=================================================================== RCS file: /home/cvs/OpenXM_contrib2/asir2000/gc/os_dep.c,v retrieving revision 1.1 retrieving revision 1.7 diff -u -p -r1.1 -r1.7 --- OpenXM_contrib2/asir2000/gc/os_dep.c 1999/12/03 07:39:10 1.1 +++ OpenXM_contrib2/asir2000/gc/os_dep.c 2003/06/24 05:11:33 1.7 @@ -1,9 +1,8 @@ -int ox_usr1_sent, ox_int_received, critical_when_signal; -static int inside_critical_section; - /* + * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers * Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved. - * Copyright (c) 1996-1997 by Silicon Graphics. All rights reserved. + * Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved. + * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved. * * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. @@ -15,7 +14,7 @@ static int inside_critical_section; * modified is included with the above copyright notice. */ -# include "gc_priv.h" +# include "private/gc_priv.h" # if defined(LINUX) && !defined(POWERPC) # include @@ -34,7 +33,7 @@ static int inside_critical_section; /* make sure the former gets defined to be the latter if appropriate. */ # include # if 2 <= __GLIBC__ -# if 0 == __GLIBC_MINOR__ +# if 2 == __GLIBC__ && 0 == __GLIBC_MINOR__ /* glibc 2.1 no longer has sigcontext.h. But signal.h */ /* has the right declaration for glibc 2.1. */ # include @@ -46,7 +45,8 @@ static int inside_critical_section; # endif /* 2 <= __GLIBC__ */ # endif # endif -# if !defined(OS2) && !defined(PCR) && !defined(AMIGA) && !defined(MACOS) +# if !defined(OS2) && !defined(PCR) && !defined(AMIGA) && !defined(MACOS) \ + && !defined(MSWINCE) # include # if !defined(MSWIN32) && !defined(SUNOS4) # include @@ -54,47 +54,50 @@ static int inside_critical_section; # endif # include -# include +# if defined(MSWINCE) +# define SIGSEGV 0 /* value is irrelevant */ +# else +# include +# endif /* Blatantly OS dependent routines, except for those that are related */ -/* dynamic loading. */ +/* to dynamic loading. */ -# if !defined(THREADS) && !defined(STACKBOTTOM) && defined(HEURISTIC2) +# if defined(HEURISTIC2) || defined(SEARCH_FOR_DATA_START) # define NEED_FIND_LIMIT # endif -# if defined(IRIX_THREADS) +# if !defined(STACKBOTTOM) && defined(HEURISTIC2) # define NEED_FIND_LIMIT # endif -# if (defined(SUNOS4) & defined(DYNAMIC_LOADING)) && !defined(PCR) +# if (defined(SUNOS4) && defined(DYNAMIC_LOADING)) && !defined(PCR) # define NEED_FIND_LIMIT # endif -# if (defined(SVR4) || defined(AUX) || defined(DGUX)) && !defined(PCR) +# if (defined(SVR4) || defined(AUX) || defined(DGUX) \ + || (defined(LINUX) && defined(SPARC))) && !defined(PCR) # define NEED_FIND_LIMIT # endif -# if defined(LINUX) && (defined(POWERPC) || defined(SPARC) || defined(ALPHA)) -# define NEED_FIND_LIMIT -# endif +#if defined(FREEBSD) && defined(I386) +# include +# if !defined(PCR) +# define NEED_FIND_LIMIT +# endif +#endif #ifdef NEED_FIND_LIMIT # include #endif -#ifdef FREEBSD -# include -#endif - #ifdef AMIGA -# include -# include -# include -# include +# define GC_AMIGA_DEF +# include "AmigaOS.c" +# undef GC_AMIGA_DEF #endif -#ifdef MSWIN32 +#if defined(MSWIN32) || defined(MSWINCE) # define WIN32_LEAN_AND_MEAN # define NOSERVICE # include @@ -112,11 +115,16 @@ static int inside_critical_section; # include # include # include +#endif + +#ifdef UNIX_LIKE # include #endif -#ifdef SUNOS5SIGS -# include +#if defined(SUNOS5SIGS) || defined (HURD) || defined(LINUX) +# ifdef SUNOS5SIGS +# include +# endif # undef setjmp # undef longjmp # define setjmp(env) sigsetjmp(env, 1) @@ -124,8 +132,13 @@ static int inside_critical_section; # define jmp_buf sigjmp_buf #endif +#ifdef DARWIN +/* for get_etext and friends */ +#include +#endif + #ifdef DJGPP - /* Apparently necessary for djgpp 2.01. May casuse problems with */ + /* Apparently necessary for djgpp 2.01. May cause problems with */ /* other versions. */ typedef long unsigned int caddr_t; #endif @@ -142,23 +155,242 @@ static int inside_critical_section; # define OPT_PROT_EXEC 0 #endif -#if defined(LINUX) && (defined(POWERPC) || defined(SPARC) || defined(ALPHA)) +#if defined(LINUX) && \ + (defined(USE_PROC_FOR_LIBRARIES) || defined(IA64) || !defined(SMALL_CONFIG)) + +/* We need to parse /proc/self/maps, either to find dynamic libraries, */ +/* and/or to find the register backing store base (IA64). Do it once */ +/* here. */ + +#define READ read + +/* Repeatedly perform a read call until the buffer is filled or */ +/* we encounter EOF. */ +ssize_t GC_repeat_read(int fd, char *buf, size_t count) +{ + ssize_t num_read = 0; + ssize_t result; + + while (num_read < count) { + result = READ(fd, buf + num_read, count - num_read); + if (result < 0) return result; + if (result == 0) break; + num_read += result; + } + return num_read; +} + +/* + * Apply fn to a buffer containing the contents of /proc/self/maps. + * Return the result of fn or, if we failed, 0. + */ + +word GC_apply_to_maps(word (*fn)(char *)) +{ + int f; + int result; + int maps_size; + char maps_temp[32768]; + char *maps_buf; + + /* Read /proc/self/maps */ + /* Note that we may not allocate, and thus can't use stdio. */ + f = open("/proc/self/maps", O_RDONLY); + if (-1 == f) return 0; + /* stat() doesn't work for /proc/self/maps, so we have to + read it to find out how large it is... */ + maps_size = 0; + do { + result = GC_repeat_read(f, maps_temp, sizeof(maps_temp)); + if (result <= 0) return 0; + maps_size += result; + } while (result == sizeof(maps_temp)); + + if (maps_size > sizeof(maps_temp)) { + /* If larger than our buffer, close and re-read it. */ + close(f); + f = open("/proc/self/maps", O_RDONLY); + if (-1 == f) return 0; + maps_buf = alloca(maps_size); + if (NULL == maps_buf) return 0; + result = GC_repeat_read(f, maps_buf, maps_size); + if (result <= 0) return 0; + } else { + /* Otherwise use the fixed size buffer */ + maps_buf = maps_temp; + } + + close(f); + maps_buf[result] = '\0'; + + /* Apply fn to result. */ + return fn(maps_buf); +} + +#endif /* Need GC_apply_to_maps */ + +#if defined(LINUX) && (defined(USE_PROC_FOR_LIBRARIES) || defined(IA64)) +// +// GC_parse_map_entry parses an entry from /proc/self/maps so we can +// locate all writable data segments that belong to shared libraries. +// The format of one of these entries and the fields we care about +// is as follows: +// XXXXXXXX-XXXXXXXX r-xp 00000000 30:05 260537 name of mapping...\n +// ^^^^^^^^ ^^^^^^^^ ^^^^ ^^ +// start end prot maj_dev +// 0 9 18 32 +// +// For 64 bit ABIs: +// 0 17 34 56 +// +// The parser is called with a pointer to the entry and the return value +// is either NULL or is advanced to the next entry(the byte after the +// trailing '\n'.) +// +#if CPP_WORDSZ == 32 +# define OFFSET_MAP_START 0 +# define OFFSET_MAP_END 9 +# define OFFSET_MAP_PROT 18 +# define OFFSET_MAP_MAJDEV 32 +# define ADDR_WIDTH 8 +#endif + +#if CPP_WORDSZ == 64 +# define OFFSET_MAP_START 0 +# define OFFSET_MAP_END 17 +# define OFFSET_MAP_PROT 34 +# define OFFSET_MAP_MAJDEV 56 +# define ADDR_WIDTH 16 +#endif + +/* + * Assign various fields of the first line in buf_ptr to *start, *end, + * *prot_buf and *maj_dev. Only *prot_buf may be set for unwritable maps. + */ +char *GC_parse_map_entry(char *buf_ptr, word *start, word *end, + char *prot_buf, unsigned int *maj_dev) +{ + int i; + char *tok; + + if (buf_ptr == NULL || *buf_ptr == '\0') { + return NULL; + } + + memcpy(prot_buf, buf_ptr+OFFSET_MAP_PROT, 4); + /* do the protections first. */ + prot_buf[4] = '\0'; + + if (prot_buf[1] == 'w') {/* we can skip all of this if it's not writable. */ + + tok = buf_ptr; + buf_ptr[OFFSET_MAP_START+ADDR_WIDTH] = '\0'; + *start = strtoul(tok, NULL, 16); + + tok = buf_ptr+OFFSET_MAP_END; + buf_ptr[OFFSET_MAP_END+ADDR_WIDTH] = '\0'; + *end = strtoul(tok, NULL, 16); + + buf_ptr += OFFSET_MAP_MAJDEV; + tok = buf_ptr; + while (*buf_ptr != ':') buf_ptr++; + *buf_ptr++ = '\0'; + *maj_dev = strtoul(tok, NULL, 16); + } + + while (*buf_ptr && *buf_ptr++ != '\n'); + + return buf_ptr; +} + +#endif /* Need to parse /proc/self/maps. */ + +#if defined(SEARCH_FOR_DATA_START) /* The I386 case can be handled without a search. The Alpha case */ /* used to be handled differently as well, but the rules changed */ /* for recent Linux versions. This seems to be the easiest way to */ /* cover all versions. */ - ptr_t GC_data_start; - extern char * GC_copyright[]; /* Any data symbol would do. */ +# ifdef LINUX + /* Some Linux distributions arrange to define __data_start. Some */ + /* define data_start as a weak symbol. The latter is technically */ + /* broken, since the user program may define data_start, in which */ + /* case we lose. Nonetheless, we try both, prefering __data_start. */ + /* We assume gcc-compatible pragmas. */ +# pragma weak __data_start + extern int __data_start[]; +# pragma weak data_start + extern int data_start[]; +# endif /* LINUX */ + extern int _end[]; + ptr_t GC_data_start; + void GC_init_linux_data_start() { extern ptr_t GC_find_limit(); - GC_data_start = GC_find_limit((ptr_t)GC_copyright, FALSE); +# ifdef LINUX + /* Try the easy approaches first: */ + if ((ptr_t)__data_start != 0) { + GC_data_start = (ptr_t)(__data_start); + return; + } + if ((ptr_t)data_start != 0) { + GC_data_start = (ptr_t)(data_start); + return; + } +# endif /* LINUX */ + GC_data_start = GC_find_limit((ptr_t)(_end), FALSE); } #endif +# ifdef ECOS + +# ifndef ECOS_GC_MEMORY_SIZE +# define ECOS_GC_MEMORY_SIZE (448 * 1024) +# endif /* ECOS_GC_MEMORY_SIZE */ + +// setjmp() function, as described in ANSI para 7.6.1.1 +#define setjmp( __env__ ) hal_setjmp( __env__ ) + +// FIXME: This is a simple way of allocating memory which is +// compatible with ECOS early releases. Later releases use a more +// sophisticated means of allocating memory than this simple static +// allocator, but this method is at least bound to work. +static char memory[ECOS_GC_MEMORY_SIZE]; +static char *brk = memory; + +static void *tiny_sbrk(ptrdiff_t increment) +{ + void *p = brk; + + brk += increment; + + if (brk > memory + sizeof memory) + { + brk -= increment; + return NULL; + } + + return p; +} +#define sbrk tiny_sbrk +# endif /* ECOS */ + +#if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__) + ptr_t GC_data_start; + + void GC_init_netbsd_elf() + { + extern ptr_t GC_find_limit(); + extern char **environ; + /* This may need to be environ, without the underscore, for */ + /* some versions. */ + GC_data_start = GC_find_limit((ptr_t)&environ, FALSE); + } +#endif + # ifdef OS2 # include @@ -263,9 +495,11 @@ void GC_enable_signals(void) # else # if !defined(PCR) && !defined(AMIGA) && !defined(MSWIN32) \ - && !defined(MACOS) && !defined(DJGPP) && !defined(DOS4GW) + && !defined(MSWINCE) \ + && !defined(MACOS) && !defined(DJGPP) && !defined(DOS4GW) \ + && !defined(NOSYS) && !defined(ECOS) -# if defined(sigmask) && !defined(UTS4) +# if defined(sigmask) && !defined(UTS4) && !defined(HURD) /* Use the traditional BSD interface */ # define SIGSET_T int # define SIG_DEL(set, signal) (set) &= ~(sigmask(signal)) @@ -322,12 +556,6 @@ void GC_disable_signals() GC_sig_disabled++; # endif SIGSETMASK(old_mask,new_mask); - if ( critical_when_signal ) - inside_critical_section = 1; - else { - inside_critical_section = 0; - critical_when_signal = 1; - } } void GC_enable_signals() @@ -337,16 +565,6 @@ void GC_enable_signals() GC_sig_disabled--; # endif SIGSETMASK(dummy,old_mask); - if ( !inside_critical_section ) { - critical_when_signal = 0; - if ( ox_usr1_sent ) { - ox_usr1_sent = 0; ox_usr1_handler(); - } - if ( ox_int_received ) { - ox_int_received = 0; int_handler(); - } - } else - inside_critical_section = 0; } # endif /* !PCR */ @@ -354,7 +572,7 @@ void GC_enable_signals() # endif /*!OS/2 */ /* Ivan Demakov: simplest way (to me) */ -#ifdef DOS4GW +#if defined (DOS4GW) void GC_disable_signals() { } void GC_enable_signals() { } #endif @@ -362,13 +580,11 @@ void GC_enable_signals() /* Find the page size */ word GC_page_size; -# ifdef MSWIN32 +# if defined(MSWIN32) || defined(MSWINCE) void GC_setpagesize() { - SYSTEM_INFO sysinfo; - - GetSystemInfo(&sysinfo); - GC_page_size = sysinfo.dwPageSize; + GetSystemInfo(&GC_sysinfo); + GC_page_size = GC_sysinfo.dwPageSize; } # else @@ -393,7 +609,7 @@ word GC_page_size; * With threads, GC_mark_roots needs to know how to do this. * Called with allocator lock held. */ -# ifdef MSWIN32 +# if defined(MSWIN32) || defined(MSWINCE) # define is_writable(prot) ((prot) == PAGE_READWRITE \ || (prot) == PAGE_WRITECOPY \ || (prot) == PAGE_EXECUTE_READWRITE \ @@ -430,8 +646,18 @@ ptr_t GC_get_stack_base() } -# else +# endif /* MS Windows */ +# ifdef BEOS +# include +ptr_t GC_get_stack_base(){ + thread_info th; + get_thread_info(find_thread(NULL),&th); + return th.stack_end; +} +# endif /* BEOS */ + + # ifdef OS2 ptr_t GC_get_stack_base() @@ -446,90 +672,48 @@ ptr_t GC_get_stack_base() return((ptr_t)(ptib -> tib_pstacklimit)); } -# else +# endif /* OS2 */ # ifdef AMIGA +# define GC_AMIGA_SB +# include "AmigaOS.c" +# undef GC_AMIGA_SB +# endif /* AMIGA */ -ptr_t GC_get_stack_base() -{ - struct Process *proc = (struct Process*)SysBase->ThisTask; - - /* Reference: Amiga Guru Book Pages: 42,567,574 */ - if (proc->pr_Task.tc_Node.ln_Type==NT_PROCESS - && proc->pr_CLI != NULL) { - /* first ULONG is StackSize */ - /*longPtr = proc->pr_ReturnAddr; - size = longPtr[0];*/ +# if defined(NEED_FIND_LIMIT) || defined(UNIX_LIKE) - return (char *)proc->pr_ReturnAddr + sizeof(ULONG); - } else { - return (char *)proc->pr_Task.tc_SPUpper; - } -} - -#if 0 /* old version */ -ptr_t GC_get_stack_base() -{ - extern struct WBStartup *_WBenchMsg; - extern long __base; - extern long __stack; - struct Task *task; - struct Process *proc; - struct CommandLineInterface *cli; - long size; - - if ((task = FindTask(0)) == 0) { - GC_err_puts("Cannot find own task structure\n"); - ABORT("task missing"); - } - proc = (struct Process *)task; - cli = BADDR(proc->pr_CLI); - - if (_WBenchMsg != 0 || cli == 0) { - size = (char *)task->tc_SPUpper - (char *)task->tc_SPLower; - } else { - size = cli->cli_DefaultStack * 4; - } - return (ptr_t)(__base + GC_max(size, __stack)); -} -#endif /* 0 */ - -# else /* !AMIGA, !OS2, ... */ - -# ifdef NEED_FIND_LIMIT - /* Some tools to implement HEURISTIC2 */ -# define MIN_PAGE_SIZE 256 /* Smallest conceivable page size, bytes */ - /* static */ jmp_buf GC_jmp_buf; - - /*ARGSUSED*/ - void GC_fault_handler(sig) - int sig; - { - longjmp(GC_jmp_buf, 1); - } - # ifdef __STDC__ typedef void (*handler)(int); # else typedef void (*handler)(); # endif -# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) +# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) || defined(HURD) static struct sigaction old_segv_act; -# if defined(_sigargs) /* !Irix6.x */ +# if defined(_sigargs) /* !Irix6.x */ || defined(HPUX) || defined(HURD) static struct sigaction old_bus_act; # endif # else static handler old_segv_handler, old_bus_handler; # endif - void GC_setup_temporary_fault_handler() +# ifdef __STDC__ + void GC_set_and_save_fault_handler(handler h) +# else + void GC_set_and_save_fault_handler(h) + handler h; +# endif { -# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) +# if defined(SUNOS5SIGS) || defined(IRIX5) \ + || defined(OSF1) || defined(HURD) struct sigaction act; - act.sa_handler = GC_fault_handler; - act.sa_flags = SA_RESTART | SA_NODEFER; + act.sa_handler = h; +# ifdef SUNOS5SIGS + act.sa_flags = SA_RESTART | SA_NODEFER; +# else + act.sa_flags = SA_RESTART; +# endif /* The presence of SA_NODEFER represents yet another gross */ /* hack. Under Solaris 2.3, siglongjmp doesn't appear to */ /* interact correctly with -lthread. We hide the confusion */ @@ -537,33 +721,54 @@ ptr_t GC_get_stack_base() /* signal mask. */ (void) sigemptyset(&act.sa_mask); -# ifdef IRIX_THREADS +# ifdef GC_IRIX_THREADS /* Older versions have a bug related to retrieving and */ /* and setting a handler at the same time. */ (void) sigaction(SIGSEGV, 0, &old_segv_act); (void) sigaction(SIGSEGV, &act, 0); # else (void) sigaction(SIGSEGV, &act, &old_segv_act); -# ifdef _sigargs /* Irix 5.x, not 6.x */ - /* Under 5.x, we may get SIGBUS. */ - /* Pthreads doesn't exist under 5.x, so we don't */ - /* have to worry in the threads case. */ +# if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \ + || defined(HPUX) || defined(HURD) + /* Under Irix 5.x or HP/UX, we may get SIGBUS. */ + /* Pthreads doesn't exist under Irix 5.x, so we */ + /* don't have to worry in the threads case. */ (void) sigaction(SIGBUS, &act, &old_bus_act); # endif -# endif /* IRIX_THREADS */ +# endif /* GC_IRIX_THREADS */ # else - old_segv_handler = signal(SIGSEGV, GC_fault_handler); + old_segv_handler = signal(SIGSEGV, h); # ifdef SIGBUS - old_bus_handler = signal(SIGBUS, GC_fault_handler); + old_bus_handler = signal(SIGBUS, h); # endif # endif } +# endif /* NEED_FIND_LIMIT || UNIX_LIKE */ + +# ifdef NEED_FIND_LIMIT + /* Some tools to implement HEURISTIC2 */ +# define MIN_PAGE_SIZE 256 /* Smallest conceivable page size, bytes */ + /* static */ jmp_buf GC_jmp_buf; + /*ARGSUSED*/ + void GC_fault_handler(sig) + int sig; + { + longjmp(GC_jmp_buf, 1); + } + + void GC_setup_temporary_fault_handler() + { + GC_set_and_save_fault_handler(GC_fault_handler); + } + void GC_reset_fault_handler() { -# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) +# if defined(SUNOS5SIGS) || defined(IRIX5) \ + || defined(OSF1) || defined(HURD) (void) sigaction(SIGSEGV, &old_segv_act, 0); -# ifdef _sigargs /* Irix 5.x, not 6.x */ +# if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \ + || defined(HPUX) || defined(HURD) (void) sigaction(SIGBUS, &old_bus_act, 0); # endif # else @@ -575,7 +780,8 @@ ptr_t GC_get_stack_base() } /* Return the first nonaddressible location > p (up) or */ - /* the smallest location q s.t. [q,p] is addressible (!up). */ + /* the smallest location q s.t. [q,p) is addressable (!up). */ + /* We assume that p (up) or p-1 (!up) is addressable. */ ptr_t GC_find_limit(p, up) ptr_t p; GC_bool up; @@ -608,11 +814,164 @@ ptr_t GC_get_stack_base() } # endif +#if defined(ECOS) || defined(NOSYS) + ptr_t GC_get_stack_base() + { + return STACKBOTTOM; + } +#endif +#ifdef LINUX_STACKBOTTOM + +#include +#include +#include + +# define STAT_SKIP 27 /* Number of fields preceding startstack */ + /* field in /proc/self/stat */ + +# pragma weak __libc_stack_end + extern ptr_t __libc_stack_end; + +# ifdef IA64 + /* Try to read the backing store base from /proc/self/maps. */ + /* We look for the writable mapping with a 0 major device, */ + /* which is as close to our frame as possible, but below it.*/ + static word backing_store_base_from_maps(char *maps) + { + char prot_buf[5]; + char *buf_ptr = maps; + word start, end; + unsigned int maj_dev; + word current_best = 0; + word dummy; + + for (;;) { + buf_ptr = GC_parse_map_entry(buf_ptr, &start, &end, prot_buf, &maj_dev); + if (buf_ptr == NULL) return current_best; + if (prot_buf[1] == 'w' && maj_dev == 0) { + if (end < (word)(&dummy) && start > current_best) current_best = start; + } + } + return current_best; + } + + static word backing_store_base_from_proc(void) + { + return GC_apply_to_maps(backing_store_base_from_maps); + } + +# pragma weak __libc_ia64_register_backing_store_base + extern ptr_t __libc_ia64_register_backing_store_base; + + ptr_t GC_get_register_stack_base(void) + { + if (0 != &__libc_ia64_register_backing_store_base + && 0 != __libc_ia64_register_backing_store_base) { + /* Glibc 2.2.4 has a bug such that for dynamically linked */ + /* executables __libc_ia64_register_backing_store_base is */ + /* defined but uninitialized during constructor calls. */ + /* Hence we check for both nonzero address and value. */ + return __libc_ia64_register_backing_store_base; + } else { + word result = backing_store_base_from_proc(); + if (0 == result) { + /* Use dumb heuristics. Works only for default configuration. */ + result = (word)GC_stackbottom - BACKING_STORE_DISPLACEMENT; + result += BACKING_STORE_ALIGNMENT - 1; + result &= ~(BACKING_STORE_ALIGNMENT - 1); + /* Verify that it's at least readable. If not, we goofed. */ + GC_noop1(*(word *)result); + } + return (ptr_t)result; + } + } +# endif + + ptr_t GC_linux_stack_base(void) + { + /* We read the stack base value from /proc/self/stat. We do this */ + /* using direct I/O system calls in order to avoid calling malloc */ + /* in case REDIRECT_MALLOC is defined. */ +# define STAT_BUF_SIZE 4096 +# define STAT_READ read + /* Should probably call the real read, if read is wrapped. */ + char stat_buf[STAT_BUF_SIZE]; + int f; + char c; + word result = 0; + size_t i, buf_offset = 0; + + /* First try the easy way. This should work for glibc 2.2 */ + if (0 != &__libc_stack_end) { +# ifdef IA64 + /* Some versions of glibc set the address 16 bytes too */ + /* low while the initialization code is running. */ + if (((word)__libc_stack_end & 0xfff) + 0x10 < 0x1000) { + return __libc_stack_end + 0x10; + } /* Otherwise it's not safe to add 16 bytes and we fall */ + /* back to using /proc. */ +# else + return __libc_stack_end; +# endif + } + f = open("/proc/self/stat", O_RDONLY); + if (f < 0 || STAT_READ(f, stat_buf, STAT_BUF_SIZE) < 2 * STAT_SKIP) { + ABORT("Couldn't read /proc/self/stat"); + } + c = stat_buf[buf_offset++]; + /* Skip the required number of fields. This number is hopefully */ + /* constant across all Linux implementations. */ + for (i = 0; i < STAT_SKIP; ++i) { + while (isspace(c)) c = stat_buf[buf_offset++]; + while (!isspace(c)) c = stat_buf[buf_offset++]; + } + while (isspace(c)) c = stat_buf[buf_offset++]; + while (isdigit(c)) { + result *= 10; + result += c - '0'; + c = stat_buf[buf_offset++]; + } + close(f); + if (result < 0x10000000) ABORT("Absurd stack bottom value"); + return (ptr_t)result; + } + +#endif /* LINUX_STACKBOTTOM */ + +#ifdef FREEBSD_STACKBOTTOM + +/* This uses an undocumented sysctl call, but at least one expert */ +/* believes it will stay. */ + +#include +#include +#include + + ptr_t GC_freebsd_stack_base(void) + { + int nm[2] = {CTL_KERN, KERN_USRSTACK}; + ptr_t base; + size_t len = sizeof(ptr_t); + int r = sysctl(nm, 2, &base, &len, NULL, 0); + + if (r) ABORT("Error getting stack base"); + + return base; + } + +#endif /* FREEBSD_STACKBOTTOM */ + +#if !defined(BEOS) && !defined(AMIGA) && !defined(MSWIN32) \ + && !defined(MSWINCE) && !defined(OS2) + ptr_t GC_get_stack_base() { +# if defined(HEURISTIC1) || defined(HEURISTIC2) || \ + defined(LINUX_STACKBOTTOM) || defined(FREEBSD_STACKBOTTOM) word dummy; ptr_t result; +# endif # define STACKBOTTOM_ALIGNMENT_M1 ((word)STACK_GRAN - 1) @@ -629,6 +988,12 @@ ptr_t GC_get_stack_base() & ~STACKBOTTOM_ALIGNMENT_M1); # endif # endif /* HEURISTIC1 */ +# ifdef LINUX_STACKBOTTOM + result = GC_linux_stack_base(); +# endif +# ifdef FREEBSD_STACKBOTTOM + result = GC_freebsd_stack_base(); +# endif # ifdef HEURISTIC2 # ifdef STACK_GROWS_DOWN result = GC_find_limit((ptr_t)(&dummy), TRUE); @@ -656,9 +1021,7 @@ ptr_t GC_get_stack_base() # endif /* STACKBOTTOM */ } -# endif /* ! AMIGA */ -# endif /* ! OS2 */ -# endif /* ! MSWIN32 */ +# endif /* ! AMIGA, !OS 2, ! MS Windows, !BEOS */ /* * Register static data segment(s) as roots. @@ -758,45 +1121,42 @@ void GC_register_data_segments() } } -# else +# else /* !OS2 */ +# if defined(MSWIN32) || defined(MSWINCE) + # ifdef MSWIN32 /* Unfortunately, we have to handle win32s very differently from NT, */ /* Since VirtualQuery has very different semantics. In particular, */ /* under win32s a VirtualQuery call on an unmapped page returns an */ - /* invalid result. Under GC_register_data_segments is a noop and */ + /* invalid result. Under NT, GC_register_data_segments is a noop and */ /* all real work is done by GC_register_dynamic_libraries. Under */ /* win32s, we cannot find the data segments associated with dll's. */ - /* We rgister the main data segment here. */ - GC_bool GC_win32s = FALSE; /* We're running under win32s. */ + /* We register the main data segment here. */ + GC_bool GC_no_win32_dlls = FALSE; + /* This used to be set for gcc, to avoid dealing with */ + /* the structured exception handling issues. But we now have */ + /* assembly code to do that right. */ - GC_bool GC_is_win32s() - { - DWORD v = GetVersion(); - - /* Check that this is not NT, and Windows major version <= 3 */ - return ((v & 0x80000000) && (v & 0xff) <= 3); - } - void GC_init_win32() { - GC_win32s = GC_is_win32s(); + /* if we're running under win32s, assume that no DLLs will be loaded */ + DWORD v = GetVersion(); + GC_no_win32_dlls |= ((v & 0x80000000) && (v & 0xff) <= 3); } - + /* Return the smallest address a such that VirtualQuery */ /* returns correct results for all addresses between a and start. */ /* Assumes VirtualQuery returns correct information for start. */ ptr_t GC_least_described_address(ptr_t start) { MEMORY_BASIC_INFORMATION buf; - SYSTEM_INFO sysinfo; DWORD result; LPVOID limit; ptr_t p; LPVOID q; - GetSystemInfo(&sysinfo); - limit = sysinfo.lpMinimumApplicationAddress; + limit = GC_sysinfo.lpMinimumApplicationAddress; p = (ptr_t)((word)start & ~(GC_page_size - 1)); for (;;) { q = (LPVOID)(p - GC_page_size); @@ -807,48 +1167,118 @@ void GC_register_data_segments() } return(p); } +# endif + +# ifndef REDIRECT_MALLOC + /* We maintain a linked list of AllocationBase values that we know */ + /* correspond to malloc heap sections. Currently this is only called */ + /* during a GC. But there is some hope that for long running */ + /* programs we will eventually see most heap sections. */ + + /* In the long run, it would be more reliable to occasionally walk */ + /* the malloc heap with HeapWalk on the default heap. But that */ + /* apparently works only for NT-based Windows. */ + + /* In the long run, a better data structure would also be nice ... */ + struct GC_malloc_heap_list { + void * allocation_base; + struct GC_malloc_heap_list *next; + } *GC_malloc_heap_l = 0; + + /* Is p the base of one of the malloc heap sections we already know */ + /* about? */ + GC_bool GC_is_malloc_heap_base(ptr_t p) + { + struct GC_malloc_heap_list *q = GC_malloc_heap_l; + + while (0 != q) { + if (q -> allocation_base == p) return TRUE; + q = q -> next; + } + return FALSE; + } + + void *GC_get_allocation_base(void *p) + { + MEMORY_BASIC_INFORMATION buf; + DWORD result = VirtualQuery(p, &buf, sizeof(buf)); + if (result != sizeof(buf)) { + ABORT("Weird VirtualQuery result"); + } + return buf.AllocationBase; + } + + size_t GC_max_root_size = 100000; /* Appr. largest root size. */ + + void GC_add_current_malloc_heap() + { + struct GC_malloc_heap_list *new_l = + malloc(sizeof(struct GC_malloc_heap_list)); + void * candidate = GC_get_allocation_base(new_l); + + if (new_l == 0) return; + if (GC_is_malloc_heap_base(candidate)) { + /* Try a little harder to find malloc heap. */ + size_t req_size = 10000; + do { + void *p = malloc(req_size); + if (0 == p) { free(new_l); return; } + candidate = GC_get_allocation_base(p); + free(p); + req_size *= 2; + } while (GC_is_malloc_heap_base(candidate) + && req_size < GC_max_root_size/10 && req_size < 500000); + if (GC_is_malloc_heap_base(candidate)) { + free(new_l); return; + } + } +# ifdef CONDPRINT + if (GC_print_stats) + GC_printf1("Found new system malloc AllocationBase at 0x%lx\n", + candidate); +# endif + new_l -> allocation_base = candidate; + new_l -> next = GC_malloc_heap_l; + GC_malloc_heap_l = new_l; + } +# endif /* REDIRECT_MALLOC */ /* Is p the start of either the malloc heap, or of one of our */ /* heap sections? */ GC_bool GC_is_heap_base (ptr_t p) { - register unsigned i; + unsigned i; # ifndef REDIRECT_MALLOC - static ptr_t malloc_heap_pointer = 0; + static word last_gc_no = -1; - if (0 == malloc_heap_pointer) { - MEMORY_BASIC_INFORMATION buf; - register DWORD result = VirtualQuery(malloc(1), &buf, sizeof(buf)); - - if (result != sizeof(buf)) { - ABORT("Weird VirtualQuery result"); - } - malloc_heap_pointer = (ptr_t)(buf.AllocationBase); + if (last_gc_no != GC_gc_no) { + GC_add_current_malloc_heap(); + last_gc_no = GC_gc_no; } - if (p == malloc_heap_pointer) return(TRUE); + if (GC_root_size > GC_max_root_size) GC_max_root_size = GC_root_size; + if (GC_is_malloc_heap_base(p)) return TRUE; # endif for (i = 0; i < GC_n_heap_bases; i++) { - if (GC_heap_bases[i] == p) return(TRUE); + if (GC_heap_bases[i] == p) return TRUE; } - return(FALSE); + return FALSE ; } - + +# ifdef MSWIN32 void GC_register_root_section(ptr_t static_root) { MEMORY_BASIC_INFORMATION buf; - SYSTEM_INFO sysinfo; DWORD result; DWORD protect; LPVOID p; char * base; char * limit, * new_limit; - if (!GC_win32s) return; + if (!GC_no_win32_dlls) return; p = base = limit = GC_least_described_address(static_root); - GetSystemInfo(&sysinfo); - while (p < sysinfo.lpMaximumApplicationAddress) { + while (p < GC_sysinfo.lpMaximumApplicationAddress) { result = VirtualQuery(p, &buf, sizeof(buf)); if (result != sizeof(buf) || buf.AllocationBase == 0 || GC_is_heap_base(buf.AllocationBase)) break; @@ -869,130 +1299,21 @@ void GC_register_data_segments() } if (base != limit) GC_add_roots_inner(base, limit, FALSE); } +#endif void GC_register_data_segments() { +# ifdef MSWIN32 static char dummy; - GC_register_root_section((ptr_t)(&dummy)); - } -# else -# ifdef AMIGA - - void GC_register_data_segments() - { - struct Process *proc; - struct CommandLineInterface *cli; - BPTR myseglist; - ULONG *data; - - int num; - - -# ifdef __GNUC__ - ULONG dataSegSize; - GC_bool found_segment = FALSE; - extern char __data_size[]; - - dataSegSize=__data_size+8; - /* Can`t find the Location of __data_size, because - it`s possible that is it, inside the segment. */ - # endif - - proc= (struct Process*)SysBase->ThisTask; - - /* Reference: Amiga Guru Book Pages: 538ff,565,573 - and XOper.asm */ - if (proc->pr_Task.tc_Node.ln_Type==NT_PROCESS) { - if (proc->pr_CLI == NULL) { - myseglist = proc->pr_SegList; - } else { - /* ProcLoaded 'Loaded as a command: '*/ - cli = BADDR(proc->pr_CLI); - myseglist = cli->cli_Module; - } - } else { - ABORT("Not a Process."); - } - - if (myseglist == NULL) { - ABORT("Arrrgh.. can't find segments, aborting"); - } - - /* xoper hunks Shell Process */ - - num=0; - for (data = (ULONG *)BADDR(myseglist); data != NULL; - data = (ULONG *)BADDR(data[0])) { - if (((ULONG) GC_register_data_segments < (ULONG) &data[1]) || - ((ULONG) GC_register_data_segments > (ULONG) &data[1] + data[-1])) { -# ifdef __GNUC__ - if (dataSegSize == data[-1]) { - found_segment = TRUE; - } -# endif - GC_add_roots_inner((char *)&data[1], - ((char *)&data[1]) + data[-1], FALSE); - } - ++num; - } /* for */ -# ifdef __GNUC__ - if (!found_segment) { - ABORT("Can`t find correct Segments.\nSolution: Use an newer version of ixemul.library"); - } -# endif } -#if 0 /* old version */ - void GC_register_data_segments() - { - extern struct WBStartup *_WBenchMsg; - struct Process *proc; - struct CommandLineInterface *cli; - BPTR myseglist; - ULONG *data; +# else /* !OS2 && !Windows */ - if ( _WBenchMsg != 0 ) { - if ((myseglist = _WBenchMsg->sm_Segment) == 0) { - GC_err_puts("No seglist from workbench\n"); - return; - } - } else { - if ((proc = (struct Process *)FindTask(0)) == 0) { - GC_err_puts("Cannot find process structure\n"); - return; - } - if ((cli = BADDR(proc->pr_CLI)) == 0) { - GC_err_puts("No CLI\n"); - return; - } - if ((myseglist = cli->cli_Module) == 0) { - GC_err_puts("No seglist from CLI\n"); - return; - } - } - - for (data = (ULONG *)BADDR(myseglist); data != 0; - data = (ULONG *)BADDR(data[0])) { -# ifdef AMIGA_SKIP_SEG - if (((ULONG) GC_register_data_segments < (ULONG) &data[1]) || - ((ULONG) GC_register_data_segments > (ULONG) &data[1] + data[-1])) { -# else - { -# endif /* AMIGA_SKIP_SEG */ - GC_add_roots_inner((char *)&data[1], - ((char *)&data[1]) + data[-1], FALSE); - } - } - } -#endif /* old version */ - - -# else - -# if (defined(SVR4) || defined(AUX) || defined(DGUX)) && !defined(PCR) -char * GC_SysVGetDataStart(max_page_size, etext_addr) +# if (defined(SVR4) || defined(AUX) || defined(DGUX) \ + || (defined(LINUX) && defined(SPARC))) && !defined(PCR) +ptr_t GC_SysVGetDataStart(max_page_size, etext_addr) int max_page_size; int * etext_addr; { @@ -1018,18 +1339,58 @@ int * etext_addr; /* string constants in the text segment, but after etext. */ /* Use plan B. Note that we now know there is a gap between */ /* text and data segments, so plan A bought us something. */ - result = (char *)GC_find_limit((ptr_t)(DATAEND) - MIN_PAGE_SIZE, FALSE); + result = (char *)GC_find_limit((ptr_t)(DATAEND), FALSE); } - return((char *)result); + return((ptr_t)result); } # endif +# if defined(FREEBSD) && defined(I386) && !defined(PCR) +/* Its unclear whether this should be identical to the above, or */ +/* whether it should apply to non-X86 architectures. */ +/* For now we don't assume that there is always an empty page after */ +/* etext. But in some cases there actually seems to be slightly more. */ +/* This also deals with holes between read-only data and writable data. */ +ptr_t GC_FreeBSDGetDataStart(max_page_size, etext_addr) +int max_page_size; +int * etext_addr; +{ + word text_end = ((word)(etext_addr) + sizeof(word) - 1) + & ~(sizeof(word) - 1); + /* etext rounded to word boundary */ + VOLATILE word next_page = (text_end + (word)max_page_size - 1) + & ~((word)max_page_size - 1); + VOLATILE ptr_t result = (ptr_t)text_end; + GC_setup_temporary_fault_handler(); + if (setjmp(GC_jmp_buf) == 0) { + /* Try reading at the address. */ + /* This should happen before there is another thread. */ + for (; next_page < (word)(DATAEND); next_page += (word)max_page_size) + *(VOLATILE char *)next_page; + GC_reset_fault_handler(); + } else { + GC_reset_fault_handler(); + /* As above, we go to plan B */ + result = GC_find_limit((ptr_t)(DATAEND), FALSE); + } + return(result); +} +# endif + + +#ifdef AMIGA + +# define GC_AMIGA_DS +# include "AmigaOS.c" +# undef GC_AMIGA_DS + +#else /* !OS2 && !Windows && !AMIGA */ + void GC_register_data_segments() { -# if !defined(PCR) && !defined(SRC_M3) && !defined(NEXT) && !defined(MACOS) \ - && !defined(MACOSX) -# if defined(REDIRECT_MALLOC) && defined(SOLARIS_THREADS) +# if !defined(PCR) && !defined(SRC_M3) && !defined(MACOS) +# if defined(REDIRECT_MALLOC) && defined(GC_SOLARIS_THREADS) /* As of Solaris 2.3, the Solaris threads implementation */ /* allocates the data structure for the initial thread with */ /* sbrk at process startup. It needs to be scanned, so that */ @@ -1040,11 +1401,11 @@ void GC_register_data_segments() GC_add_roots_inner(DATASTART, (char *)sbrk(0), FALSE); # else GC_add_roots_inner(DATASTART, (char *)(DATAEND), FALSE); +# if defined(DATASTART2) + GC_add_roots_inner(DATASTART2, (char *)(DATAEND2), FALSE); +# endif # endif # endif -# if !defined(PCR) && (defined(NEXT) || defined(MACOSX)) - GC_add_roots_inner(DATASTART, (char *) get_end(), FALSE); -# endif # if defined(MACOS) { # if defined(THINK_C) @@ -1084,15 +1445,16 @@ void GC_register_data_segments() } # endif /* ! AMIGA */ -# endif /* ! MSWIN32 */ +# endif /* ! MSWIN32 && ! MSWINCE*/ # endif /* ! OS2 */ /* * Auxiliary routines for obtaining memory from OS. */ - + # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) \ - && !defined(MSWIN32) && !defined(MACOS) && !defined(DOS4GW) + && !defined(MSWIN32) && !defined(MSWINCE) \ + && !defined(MACOS) && !defined(DOS4GW) # ifdef SUNOS4 extern caddr_t sbrk(); @@ -1103,6 +1465,7 @@ void GC_register_data_segments() # define SBRK_ARG_T int # endif + # ifdef RS6000 /* The compiler seems to generate speculative reads one past the end of */ /* an allocated object. Hence we need to make sure that the page */ @@ -1135,7 +1498,7 @@ word bytes; #else /* Not RS6000 */ #if defined(USE_MMAP) -/* Tested only under IRIX5 and Solaris 2 */ +/* Tested only under Linux, IRIX5 and Solaris 2 */ #ifdef USE_MMAP_FIXED # define GC_MMAP_FLAGS MAP_FIXED | MAP_PRIVATE @@ -1145,24 +1508,50 @@ word bytes; # define GC_MMAP_FLAGS MAP_PRIVATE #endif +#ifndef HEAP_START +# define HEAP_START 0 +#endif + ptr_t GC_unix_get_mem(bytes) word bytes; { - static GC_bool initialized = FALSE; - static int fd; void *result; static ptr_t last_addr = HEAP_START; - if (!initialized) { - fd = open("/dev/zero", O_RDONLY); - initialized = TRUE; - } +# ifndef USE_MMAP_ANON + static GC_bool initialized = FALSE; + static int fd; + + if (!initialized) { + fd = open("/dev/zero", O_RDONLY); + fcntl(fd, F_SETFD, FD_CLOEXEC); + initialized = TRUE; + } +# endif + if (bytes & (GC_page_size -1)) ABORT("Bad GET_MEM arg"); - result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC, - GC_MMAP_FLAGS, fd, 0/* offset */); +# ifdef USE_MMAP_ANON + result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC, + GC_MMAP_FLAGS | MAP_ANON, -1, 0/* offset */); +# else + result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC, + GC_MMAP_FLAGS, fd, 0/* offset */); +# endif if (result == MAP_FAILED) return(0); last_addr = (ptr_t)result + bytes + GC_page_size - 1; last_addr = (ptr_t)((word)last_addr & ~(GC_page_size - 1)); +# if !defined(LINUX) + if (last_addr == 0) { + /* Oops. We got the end of the address space. This isn't */ + /* usable by arbitrary C code, since one-past-end pointers */ + /* don't work, so we discard it and try again. */ + munmap(result, (size_t)(-GC_page_size) - (size_t)result); + /* Leave last page mapped, so we can't repeat. */ + return GC_unix_get_mem(bytes); + } +# else + GC_ASSERT(last_addr != 0); +# endif return((ptr_t)result); } @@ -1216,22 +1605,41 @@ void * os2_alloc(size_t bytes) # endif /* OS2 */ +# if defined(MSWIN32) || defined(MSWINCE) +SYSTEM_INFO GC_sysinfo; +# endif + # ifdef MSWIN32 + +# ifdef USE_GLOBAL_ALLOC +# define GLOBAL_ALLOC_TEST 1 +# else +# define GLOBAL_ALLOC_TEST GC_no_win32_dlls +# endif + word GC_n_heap_bases = 0; ptr_t GC_win32_get_mem(bytes) word bytes; { ptr_t result; - - if (GC_win32s) { + + if (GLOBAL_ALLOC_TEST) { /* VirtualAlloc doesn't like PAGE_EXECUTE_READWRITE. */ /* There are also unconfirmed rumors of other */ /* problems, so we dodge the issue. */ result = (ptr_t) GlobalAlloc(0, bytes + HBLKSIZE); result = (ptr_t)(((word)result + HBLKSIZE) & ~(HBLKSIZE-1)); } else { - result = (ptr_t) VirtualAlloc(NULL, bytes, + /* VirtualProtect only works on regions returned by a */ + /* single VirtualAlloc call. Thus we allocate one */ + /* extra page, which will prevent merging of blocks */ + /* in separate regions, and eliminate any temptation */ + /* to call VirtualProtect on a range spanning regions. */ + /* This wastes a small amount of memory, and risks */ + /* increased fragmentation. But better alternatives */ + /* would require effort. */ + result = (ptr_t) VirtualAlloc(NULL, bytes + 1, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE); } @@ -1245,28 +1653,93 @@ word bytes; void GC_win32_free_heap () { - if (GC_win32s) { + if (GC_no_win32_dlls) { while (GC_n_heap_bases > 0) { GlobalFree (GC_heap_bases[--GC_n_heap_bases]); GC_heap_bases[GC_n_heap_bases] = 0; } } } +# endif +#ifdef AMIGA +# define GC_AMIGA_AM +# include "AmigaOS.c" +# undef GC_AMIGA_AM +#endif + +# ifdef MSWINCE +word GC_n_heap_bases = 0; + +ptr_t GC_wince_get_mem(bytes) +word bytes; +{ + ptr_t result; + word i; + + /* Round up allocation size to multiple of page size */ + bytes = (bytes + GC_page_size-1) & ~(GC_page_size-1); + + /* Try to find reserved, uncommitted pages */ + for (i = 0; i < GC_n_heap_bases; i++) { + if (((word)(-(signed_word)GC_heap_lengths[i]) + & (GC_sysinfo.dwAllocationGranularity-1)) + >= bytes) { + result = GC_heap_bases[i] + GC_heap_lengths[i]; + break; + } + } + + if (i == GC_n_heap_bases) { + /* Reserve more pages */ + word res_bytes = (bytes + GC_sysinfo.dwAllocationGranularity-1) + & ~(GC_sysinfo.dwAllocationGranularity-1); + /* If we ever support MPROTECT_VDB here, we will probably need to */ + /* ensure that res_bytes is strictly > bytes, so that VirtualProtect */ + /* never spans regions. It seems to be OK for a VirtualFree argument */ + /* to span regions, so we should be OK for now. */ + result = (ptr_t) VirtualAlloc(NULL, res_bytes, + MEM_RESERVE | MEM_TOP_DOWN, + PAGE_EXECUTE_READWRITE); + if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result"); + /* If I read the documentation correctly, this can */ + /* only happen if HBLKSIZE > 64k or not a power of 2. */ + if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections"); + GC_heap_bases[GC_n_heap_bases] = result; + GC_heap_lengths[GC_n_heap_bases] = 0; + GC_n_heap_bases++; + } + + /* Commit pages */ + result = (ptr_t) VirtualAlloc(result, bytes, + MEM_COMMIT, + PAGE_EXECUTE_READWRITE); + if (result != NULL) { + if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result"); + GC_heap_lengths[i] += bytes; + } + + return(result); +} # endif #ifdef USE_MUNMAP -/* For now, this only works on some Unix-like systems. If you */ -/* have something else, don't define USE_MUNMAP. */ +/* For now, this only works on Win32/WinCE and some Unix-like */ +/* systems. If you have something else, don't define */ +/* USE_MUNMAP. */ /* We assume ANSI C to support this feature. */ + +#if !defined(MSWIN32) && !defined(MSWINCE) + #include #include #include #include -#include +#endif + /* Compute a page aligned starting address for the unmap */ /* operation on a block of size bytes starting at start. */ /* Return 0 if the block is too small to make this feasible. */ @@ -1289,6 +1762,14 @@ ptr_t GC_unmap_end(ptr_t start, word bytes) return end_addr; } +/* Under Win32/WinCE we commit (map) and decommit (unmap) */ +/* memory using VirtualAlloc and VirtualFree. These functions */ +/* work on individual allocations of virtual memory, made */ +/* previously using VirtualAlloc with the MEM_RESERVE flag. */ +/* The ranges we need to (de)commit may span several of these */ +/* allocations; therefore we use VirtualQuery to check */ +/* allocation lengths, and split up the range as necessary. */ + /* We assume that GC_remap is called on exactly the same range */ /* as a previous call to GC_unmap. It is safe to consistently */ /* round the endpoints in both places. */ @@ -1298,8 +1779,24 @@ void GC_unmap(ptr_t start, word bytes) ptr_t end_addr = GC_unmap_end(start, bytes); word len = end_addr - start_addr; if (0 == start_addr) return; - if (munmap(start_addr, len) != 0) ABORT("munmap failed"); - GC_unmapped_bytes += len; +# if defined(MSWIN32) || defined(MSWINCE) + while (len != 0) { + MEMORY_BASIC_INFORMATION mem_info; + GC_word free_len; + if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info)) + != sizeof(mem_info)) + ABORT("Weird VirtualQuery result"); + free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize; + if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT)) + ABORT("VirtualFree failed"); + GC_unmapped_bytes += free_len; + start_addr += free_len; + len -= free_len; + } +# else + if (munmap(start_addr, len) != 0) ABORT("munmap failed"); + GC_unmapped_bytes += len; +# endif } @@ -1311,14 +1808,36 @@ void GC_remap(ptr_t start, word bytes) word len = end_addr - start_addr; ptr_t result; - if (-1 == zero_descr) zero_descr = open("/dev/zero", O_RDWR); - if (0 == start_addr) return; - result = mmap(start_addr, len, PROT_READ | PROT_WRITE | OPT_PROT_EXEC, - MAP_FIXED | MAP_PRIVATE, zero_descr, 0); - if (result != start_addr) { - ABORT("mmap remapping failed"); - } - GC_unmapped_bytes -= len; +# if defined(MSWIN32) || defined(MSWINCE) + if (0 == start_addr) return; + while (len != 0) { + MEMORY_BASIC_INFORMATION mem_info; + GC_word alloc_len; + if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info)) + != sizeof(mem_info)) + ABORT("Weird VirtualQuery result"); + alloc_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize; + result = VirtualAlloc(start_addr, alloc_len, + MEM_COMMIT, + PAGE_EXECUTE_READWRITE); + if (result != start_addr) { + ABORT("VirtualAlloc remapping failed"); + } + GC_unmapped_bytes -= alloc_len; + start_addr += alloc_len; + len -= alloc_len; + } +# else + if (-1 == zero_descr) zero_descr = open("/dev/zero", O_RDWR); + fcntl(zero_descr, F_SETFD, FD_CLOEXEC); + if (0 == start_addr) return; + result = mmap(start_addr, len, PROT_READ | PROT_WRITE | OPT_PROT_EXEC, + MAP_FIXED | MAP_PRIVATE, zero_descr, 0); + if (result != start_addr) { + ABORT("mmap remapping failed"); + } + GC_unmapped_bytes -= len; +# endif } /* Two adjacent blocks have already been unmapped and are about to */ @@ -1339,16 +1858,31 @@ void GC_unmap_gap(ptr_t start1, word bytes1, ptr_t sta if (0 == start2_addr) end_addr = GC_unmap_end(start1, bytes1 + bytes2); if (0 == start_addr) return; len = end_addr - start_addr; - if (len != 0 && munmap(start_addr, len) != 0) ABORT("munmap failed"); - GC_unmapped_bytes += len; +# if defined(MSWIN32) || defined(MSWINCE) + while (len != 0) { + MEMORY_BASIC_INFORMATION mem_info; + GC_word free_len; + if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info)) + != sizeof(mem_info)) + ABORT("Weird VirtualQuery result"); + free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize; + if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT)) + ABORT("VirtualFree failed"); + GC_unmapped_bytes += free_len; + start_addr += free_len; + len -= free_len; + } +# else + if (len != 0 && munmap(start_addr, len) != 0) ABORT("munmap failed"); + GC_unmapped_bytes += len; +# endif } #endif /* USE_MUNMAP */ /* Routine for pushing any additional roots. In THREADS */ /* environment, this is also responsible for marking from */ -/* thread stacks. In the SRC_M3 case, it also handles */ -/* global variables. */ +/* thread stacks. */ #ifndef THREADS void (*GC_push_other_roots)() = 0; #else /* THREADS */ @@ -1375,7 +1909,7 @@ PCR_ERes GC_push_old_obj(void *p, size_t size, PCR_Any } -void GC_default_push_other_roots() +void GC_default_push_other_roots GC_PROTO((void)) { /* Traverse data allocated by previous memory managers. */ { @@ -1403,6 +1937,10 @@ void GC_default_push_other_roots() --> misconfigured # endif +void GC_push_thread_structures GC_PROTO((void)) +{ + /* Not our responsibibility. */ +} extern void ThreadF__ProcessStacks(); @@ -1420,37 +1958,19 @@ int dummy3; { word q = *p; - if ((ptr_t)(q) >= GC_least_plausible_heap_addr - && (ptr_t)(q) < GC_greatest_plausible_heap_addr) { - GC_push_one_checked(q,FALSE); - } + GC_PUSH_ONE_STACK(q, p); } /* M3 set equivalent to RTHeap.TracedRefTypes */ typedef struct { int elts[1]; } RefTypeSet; RefTypeSet GC_TracedRefTypes = {{0x1}}; -/* From finalize.c */ -extern void GC_push_finalizer_structures(); - -/* From stubborn.c: */ -# ifdef STUBBORN_ALLOC - extern GC_PTR * GC_changing_list_start; -# endif - - -void GC_default_push_other_roots() +void GC_default_push_other_roots GC_PROTO((void)) { - /* Use the M3 provided routine for finding static roots. */ - /* This is a bit dubious, since it presumes no C roots. */ - /* We handle the collector roots explicitly. */ - { -# ifdef STUBBORN_ALLOC - GC_push_one(GC_changing_list_start); -# endif - GC_push_finalizer_structures(); - RTMain__GlobalMapProc(GC_m3_push_root, 0, GC_TracedRefTypes); - } + /* Use the M3 provided routine for finding static roots. */ + /* This is a bit dubious, since it presumes no C roots. */ + /* We handle the collector roots explicitly in GC_push_roots */ + RTMain__GlobalMapProc(GC_m3_push_root, 0, GC_TracedRefTypes); if (GC_words_allocd > 0) { ThreadF__ProcessStacks(GC_push_thread_stack); } @@ -1460,26 +1980,25 @@ void GC_default_push_other_roots() # endif /* SRC_M3 */ -# if defined(SOLARIS_THREADS) || defined(WIN32_THREADS) \ - || defined(IRIX_THREADS) || defined(LINUX_THREADS) \ - || defined(IRIX_PCR_THREADS) +# if defined(GC_SOLARIS_THREADS) || defined(GC_PTHREADS) || \ + defined(GC_WIN32_THREADS) extern void GC_push_all_stacks(); -void GC_default_push_other_roots() +void GC_default_push_other_roots GC_PROTO((void)) { GC_push_all_stacks(); } -# endif /* SOLARIS_THREADS || ... */ +# endif /* GC_SOLARIS_THREADS || GC_PTHREADS */ -void (*GC_push_other_roots)() = GC_default_push_other_roots; +void (*GC_push_other_roots) GC_PROTO((void)) = GC_default_push_other_roots; -#endif +#endif /* THREADS */ /* * Routines for accessing dirty bits on virtual pages. - * We plan to eventaually implement four strategies for doing so: + * We plan to eventually implement four strategies for doing so: * DEFAULT_VDB: A simple dummy implementation that treats every page * as possibly dirty. This makes incremental collection * useless, but the implementation is still correct. @@ -1497,7 +2016,6 @@ void (*GC_push_other_roots)() = GC_default_push_other_ * make sure that other system calls are similarly protected * or write only to the stack. */ - GC_bool GC_dirty_maintained = FALSE; # ifdef DEFAULT_VDB @@ -1511,6 +2029,9 @@ GC_bool GC_dirty_maintained = FALSE; /* Initialize virtual dirty bit implementation. */ void GC_dirty_init() { +# ifdef PRINTSTATS + GC_printf0("Initializing DEFAULT_VDB...\n"); +# endif GC_dirty_maintained = TRUE; } @@ -1552,11 +2073,18 @@ word n; { } -/* A call hints that h is about to be written. */ -/* May speed up some dirty bit implementations. */ +/* A call that: */ +/* I) hints that [h, h+nblocks) is about to be written. */ +/* II) guarantees that protection is removed. */ +/* (I) may speed up some dirty bit implementations. */ +/* (II) may be essential if we need to ensure that */ +/* pointer-free system call buffers in the heap are */ +/* not protected. */ /*ARGSUSED*/ -void GC_write_hint(h) +void GC_remove_protection(h, nblocks, is_ptrfree) struct hblk *h; +word nblocks; +GC_bool is_ptrfree; { } @@ -1572,36 +2100,59 @@ struct hblk *h; /* * This implementation maintains dirty bits itself by catching write * faults and keeping track of them. We assume nobody else catches - * SIGBUS or SIGSEGV. We assume no write faults occur in system calls - * except as a result of a read system call. This means clients must - * either ensure that system calls do not touch the heap, or must - * provide their own wrappers analogous to the one for read. + * SIGBUS or SIGSEGV. We assume no write faults occur in system calls. + * This means that clients must ensure that system calls don't write + * to the write-protected heap. Probably the best way to do this is to + * ensure that system calls write at most to POINTERFREE objects in the + * heap, and do even that only if we are on a platform on which those + * are not protected. Another alternative is to wrap system calls + * (see example for read below), but the current implementation holds + * a lock across blocking calls, making it problematic for multithreaded + * applications. * We assume the page size is a multiple of HBLKSIZE. - * This implementation is currently SunOS 4.X and IRIX 5.X specific, though we - * tried to use portable code where easily possible. It is known - * not to work under a number of other systems. + * We prefer them to be the same. We avoid protecting POINTERFREE + * objects only if they are the same. */ -# ifndef MSWIN32 +# if !defined(MSWIN32) && !defined(MSWINCE) && !defined(DARWIN) # include # include # include # define PROTECT(addr, len) \ - if (mprotect((caddr_t)(addr), (int)(len), \ + if (mprotect((caddr_t)(addr), (size_t)(len), \ PROT_READ | OPT_PROT_EXEC) < 0) { \ ABORT("mprotect failed"); \ } # define UNPROTECT(addr, len) \ - if (mprotect((caddr_t)(addr), (int)(len), \ + if (mprotect((caddr_t)(addr), (size_t)(len), \ PROT_WRITE | PROT_READ | OPT_PROT_EXEC ) < 0) { \ ABORT("un-mprotect failed"); \ } # else -# include +# ifdef DARWIN + /* Using vm_protect (mach syscall) over mprotect (BSD syscall) seems to + decrease the likelihood of some of the problems described below. */ + #include + extern mach_port_t GC_task_self; + #define PROTECT(addr,len) \ + if(vm_protect(GC_task_self,(vm_address_t)(addr),(vm_size_t)(len), \ + FALSE,VM_PROT_READ) != KERN_SUCCESS) { \ + ABORT("vm_portect failed"); \ + } + #define UNPROTECT(addr,len) \ + if(vm_protect(GC_task_self,(vm_address_t)(addr),(vm_size_t)(len), \ + FALSE,VM_PROT_READ|VM_PROT_WRITE) != KERN_SUCCESS) { \ + ABORT("vm_portect failed"); \ + } +# else + +# ifndef MSWINCE +# include +# endif static DWORD protect_junk; # define PROTECT(addr, len) \ @@ -1616,36 +2167,71 @@ struct hblk *h; &protect_junk)) { \ ABORT("un-VirtualProtect failed"); \ } - -# endif +# endif /* !DARWIN */ +# endif /* MSWIN32 || MSWINCE || DARWIN */ #if defined(SUNOS4) || defined(FREEBSD) typedef void (* SIG_PF)(); -#endif -#if defined(SUNOS5SIGS) || defined(OSF1) || defined(LINUX) +#endif /* SUNOS4 || FREEBSD */ + +#if defined(SUNOS5SIGS) || defined(OSF1) || defined(LINUX) \ + || defined(HURD) +# ifdef __STDC__ typedef void (* SIG_PF)(int); -#endif +# else + typedef void (* SIG_PF)(); +# endif +#endif /* SUNOS5SIGS || OSF1 || LINUX || HURD */ + #if defined(MSWIN32) typedef LPTOP_LEVEL_EXCEPTION_FILTER SIG_PF; # undef SIG_DFL # define SIG_DFL (LPTOP_LEVEL_EXCEPTION_FILTER) (-1) #endif +#if defined(MSWINCE) + typedef LONG (WINAPI *SIG_PF)(struct _EXCEPTION_POINTERS *); +# undef SIG_DFL +# define SIG_DFL (SIG_PF) (-1) +#endif -#if defined(IRIX5) || defined(OSF1) +#if defined(IRIX5) || defined(OSF1) || defined(HURD) typedef void (* REAL_SIG_PF)(int, int, struct sigcontext *); -#endif +#endif /* IRIX5 || OSF1 || HURD */ + #if defined(SUNOS5SIGS) - typedef void (* REAL_SIG_PF)(int, struct siginfo *, void *); -#endif +# ifdef HPUX +# define SIGINFO __siginfo +# else +# define SIGINFO siginfo +# endif +# ifdef __STDC__ + typedef void (* REAL_SIG_PF)(int, struct SIGINFO *, void *); +# else + typedef void (* REAL_SIG_PF)(); +# endif +#endif /* SUNOS5SIGS */ + #if defined(LINUX) -# include -# if (LINUX_VERSION_CODE >= 0x20100) && !defined(M68K) || defined(ALPHA) +# if __GLIBC__ > 2 || __GLIBC__ == 2 && __GLIBC_MINOR__ >= 2 typedef struct sigcontext s_c; +# else /* glibc < 2.2 */ +# include +# if (LINUX_VERSION_CODE >= 0x20100) && !defined(M68K) || defined(ALPHA) || defined(ARM32) + typedef struct sigcontext s_c; +# else + typedef struct sigcontext_struct s_c; +# endif +# endif /* glibc < 2.2 */ +# if defined(ALPHA) || defined(M68K) + typedef void (* REAL_SIG_PF)(int, int, s_c *); # else - typedef struct sigcontext_struct s_c; +# if defined(IA64) || defined(HP_PA) + typedef void (* REAL_SIG_PF)(int, siginfo_t *, s_c *); +# else + typedef void (* REAL_SIG_PF)(int, s_c); +# endif # endif # ifdef ALPHA - typedef void (* REAL_SIG_PF)(int, int, s_c *); /* Retrieve fault address from sigcontext structure by decoding */ /* instruction. */ char * get_fault_addr(s_c *sc) { @@ -1657,15 +2243,64 @@ struct hblk *h; faultaddr += (word) (((int)instr << 16) >> 16); return (char *)faultaddr; } -# else /* !ALPHA */ - typedef void (* REAL_SIG_PF)(int, s_c); # endif /* !ALPHA */ -# endif +# endif /* LINUX */ +#ifndef DARWIN SIG_PF GC_old_bus_handler; SIG_PF GC_old_segv_handler; /* Also old MSWIN32 ACCESS_VIOLATION filter */ +#endif /* !DARWIN */ +#if defined(THREADS) +/* We need to lock around the bitmap update in the write fault handler */ +/* in order to avoid the risk of losing a bit. We do this with a */ +/* test-and-set spin lock if we know how to do that. Otherwise we */ +/* check whether we are already in the handler and use the dumb but */ +/* safe fallback algorithm of setting all bits in the word. */ +/* Contention should be very rare, so we do the minimum to handle it */ +/* correctly. */ +#ifdef GC_TEST_AND_SET_DEFINED + static VOLATILE unsigned int fault_handler_lock = 0; + void async_set_pht_entry_from_index(VOLATILE page_hash_table db, int index) { + while (GC_test_and_set(&fault_handler_lock)) {} + /* Could also revert to set_pht_entry_from_index_safe if initial */ + /* GC_test_and_set fails. */ + set_pht_entry_from_index(db, index); + GC_clear(&fault_handler_lock); + } +#else /* !GC_TEST_AND_SET_DEFINED */ + /* THIS IS INCORRECT! The dirty bit vector may be temporarily wrong, */ + /* just before we notice the conflict and correct it. We may end up */ + /* looking at it while it's wrong. But this requires contention */ + /* exactly when a GC is triggered, which seems far less likely to */ + /* fail than the old code, which had no reported failures. Thus we */ + /* leave it this way while we think of something better, or support */ + /* GC_test_and_set on the remaining platforms. */ + static VOLATILE word currently_updating = 0; + void async_set_pht_entry_from_index(VOLATILE page_hash_table db, int index) { + unsigned int update_dummy; + currently_updating = (word)(&update_dummy); + set_pht_entry_from_index(db, index); + /* If we get contention in the 10 or so instruction window here, */ + /* and we get stopped by a GC between the two updates, we lose! */ + if (currently_updating != (word)(&update_dummy)) { + set_pht_entry_from_index_safe(db, index); + /* We claim that if two threads concurrently try to update the */ + /* dirty bit vector, the first one to execute UPDATE_START */ + /* will see it changed when UPDATE_END is executed. (Note that */ + /* &update_dummy must differ in two distinct threads.) It */ + /* will then execute set_pht_entry_from_index_safe, thus */ + /* returning us to a safe state, though not soon enough. */ + } + } +#endif /* !GC_TEST_AND_SET_DEFINED */ +#else /* !THREADS */ +# define async_set_pht_entry_from_index(db, index) \ + set_pht_entry_from_index(db, index) +#endif /* !THREADS */ + /*ARGSUSED*/ +#if !defined(DARWIN) # if defined (SUNOS4) || defined(FREEBSD) void GC_write_fault_handler(sig, code, scp, addr) int sig, code; @@ -1681,44 +2316,80 @@ SIG_PF GC_old_segv_handler; /* Also old MSWIN32 ACCESS # define SIG_OK (sig == SIGBUS) # define CODE_OK (code == BUS_PAGE_FAULT) # endif -# endif -# if defined(IRIX5) || defined(OSF1) +# endif /* SUNOS4 || FREEBSD */ + +# if defined(IRIX5) || defined(OSF1) || defined(HURD) # include void GC_write_fault_handler(int sig, int code, struct sigcontext *scp) -# define SIG_OK (sig == SIGSEGV) # ifdef OSF1 +# define SIG_OK (sig == SIGSEGV) # define CODE_OK (code == 2 /* experimentally determined */) # endif # ifdef IRIX5 +# define SIG_OK (sig == SIGSEGV) # define CODE_OK (code == EACCES) # endif -# endif +# ifdef HURD +# define SIG_OK (sig == SIGBUS || sig == SIGSEGV) +# define CODE_OK TRUE +# endif +# endif /* IRIX5 || OSF1 || HURD */ + # if defined(LINUX) -# ifdef ALPHA +# if defined(ALPHA) || defined(M68K) void GC_write_fault_handler(int sig, int code, s_c * sc) # else - void GC_write_fault_handler(int sig, s_c sc) +# if defined(IA64) || defined(HP_PA) + void GC_write_fault_handler(int sig, siginfo_t * si, s_c * scp) +# else +# if defined(ARM32) + void GC_write_fault_handler(int sig, int a2, int a3, int a4, s_c sc) +# else + void GC_write_fault_handler(int sig, s_c sc) +# endif +# endif # endif # define SIG_OK (sig == SIGSEGV) # define CODE_OK TRUE - /* Empirically c.trapno == 14, but is that useful? */ - /* We assume Intel architecture, so alignment */ - /* faults are not possible. */ -# endif + /* Empirically c.trapno == 14, on IA32, but is that useful? */ + /* Should probably consider alignment issues on other */ + /* architectures. */ +# endif /* LINUX */ + # if defined(SUNOS5SIGS) - void GC_write_fault_handler(int sig, struct siginfo *scp, void * context) -# define SIG_OK (sig == SIGSEGV) -# define CODE_OK (scp -> si_code == SEGV_ACCERR) -# endif -# if defined(MSWIN32) +# ifdef __STDC__ + void GC_write_fault_handler(int sig, struct SIGINFO *scp, void * context) +# else + void GC_write_fault_handler(sig, scp, context) + int sig; + struct SIGINFO *scp; + void * context; +# endif +# ifdef HPUX +# define SIG_OK (sig == SIGSEGV || sig == SIGBUS) +# define CODE_OK (scp -> si_code == SEGV_ACCERR) \ + || (scp -> si_code == BUS_ADRERR) \ + || (scp -> si_code == BUS_UNKNOWN) \ + || (scp -> si_code == SEGV_UNKNOWN) \ + || (scp -> si_code == BUS_OBJERR) +# else +# define SIG_OK (sig == SIGSEGV) +# define CODE_OK (scp -> si_code == SEGV_ACCERR) +# endif +# endif /* SUNOS5SIGS */ + +# if defined(MSWIN32) || defined(MSWINCE) LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info) # define SIG_OK (exc_info -> ExceptionRecord -> ExceptionCode == \ - EXCEPTION_ACCESS_VIOLATION) + STATUS_ACCESS_VIOLATION) # define CODE_OK (exc_info -> ExceptionRecord -> ExceptionInformation[0] == 1) /* Write fault */ -# endif +# endif /* MSWIN32 || MSWINCE */ { register unsigned i; +# if defined(HURD) + char *addr = (char *) code; +# endif # ifdef IRIX5 char * addr = (char *) (size_t) (scp -> sc_badvaddr); # endif @@ -1729,13 +2400,13 @@ SIG_PF GC_old_segv_handler; /* Also old MSWIN32 ACCESS char * addr = (char *) (scp -> si_addr); # endif # ifdef LINUX -# ifdef I386 +# if defined(I386) || defined (X86_64) char * addr = (char *) (sc.cr2); # else # if defined(M68K) char * addr = NULL; - struct sigcontext *scp = (struct sigcontext *)(&sc); + struct sigcontext *scp = (struct sigcontext *)(sc); int format = (scp->sc_formatvec >> 12) & 0xf; unsigned long *framedata = (unsigned long *)(scp + 1); @@ -1747,6 +2418,10 @@ SIG_PF GC_old_segv_handler; /* Also old MSWIN32 ACCESS } else if (format == 7) { /* 68040 */ ea = framedata[3]; + if (framedata[1] & 0x08000000) { + /* correct addr on misaligned access */ + ea = (ea+4095)&(~4095); + } } else if (format == 4) { /* 68060 */ ea = framedata[0]; @@ -1760,12 +2435,27 @@ SIG_PF GC_old_segv_handler; /* Also old MSWIN32 ACCESS # ifdef ALPHA char * addr = get_fault_addr(sc); # else - --> architecture not supported +# if defined(IA64) || defined(HP_PA) + char * addr = si -> si_addr; + /* I believe this is claimed to work on all platforms for */ + /* Linux 2.3.47 and later. Hopefully we don't have to */ + /* worry about earlier kernels on IA64. */ +# else +# if defined(POWERPC) + char * addr = (char *) (sc.regs->dar); +# else +# if defined(ARM32) + char * addr = (char *)sc.fault_address; +# else + --> architecture not supported +# endif +# endif +# endif # endif # endif # endif # endif -# if defined(MSWIN32) +# if defined(MSWIN32) || defined(MSWINCE) char * addr = (char *) (exc_info -> ExceptionRecord -> ExceptionInformation[1]); # define sig SIGSEGV @@ -1797,7 +2487,7 @@ SIG_PF GC_old_segv_handler; /* Also old MSWIN32 ACCESS old_handler = GC_old_bus_handler; } if (old_handler == SIG_DFL) { -# ifndef MSWIN32 +# if !defined(MSWIN32) && !defined(MSWINCE) GC_err_printf1("Segfault at 0x%lx\n", addr); ABORT("Unexpected bus error or segmentation fault"); # else @@ -1813,14 +2503,18 @@ SIG_PF GC_old_segv_handler; /* Also old MSWIN32 ACCESS return; # endif # if defined (LINUX) -# ifdef ALPHA +# if defined(ALPHA) || defined(M68K) (*(REAL_SIG_PF)old_handler) (sig, code, sc); # else +# if defined(IA64) || defined(HP_PA) + (*(REAL_SIG_PF)old_handler) (sig, si, scp); +# else (*(REAL_SIG_PF)old_handler) (sig, sc); +# endif # endif return; # endif -# if defined (IRIX5) || defined(OSF1) +# if defined (IRIX5) || defined(OSF1) || defined(HURD) (*(REAL_SIG_PF)old_handler) (sig, code, scp); return; # endif @@ -1829,72 +2523,98 @@ SIG_PF GC_old_segv_handler; /* Also old MSWIN32 ACCESS # endif } } + UNPROTECT(h, GC_page_size); + /* We need to make sure that no collection occurs between */ + /* the UNPROTECT and the setting of the dirty bit. Otherwise */ + /* a write by a third thread might go unnoticed. Reversing */ + /* the order is just as bad, since we would end up unprotecting */ + /* a page in a GC cycle during which it's not marked. */ + /* Currently we do this by disabling the thread stopping */ + /* signals while this handler is running. An alternative might */ + /* be to record the fact that we're about to unprotect, or */ + /* have just unprotected a page in the GC's thread structure, */ + /* and then to have the thread stopping code set the dirty */ + /* flag, if necessary. */ for (i = 0; i < divHBLKSZ(GC_page_size); i++) { register int index = PHT_HASH(h+i); - set_pht_entry_from_index(GC_dirty_pages, index); + async_set_pht_entry_from_index(GC_dirty_pages, index); } - UNPROTECT(h, GC_page_size); -# if defined(OSF1) || defined(LINUX) +# if defined(OSF1) /* These reset the signal handler each time by default. */ signal(SIGSEGV, (SIG_PF) GC_write_fault_handler); # endif /* The write may not take place before dirty bits are read. */ /* But then we'll fault again ... */ -# ifdef MSWIN32 +# if defined(MSWIN32) || defined(MSWINCE) return(EXCEPTION_CONTINUE_EXECUTION); # else return; # endif } -#ifdef MSWIN32 +#if defined(MSWIN32) || defined(MSWINCE) return EXCEPTION_CONTINUE_SEARCH; #else GC_err_printf1("Segfault at 0x%lx\n", addr); ABORT("Unexpected bus error or segmentation fault"); #endif } +#endif /* !DARWIN */ /* * We hold the allocation lock. We expect block h to be written - * shortly. + * shortly. Ensure that all pages containing any part of the n hblks + * starting at h are no longer protected. If is_ptrfree is false, + * also ensure that they will subsequently appear to be dirty. */ -void GC_write_hint(h) +void GC_remove_protection(h, nblocks, is_ptrfree) struct hblk *h; +word nblocks; +GC_bool is_ptrfree; { - register struct hblk * h_trunc; - register unsigned i; - register GC_bool found_clean; + struct hblk * h_trunc; /* Truncated to page boundary */ + struct hblk * h_end; /* Page boundary following block end */ + struct hblk * current; + GC_bool found_clean; if (!GC_dirty_maintained) return; h_trunc = (struct hblk *)((word)h & ~(GC_page_size-1)); + h_end = (struct hblk *)(((word)(h + nblocks) + GC_page_size-1) + & ~(GC_page_size-1)); found_clean = FALSE; - for (i = 0; i < divHBLKSZ(GC_page_size); i++) { - register int index = PHT_HASH(h_trunc+i); + for (current = h_trunc; current < h_end; ++current) { + int index = PHT_HASH(current); - if (!get_pht_entry_from_index(GC_dirty_pages, index)) { - found_clean = TRUE; - set_pht_entry_from_index(GC_dirty_pages, index); + if (!is_ptrfree || current < h || current >= h + nblocks) { + async_set_pht_entry_from_index(GC_dirty_pages, index); } } - if (found_clean) { - UNPROTECT(h_trunc, GC_page_size); - } + UNPROTECT(h_trunc, (ptr_t)h_end - (ptr_t)h_trunc); } +#if !defined(DARWIN) void GC_dirty_init() { -#if defined(SUNOS5SIGS) || defined(IRIX5) /* || defined(OSF1) */ - struct sigaction act, oldact; -# ifdef IRIX5 +# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(LINUX) || \ + defined(OSF1) || defined(HURD) + struct sigaction act, oldact; + /* We should probably specify SA_SIGINFO for Linux, and handle */ + /* the different architectures more uniformly. */ +# if defined(IRIX5) || defined(LINUX) || defined(OSF1) || defined(HURD) act.sa_flags = SA_RESTART; - act.sa_handler = GC_write_fault_handler; -# else + act.sa_handler = (SIG_PF)GC_write_fault_handler; +# else act.sa_flags = SA_RESTART | SA_SIGINFO; act.sa_sigaction = GC_write_fault_handler; -# endif - (void)sigemptyset(&act.sa_mask); -#endif +# endif + (void)sigemptyset(&act.sa_mask); +# ifdef SIG_SUSPEND + /* Arrange to postpone SIG_SUSPEND while we're in a write fault */ + /* handler. This effectively makes the handler atomic w.r.t. */ + /* stopping the world for GC. */ + (void)sigaddset(&act.sa_mask, SIG_SUSPEND); +# endif /* SIG_SUSPEND */ +# endif # ifdef PRINTSTATS GC_printf0("Inititalizing mprotect virtual dirty bit implementation\n"); # endif @@ -1915,7 +2635,7 @@ void GC_dirty_init() # endif } # endif -# if defined(OSF1) || defined(SUNOS4) || defined(LINUX) +# if defined(SUNOS4) GC_old_segv_handler = signal(SIGSEGV, (SIG_PF)GC_write_fault_handler); if (GC_old_segv_handler == SIG_IGN) { GC_err_printf0("Previously ignored segmentation violation!?"); @@ -1927,18 +2647,23 @@ void GC_dirty_init() # endif } # endif -# if defined(SUNOS5SIGS) || defined(IRIX5) -# if defined(IRIX_THREADS) || defined(IRIX_PCR_THREADS) +# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(LINUX) \ + || defined(OSF1) || defined(HURD) + /* SUNOS5SIGS includes HPUX */ +# if defined(GC_IRIX_THREADS) sigaction(SIGSEGV, 0, &oldact); sigaction(SIGSEGV, &act, 0); # else - sigaction(SIGSEGV, &act, &oldact); + { + int res = sigaction(SIGSEGV, &act, &oldact); + if (res != 0) ABORT("Sigaction failed"); + } # endif -# if defined(_sigargs) +# if defined(_sigargs) || defined(HURD) || !defined(SA_SIGINFO) /* This is Irix 5.x, not 6.x. Irix 5.x does not have */ /* sa_sigaction. */ GC_old_segv_handler = oldact.sa_handler; -# else /* Irix 6.x or SUNOS5SIGS */ +# else /* Irix 6.x or SUNOS5SIGS or LINUX */ if (oldact.sa_flags & SA_SIGINFO) { GC_old_segv_handler = (SIG_PF)(oldact.sa_sigaction); } else { @@ -1954,7 +2679,20 @@ void GC_dirty_init() GC_err_printf0("Replaced other SIGSEGV handler\n"); # endif } -# endif +# endif +# if defined(HPUX) || defined(LINUX) || defined(HURD) + sigaction(SIGBUS, &act, &oldact); + GC_old_bus_handler = oldact.sa_handler; + if (GC_old_bus_handler == SIG_IGN) { + GC_err_printf0("Previously ignored bus error!?"); + GC_old_bus_handler = SIG_DFL; + } + if (GC_old_bus_handler != SIG_DFL) { +# ifdef PRINTSTATS + GC_err_printf0("Replaced other SIGBUS handler\n"); +# endif + } +# endif /* HPUX || LINUX || HURD */ # if defined(MSWIN32) GC_old_segv_handler = SetUnhandledExceptionFilter(GC_write_fault_handler); if (GC_old_segv_handler != NULL) { @@ -1966,19 +2704,79 @@ void GC_dirty_init() } # endif } +#endif /* !DARWIN */ +int GC_incremental_protection_needs() +{ + if (GC_page_size == HBLKSIZE) { + return GC_PROTECTS_POINTER_HEAP; + } else { + return GC_PROTECTS_POINTER_HEAP | GC_PROTECTS_PTRFREE_HEAP; + } +} +#define HAVE_INCREMENTAL_PROTECTION_NEEDS +#define IS_PTRFREE(hhdr) ((hhdr)->hb_descr == 0) + +#define PAGE_ALIGNED(x) !((word)(x) & (GC_page_size - 1)) void GC_protect_heap() { ptr_t start; word len; + struct hblk * current; + struct hblk * current_start; /* Start of block to be protected. */ + struct hblk * limit; unsigned i; - + GC_bool protect_all = + (0 != (GC_incremental_protection_needs() & GC_PROTECTS_PTRFREE_HEAP)); for (i = 0; i < GC_n_heap_sects; i++) { start = GC_heap_sects[i].hs_start; len = GC_heap_sects[i].hs_bytes; - PROTECT(start, len); + if (protect_all) { + PROTECT(start, len); + } else { + GC_ASSERT(PAGE_ALIGNED(len)) + GC_ASSERT(PAGE_ALIGNED(start)) + current_start = current = (struct hblk *)start; + limit = (struct hblk *)(start + len); + while (current < limit) { + hdr * hhdr; + word nhblks; + GC_bool is_ptrfree; + + GC_ASSERT(PAGE_ALIGNED(current)); + GET_HDR(current, hhdr); + if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) { + /* This can happen only if we're at the beginning of a */ + /* heap segment, and a block spans heap segments. */ + /* We will handle that block as part of the preceding */ + /* segment. */ + GC_ASSERT(current_start == current); + current_start = ++current; + continue; + } + if (HBLK_IS_FREE(hhdr)) { + GC_ASSERT(PAGE_ALIGNED(hhdr -> hb_sz)); + nhblks = divHBLKSZ(hhdr -> hb_sz); + is_ptrfree = TRUE; /* dirty on alloc */ + } else { + nhblks = OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz); + is_ptrfree = IS_PTRFREE(hhdr); + } + if (is_ptrfree) { + if (current_start < current) { + PROTECT(current_start, (ptr_t)current - (ptr_t)current_start); + } + current_start = (current += nhblks); + } else { + current += nhblks; + } + } + if (current_start < current) { + PROTECT(current_start, (ptr_t)current - (ptr_t)current_start); + } + } } } @@ -2007,15 +2805,23 @@ struct hblk * h; * happens to work. * On other systems, SET_LOCK_HOLDER and friends must be suitably defined. */ + +static GC_bool syscall_acquired_lock = FALSE; /* Protected by GC lock. */ void GC_begin_syscall() { - if (!I_HOLD_LOCK()) LOCK(); + if (!I_HOLD_LOCK()) { + LOCK(); + syscall_acquired_lock = TRUE; + } } void GC_end_syscall() { - if (!I_HOLD_LOCK()) UNLOCK(); + if (syscall_acquired_lock) { + syscall_acquired_lock = FALSE; + UNLOCK(); + } } void GC_unprotect_range(addr, len) @@ -2027,7 +2833,7 @@ word len; register struct hblk *h; ptr_t obj_start; - if (!GC_incremental) return; + if (!GC_dirty_maintained) return; obj_start = GC_base(addr); if (obj_start == 0) return; if (GC_base(addr + len - 1) != obj_start) { @@ -2039,18 +2845,32 @@ word len; for (h = start_block; h <= end_block; h++) { register word index = PHT_HASH(h); - set_pht_entry_from_index(GC_dirty_pages, index); + async_set_pht_entry_from_index(GC_dirty_pages, index); } UNPROTECT(start_block, ((ptr_t)end_block - (ptr_t)start_block) + HBLKSIZE); } -#ifndef MSWIN32 -/* Replacement for UNIX system call. */ -/* Other calls that write to the heap */ -/* should be handled similarly. */ +#if 0 + +/* We no longer wrap read by default, since that was causing too many */ +/* problems. It is preferred that the client instead avoids writing */ +/* to the write-protected heap with a system call. */ +/* This still serves as sample code if you do want to wrap system calls.*/ + +#if !defined(MSWIN32) && !defined(MSWINCE) && !defined(GC_USE_LD_WRAP) +/* Replacement for UNIX system call. */ +/* Other calls that write to the heap should be handled similarly. */ +/* Note that this doesn't work well for blocking reads: It will hold */ +/* the allocation lock for the entire duration of the call. Multithreaded */ +/* clients should really ensure that it won't block, either by setting */ +/* the descriptor nonblocking, or by calling select or poll first, to */ +/* make sure that input is available. */ +/* Another, preferred alternative is to ensure that system calls never */ +/* write to the protected heap (see above). */ # if defined(__STDC__) && !defined(SUNOS4) # include +# include ssize_t read(int fd, void *buf, size_t nbyte) # else # ifndef LINT @@ -2067,10 +2887,12 @@ word len; GC_begin_syscall(); GC_unprotect_range(buf, (word)nbyte); -# ifdef IRIX5 +# if defined(IRIX5) || defined(GC_LINUX_THREADS) /* Indirect system call may not always be easily available. */ /* We could call _read, but that would interfere with the */ /* libpthread interception of read. */ + /* On Linux, we have to be careful with the linuxthreads */ + /* read interception. */ { struct iovec iov; @@ -2079,13 +2901,44 @@ word len; result = readv(fd, &iov, 1); } # else - result = syscall(SYS_read, fd, buf, nbyte); +# if defined(HURD) + result = __read(fd, buf, nbyte); +# else + /* The two zero args at the end of this list are because one + IA-64 syscall() implementation actually requires six args + to be passed, even though they aren't always used. */ + result = syscall(SYS_read, fd, buf, nbyte, 0, 0); +# endif /* !HURD */ # endif GC_end_syscall(); return(result); } -#endif /* !MSWIN32 */ +#endif /* !MSWIN32 && !MSWINCE && !GC_LINUX_THREADS */ +#if defined(GC_USE_LD_WRAP) && !defined(THREADS) + /* We use the GNU ld call wrapping facility. */ + /* This requires that the linker be invoked with "--wrap read". */ + /* This can be done by passing -Wl,"--wrap read" to gcc. */ + /* I'm not sure that this actually wraps whatever version of read */ + /* is called by stdio. That code also mentions __read. */ +# include + ssize_t __wrap_read(int fd, void *buf, size_t nbyte) + { + int result; + + GC_begin_syscall(); + GC_unprotect_range(buf, (word)nbyte); + result = __real_read(fd, buf, nbyte); + GC_end_syscall(); + return(result); + } + + /* We should probably also do this for __read, or whatever stdio */ + /* actually calls. */ +#endif + +#endif /* 0 */ + /*ARGSUSED*/ GC_bool GC_page_was_ever_dirty(h) struct hblk *h; @@ -2123,13 +2976,12 @@ word n; #include #include #include -#include #define INITIAL_BUF_SZ 4096 word GC_proc_buf_size = INITIAL_BUF_SZ; char *GC_proc_buf; -#ifdef SOLARIS_THREADS +#ifdef GC_SOLARIS_THREADS /* We don't have exact sp values for threads. So we count on */ /* occasionally declaring stack pages to be fresh. Thus we */ /* need a real implementation of GC_is_fresh. We can't clear */ @@ -2180,11 +3032,12 @@ void GC_dirty_init() } GC_proc_fd = syscall(SYS_ioctl, fd, PIOCOPENPD, 0); close(fd); + syscall(SYS_fcntl, GC_proc_fd, F_SETFD, FD_CLOEXEC); if (GC_proc_fd < 0) { ABORT("/proc ioctl failed"); } GC_proc_buf = GC_scratch_alloc(GC_proc_buf_size); -# ifdef SOLARIS_THREADS +# ifdef GC_SOLARIS_THREADS GC_fresh_pages = (struct hblk **) GC_scratch_alloc(MAX_FRESH_PAGES * sizeof (struct hblk *)); if (GC_fresh_pages == 0) { @@ -2197,12 +3050,14 @@ void GC_dirty_init() /* Ignore write hints. They don't help us here. */ /*ARGSUSED*/ -void GC_write_hint(h) +void GC_remove_protection(h, nblocks, is_ptrfree) struct hblk *h; +word nblocks; +GC_bool is_ptrfree; { } -#ifdef SOLARIS_THREADS +#ifdef GC_SOLARIS_THREADS # define READ(fd,buf,nbytes) syscall(SYS_read, fd, buf, nbytes) #else # define READ(fd,buf,nbytes) read(fd, buf, nbytes) @@ -2241,7 +3096,7 @@ int dummy; /* Punt: */ memset(GC_grungy_pages, 0xff, sizeof (page_hash_table)); memset(GC_written_pages, 0xff, sizeof(page_hash_table)); -# ifdef SOLARIS_THREADS +# ifdef GC_SOLARIS_THREADS BZERO(GC_fresh_pages, MAX_FRESH_PAGES * sizeof (struct hblk *)); # endif @@ -2271,7 +3126,7 @@ int dummy; register word index = PHT_HASH(h); set_pht_entry_from_index(GC_grungy_pages, index); -# ifdef SOLARIS_THREADS +# ifdef GC_SOLARIS_THREADS { register int slot = FRESH_PAGE_SLOT(h); @@ -2289,7 +3144,7 @@ int dummy; } /* Update GC_written_pages. */ GC_or_pages(GC_written_pages, GC_grungy_pages); -# ifdef SOLARIS_THREADS +# ifdef GC_SOLARIS_THREADS /* Make sure that old stacks are considered completely clean */ /* unless written again. */ GC_old_stacks_are_fresh(); @@ -2305,7 +3160,7 @@ struct hblk *h; register GC_bool result; result = get_pht_entry_from_index(GC_grungy_pages, index); -# ifdef SOLARIS_THREADS +# ifdef GC_SOLARIS_THREADS if (result && PAGE_IS_FRESH(h)) result = FALSE; /* This happens only if page was declared fresh since */ /* the read_dirty call, e.g. because it's in an unused */ @@ -2323,7 +3178,7 @@ struct hblk *h; register GC_bool result; result = get_pht_entry_from_index(GC_written_pages, index); -# ifdef SOLARIS_THREADS +# ifdef GC_SOLARIS_THREADS if (result && PAGE_IS_FRESH(h)) result = FALSE; # endif return(result); @@ -2337,7 +3192,7 @@ word n; register word index; -# ifdef SOLARIS_THREADS +# ifdef GC_SOLARIS_THREADS register word i; if (GC_fresh_pages != 0) { @@ -2406,42 +3261,659 @@ struct hblk *h; } /*ARGSUSED*/ -void GC_write_hint(h) +void GC_remove_protection(h, nblocks, is_ptrfree) struct hblk *h; +word nblocks; +GC_bool is_ptrfree; { - PCR_VD_WriteProtectDisable(h, HBLKSIZE); - PCR_VD_WriteProtectEnable(h, HBLKSIZE); + PCR_VD_WriteProtectDisable(h, nblocks*HBLKSIZE); + PCR_VD_WriteProtectEnable(h, nblocks*HBLKSIZE); } # endif /* PCR_VDB */ +#if defined(MPROTECT_VDB) && defined(DARWIN) +/* The following sources were used as a *reference* for this exception handling + code: + 1. Apple's mach/xnu documentation + 2. Timothy J. Wood's "Mach Exception Handlers 101" post to the + omnigroup's macosx-dev list. + www.omnigroup.com/mailman/archive/macosx-dev/2000-June/002030.html + 3. macosx-nat.c from Apple's GDB source code. +*/ + +/* There seem to be numerous problems with darwin's mach exception handling. + I'm pretty sure they are not problems in my code. Search for + BROKEN_EXCEPTION_HANDLING for more information. */ +#define BROKEN_EXCEPTION_HANDLING + +#include +#include +#include +#include +#include +#include + +/* These are not defined in any header, although they are documented */ +extern boolean_t exc_server(mach_msg_header_t *,mach_msg_header_t *); +extern kern_return_t exception_raise( + mach_port_t,mach_port_t,mach_port_t, + exception_type_t,exception_data_t,mach_msg_type_number_t); +extern kern_return_t exception_raise_state( + mach_port_t,mach_port_t,mach_port_t, + exception_type_t,exception_data_t,mach_msg_type_number_t, + thread_state_flavor_t*,thread_state_t,mach_msg_type_number_t, + thread_state_t,mach_msg_type_number_t*); +extern kern_return_t exception_raise_state_identity( + mach_port_t,mach_port_t,mach_port_t, + exception_type_t,exception_data_t,mach_msg_type_number_t, + thread_state_flavor_t*,thread_state_t,mach_msg_type_number_t, + thread_state_t,mach_msg_type_number_t*); + + +#define MAX_EXCEPTION_PORTS 16 + +static mach_port_t GC_task_self; + +static struct { + mach_msg_type_number_t count; + exception_mask_t masks[MAX_EXCEPTION_PORTS]; + exception_handler_t ports[MAX_EXCEPTION_PORTS]; + exception_behavior_t behaviors[MAX_EXCEPTION_PORTS]; + thread_state_flavor_t flavors[MAX_EXCEPTION_PORTS]; +} GC_old_exc_ports; + +static struct { + mach_port_t exception; +#if defined(THREADS) + mach_port_t reply; +#endif +} GC_ports; + +typedef struct { + mach_msg_header_t head; +} GC_msg_t; + +typedef enum { + GC_MP_NORMAL, GC_MP_DISCARDING, GC_MP_STOPPED +} GC_mprotect_state_t; + +/* FIXME: 1 and 2 seem to be safe to use in the msgh_id field, + but it isn't documented. Use the source and see if they + should be ok. */ +#define ID_STOP 1 +#define ID_RESUME 2 + +/* These values are only used on the reply port */ +#define ID_ACK 3 + +#if defined(THREADS) + +GC_mprotect_state_t GC_mprotect_state; + +/* The following should ONLY be called when the world is stopped */ +static void GC_mprotect_thread_notify(mach_msg_id_t id) { + struct { + GC_msg_t msg; + mach_msg_trailer_t trailer; + } buf; + mach_msg_return_t r; + /* remote, local */ + buf.msg.head.msgh_bits = + MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND,0); + buf.msg.head.msgh_size = sizeof(buf.msg); + buf.msg.head.msgh_remote_port = GC_ports.exception; + buf.msg.head.msgh_local_port = MACH_PORT_NULL; + buf.msg.head.msgh_id = id; + + r = mach_msg( + &buf.msg.head, + MACH_SEND_MSG|MACH_RCV_MSG|MACH_RCV_LARGE, + sizeof(buf.msg), + sizeof(buf), + GC_ports.reply, + MACH_MSG_TIMEOUT_NONE, + MACH_PORT_NULL); + if(r != MACH_MSG_SUCCESS) + ABORT("mach_msg failed in GC_mprotect_thread_notify"); + if(buf.msg.head.msgh_id != ID_ACK) + ABORT("invalid ack in GC_mprotect_thread_notify"); +} + +/* Should only be called by the mprotect thread */ +static void GC_mprotect_thread_reply() { + GC_msg_t msg; + mach_msg_return_t r; + /* remote, local */ + msg.head.msgh_bits = + MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND,0); + msg.head.msgh_size = sizeof(msg); + msg.head.msgh_remote_port = GC_ports.reply; + msg.head.msgh_local_port = MACH_PORT_NULL; + msg.head.msgh_id = ID_ACK; + + r = mach_msg( + &msg.head, + MACH_SEND_MSG, + sizeof(msg), + 0, + MACH_PORT_NULL, + MACH_MSG_TIMEOUT_NONE, + MACH_PORT_NULL); + if(r != MACH_MSG_SUCCESS) + ABORT("mach_msg failed in GC_mprotect_thread_reply"); +} + +void GC_mprotect_stop() { + GC_mprotect_thread_notify(ID_STOP); +} +void GC_mprotect_resume() { + GC_mprotect_thread_notify(ID_RESUME); +} + +#else /* !THREADS */ +/* The compiler should optimize away any GC_mprotect_state computations */ +#define GC_mprotect_state GC_MP_NORMAL +#endif + +static void *GC_mprotect_thread(void *arg) { + mach_msg_return_t r; + /* These two structures contain some private kernel data. We don't need to + access any of it so we don't bother defining a proper struct. The + correct definitions are in the xnu source code. */ + struct { + mach_msg_header_t head; + char data[256]; + } reply; + struct { + mach_msg_header_t head; + mach_msg_body_t msgh_body; + char data[1024]; + } msg; + + mach_msg_id_t id; + + for(;;) { + r = mach_msg( + &msg.head, + MACH_RCV_MSG|MACH_RCV_LARGE| + (GC_mprotect_state == GC_MP_DISCARDING ? MACH_RCV_TIMEOUT : 0), + 0, + sizeof(msg), + GC_ports.exception, + GC_mprotect_state == GC_MP_DISCARDING ? 0 : MACH_MSG_TIMEOUT_NONE, + MACH_PORT_NULL); + + id = r == MACH_MSG_SUCCESS ? msg.head.msgh_id : -1; + +#if defined(THREADS) + if(GC_mprotect_state == GC_MP_DISCARDING) { + if(r == MACH_RCV_TIMED_OUT) { + GC_mprotect_state = GC_MP_STOPPED; + GC_mprotect_thread_reply(); + continue; + } + if(r == MACH_MSG_SUCCESS && (id == ID_STOP || id == ID_RESUME)) + ABORT("out of order mprotect thread request"); + } +#endif + + if(r != MACH_MSG_SUCCESS) { + GC_err_printf2("mach_msg failed with %d %s\n", + (int)r,mach_error_string(r)); + ABORT("mach_msg failed"); + } + + switch(id) { +#if defined(THREADS) + case ID_STOP: + if(GC_mprotect_state != GC_MP_NORMAL) + ABORT("Called mprotect_stop when state wasn't normal"); + GC_mprotect_state = GC_MP_DISCARDING; + break; + case ID_RESUME: + if(GC_mprotect_state != GC_MP_STOPPED) + ABORT("Called mprotect_resume when state wasn't stopped"); + GC_mprotect_state = GC_MP_NORMAL; + GC_mprotect_thread_reply(); + break; +#endif /* THREADS */ + default: + /* Handle the message (calls catch_exception_raise) */ + if(!exc_server(&msg.head,&reply.head)) + ABORT("exc_server failed"); + /* Send the reply */ + r = mach_msg( + &reply.head, + MACH_SEND_MSG, + reply.head.msgh_size, + 0, + MACH_PORT_NULL, + MACH_MSG_TIMEOUT_NONE, + MACH_PORT_NULL); + if(r != MACH_MSG_SUCCESS) { + /* This will fail if the thread dies, but the thread shouldn't + die... */ + #ifdef BROKEN_EXCEPTION_HANDLING + GC_err_printf2( + "mach_msg failed with %d %s while sending exc reply\n", + (int)r,mach_error_string(r)); + #else + ABORT("mach_msg failed while sending exception reply"); + #endif + } + } /* switch */ + } /* for(;;) */ + /* NOT REACHED */ + return NULL; +} + +/* All this SIGBUS code shouldn't be necessary. All protection faults should + be going throught the mach exception handler. However, it seems a SIGBUS is + occasionally sent for some unknown reason. Even more odd, it seems to be + meaningless and safe to ignore. */ +#ifdef BROKEN_EXCEPTION_HANDLING + +typedef void (* SIG_PF)(); +static SIG_PF GC_old_bus_handler; + +/* Updates to this aren't atomic, but the SIGBUSs seem pretty rare. + Even if this doesn't get updated property, it isn't really a problem */ +static int GC_sigbus_count; + +static void GC_darwin_sigbus(int num,siginfo_t *sip,void *context) { + if(num != SIGBUS) ABORT("Got a non-sigbus signal in the sigbus handler"); + + /* Ugh... some seem safe to ignore, but too many in a row probably means + trouble. GC_sigbus_count is reset for each mach exception that is + handled */ + if(GC_sigbus_count >= 8) { + ABORT("Got more than 8 SIGBUSs in a row!"); + } else { + GC_sigbus_count++; + GC_err_printf0("GC: WARNING: Ignoring SIGBUS.\n"); + } +} +#endif /* BROKEN_EXCEPTION_HANDLING */ + +void GC_dirty_init() { + kern_return_t r; + mach_port_t me; + pthread_t thread; + pthread_attr_t attr; + exception_mask_t mask; + +# ifdef PRINTSTATS + GC_printf0("Inititalizing mach/darwin mprotect virtual dirty bit " + "implementation\n"); +# endif +# ifdef BROKEN_EXCEPTION_HANDLING + GC_err_printf0("GC: WARNING: Enabling workarounds for various darwin " + "exception handling bugs.\n"); +# endif + GC_dirty_maintained = TRUE; + if (GC_page_size % HBLKSIZE != 0) { + GC_err_printf0("Page size not multiple of HBLKSIZE\n"); + ABORT("Page size not multiple of HBLKSIZE"); + } + + GC_task_self = me = mach_task_self(); + + r = mach_port_allocate(me,MACH_PORT_RIGHT_RECEIVE,&GC_ports.exception); + if(r != KERN_SUCCESS) ABORT("mach_port_allocate failed (exception port)"); + + r = mach_port_insert_right(me,GC_ports.exception,GC_ports.exception, + MACH_MSG_TYPE_MAKE_SEND); + if(r != KERN_SUCCESS) + ABORT("mach_port_insert_right failed (exception port)"); + + #if defined(THREADS) + r = mach_port_allocate(me,MACH_PORT_RIGHT_RECEIVE,&GC_ports.reply); + if(r != KERN_SUCCESS) ABORT("mach_port_allocate failed (reply port)"); + #endif + + /* The exceptions we want to catch */ + mask = EXC_MASK_BAD_ACCESS; + + r = task_get_exception_ports( + me, + mask, + GC_old_exc_ports.masks, + &GC_old_exc_ports.count, + GC_old_exc_ports.ports, + GC_old_exc_ports.behaviors, + GC_old_exc_ports.flavors + ); + if(r != KERN_SUCCESS) ABORT("task_get_exception_ports failed"); + + r = task_set_exception_ports( + me, + mask, + GC_ports.exception, + EXCEPTION_DEFAULT, + MACHINE_THREAD_STATE + ); + if(r != KERN_SUCCESS) ABORT("task_set_exception_ports failed"); + + if(pthread_attr_init(&attr) != 0) ABORT("pthread_attr_init failed"); + if(pthread_attr_setdetachstate(&attr,PTHREAD_CREATE_DETACHED) != 0) + ABORT("pthread_attr_setdetachedstate failed"); + +# undef pthread_create + /* This will call the real pthread function, not our wrapper */ + if(pthread_create(&thread,&attr,GC_mprotect_thread,NULL) != 0) + ABORT("pthread_create failed"); + pthread_attr_destroy(&attr); + + /* Setup the sigbus handler for ignoring the meaningless SIGBUSs */ + #ifdef BROKEN_EXCEPTION_HANDLING + { + struct sigaction sa, oldsa; + sa.sa_handler = (SIG_PF)GC_darwin_sigbus; + sigemptyset(&sa.sa_mask); + sa.sa_flags = SA_RESTART|SA_SIGINFO; + if(sigaction(SIGBUS,&sa,&oldsa) < 0) ABORT("sigaction"); + GC_old_bus_handler = (SIG_PF)oldsa.sa_handler; + if (GC_old_bus_handler != SIG_DFL) { +# ifdef PRINTSTATS + GC_err_printf0("Replaced other SIGBUS handler\n"); +# endif + } + } + #endif /* BROKEN_EXCEPTION_HANDLING */ +} + +/* The source code for Apple's GDB was used as a reference for the exception + forwarding code. This code is similar to be GDB code only because there is + only one way to do it. */ +static kern_return_t GC_forward_exception( + mach_port_t thread, + mach_port_t task, + exception_type_t exception, + exception_data_t data, + mach_msg_type_number_t data_count +) { + int i; + kern_return_t r; + mach_port_t port; + exception_behavior_t behavior; + thread_state_flavor_t flavor; + + thread_state_data_t thread_state; + mach_msg_type_number_t thread_state_count = THREAD_STATE_MAX; + + for(i=0;i 0 ? code[0] : -1, + code_count > 1 ? code[1] : -1); + #endif + return FWD(); + } + + r = thread_get_state(thread,flavor, + (natural_t*)&exc_state,&exc_state_count); + if(r != KERN_SUCCESS) { + /* The thread is supposed to be suspended while the exception handler + is called. This shouldn't fail. */ + #ifdef BROKEN_EXCEPTION_HANDLING + GC_err_printf0("thread_get_state failed in " + "catch_exception_raise\n"); + return KERN_SUCCESS; + #else + ABORT("thread_get_state failed in catch_exception_raise"); + #endif + } + + /* This is the address that caused the fault */ + addr = (char*) exc_state.dar; + + if((HDR(addr)) == 0) { + /* Ugh... just like the SIGBUS problem above, it seems we get a bogus + KERN_PROTECTION_FAILURE every once and a while. We wait till we get + a bunch in a row before doing anything about it. If a "real" fault + ever occurres it'll just keep faulting over and over and we'll hit + the limit pretty quickly. */ + #ifdef BROKEN_EXCEPTION_HANDLING + static char *last_fault; + static int last_fault_count; + + if(addr != last_fault) { + last_fault = addr; + last_fault_count = 0; + } + if(++last_fault_count < 32) { + if(last_fault_count == 1) + GC_err_printf1( + "GC: WARNING: Ignoring KERN_PROTECTION_FAILURE at %p\n", + addr); + return KERN_SUCCESS; + } + + GC_err_printf1("Unexpected KERN_PROTECTION_FAILURE at %p\n",addr); + /* Can't pass it along to the signal handler because that is + ignoring SIGBUS signals. We also shouldn't call ABORT here as + signals don't always work too well from the exception handler. */ + GC_err_printf0("Aborting\n"); + exit(EXIT_FAILURE); + #else /* BROKEN_EXCEPTION_HANDLING */ + /* Pass it along to the next exception handler + (which should call SIGBUS/SIGSEGV) */ + return FWD(); + #endif /* !BROKEN_EXCEPTION_HANDLING */ + } + + #ifdef BROKEN_EXCEPTION_HANDLING + /* Reset the number of consecutive SIGBUSs */ + GC_sigbus_count = 0; + #endif + + if(GC_mprotect_state == GC_MP_NORMAL) { /* common case */ + h = (struct hblk*)((word)addr & ~(GC_page_size-1)); + UNPROTECT(h, GC_page_size); + for (i = 0; i < divHBLKSZ(GC_page_size); i++) { + register int index = PHT_HASH(h+i); + async_set_pht_entry_from_index(GC_dirty_pages, index); + } + } else if(GC_mprotect_state == GC_MP_DISCARDING) { + /* Lie to the thread for now. No sense UNPROTECT()ing the memory + when we're just going to PROTECT() it again later. The thread + will just fault again once it resumes */ + } else { + /* Shouldn't happen, i don't think */ + GC_printf0("KERN_PROTECTION_FAILURE while world is stopped\n"); + return FWD(); + } + return KERN_SUCCESS; +} +#undef FWD + +/* These should never be called, but just in case... */ +kern_return_t catch_exception_raise_state(mach_port_name_t exception_port, + int exception, exception_data_t code, mach_msg_type_number_t codeCnt, + int flavor, thread_state_t old_state, int old_stateCnt, + thread_state_t new_state, int new_stateCnt) +{ + ABORT("catch_exception_raise_state"); + return(KERN_INVALID_ARGUMENT); +} +kern_return_t catch_exception_raise_state_identity( + mach_port_name_t exception_port, mach_port_t thread, mach_port_t task, + int exception, exception_data_t code, mach_msg_type_number_t codeCnt, + int flavor, thread_state_t old_state, int old_stateCnt, + thread_state_t new_state, int new_stateCnt) +{ + ABORT("catch_exception_raise_state_identity"); + return(KERN_INVALID_ARGUMENT); +} + + +#endif /* DARWIN && MPROTECT_VDB */ + +# ifndef HAVE_INCREMENTAL_PROTECTION_NEEDS + int GC_incremental_protection_needs() + { + return GC_PROTECTS_NONE; + } +# endif /* !HAVE_INCREMENTAL_PROTECTION_NEEDS */ + /* * Call stack save code for debugging. * Should probably be in mach_dep.c, but that requires reorganization. */ -#if defined(SPARC) && !defined(LINUX) -# if defined(SUNOS4) -# include -# else -# if defined (DRSNX) -# include -# else -# if defined(OPENBSD) -# include -# else -# include -# endif -# endif -# endif -# if NARGS > 6 + +/* I suspect the following works for most X86 *nix variants, so */ +/* long as the frame pointer is explicitly stored. In the case of gcc, */ +/* compiler flags (e.g. -fomit-frame-pointer) determine whether it is. */ +#if defined(I386) && defined(LINUX) && defined(SAVE_CALL_CHAIN) +# include + + struct frame { + struct frame *fr_savfp; + long fr_savpc; + long fr_arg[NARGS]; /* All the arguments go here. */ + }; +#endif + +#if defined(SPARC) +# if defined(LINUX) +# include + + struct frame { + long fr_local[8]; + long fr_arg[6]; + struct frame *fr_savfp; + long fr_savpc; +# ifndef __arch64__ + char *fr_stret; +# endif + long fr_argd[6]; + long fr_argx[0]; + }; +# else +# if defined(SUNOS4) +# include +# else +# if defined (DRSNX) +# include +# else +# if defined(OPENBSD) || defined(NETBSD) +# include +# else +# include +# endif +# endif +# endif +# endif +# if NARGS > 6 --> We only know how to to get the first 6 arguments -# endif +# endif +#endif /* SPARC */ -#ifdef SAVE_CALL_CHAIN +#ifdef NEED_CALLINFO /* Fill in the pc and argument information for up to NFRAMES of my */ /* callers. Ignore my frame and my callers frame. */ -#ifdef OPENBSD +#ifdef LINUX +# include +#endif + +#endif /* NEED_CALLINFO */ + +#ifdef SAVE_CALL_CHAIN + +#if NARGS == 0 && NFRAMES % 2 == 0 /* No padding */ \ + && defined(GC_HAVE_BUILTIN_BACKTRACE) + +#include + +void GC_save_callers (info) +struct callinfo info[NFRAMES]; +{ + void * tmp_info[NFRAMES + 1]; + int npcs, i; +# define IGNORE_FRAMES 1 + + /* We retrieve NFRAMES+1 pc values, but discard the first, since it */ + /* points to our own frame. */ + GC_ASSERT(sizeof(struct callinfo) == sizeof(void *)); + npcs = backtrace((void **)tmp_info, NFRAMES + IGNORE_FRAMES); + BCOPY(tmp_info+IGNORE_FRAMES, info, (npcs - IGNORE_FRAMES) * sizeof(void *)); + for (i = npcs - IGNORE_FRAMES; i < NFRAMES; ++i) info[i].ci_pc = 0; +} + +#else /* No builtin backtrace; do it ourselves */ + +#if (defined(OPENBSD) || defined(NETBSD)) && defined(SPARC) # define FR_SAVFP fr_fp # define FR_SAVPC fr_pc #else @@ -2449,30 +3921,199 @@ struct hblk *h; # define FR_SAVPC fr_savpc #endif +#if defined(SPARC) && (defined(__arch64__) || defined(__sparcv9)) +# define BIAS 2047 +#else +# define BIAS 0 +#endif + void GC_save_callers (info) struct callinfo info[NFRAMES]; { struct frame *frame; struct frame *fp; int nframes = 0; - word GC_save_regs_in_stack(); - - frame = (struct frame *) GC_save_regs_in_stack (); +# ifdef I386 + /* We assume this is turned on only with gcc as the compiler. */ + asm("movl %%ebp,%0" : "=r"(frame)); + fp = frame; +# else + frame = (struct frame *) GC_save_regs_in_stack (); + fp = (struct frame *)((long) frame -> FR_SAVFP + BIAS); +#endif - for (fp = frame -> FR_SAVFP; fp != 0 && nframes < NFRAMES; - fp = fp -> FR_SAVFP, nframes++) { + for (; (!(fp HOTTER_THAN frame) && !(GC_stackbottom HOTTER_THAN (ptr_t)fp) + && (nframes < NFRAMES)); + fp = (struct frame *)((long) fp -> FR_SAVFP + BIAS), nframes++) { register int i; info[nframes].ci_pc = fp->FR_SAVPC; - for (i = 0; i < NARGS; i++) { - info[nframes].ci_arg[i] = ~(fp->fr_arg[i]); - } +# if NARGS > 0 + for (i = 0; i < NARGS; i++) { + info[nframes].ci_arg[i] = ~(fp->fr_arg[i]); + } +# endif /* NARGS > 0 */ } if (nframes < NFRAMES) info[nframes].ci_pc = 0; } +#endif /* No builtin backtrace */ + #endif /* SAVE_CALL_CHAIN */ -#endif /* SPARC */ +#ifdef NEED_CALLINFO + +/* Print info to stderr. We do NOT hold the allocation lock */ +void GC_print_callers (info) +struct callinfo info[NFRAMES]; +{ + register int i; + static int reentry_count = 0; + GC_bool stop = FALSE; + + LOCK(); + ++reentry_count; + UNLOCK(); + +# if NFRAMES == 1 + GC_err_printf0("\tCaller at allocation:\n"); +# else + GC_err_printf0("\tCall chain at allocation:\n"); +# endif + for (i = 0; i < NFRAMES && !stop ; i++) { + if (info[i].ci_pc == 0) break; +# if NARGS > 0 + { + int j; + + GC_err_printf0("\t\targs: "); + for (j = 0; j < NARGS; j++) { + if (j != 0) GC_err_printf0(", "); + GC_err_printf2("%d (0x%X)", ~(info[i].ci_arg[j]), + ~(info[i].ci_arg[j])); + } + GC_err_printf0("\n"); + } +# endif + if (reentry_count > 1) { + /* We were called during an allocation during */ + /* a previous GC_print_callers call; punt. */ + GC_err_printf1("\t\t##PC##= 0x%lx\n", info[i].ci_pc); + continue; + } + { +# ifdef LINUX + FILE *pipe; +# endif +# if defined(GC_HAVE_BUILTIN_BACKTRACE) + char **sym_name = + backtrace_symbols((void **)(&(info[i].ci_pc)), 1); + char *name = sym_name[0]; +# else + char buf[40]; + char *name = buf; + sprintf(buf, "##PC##= 0x%lx", info[i].ci_pc); +# endif +# if defined(LINUX) && !defined(SMALL_CONFIG) + /* Try for a line number. */ + { +# define EXE_SZ 100 + static char exe_name[EXE_SZ]; +# define CMD_SZ 200 + char cmd_buf[CMD_SZ]; +# define RESULT_SZ 200 + static char result_buf[RESULT_SZ]; + size_t result_len; + static GC_bool found_exe_name = FALSE; + static GC_bool will_fail = FALSE; + int ret_code; + /* Try to get it via a hairy and expensive scheme. */ + /* First we get the name of the executable: */ + if (will_fail) goto out; + if (!found_exe_name) { + ret_code = readlink("/proc/self/exe", exe_name, EXE_SZ); + if (ret_code < 0 || ret_code >= EXE_SZ + || exe_name[0] != '/') { + will_fail = TRUE; /* Dont try again. */ + goto out; + } + exe_name[ret_code] = '\0'; + found_exe_name = TRUE; + } + /* Then we use popen to start addr2line -e */ + /* There are faster ways to do this, but hopefully this */ + /* isn't time critical. */ + sprintf(cmd_buf, "/usr/bin/addr2line -f -e %s 0x%lx", exe_name, + (unsigned long)info[i].ci_pc); + pipe = popen(cmd_buf, "r"); + if (pipe == NULL + || (result_len = fread(result_buf, 1, RESULT_SZ - 1, pipe)) + == 0) { + if (pipe != NULL) pclose(pipe); + will_fail = TRUE; + goto out; + } + if (result_buf[result_len - 1] == '\n') --result_len; + result_buf[result_len] = 0; + if (result_buf[0] == '?' + || result_buf[result_len-2] == ':' + && result_buf[result_len-1] == '0') { + pclose(pipe); + goto out; + } + /* Get rid of embedded newline, if any. Test for "main" */ + { + char * nl = strchr(result_buf, '\n'); + if (nl != NULL && nl < result_buf + result_len) { + *nl = ':'; + } + if (strncmp(result_buf, "main", nl - result_buf) == 0) { + stop = TRUE; + } + } + if (result_len < RESULT_SZ - 25) { + /* Add in hex address */ + sprintf(result_buf + result_len, " [0x%lx]", + (unsigned long)info[i].ci_pc); + } + name = result_buf; + pclose(pipe); + out:; + } +# endif /* LINUX */ + GC_err_printf1("\t\t%s\n", name); +# if defined(GC_HAVE_BUILTIN_BACKTRACE) + free(sym_name); /* May call GC_free; that's OK */ +# endif + } + } + LOCK(); + --reentry_count; + UNLOCK(); +} + +#endif /* NEED_CALLINFO */ + + + +#if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG) + +/* Dump /proc/self/maps to GC_stderr, to enable looking up names for + addresses in FIND_LEAK output. */ + +static word dump_maps(char *maps) +{ + GC_err_write(maps, strlen(maps)); + return 1; +} + +void GC_print_address_map() +{ + GC_err_printf0("---------- Begin address map ----------\n"); + GC_apply_to_maps(dump_maps); + GC_err_printf0("---------- End address map ----------\n"); +} + +#endif