921:     /* This requires that the linker be invoked with "--wrap read".    */
                   2922:     /* This can be done by passing -Wl,"--wrap read" to gcc.           */
                   2923:     /* I'm not sure that this actually wraps whatever version of read  */
                   2924:     /* is called by stdio.  That code also mentions __read.            */
                   2925: #   include <unistd.h>
                   2926:     ssize_t __wrap_read(int fd, void *buf, size_t nbyte)
                   2927:     {
                   2928:        int result;
                   2929:
                   2930:        GC_begin_syscall();
                   2931:        GC_unprotect_range(buf, (word)nbyte);
                   2932:        result = __real_read(fd, buf, nbyte);
                   2933:        GC_end_syscall();
                   2934:        return(result);
                   2935:     }
                   2936:
                   2937:     /* We should probably also do this for __read, or whatever stdio   */
                   2938:     /* actually calls.                                                 */
                   2939: #endif
1.1       noro     2940:
1.6       noro     2941: #endif /* 0 */
                   2942:
1.1       noro     2943: /*ARGSUSED*/
                   2944: GC_bool GC_page_was_ever_dirty(h)
                   2945: struct hblk *h;
                   2946: {
                   2947:     return(TRUE);
                   2948: }
                   2949:
                   2950: /* Reset the n pages starting at h to "was never dirty" status.        */
                   2951: /*ARGSUSED*/
                   2952: void GC_is_fresh(h, n)
                   2953: struct hblk *h;
                   2954: word n;
                   2955: {
                   2956: }
                   2957:
                   2958: # endif /* MPROTECT_VDB */
                   2959:
                   2960: # ifdef PROC_VDB
                   2961:
                   2962: /*
                   2963:  * See DEFAULT_VDB for interface descriptions.
                   2964:  */
                   2965:
                   2966: /*
                   2967:  * This implementaion assumes a Solaris 2.X like /proc pseudo-file-system
                   2968:  * from which we can read page modified bits.  This facility is far from
                   2969:  * optimal (e.g. we would like to get the info for only some of the
                   2970:  * address space), but it avoids intercepting system calls.
                   2971:  */
                   2972:
                   2973: #include <errno.h>
                   2974: #include <sys/types.h>
                   2975: #include <sys/signal.h>
                   2976: #include <sys/fault.h>
                   2977: #include <sys/syscall.h>
                   2978: #include <sys/procfs.h>
                   2979: #include <sys/stat.h>
                   2980:
                   2981: #define INITIAL_BUF_SZ 4096
                   2982: word GC_proc_buf_size = INITIAL_BUF_SZ;
                   2983: char *GC_proc_buf;
                   2984:
1.6       noro     2985: #ifdef GC_SOLARIS_THREADS
1.1       noro     2986: /* We don't have exact sp values for threads.  So we count on  */
                   2987: /* occasionally declaring stack pages to be fresh.  Thus we    */
                   2988: /* need a real implementation of GC_is_fresh.  We can't clear  */
                   2989: /* entries in GC_written_pages, since that would declare all   */
                   2990: /* pages with the given hash address to be fresh.              */
                   2991: #   define MAX_FRESH_PAGES 8*1024      /* Must be power of 2 */
                   2992:     struct hblk ** GC_fresh_pages;     /* A direct mapped cache.       */
                   2993:                                        /* Collisions are dropped.      */
                   2994:
                   2995: #   define FRESH_PAGE_SLOT(h) (divHBLKSZ((word)(h)) & (MAX_FRESH_PAGES-1))
                   2996: #   define ADD_FRESH_PAGE(h) \
                   2997:        GC_fresh_pages[FRESH_PAGE_SLOT(h)] = (h)
                   2998: #   define PAGE_IS_FRESH(h) \
                   2999:        (GC_fresh_pages[FRESH_PAGE_SLOT(h)] == (h) && (h) != 0)
                   3000: #endif
                   3001:
                   3002: /* Add all pages in pht2 to pht1 */
                   3003: void GC_or_pages(pht1, pht2)
                   3004: page_hash_table pht1, pht2;
                   3005: {
                   3006:     register int i;
                   3007:
                   3008:     for (i = 0; i < PHT_SIZE; i++) pht1[i] |= pht2[i];
                   3009: }
                   3010:
                   3011: int GC_proc_fd;
                   3012:
                   3013: void GC_dirty_init()
                   3014: {
                   3015:     int fd;
                   3016:     char buf[30];
                   3017:
                   3018:     GC_dirty_maintained = TRUE;
                   3019:     if (GC_words_allocd != 0 || GC_words_allocd_before_gc != 0) {
                   3020:        register int i;
                   3021:
                   3022:         for (i = 0; i < PHT_SIZE; i++) GC_written_pages[i] = (word)(-1);
                   3023: #       ifdef PRINTSTATS
                   3024:            GC_printf1("Allocated words:%lu:all pages may have been written\n",
                   3025:                       (unsigned long)
                   3026:                                (GC_words_allocd + GC_words_allocd_before_gc));
                   3027: #      endif
                   3028:     }
                   3029:     sprintf(buf, "/proc/%d", getpid());
                   3030:     fd = open(buf, O_RDONLY);
                   3031:     if (fd < 0) {
                   3032:        ABORT("/proc open failed");
                   3033:     }
                   3034:     GC_proc_fd = syscall(SYS_ioctl, fd, PIOCOPENPD, 0);
                   3035:     close(fd);
1.7       noro     3036:     syscall(SYS_fcntl, GC_proc_fd, F_SETFD, FD_CLOEXEC);
1.1       noro     3037:     if (GC_proc_fd < 0) {
                   3038:        ABORT("/proc ioctl failed");
                   3039:     }
                   3040:     GC_proc_buf = GC_scratch_alloc(GC_proc_buf_size);
1.6       noro     3041: #   ifdef GC_SOLARIS_THREADS
1.1       noro     3042:        GC_fresh_pages = (struct hblk **)
                   3043:          GC_scratch_alloc(MAX_FRESH_PAGES * sizeof (struct hblk *));
                   3044:        if (GC_fresh_pages == 0) {
                   3045:            GC_err_printf0("No space for fresh pages\n");
                   3046:            EXIT();
                   3047:        }
                   3048:        BZERO(GC_fresh_pages, MAX_FRESH_PAGES * sizeof (struct hblk *));
                   3049: #   endif
                   3050: }
                   3051:
                   3052: /* Ignore write hints. They don't help us here.        */
                   3053: /*ARGSUSED*/
1.6       noro     3054: void GC_remove_protection(h, nblocks, is_ptrfree)
1.1       noro     3055: struct hblk *h;
1.6       noro     3056: word nblocks;
                   3057: GC_bool is_ptrfree;
1.1       noro     3058: {
                   3059: }
                   3060:
1.6       noro     3061: #ifdef GC_SOLARIS_THREADS
1.1       noro     3062: #   define READ(fd,buf,nbytes) syscall(SYS_read, fd, buf, nbytes)
                   3063: #else
                   3064: #   define READ(fd,buf,nbytes) read(fd, buf, nbytes)
                   3065: #endif
                   3066:
                   3067: void GC_read_dirty()
                   3068: {
                   3069:     unsigned long ps, np;
                   3070:     int nmaps;
                   3071:     ptr_t vaddr;
                   3072:     struct prasmap * map;
                   3073:     char * bufp;
                   3074:     ptr_t current_addr, limit;
                   3075:     int i;
                   3076: int dummy;
                   3077:
                   3078:     BZERO(GC_grungy_pages, (sizeof GC_grungy_pages));
                   3079:
                   3080:     bufp = GC_proc_buf;
                   3081:     if (READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
                   3082: #      ifdef PRINTSTATS
                   3083:             GC_printf1("/proc read failed: GC_proc_buf_size = %lu\n",
                   3084:                       GC_proc_buf_size);
                   3085: #      endif
                   3086:         {
                   3087:             /* Retry with larger buffer. */
                   3088:             word new_size = 2 * GC_proc_buf_size;
                   3089:             char * new_buf = GC_scratch_alloc(new_size);
                   3090:
                   3091:             if (new_buf != 0) {
                   3092:                 GC_proc_buf = bufp = new_buf;
                   3093:                 GC_proc_buf_size = new_size;
                   3094:             }
                   3095:             if (syscall(SYS_read, GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
                   3096:                 WARN("Insufficient space for /proc read\n", 0);
                   3097:                 /* Punt:       */
                   3098:                memset(GC_grungy_pages, 0xff, sizeof (page_hash_table));
                   3099:                memset(GC_written_pages, 0xff, sizeof(page_hash_table));
1.6       noro     3100: #              ifdef GC_SOLARIS_THREADS
1.1       noro     3101:                    BZERO(GC_fresh_pages,
                   3102:                          MAX_FRESH_PAGES * sizeof (struct hblk *));
                   3103: #              endif
                   3104:                return;
                   3105:             }
                   3106:         }
                   3107:     }
                   3108:     /* Copy dirty bits into GC_grungy_pages */
                   3109:        nmaps = ((struct prpageheader *)bufp) -> pr_nmap;
                   3110:        /* printf( "nmaps = %d, PG_REFERENCED = %d, PG_MODIFIED = %d\n",
                   3111:                     nmaps, PG_REFERENCED, PG_MODIFIED); */
                   3112:        bufp = bufp + sizeof(struct prpageheader);
                   3113:        for (i = 0; i < nmaps; i++) {
                   3114:            map = (struct prasmap *)bufp;
                   3115:            vaddr = (ptr_t)(map -> pr_vaddr);
                   3116:            ps = map -> pr_pagesize;
                   3117:            np = map -> pr_npage;
                   3118:            /* printf("vaddr = 0x%X, ps = 0x%X, np = 0x%X\n", vaddr, ps, np); */
                   3119:            limit = vaddr + ps * np;
                   3120:            bufp += sizeof (struct prasmap);
                   3121:            for (current_addr = vaddr;
                   3122:                 current_addr < limit; current_addr += ps){
                   3123:                if ((*bufp++) & PG_MODIFIED) {
                   3124:                    register struct hblk * h = (struct hblk *) current_addr;
                   3125:
                   3126:                    while ((ptr_t)h < current_addr + ps) {
                   3127:                        register word index = PHT_HASH(h);
                   3128:
                   3129:                        set_pht_entry_from_index(GC_grungy_pages, index);
1.6       noro     3130: #                      ifdef GC_SOLARIS_THREADS
1.1       noro     3131:                          {
                   3132:                            register int slot = FRESH_PAGE_SLOT(h);
                   3133:
                   3134:                            if (GC_fresh_pages[slot] == h) {
                   3135:                                GC_fresh_pages[slot] = 0;
                   3136:                            }
                   3137:                          }
                   3138: #                      endif
                   3139:                        h++;
                   3140:                    }
                   3141:                }
                   3142:            }
                   3143:            bufp += sizeof(long) - 1;
                   3144:            bufp = (char *)((unsigned long)bufp & ~(sizeof(long)-1));
                   3145:        }
                   3146:     /* Update GC_written_pages. */
                   3147:         GC_or_pages(GC_written_pages, GC_grungy_pages);
1.6       noro     3148: #   ifdef GC_SOLARIS_THREADS
1.1       noro     3149:       /* Make sure that old stacks are considered completely clean     */
                   3150:       /* unless written again.                                         */
                   3151:        GC_old_stacks_are_fresh();
                   3152: #   endif
                   3153: }
                   3154:
                   3155: #undef READ
                   3156:
                   3157: GC_bool GC_page_was_dirty(h)
                   3158: struct hblk *h;
                   3159: {
                   3160:     register word index = PHT_HASH(h);
                   3161:     register GC_bool result;
                   3162:
                   3163:     result = get_pht_entry_from_index(GC_grungy_pages, index);
1.6       noro     3164: #   ifdef GC_SOLARIS_THREADS
1.1       noro     3165:        if (result && PAGE_IS_FRESH(h)) result = FALSE;
                   3166:        /* This happens only if page was declared fresh since   */
                   3167:        /* the read_dirty call, e.g. because it's in an unused  */
                   3168:        /* thread stack.  It's OK to treat it as clean, in      */
                   3169:        /* that case.  And it's consistent with                 */
                   3170:        /* GC_page_was_ever_dirty.                              */
                   3171: #   endif
                   3172:     return(result);
                   3173: }
                   3174:
                   3175: GC_bool GC_page_was_ever_dirty(h)
                   3176: struct hblk *h;
                   3177: {
                   3178:     register word index = PHT_HASH(h);
                   3179:     register GC_bool result;
                   3180:
                   3181:     result = get_pht_entry_from_index(GC_written_pages, index);
1.6       noro     3182: #   ifdef GC_SOLARIS_THREADS
1.1       noro     3183:        if (result && PAGE_IS_FRESH(h)) result = FALSE;
                   3184: #   endif
                   3185:     return(result);
                   3186: }
                   3187:
                   3188: /* Caller holds allocation lock.       */
                   3189: void GC_is_fresh(h, n)
                   3190: struct hblk *h;
                   3191: word n;
                   3192: {
                   3193:
                   3194:     register word index;
                   3195:
1.6       noro     3196: #   ifdef GC_SOLARIS_THREADS
1.1       noro     3197:       register word i;
                   3198:
                   3199:       if (GC_fresh_pages != 0) {
                   3200:         for (i = 0; i < n; i++) {
                   3201:           ADD_FRESH_PAGE(h + i);
                   3202:         }
                   3203:       }
                   3204: #   endif
                   3205: }
                   3206:
                   3207: # endif /* PROC_VDB */
                   3208:
                   3209:
                   3210: # ifdef PCR_VDB
                   3211:
                   3212: # include "vd/PCR_VD.h"
                   3213:
                   3214: # define NPAGES (32*1024)      /* 128 MB */
                   3215:
                   3216: PCR_VD_DB  GC_grungy_bits[NPAGES];
                   3217:
                   3218: ptr_t GC_vd_base;      /* Address corresponding to GC_grungy_bits[0]   */
                   3219:                        /* HBLKSIZE aligned.                            */
                   3220:
                   3221: void GC_dirty_init()
                   3222: {
                   3223:     GC_dirty_maintained = TRUE;
                   3224:     /* For the time being, we assume the heap generally grows up */
                   3225:     GC_vd_base = GC_heap_sects[0].hs_start;
                   3226:     if (GC_vd_base == 0) {
                   3227:        ABORT("Bad initial heap segment");
                   3228:     }
                   3229:     if (PCR_VD_Start(HBLKSIZE, GC_vd_base, NPAGES*HBLKSIZE)
                   3230:        != PCR_ERes_okay) {
                   3231:        ABORT("dirty bit initialization failed");
                   3232:     }
                   3233: }
                   3234:
                   3235: void GC_read_dirty()
                   3236: {
                   3237:     /* lazily enable dirty bits on newly added heap sects */
                   3238:     {
                   3239:         static int onhs = 0;
                   3240:         int nhs = GC_n_heap_sects;
                   3241:         for( ; onhs < nhs; onhs++ ) {
                   3242:             PCR_VD_WriteProtectEnable(
                   3243:                     GC_heap_sects[onhs].hs_start,
                   3244:                     GC_heap_sects[onhs].hs_bytes );
                   3245:         }
                   3246:     }
                   3247:
                   3248:
                   3249:     if (PCR_VD_Clear(GC_vd_base, NPAGES*HBLKSIZE, GC_grungy_bits)
                   3250:         != PCR_ERes_okay) {
                   3251:        ABORT("dirty bit read failed");
                   3252:     }
                   3253: }
                   3254:
                   3255: GC_bool GC_page_was_dirty(h)
                   3256: struct hblk *h;
                   3257: {
                   3258:     if((ptr_t)h < GC_vd_base || (ptr_t)h >= GC_vd_base + NPAGES*HBLKSIZE) {
                   3259:        return(TRUE);
                   3260:     }
                   3261:     return(GC_grungy_bits[h - (struct hblk *)GC_vd_base] & PCR_VD_DB_dirtyBit);
                   3262: }
                   3263:
                   3264: /*ARGSUSED*/
1.6       noro     3265: void GC_remove_protection(h, nblocks, is_ptrfree)
1.1       noro     3266: struct hblk *h;
1.6       noro     3267: word nblocks;
                   3268: GC_bool is_ptrfree;
1.1       noro     3269: {
1.6       noro     3270:     PCR_VD_WriteProtectDisable(h, nblocks*HBLKSIZE);
                   3271:     PCR_VD_WriteProtectEnable(h, nblocks*HBLKSIZE);
1.1       noro     3272: }
                   3273:
                   3274: # endif /* PCR_VDB */
                   3275:
1.7       noro     3276: #if defined(MPROTECT_VDB) && defined(DARWIN)
                   3277: /* The following sources were used as a *reference* for this exception handling
                   3278:    code:
                   3279:       1. Apple's mach/xnu documentation
                   3280:       2. Timothy J. Wood's "Mach Exception Handlers 101" post to the
                   3281:          omnigroup's macosx-dev list.
                   3282:          www.omnigroup.com/mailman/archive/macosx-dev/2000-June/002030.html
                   3283:       3. macosx-nat.c from Apple's GDB source code.
                   3284: */
                   3285:
                   3286: /* There seem to be numerous problems with darwin's mach exception handling.
                   3287:    I'm pretty sure they are not problems in my code. Search for
                   3288:    BROKEN_EXCEPTION_HANDLING for more information. */
                   3289: #define BROKEN_EXCEPTION_HANDLING
                   3290:
                   3291: #include <mach/mach.h>
                   3292: #include <mach/mach_error.h>
                   3293: #include <mach/thread_status.h>
                   3294: #include <mach/exception.h>
                   3295: #include <mach/task.h>
                   3296: #include <pthread.h>
                   3297:
                   3298: /* These are not defined in any header, although they are documented */
                   3299: extern boolean_t exc_server(mach_msg_header_t *,mach_msg_header_t *);
                   3300: extern kern_return_t exception_raise(
                   3301:     mach_port_t,mach_port_t,mach_port_t,
                   3302:     exception_type_t,exception_data_t,mach_msg_type_number_t);
                   3303: extern kern_return_t exception_raise_state(
                   3304:     mach_port_t,mach_port_t,mach_port_t,
                   3305:     exception_type_t,exception_data_t,mach_msg_type_number_t,
                   3306:     thread_state_flavor_t*,thread_state_t,mach_msg_type_number_t,
                   3307:     thread_state_t,mach_msg_type_number_t*);
                   3308: extern kern_return_t exception_raise_state_identity(
                   3309:     mach_port_t,mach_port_t,mach_port_t,
                   3310:     exception_type_t,exception_data_t,mach_msg_type_number_t,
                   3311:     thread_state_flavor_t*,thread_state_t,mach_msg_type_number_t,
                   3312:     thread_state_t,mach_msg_type_number_t*);
                   3313:
                   3314:
                   3315: #define MAX_EXCEPTION_PORTS 16
                   3316:
                   3317: static mach_port_t GC_task_self;
                   3318:
                   3319: static struct {
                   3320:     mach_msg_type_number_t count;
                   3321:     exception_mask_t      masks[MAX_EXCEPTION_PORTS];
                   3322:     exception_handler_t   ports[MAX_EXCEPTION_PORTS];
                   3323:     exception_behavior_t  behaviors[MAX_EXCEPTION_PORTS];
                   3324:     thread_state_flavor_t flavors[MAX_EXCEPTION_PORTS];
                   3325: } GC_old_exc_ports;
                   3326:
                   3327: static struct {
                   3328:     mach_port_t exception;
                   3329: #if defined(THREADS)
                   3330:     mach_port_t reply;
                   3331: #endif
                   3332: } GC_ports;
                   3333:
                   3334: typedef struct {
                   3335:     mach_msg_header_t head;
                   3336: } GC_msg_t;
                   3337:
                   3338: typedef enum {
                   3339:     GC_MP_NORMAL, GC_MP_DISCARDING, GC_MP_STOPPED
                   3340: } GC_mprotect_state_t;
                   3341:
                   3342: /* FIXME: 1 and 2 seem to be safe to use in the msgh_id field,
                   3343:    but it isn't  documented. Use the source and see if they
                   3344:    should be ok. */
                   3345: #define ID_STOP 1
                   3346: #define ID_RESUME 2
                   3347:
                   3348: /* These values are only used on the reply port */
                   3349: #define ID_ACK 3
                   3350:
                   3351: #if defined(THREADS)
                   3352:
                   3353: GC_mprotect_state_t GC_mprotect_state;
                   3354:
                   3355: /* The following should ONLY be called when the world is stopped  */
                   3356: static void GC_mprotect_thread_notify(mach_msg_id_t id) {
                   3357:     struct {
                   3358:         GC_msg_t msg;
                   3359:         mach_msg_trailer_t trailer;
                   3360:     } buf;
                   3361:     mach_msg_return_t r;
                   3362:     /* remote, local */
                   3363:     buf.msg.head.msgh_bits =
                   3364:         MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND,0);
                   3365:     buf.msg.head.msgh_size = sizeof(buf.msg);
                   3366:     buf.msg.head.msgh_remote_port = GC_ports.exception;
                   3367:     buf.msg.head.msgh_local_port = MACH_PORT_NULL;
                   3368:     buf.msg.head.msgh_id = id;
                   3369:
                   3370:     r = mach_msg(
                   3371:         &buf.msg.head,
                   3372:         MACH_SEND_MSG|MACH_RCV_MSG|MACH_RCV_LARGE,
                   3373:         sizeof(buf.msg),
                   3374:         sizeof(buf),
                   3375:         GC_ports.reply,
                   3376:         MACH_MSG_TIMEOUT_NONE,
                   3377:         MACH_PORT_NULL);
                   3378:     if(r != MACH_MSG_SUCCESS)
                   3379:        ABORT("mach_msg failed in GC_mprotect_thread_notify");
                   3380:     if(buf.msg.head.msgh_id != ID_ACK)
                   3381:         ABORT("invalid ack in GC_mprotect_thread_notify");
                   3382: }
                   3383:
                   3384: /* Should only be called by the mprotect thread */
                   3385: static void GC_mprotect_thread_reply() {
                   3386:     GC_msg_t msg;
                   3387:     mach_msg_return_t r;
                   3388:     /* remote, local */
                   3389:     msg.head.msgh_bits =
                   3390:         MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND,0);
                   3391:     msg.head.msgh_size = sizeof(msg);
                   3392:     msg.head.msgh_remote_port = GC_ports.reply;
                   3393:     msg.head.msgh_local_port = MACH_PORT_NULL;
                   3394:     msg.head.msgh_id = ID_ACK;
                   3395:
                   3396:     r = mach_msg(
                   3397:         &msg.head,
                   3398:         MACH_SEND_MSG,
                   3399:         sizeof(msg),
                   3400:         0,
                   3401:         MACH_PORT_NULL,
                   3402:         MACH_MSG_TIMEOUT_NONE,
                   3403:         MACH_PORT_NULL);
                   3404:     if(r != MACH_MSG_SUCCESS)
                   3405:        ABORT("mach_msg failed in GC_mprotect_thread_reply");
                   3406: }
                   3407:
                   3408: void GC_mprotect_stop() {
                   3409:     GC_mprotect_thread_notify(ID_STOP);
                   3410: }
                   3411: void GC_mprotect_resume() {
                   3412:     GC_mprotect_thread_notify(ID_RESUME);
                   3413: }
                   3414:
                   3415: #else /* !THREADS */
                   3416: /* The compiler should optimize away any GC_mprotect_state computations */
                   3417: #define GC_mprotect_state GC_MP_NORMAL
                   3418: #endif
                   3419:
                   3420: static void *GC_mprotect_thread(void *arg) {
                   3421:     mach_msg_return_t r;
                   3422:     /* These two structures contain some private kernel data. We don't need to
                   3423:        access any of it so we don't bother defining a proper struct. The
                   3424:        correct definitions are in the xnu source code. */
                   3425:     struct {
                   3426:         mach_msg_header_t head;
                   3427:         char data[256];
                   3428:     } reply;
                   3429:     struct {
                   3430:         mach_msg_header_t head;
                   3431:         mach_msg_body_t msgh_body;
                   3432:         char data[1024];
                   3433:     } msg;
                   3434:
                   3435:     mach_msg_id_t id;
                   3436:
                   3437:     for(;;) {
                   3438:         r = mach_msg(
                   3439:             &msg.head,
                   3440:             MACH_RCV_MSG|MACH_RCV_LARGE|
                   3441:                 (GC_mprotect_state == GC_MP_DISCARDING ? MACH_RCV_TIMEOUT : 0),
                   3442:             0,
                   3443:             sizeof(msg),
                   3444:             GC_ports.exception,
                   3445:             GC_mprotect_state == GC_MP_DISCARDING ? 0 : MACH_MSG_TIMEOUT_NONE,
                   3446:             MACH_PORT_NULL);
                   3447:
                   3448:         id = r == MACH_MSG_SUCCESS ? msg.head.msgh_id : -1;
                   3449:
                   3450: #if defined(THREADS)
                   3451:         if(GC_mprotect_state == GC_MP_DISCARDING) {
                   3452:             if(r == MACH_RCV_TIMED_OUT) {
                   3453:                 GC_mprotect_state = GC_MP_STOPPED;
                   3454:                 GC_mprotect_thread_reply();
                   3455:                 continue;
                   3456:             }
                   3457:             if(r == MACH_MSG_SUCCESS && (id == ID_STOP || id == ID_RESUME))
                   3458:                 ABORT("out of order mprotect thread request");
                   3459:         }
                   3460: #endif
                   3461:
                   3462:         if(r != MACH_MSG_SUCCESS) {
                   3463:             GC_err_printf2("mach_msg failed with %d %s\n",
                   3464:                 (int)r,mach_error_string(r));
                   3465:             ABORT("mach_msg failed");
                   3466:         }
                   3467:
                   3468:         switch(id) {
                   3469: #if defined(THREADS)
                   3470:             case ID_STOP:
                   3471:                 if(GC_mprotect_state != GC_MP_NORMAL)
                   3472:                     ABORT("Called mprotect_stop when state wasn't normal");
                   3473:                 GC_mprotect_state = GC_MP_DISCARDING;
                   3474:                 break;
                   3475:             case ID_RESUME:
                   3476:                 if(GC_mprotect_state != GC_MP_STOPPED)
                   3477:                     ABORT("Called mprotect_resume when state wasn't stopped");
                   3478:                 GC_mprotect_state = GC_MP_NORMAL;
                   3479:                 GC_mprotect_thread_reply();
                   3480:                 break;
                   3481: #endif /* THREADS */
                   3482:             default:
                   3483:                    /* Handle the message (calls catch_exception_raise) */
                   3484:                if(!exc_server(&msg.head,&reply.head))
                   3485:                     ABORT("exc_server failed");
                   3486:                 /* Send the reply */
                   3487:                 r = mach_msg(
                   3488:                     &reply.head,
                   3489:                     MACH_SEND_MSG,
                   3490:                     reply.head.msgh_size,
                   3491:                     0,
                   3492:                     MACH_PORT_NULL,
                   3493:                     MACH_MSG_TIMEOUT_NONE,
                   3494:                     MACH_PORT_NULL);
                   3495:                if(r != MACH_MSG_SUCCESS) {
                   3496:                        /* This will fail if the thread dies, but the thread shouldn't
                   3497:                           die... */
                   3498:                        #ifdef BROKEN_EXCEPTION_HANDLING
                   3499:                        GC_err_printf2(
                   3500:                         "mach_msg failed with %d %s while sending exc reply\n",
                   3501:                         (int)r,mach_error_string(r));
                   3502:                #else
                   3503:                        ABORT("mach_msg failed while sending exception reply");
                   3504:                #endif
                   3505:                }
                   3506:         } /* switch */
                   3507:     } /* for(;;) */
                   3508:     /* NOT REACHED */
                   3509:     return NULL;
                   3510: }
                   3511:
                   3512: /* All this SIGBUS code shouldn't be necessary. All protection faults should
                   3513:    be going throught the mach exception handler. However, it seems a SIGBUS is
                   3514:    occasionally sent for some unknown reason. Even more odd, it seems to be
                   3515:    meaningless and safe to ignore. */
                   3516: #ifdef BROKEN_EXCEPTION_HANDLING
                   3517:
                   3518: typedef void (* SIG_PF)();
                   3519: static SIG_PF GC_old_bus_handler;
                   3520:
                   3521: /* Updates to this aren't atomic, but the SIGBUSs seem pretty rare.
                   3522:    Even if this doesn't get updated property, it isn't really a problem */
                   3523: static int GC_sigbus_count;
                   3524:
                   3525: static void GC_darwin_sigbus(int num,siginfo_t *sip,void *context) {
                   3526:     if(num != SIGBUS) ABORT("Got a non-sigbus signal in the sigbus handler");
                   3527:
                   3528:     /* Ugh... some seem safe to ignore, but too many in a row probably means
                   3529:        trouble. GC_sigbus_count is reset for each mach exception that is
                   3530:        handled */
                   3531:     if(GC_sigbus_count >= 8) {
                   3532:         ABORT("Got more than 8 SIGBUSs in a row!");
                   3533:     } else {
                   3534:         GC_sigbus_count++;
                   3535:         GC_err_printf0("GC: WARNING: Ignoring SIGBUS.\n");
                   3536:     }
                   3537: }
                   3538: #endif /* BROKEN_EXCEPTION_HANDLING */
                   3539:
                   3540: void GC_dirty_init() {
                   3541:     kern_return_t r;
                   3542:     mach_port_t me;
                   3543:     pthread_t thread;
                   3544:     pthread_attr_t attr;
                   3545:     exception_mask_t mask;
                   3546:
                   3547: #   ifdef PRINTSTATS
                   3548:         GC_printf0("Inititalizing mach/darwin mprotect virtual dirty bit "
                   3549:             "implementation\n");
                   3550: #   endif
                   3551: #      ifdef BROKEN_EXCEPTION_HANDLING
                   3552:         GC_err_printf0("GC: WARNING: Enabling workarounds for various darwin "
                   3553:             "exception handling bugs.\n");
                   3554: #      endif
                   3555:     GC_dirty_maintained = TRUE;
                   3556:     if (GC_page_size % HBLKSIZE != 0) {
                   3557:         GC_err_printf0("Page size not multiple of HBLKSIZE\n");
                   3558:         ABORT("Page size not multiple of HBLKSIZE");
                   3559:     }
                   3560:
                   3561:     GC_task_self = me = mach_task_self();
                   3562:
                   3563:     r = mach_port_allocate(me,MACH_PORT_RIGHT_RECEIVE,&GC_ports.exception);
                   3564:     if(r != KERN_SUCCESS) ABORT("mach_port_allocate failed (exception port)");
                   3565:
                   3566:     r = mach_port_insert_right(me,GC_ports.exception,GC_ports.exception,
                   3567:        MACH_MSG_TYPE_MAKE_SEND);
                   3568:     if(r != KERN_SUCCESS)
                   3569:        ABORT("mach_port_insert_right failed (exception port)");
                   3570:
                   3571:     #if defined(THREADS)
                   3572:         r = mach_port_allocate(me,MACH_PORT_RIGHT_RECEIVE,&GC_ports.reply);
                   3573:         if(r != KERN_SUCCESS) ABORT("mach_port_allocate failed (reply port)");
                   3574:     #endif
                   3575:
                   3576:     /* The exceptions we want to catch */
                   3577:     mask = EXC_MASK_BAD_ACCESS;
                   3578:
                   3579:     r = task_get_exception_ports(
                   3580:         me,
                   3581:         mask,
                   3582:         GC_old_exc_ports.masks,
                   3583:         &GC_old_exc_ports.count,
                   3584:         GC_old_exc_ports.ports,
                   3585:         GC_old_exc_ports.behaviors,
                   3586:         GC_old_exc_ports.flavors
                   3587:     );
                   3588:     if(r != KERN_SUCCESS) ABORT("task_get_exception_ports failed");
                   3589:
                   3590:     r = task_set_exception_ports(
                   3591:         me,
                   3592:         mask,
                   3593:         GC_ports.exception,
                   3594:         EXCEPTION_DEFAULT,
                   3595:         MACHINE_THREAD_STATE
                   3596:     );
                   3597:     if(r != KERN_SUCCESS) ABORT("task_set_exception_ports failed");
                   3598:
                   3599:     if(pthread_attr_init(&attr) != 0) ABORT("pthread_attr_init failed");
                   3600:     if(pthread_attr_setdetachstate(&attr,PTHREAD_CREATE_DETACHED) != 0)
                   3601:         ABORT("pthread_attr_setdetachedstate failed");
                   3602:
                   3603: #      undef pthread_create
                   3604:     /* This will call the real pthread function, not our wrapper */
                   3605:     if(pthread_create(&thread,&attr,GC_mprotect_thread,NULL) != 0)
                   3606:         ABORT("pthread_create failed");
                   3607:     pthread_attr_destroy(&attr);
                   3608:
                   3609:     /* Setup the sigbus handler for ignoring the meaningless SIGBUSs */
                   3610:     #ifdef BROKEN_EXCEPTION_HANDLING
                   3611:     {
                   3612:         struct sigaction sa, oldsa;
                   3613:         sa.sa_handler = (SIG_PF)GC_darwin_sigbus;
                   3614:         sigemptyset(&sa.sa_mask);
                   3615:         sa.sa_flags = SA_RESTART|SA_SIGINFO;
                   3616:         if(sigaction(SIGBUS,&sa,&oldsa) < 0) ABORT("sigaction");
                   3617:         GC_old_bus_handler = (SIG_PF)oldsa.sa_handler;
                   3618:         if (GC_old_bus_handler != SIG_DFL) {
                   3619: #              ifdef PRINTSTATS
                   3620:                 GC_err_printf0("Replaced other SIGBUS handler\n");
                   3621: #              endif
                   3622:         }
                   3623:     }
                   3624:     #endif /* BROKEN_EXCEPTION_HANDLING  */
                   3625: }
                   3626:
                   3627: /* The source code for Apple's GDB was used as a reference for the exception
                   3628:    forwarding code. This code is similar to be GDB code only because there is
                   3629:    only one way to do it. */
                   3630: static kern_return_t GC_forward_exception(
                   3631:         mach_port_t thread,
                   3632:         mach_port_t task,
                   3633:         exception_type_t exception,
                   3634:         exception_data_t data,
                   3635:         mach_msg_type_number_t data_count
                   3636: ) {
                   3637:     int i;
                   3638:     kern_return_t r;
                   3639:     mach_port_t port;
                   3640:     exception_behavior_t behavior;
                   3641:     thread_state_flavor_t flavor;
                   3642:
                   3643:     thread_state_data_t thread_state;
                   3644:     mach_msg_type_number_t thread_state_count = THREAD_STATE_MAX;
                   3645:
                   3646:     for(i=0;i<GC_old_exc_ports.count;i++)
                   3647:         if(GC_old_exc_ports.masks[i] & (1 << exception))
                   3648:             break;
                   3649:     if(i==GC_old_exc_ports.count) ABORT("No handler for exception!");
                   3650:
                   3651:     port = GC_old_exc_ports.ports[i];
                   3652:     behavior = GC_old_exc_ports.behaviors[i];
                   3653:     flavor = GC_old_exc_ports.flavors[i];
                   3654:
                   3655:     if(behavior != EXCEPTION_DEFAULT) {
                   3656:         r = thread_get_state(thread,flavor,thread_state,&thread_state_count);
                   3657:         if(r != KERN_SUCCESS)
                   3658:             ABORT("thread_get_state failed in forward_exception");
                   3659:     }
                   3660:
                   3661:     switch(behavior) {
                   3662:         case EXCEPTION_DEFAULT:
                   3663:             r = exception_raise(port,thread,task,exception,data,data_count);
                   3664:             break;
                   3665:         case EXCEPTION_STATE:
                   3666:             r = exception_raise_state(port,thread,task,exception,data,
                   3667:                 data_count,&flavor,thread_state,thread_state_count,
                   3668:                 thread_state,&thread_state_count);
                   3669:             break;
                   3670:         case EXCEPTION_STATE_IDENTITY:
                   3671:             r = exception_raise_state_identity(port,thread,task,exception,data,
                   3672:                 data_count,&flavor,thread_state,thread_state_count,
                   3673:                 thread_state,&thread_state_count);
                   3674:             break;
                   3675:         default:
                   3676:             r = KERN_FAILURE; /* make gcc happy */
                   3677:             ABORT("forward_exception: unknown behavior");
                   3678:             break;
                   3679:     }
                   3680:
                   3681:     if(behavior != EXCEPTION_DEFAULT) {
                   3682:         r = thread_set_state(thread,flavor,thread_state,thread_state_count);
                   3683:         if(r != KERN_SUCCESS)
                   3684:             ABORT("thread_set_state failed in forward_exception");
                   3685:     }
                   3686:
                   3687:     return r;
                   3688: }
                   3689:
                   3690: #define FWD() GC_forward_exception(thread,task,exception,code,code_count)
                   3691:
                   3692: /* This violates the namespace rules but there isn't anything that can be done
                   3693:    about it. The exception handling stuff is hard coded to call this */
                   3694: kern_return_t
                   3695: catch_exception_raise(
                   3696:    mach_port_t exception_port,mach_port_t thread,mach_port_t task,
                   3697:    exception_type_t exception,exception_data_t code,
                   3698:    mach_msg_type_number_t code_count
                   3699: ) {
                   3700:     kern_return_t r;
                   3701:     char *addr;
                   3702:     struct hblk *h;
                   3703:     int i;
                   3704: #ifdef POWERPC
                   3705:     thread_state_flavor_t flavor = PPC_EXCEPTION_STATE;
                   3706:     mach_msg_type_number_t exc_state_count = PPC_EXCEPTION_STATE_COUNT;
                   3707:     ppc_exception_state_t exc_state;
                   3708: #else
                   3709: #      error FIXME for non-ppc darwin
                   3710: #endif
                   3711:
                   3712:
                   3713:     if(exception != EXC_BAD_ACCESS || code[0] != KERN_PROTECTION_FAILURE) {
                   3714:         #ifdef DEBUG_EXCEPTION_HANDLING
                   3715:         /* We aren't interested, pass it on to the old handler */
                   3716:         GC_printf3("Exception: 0x%x Code: 0x%x 0x%x in catch....\n",
                   3717:             exception,
                   3718:             code_count > 0 ? code[0] : -1,
                   3719:             code_count > 1 ? code[1] : -1);
                   3720:         #endif
                   3721:         return FWD();
                   3722:     }
                   3723:
                   3724:     r = thread_get_state(thread,flavor,
                   3725:         (natural_t*)&exc_state,&exc_state_count);
                   3726:     if(r != KERN_SUCCESS) {
                   3727:         /* The thread is supposed to be suspended while the exception handler
                   3728:            is called. This shouldn't fail. */
                   3729:         #ifdef BROKEN_EXCEPTION_HANDLING
                   3730:             GC_err_printf0("thread_get_state failed in "
                   3731:                 "catch_exception_raise\n");
                   3732:             return KERN_SUCCESS;
                   3733:         #else
                   3734:             ABORT("thread_get_state failed in catch_exception_raise");
                   3735:         #endif
                   3736:     }
                   3737:
                   3738:     /* This is the address that caused the fault */
                   3739:     addr = (char*) exc_state.dar;
                   3740:
                   3741:     if((HDR(addr)) == 0) {
                   3742:         /* Ugh... just like the SIGBUS problem above, it seems we get a bogus
                   3743:            KERN_PROTECTION_FAILURE every once and a while. We wait till we get
                   3744:            a bunch in a row before doing anything about it. If a "real" fault
                   3745:            ever occurres it'll just keep faulting over and over and we'll hit
                   3746:            the limit pretty quickly. */
                   3747:         #ifdef BROKEN_EXCEPTION_HANDLING
                   3748:             static char *last_fault;
                   3749:             static int last_fault_count;
                   3750:
                   3751:             if(addr != last_fault) {
                   3752:                 last_fault = addr;
                   3753:                 last_fault_count = 0;
                   3754:             }
                   3755:             if(++last_fault_count < 32) {
                   3756:                 if(last_fault_count == 1)
                   3757:                     GC_err_printf1(
                   3758:                         "GC: WARNING: Ignoring KERN_PROTECTION_FAILURE at %p\n",
                   3759:                         addr);
                   3760:                 return KERN_SUCCESS;
                   3761:             }
                   3762:
                   3763:             GC_err_printf1("Unexpected KERN_PROTECTION_FAILURE at %p\n",addr);
                   3764:             /* Can't pass it along to the signal handler because that is
                   3765:                ignoring SIGBUS signals. We also shouldn't call ABORT here as
                   3766:                signals don't always work too well from the exception handler. */
                   3767:             GC_err_printf0("Aborting\n");
                   3768:             exit(EXIT_FAILURE);
                   3769:         #else /* BROKEN_EXCEPTION_HANDLING */
                   3770:             /* Pass it along to the next exception handler
                   3771:                (which should call SIGBUS/SIGSEGV) */
                   3772:             return FWD();
                   3773:         #endif /* !BROKEN_EXCEPTION_HANDLING */
                   3774:     }
                   3775:
                   3776:     #ifdef BROKEN_EXCEPTION_HANDLING
                   3777:         /* Reset the number of consecutive SIGBUSs */
                   3778:         GC_sigbus_count = 0;
                   3779:     #endif
                   3780:
                   3781:     if(GC_mprotect_state == GC_MP_NORMAL) { /* common case */
                   3782:         h = (struct hblk*)((word)addr & ~(GC_page_size-1));
                   3783:         UNPROTECT(h, GC_page_size);
                   3784:         for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
                   3785:             register int index = PHT_HASH(h+i);
                   3786:             async_set_pht_entry_from_index(GC_dirty_pages, index);
                   3787:         }
                   3788:     } else if(GC_mprotect_state == GC_MP_DISCARDING) {
                   3789:         /* Lie to the thread for now. No sense UNPROTECT()ing the memory
                   3790:            when we're just going to PROTECT() it again later. The thread
                   3791:            will just fault again once it resumes */
                   3792:     } else {
                   3793:         /* Shouldn't happen, i don't think */
                   3794:         GC_printf0("KERN_PROTECTION_FAILURE while world is stopped\n");
                   3795:         return FWD();
                   3796:     }
                   3797:     return KERN_SUCCESS;
                   3798: }
                   3799: #undef FWD
                   3800:
                   3801: /* These should never be called, but just in case...  */
                   3802: kern_return_t catch_exception_raise_state(mach_port_name_t exception_port,
                   3803:     int exception, exception_data_t code, mach_msg_type_number_t codeCnt,
                   3804:     int flavor, thread_state_t old_state, int old_stateCnt,
                   3805:     thread_state_t new_state, int new_stateCnt)
                   3806: {
                   3807:     ABORT("catch_exception_raise_state");
                   3808:     return(KERN_INVALID_ARGUMENT);
                   3809: }
                   3810: kern_return_t catch_exception_raise_state_identity(
                   3811:     mach_port_name_t exception_port, mach_port_t thread, mach_port_t task,
                   3812:     int exception, exception_data_t code, mach_msg_type_number_t codeCnt,
                   3813:     int flavor, thread_state_t old_state, int old_stateCnt,
                   3814:     thread_state_t new_state, int new_stateCnt)
                   3815: {
                   3816:     ABORT("catch_exception_raise_state_identity");
                   3817:     return(KERN_INVALID_ARGUMENT);
                   3818: }
                   3819:
                   3820:
                   3821: #endif /* DARWIN && MPROTECT_VDB */
                   3822:
1.6       noro     3823: # ifndef HAVE_INCREMENTAL_PROTECTION_NEEDS
                   3824:   int GC_incremental_protection_needs()
                   3825:   {
                   3826:     return GC_PROTECTS_NONE;
                   3827:   }
                   3828: # endif /* !HAVE_INCREMENTAL_PROTECTION_NEEDS */
                   3829:
1.1       noro     3830: /*
                   3831:  * Call stack save code for debugging.
                   3832:  * Should probably be in mach_dep.c, but that requires reorganization.
                   3833:  */
1.4       noro     3834:
                   3835: /* I suspect the following works for most X86 *nix variants, so        */
                   3836: /* long as the frame pointer is explicitly stored.  In the case of gcc,        */
                   3837: /* compiler flags (e.g. -fomit-frame-pointer) determine whether it is. */
                   3838: #if defined(I386) && defined(LINUX) && defined(SAVE_CALL_CHAIN)
1.6       noro     3839: #   include <features.h>
                   3840:
1.4       noro     3841:     struct frame {
                   3842:        struct frame *fr_savfp;
                   3843:        long    fr_savpc;
                   3844:         long   fr_arg[NARGS];  /* All the arguments go here.   */
                   3845:     };
                   3846: #endif
                   3847:
                   3848: #if defined(SPARC)
                   3849: #  if defined(LINUX)
1.6       noro     3850: #    include <features.h>
                   3851:
1.4       noro     3852:      struct frame {
                   3853:        long    fr_local[8];
                   3854:        long    fr_arg[6];
                   3855:        struct frame *fr_savfp;
                   3856:        long    fr_savpc;
                   3857: #       ifndef __arch64__
                   3858:          char  *fr_stret;
                   3859: #       endif
                   3860:        long    fr_argd[6];
                   3861:        long    fr_argx[0];
                   3862:      };
                   3863: #  else
                   3864: #    if defined(SUNOS4)
                   3865: #      include <machine/frame.h>
                   3866: #    else
                   3867: #      if defined (DRSNX)
                   3868: #       include <sys/sparc/frame.h>
                   3869: #      else
                   3870: #       if defined(OPENBSD) || defined(NETBSD)
                   3871: #         include <frame.h>
                   3872: #       else
                   3873: #         include <sys/frame.h>
                   3874: #       endif
                   3875: #      endif
                   3876: #    endif
                   3877: #  endif
                   3878: #  if NARGS > 6
1.1       noro     3879:        --> We only know how to to get the first 6 arguments
1.4       noro     3880: #  endif
                   3881: #endif /* SPARC */
1.1       noro     3882:
1.6       noro     3883: #ifdef  NEED_CALLINFO
1.1       noro     3884: /* Fill in the pc and argument information for up to NFRAMES of my     */
                   3885: /* callers.  Ignore my frame and my callers frame.                     */
                   3886:
1.6       noro     3887: #ifdef LINUX
                   3888: #   include <unistd.h>
                   3889: #endif
                   3890:
                   3891: #endif /* NEED_CALLINFO */
                   3892:
                   3893: #ifdef SAVE_CALL_CHAIN
                   3894:
                   3895: #if NARGS == 0 && NFRAMES % 2 == 0 /* No padding */ \
1.7       noro     3896:     && defined(GC_HAVE_BUILTIN_BACKTRACE)
                   3897:
                   3898: #include <execinfo.h>
1.6       noro     3899:
                   3900: void GC_save_callers (info)
                   3901: struct callinfo info[NFRAMES];
                   3902: {
                   3903:   void * tmp_info[NFRAMES + 1];
                   3904:   int npcs, i;
                   3905: # define IGNORE_FRAMES 1
                   3906:
                   3907:   /* We retrieve NFRAMES+1 pc values, but discard the first, since it  */
                   3908:   /* points to our own frame.                                          */
                   3909:   GC_ASSERT(sizeof(struct callinfo) == sizeof(void *));
                   3910:   npcs = backtrace((void **)tmp_info, NFRAMES + IGNORE_FRAMES);
                   3911:   BCOPY(tmp_info+IGNORE_FRAMES, info, (npcs - IGNORE_FRAMES) * sizeof(void *));
                   3912:   for (i = npcs - IGNORE_FRAMES; i < NFRAMES; ++i) info[i].ci_pc = 0;
                   3913: }
                   3914:
                   3915: #else /* No builtin backtrace; do it ourselves */
                   3916:
1.4       noro     3917: #if (defined(OPENBSD) || defined(NETBSD)) && defined(SPARC)
1.1       noro     3918: #  define FR_SAVFP fr_fp
                   3919: #  define FR_SAVPC fr_pc
                   3920: #else
                   3921: #  define FR_SAVFP fr_savfp
                   3922: #  define FR_SAVPC fr_savpc
                   3923: #endif
                   3924:
1.4       noro     3925: #if defined(SPARC) && (defined(__arch64__) || defined(__sparcv9))
                   3926: #   define BIAS 2047
                   3927: #else
                   3928: #   define BIAS 0
                   3929: #endif
                   3930:
1.1       noro     3931: void GC_save_callers (info)
                   3932: struct callinfo info[NFRAMES];
                   3933: {
                   3934:   struct frame *frame;
                   3935:   struct frame *fp;
                   3936:   int nframes = 0;
1.4       noro     3937: # ifdef I386
                   3938:     /* We assume this is turned on only with gcc as the compiler. */
                   3939:     asm("movl %%ebp,%0" : "=r"(frame));
                   3940:     fp = frame;
                   3941: # else
                   3942:     frame = (struct frame *) GC_save_regs_in_stack ();
                   3943:     fp = (struct frame *)((long) frame -> FR_SAVFP + BIAS);
                   3944: #endif
1.1       noro     3945:
1.4       noro     3946:    for (; (!(fp HOTTER_THAN frame) && !(GC_stackbottom HOTTER_THAN (ptr_t)fp)
                   3947:           && (nframes < NFRAMES));
                   3948:        fp = (struct frame *)((long) fp -> FR_SAVFP + BIAS), nframes++) {
1.1       noro     3949:       register int i;
                   3950:
                   3951:       info[nframes].ci_pc = fp->FR_SAVPC;
1.6       noro     3952: #     if NARGS > 0
                   3953:         for (i = 0; i < NARGS; i++) {
                   3954:          info[nframes].ci_arg[i] = ~(fp->fr_arg[i]);
                   3955:         }
                   3956: #     endif /* NARGS > 0 */
1.1       noro     3957:   }
                   3958:   if (nframes < NFRAMES) info[nframes].ci_pc = 0;
                   3959: }
                   3960:
1.6       noro     3961: #endif /* No builtin backtrace */
                   3962:
1.1       noro     3963: #endif /* SAVE_CALL_CHAIN */
1.6       noro     3964:
                   3965: #ifdef NEED_CALLINFO
                   3966:
                   3967: /* Print info to stderr.  We do NOT hold the allocation lock */
                   3968: void GC_print_callers (info)
                   3969: struct callinfo info[NFRAMES];
                   3970: {
                   3971:     register int i;
                   3972:     static int reentry_count = 0;
1.7       noro     3973:     GC_bool stop = FALSE;
1.6       noro     3974:
                   3975:     LOCK();
                   3976:       ++reentry_count;
                   3977:     UNLOCK();
                   3978:
                   3979: #   if NFRAMES == 1
                   3980:       GC_err_printf0("\tCaller at allocation:\n");
                   3981: #   else
                   3982:       GC_err_printf0("\tCall chain at allocation:\n");
                   3983: #   endif
1.7       noro     3984:     for (i = 0; i < NFRAMES && !stop ; i++) {
1.6       noro     3985:        if (info[i].ci_pc == 0) break;
                   3986: #      if NARGS > 0
                   3987:        {
                   3988:          int j;
                   3989:
                   3990:          GC_err_printf0("\t\targs: ");
                   3991:          for (j = 0; j < NARGS; j++) {
                   3992:            if (j != 0) GC_err_printf0(", ");
                   3993:            GC_err_printf2("%d (0x%X)", ~(info[i].ci_arg[j]),
                   3994:                                        ~(info[i].ci_arg[j]));
                   3995:          }
                   3996:          GC_err_printf0("\n");
                   3997:        }
                   3998: #      endif
                   3999:         if (reentry_count > 1) {
                   4000:            /* We were called during an allocation during       */
                   4001:            /* a previous GC_print_callers call; punt.          */
                   4002:            GC_err_printf1("\t\t##PC##= 0x%lx\n", info[i].ci_pc);
                   4003:            continue;
                   4004:        }
                   4005:        {
                   4006: #        ifdef LINUX
                   4007:            FILE *pipe;
                   4008: #        endif
1.7       noro     4009: #        if defined(GC_HAVE_BUILTIN_BACKTRACE)
1.6       noro     4010:            char **sym_name =
                   4011:              backtrace_symbols((void **)(&(info[i].ci_pc)), 1);
                   4012:            char *name = sym_name[0];
                   4013: #        else
                   4014:            char buf[40];
                   4015:            char *name = buf;
                   4016:            sprintf(buf, "##PC##= 0x%lx", info[i].ci_pc);
                   4017: #        endif
1.7       noro     4018: #        if defined(LINUX) && !defined(SMALL_CONFIG)
                   4019:            /* Try for a line number. */
                   4020:            {
1.6       noro     4021: #              define EXE_SZ 100
                   4022:                static char exe_name[EXE_SZ];
                   4023: #              define CMD_SZ 200
                   4024:                char cmd_buf[CMD_SZ];
                   4025: #              define RESULT_SZ 200
                   4026:                static char result_buf[RESULT_SZ];
                   4027:                size_t result_len;
                   4028:                static GC_bool found_exe_name = FALSE;
                   4029:                static GC_bool will_fail = FALSE;
                   4030:                int ret_code;
                   4031:                /* Try to get it via a hairy and expensive scheme.      */
                   4032:                /* First we get the name of the executable:             */
                   4033:                if (will_fail) goto out;
                   4034:                if (!found_exe_name) {
                   4035:                  ret_code = readlink("/proc/self/exe", exe_name, EXE_SZ);
                   4036:                  if (ret_code < 0 || ret_code >= EXE_SZ
                   4037:                      || exe_name[0] != '/') {
                   4038:                    will_fail = TRUE;   /* Dont try again. */
                   4039:                    goto out;
                   4040:                  }
                   4041:                  exe_name[ret_code] = '\0';
                   4042:                  found_exe_name = TRUE;
                   4043:                }
                   4044:                /* Then we use popen to start addr2line -e <exe> <addr> */
                   4045:                /* There are faster ways to do this, but hopefully this */
                   4046:                /* isn't time critical.                                 */
1.7       noro     4047:                sprintf(cmd_buf, "/usr/bin/addr2line -f -e %s 0x%lx", exe_name,
1.6       noro     4048:                                 (unsigned long)info[i].ci_pc);
                   4049:                pipe = popen(cmd_buf, "r");
1.7       noro     4050:                if (pipe == NULL
                   4051:                    || (result_len = fread(result_buf, 1, RESULT_SZ - 1, pipe))
                   4052:                       == 0) {
                   4053:                  if (pipe != NULL) pclose(pipe);
1.6       noro     4054:                  will_fail = TRUE;
                   4055:                  goto out;
                   4056:                }
                   4057:                if (result_buf[result_len - 1] == '\n') --result_len;
1.7       noro     4058:                result_buf[result_len] = 0;
1.6       noro     4059:                if (result_buf[0] == '?'
                   4060:                    || result_buf[result_len-2] == ':'
1.7       noro     4061:                       && result_buf[result_len-1] == '0') {
                   4062:                    pclose(pipe);
1.6       noro     4063:                    goto out;
1.7       noro     4064:                }
                   4065:                /* Get rid of embedded newline, if any.  Test for "main" */
                   4066:                {
                   4067:                   char * nl = strchr(result_buf, '\n');
                   4068:                   if (nl != NULL && nl < result_buf + result_len) {
                   4069:                     *nl = ':';
                   4070:                   }
                   4071:                   if (strncmp(result_buf, "main", nl - result_buf) == 0) {
                   4072:                     stop = TRUE;
                   4073:                   }
                   4074:                }
1.6       noro     4075:                if (result_len < RESULT_SZ - 25) {
                   4076:                  /* Add in hex address */
                   4077:                    sprintf(result_buf + result_len, " [0x%lx]",
                   4078:                          (unsigned long)info[i].ci_pc);
                   4079:                }
                   4080:                name = result_buf;
                   4081:                pclose(pipe);
1.7       noro     4082:                out:;
1.6       noro     4083:            }
                   4084: #        endif /* LINUX */
                   4085:          GC_err_printf1("\t\t%s\n", name);
1.7       noro     4086: #        if defined(GC_HAVE_BUILTIN_BACKTRACE)
                   4087:            free(sym_name);  /* May call GC_free; that's OK */
                   4088: #         endif
1.6       noro     4089:        }
                   4090:     }
                   4091:     LOCK();
                   4092:       --reentry_count;
                   4093:     UNLOCK();
                   4094: }
                   4095:
                   4096: #endif /* NEED_CALLINFO */
1.1       noro     4097:
1.4       noro     4098:
                   4099:
                   4100: #if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG)
                   4101:
                   4102: /* Dump /proc/self/maps to GC_stderr, to enable looking up names for
                   4103:    addresses in FIND_LEAK output. */
                   4104:
1.7       noro     4105: static word dump_maps(char *maps)
                   4106: {
                   4107:     GC_err_write(maps, strlen(maps));
                   4108:     return 1;
                   4109: }
                   4110:
1.4       noro     4111: void GC_print_address_map()
                   4112: {
                   4113:     GC_err_printf0("---------- Begin address map ----------\n");
1.7       noro     4114:     GC_apply_to_maps(dump_maps);
1.4       noro     4115:     GC_err_printf0("---------- End address map ----------\n");
                   4116: }
                   4117:
                   4118: #endif
1.1       noro     4119:
                   4120:

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