2 * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
3 * Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved.
4 * Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved.
5 * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved.
7 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
8 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
10 * Permission is hereby granted to use or copy this program
11 * for any purpose, provided the above notices are retained on all copies.
12 * Permission to modify the code and to distribute modified code is granted,
13 * provided the above notices are retained, and a notice that the code was
14 * modified is included with the above copyright notice.
17 # include "private/gc_priv.h"
19 # if defined(LINUX) && !defined(POWERPC)
20 # include <linux/version.h>
21 # if (LINUX_VERSION_CODE <= 0x10400)
22 /* Ugly hack to get struct sigcontext_struct definition. Required */
23 /* for some early 1.3.X releases. Will hopefully go away soon. */
24 /* in some later Linux releases, asm/sigcontext.h may have to */
25 /* be included instead. */
27 # include <asm/signal.h>
30 /* Kernels prior to 2.1.1 defined struct sigcontext_struct instead of */
31 /* struct sigcontext. libc6 (glibc2) uses "struct sigcontext" in */
32 /* prototypes, so we have to include the top-level sigcontext.h to */
33 /* make sure the former gets defined to be the latter if appropriate. */
34 # include <features.h>
36 # if 2 == __GLIBC__ && 0 == __GLIBC_MINOR__
37 /* glibc 2.1 no longer has sigcontext.h. But signal.h */
38 /* has the right declaration for glibc 2.1. */
39 # include <sigcontext.h>
40 # endif /* 0 == __GLIBC_MINOR__ */
41 # else /* not 2 <= __GLIBC__ */
42 /* libc5 doesn't have <sigcontext.h>: go directly with the kernel */
43 /* one. Check LINUX_VERSION_CODE to see which we should reference. */
44 # include <asm/sigcontext.h>
45 # endif /* 2 <= __GLIBC__ */
48 # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) && !defined(MACOS) \
50 # include <sys/types.h>
51 # if !defined(MSWIN32) && !defined(SUNOS4)
58 # define SIGSEGV 0 /* value is irrelevant */
63 /* Blatantly OS dependent routines, except for those that are related */
64 /* to dynamic loading. */
66 # if defined(HEURISTIC2) || defined(SEARCH_FOR_DATA_START)
67 # define NEED_FIND_LIMIT
70 # if !defined(STACKBOTTOM) && defined(HEURISTIC2)
71 # define NEED_FIND_LIMIT
74 # if (defined(SUNOS4) && defined(DYNAMIC_LOADING)) && !defined(PCR)
75 # define NEED_FIND_LIMIT
78 # if (defined(SVR4) || defined(AUX) || defined(DGUX) \
79 || (defined(LINUX) && defined(SPARC))) && !defined(PCR)
80 # define NEED_FIND_LIMIT
83 #if defined(FREEBSD) && defined(I386)
84 # include <machine/trap.h>
86 # define NEED_FIND_LIMIT
90 #if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__) \
91 && !defined(NEED_FIND_LIMIT)
92 /* Used by GC_init_netbsd_elf() below. */
93 # define NEED_FIND_LIMIT
96 #ifdef NEED_FIND_LIMIT
101 # define GC_AMIGA_DEF
102 # include "AmigaOS.c"
106 #if defined(MSWIN32) || defined(MSWINCE)
107 # define WIN32_LEAN_AND_MEAN
109 # include <windows.h>
113 # include <Processes.h>
117 # include <sys/uio.h>
118 # include <malloc.h> /* for locking */
120 #if defined(USE_MUNMAP)
122 --> USE_MUNMAP requires USE_MMAP
125 #if defined(USE_MMAP) || defined(USE_MUNMAP) || defined(FALLBACK_TO_MMAP)
126 # include <sys/types.h>
127 # include <sys/mman.h>
128 # include <sys/stat.h>
136 #if (defined(SUNOS5SIGS) || defined (HURD) || defined(LINUX) || defined(NETBSD)) && !defined(FREEBSD)
138 # include <sys/siginfo.h>
140 /* Define SETJMP and friends to be the version that restores */
141 /* the signal mask. */
142 # define SETJMP(env) sigsetjmp(env, 1)
143 # define LONGJMP(env, val) siglongjmp(env, val)
144 # define JMP_BUF sigjmp_buf
146 # define SETJMP(env) setjmp(env)
147 # define LONGJMP(env, val) longjmp(env, val)
148 # define JMP_BUF jmp_buf
152 /* for get_etext and friends */
153 #include <mach-o/getsect.h>
157 /* Apparently necessary for djgpp 2.01. May cause problems with */
158 /* other versions. */
159 typedef long unsigned int caddr_t;
163 # include "il/PCR_IL.h"
164 # include "th/PCR_ThCtl.h"
165 # include "mm/PCR_MM.h"
168 #if !defined(NO_EXECUTE_PERMISSION)
169 # define OPT_PROT_EXEC PROT_EXEC
171 # define OPT_PROT_EXEC 0
174 #if defined(LINUX) && \
175 (defined(USE_PROC_FOR_LIBRARIES) || defined(IA64) || !defined(SMALL_CONFIG))
177 /* We need to parse /proc/self/maps, either to find dynamic libraries, */
178 /* and/or to find the register backing store base (IA64). Do it once */
183 /* Repeatedly perform a read call until the buffer is filled or */
184 /* we encounter EOF. */
185 ssize_t GC_repeat_read(int fd, char *buf, size_t count)
187 ssize_t num_read = 0;
190 while (num_read < count) {
191 result = READ(fd, buf + num_read, count - num_read);
192 if (result < 0) return result;
193 if (result == 0) break;
200 * Apply fn to a buffer containing the contents of /proc/self/maps.
201 * Return the result of fn or, if we failed, 0.
202 * We currently do nothing to /proc/self/maps other than simply read
203 * it. This code could be simplified if we could determine its size
207 word GC_apply_to_maps(word (*fn)(char *))
211 size_t maps_size = 4000; /* Initial guess. */
212 static char init_buf[1];
213 static char *maps_buf = init_buf;
214 static size_t maps_buf_sz = 1;
216 /* Read /proc/self/maps, growing maps_buf as necessary. */
217 /* Note that we may not allocate conventionally, and */
218 /* thus can't use stdio. */
220 if (maps_size >= maps_buf_sz) {
221 /* Grow only by powers of 2, since we leak "too small" buffers. */
222 while (maps_size >= maps_buf_sz) maps_buf_sz *= 2;
223 maps_buf = GC_scratch_alloc(maps_buf_sz);
224 if (maps_buf == 0) return 0;
226 f = open("/proc/self/maps", O_RDONLY);
227 if (-1 == f) return 0;
230 result = GC_repeat_read(f, maps_buf, maps_buf_sz-1);
231 if (result <= 0) return 0;
233 } while (result == maps_buf_sz-1);
235 } while (maps_size >= maps_buf_sz);
236 maps_buf[maps_size] = '\0';
238 /* Apply fn to result. */
242 #endif /* Need GC_apply_to_maps */
244 #if defined(LINUX) && (defined(USE_PROC_FOR_LIBRARIES) || defined(IA64))
246 // GC_parse_map_entry parses an entry from /proc/self/maps so we can
247 // locate all writable data segments that belong to shared libraries.
248 // The format of one of these entries and the fields we care about
250 // XXXXXXXX-XXXXXXXX r-xp 00000000 30:05 260537 name of mapping...\n
251 // ^^^^^^^^ ^^^^^^^^ ^^^^ ^^
252 // start end prot maj_dev
258 // The parser is called with a pointer to the entry and the return value
259 // is either NULL or is advanced to the next entry(the byte after the
263 # define OFFSET_MAP_START 0
264 # define OFFSET_MAP_END 9
265 # define OFFSET_MAP_PROT 18
266 # define OFFSET_MAP_MAJDEV 32
267 # define ADDR_WIDTH 8
271 # define OFFSET_MAP_START 0
272 # define OFFSET_MAP_END 17
273 # define OFFSET_MAP_PROT 34
274 # define OFFSET_MAP_MAJDEV 56
275 # define ADDR_WIDTH 16
279 * Assign various fields of the first line in buf_ptr to *start, *end,
280 * *prot_buf and *maj_dev. Only *prot_buf may be set for unwritable maps.
282 char *GC_parse_map_entry(char *buf_ptr, word *start, word *end,
283 char *prot_buf, unsigned int *maj_dev)
288 if (buf_ptr == NULL || *buf_ptr == '\0') {
292 memcpy(prot_buf, buf_ptr+OFFSET_MAP_PROT, 4);
293 /* do the protections first. */
296 if (prot_buf[1] == 'w') {/* we can skip all of this if it's not writable. */
299 buf_ptr[OFFSET_MAP_START+ADDR_WIDTH] = '\0';
300 *start = strtoul(tok, NULL, 16);
302 tok = buf_ptr+OFFSET_MAP_END;
303 buf_ptr[OFFSET_MAP_END+ADDR_WIDTH] = '\0';
304 *end = strtoul(tok, NULL, 16);
306 buf_ptr += OFFSET_MAP_MAJDEV;
308 while (*buf_ptr != ':') buf_ptr++;
310 *maj_dev = strtoul(tok, NULL, 16);
313 while (*buf_ptr && *buf_ptr++ != '\n');
318 #endif /* Need to parse /proc/self/maps. */
320 #if defined(SEARCH_FOR_DATA_START)
321 /* The I386 case can be handled without a search. The Alpha case */
322 /* used to be handled differently as well, but the rules changed */
323 /* for recent Linux versions. This seems to be the easiest way to */
324 /* cover all versions. */
327 /* Some Linux distributions arrange to define __data_start. Some */
328 /* define data_start as a weak symbol. The latter is technically */
329 /* broken, since the user program may define data_start, in which */
330 /* case we lose. Nonetheless, we try both, prefering __data_start. */
331 /* We assume gcc-compatible pragmas. */
332 # pragma weak __data_start
333 extern int __data_start[];
334 # pragma weak data_start
335 extern int data_start[];
341 void GC_init_linux_data_start()
343 extern ptr_t GC_find_limit();
346 /* Try the easy approaches first: */
347 if ((ptr_t)__data_start != 0) {
348 GC_data_start = (ptr_t)(__data_start);
351 if ((ptr_t)data_start != 0) {
352 GC_data_start = (ptr_t)(data_start);
356 GC_data_start = GC_find_limit((ptr_t)(_end), FALSE);
362 # ifndef ECOS_GC_MEMORY_SIZE
363 # define ECOS_GC_MEMORY_SIZE (448 * 1024)
364 # endif /* ECOS_GC_MEMORY_SIZE */
366 // setjmp() function, as described in ANSI para 7.6.1.1
368 #define SETJMP( __env__ ) hal_setjmp( __env__ )
370 // FIXME: This is a simple way of allocating memory which is
371 // compatible with ECOS early releases. Later releases use a more
372 // sophisticated means of allocating memory than this simple static
373 // allocator, but this method is at least bound to work.
374 static char memory[ECOS_GC_MEMORY_SIZE];
375 static char *brk = memory;
377 static void *tiny_sbrk(ptrdiff_t increment)
383 if (brk > memory + sizeof memory)
391 #define sbrk tiny_sbrk
394 #if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__)
397 void GC_init_netbsd_elf()
399 extern ptr_t GC_find_limit();
400 extern char **environ;
401 /* This may need to be environ, without the underscore, for */
403 GC_data_start = GC_find_limit((ptr_t)&environ, FALSE);
411 # if !defined(__IBMC__) && !defined(__WATCOMC__) /* e.g. EMX */
414 unsigned short magic_number;
415 unsigned short padding[29];
419 #define E_MAGIC(x) (x).magic_number
420 #define EMAGIC 0x5A4D
421 #define E_LFANEW(x) (x).new_exe_offset
424 unsigned char magic_number[2];
425 unsigned char byte_order;
426 unsigned char word_order;
427 unsigned long exe_format_level;
430 unsigned long padding1[13];
431 unsigned long object_table_offset;
432 unsigned long object_count;
433 unsigned long padding2[31];
436 #define E32_MAGIC1(x) (x).magic_number[0]
437 #define E32MAGIC1 'L'
438 #define E32_MAGIC2(x) (x).magic_number[1]
439 #define E32MAGIC2 'X'
440 #define E32_BORDER(x) (x).byte_order
442 #define E32_WORDER(x) (x).word_order
444 #define E32_CPU(x) (x).cpu
446 #define E32_OBJTAB(x) (x).object_table_offset
447 #define E32_OBJCNT(x) (x).object_count
453 unsigned long pagemap;
454 unsigned long mapsize;
455 unsigned long reserved;
458 #define O32_FLAGS(x) (x).flags
459 #define OBJREAD 0x0001L
460 #define OBJWRITE 0x0002L
461 #define OBJINVALID 0x0080L
462 #define O32_SIZE(x) (x).size
463 #define O32_BASE(x) (x).base
465 # else /* IBM's compiler */
467 /* A kludge to get around what appears to be a header file bug */
469 # define WORD unsigned short
472 # define DWORD unsigned long
479 # endif /* __IBMC__ */
481 # define INCL_DOSEXCEPTIONS
482 # define INCL_DOSPROCESS
483 # define INCL_DOSERRORS
484 # define INCL_DOSMODULEMGR
485 # define INCL_DOSMEMMGR
489 /* Disable and enable signals during nontrivial allocations */
491 void GC_disable_signals(void)
495 DosEnterMustComplete(&nest);
496 if (nest != 1) ABORT("nested GC_disable_signals");
499 void GC_enable_signals(void)
503 DosExitMustComplete(&nest);
504 if (nest != 0) ABORT("GC_enable_signals");
510 # if !defined(PCR) && !defined(AMIGA) && !defined(MSWIN32) \
511 && !defined(MSWINCE) \
512 && !defined(MACOS) && !defined(DJGPP) && !defined(DOS4GW) \
513 && !defined(NOSYS) && !defined(ECOS)
515 # if defined(sigmask) && !defined(UTS4) && !defined(HURD)
516 /* Use the traditional BSD interface */
517 # define SIGSET_T int
518 # define SIG_DEL(set, signal) (set) &= ~(sigmask(signal))
519 # define SIG_FILL(set) (set) = 0x7fffffff
520 /* Setting the leading bit appears to provoke a bug in some */
521 /* longjmp implementations. Most systems appear not to have */
523 # define SIGSETMASK(old, new) (old) = sigsetmask(new)
525 /* Use POSIX/SYSV interface */
526 # define SIGSET_T sigset_t
527 # define SIG_DEL(set, signal) sigdelset(&(set), (signal))
528 # define SIG_FILL(set) sigfillset(&set)
529 # define SIGSETMASK(old, new) sigprocmask(SIG_SETMASK, &(new), &(old))
532 static GC_bool mask_initialized = FALSE;
534 static SIGSET_T new_mask;
536 static SIGSET_T old_mask;
538 static SIGSET_T dummy;
540 #if defined(PRINTSTATS) && !defined(THREADS)
541 # define CHECK_SIGNALS
542 int GC_sig_disabled = 0;
545 void GC_disable_signals()
547 if (!mask_initialized) {
550 SIG_DEL(new_mask, SIGSEGV);
551 SIG_DEL(new_mask, SIGILL);
552 SIG_DEL(new_mask, SIGQUIT);
554 SIG_DEL(new_mask, SIGBUS);
557 SIG_DEL(new_mask, SIGIOT);
560 SIG_DEL(new_mask, SIGEMT);
563 SIG_DEL(new_mask, SIGTRAP);
565 mask_initialized = TRUE;
567 # ifdef CHECK_SIGNALS
568 if (GC_sig_disabled != 0) ABORT("Nested disables");
571 SIGSETMASK(old_mask,new_mask);
574 void GC_enable_signals()
576 # ifdef CHECK_SIGNALS
577 if (GC_sig_disabled != 1) ABORT("Unmatched enable");
580 SIGSETMASK(dummy,old_mask);
587 /* Ivan Demakov: simplest way (to me) */
589 void GC_disable_signals() { }
590 void GC_enable_signals() { }
593 /* Find the page size */
596 # if defined(MSWIN32) || defined(MSWINCE)
597 void GC_setpagesize()
599 GetSystemInfo(&GC_sysinfo);
600 GC_page_size = GC_sysinfo.dwPageSize;
604 # if defined(MPROTECT_VDB) || defined(PROC_VDB) || defined(USE_MMAP) \
605 || defined(USE_MUNMAP) || defined(FALLBACK_TO_MMAP)
606 void GC_setpagesize()
608 GC_page_size = GETPAGESIZE();
611 /* It's acceptable to fake it. */
612 void GC_setpagesize()
614 GC_page_size = HBLKSIZE;
620 * Find the base of the stack.
621 * Used only in single-threaded environment.
622 * With threads, GC_mark_roots needs to know how to do this.
623 * Called with allocator lock held.
625 # if defined(MSWIN32) || defined(MSWINCE)
626 # define is_writable(prot) ((prot) == PAGE_READWRITE \
627 || (prot) == PAGE_WRITECOPY \
628 || (prot) == PAGE_EXECUTE_READWRITE \
629 || (prot) == PAGE_EXECUTE_WRITECOPY)
630 /* Return the number of bytes that are writable starting at p. */
631 /* The pointer p is assumed to be page aligned. */
632 /* If base is not 0, *base becomes the beginning of the */
633 /* allocation region containing p. */
634 word GC_get_writable_length(ptr_t p, ptr_t *base)
636 MEMORY_BASIC_INFORMATION buf;
640 result = VirtualQuery(p, &buf, sizeof(buf));
641 if (result != sizeof(buf)) ABORT("Weird VirtualQuery result");
642 if (base != 0) *base = (ptr_t)(buf.AllocationBase);
643 protect = (buf.Protect & ~(PAGE_GUARD | PAGE_NOCACHE));
644 if (!is_writable(protect)) {
647 if (buf.State != MEM_COMMIT) return(0);
648 return(buf.RegionSize);
651 ptr_t GC_get_stack_base()
654 ptr_t sp = (ptr_t)(&dummy);
655 ptr_t trunc_sp = (ptr_t)((word)sp & ~(GC_page_size - 1));
656 word size = GC_get_writable_length(trunc_sp, 0);
658 return(trunc_sp + size);
662 # endif /* MS Windows */
665 # include <kernel/OS.h>
666 ptr_t GC_get_stack_base(){
668 get_thread_info(find_thread(NULL),&th);
676 ptr_t GC_get_stack_base()
681 if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
682 GC_err_printf0("DosGetInfoBlocks failed\n");
683 ABORT("DosGetInfoBlocks failed\n");
685 return((ptr_t)(ptib -> tib_pstacklimit));
692 # include "AmigaOS.c"
696 # if defined(NEED_FIND_LIMIT) || defined(UNIX_LIKE)
699 typedef void (*handler)(int);
701 typedef void (*handler)();
704 # if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) \
705 || defined(HURD) || defined(NETBSD) || defined(FREEBSD)
706 static struct sigaction old_segv_act;
707 # if defined(_sigargs) /* !Irix6.x */ || defined(HPUX) \
708 || defined(HURD) || defined(NETBSD) || defined(FREEBSD)
709 static struct sigaction old_bus_act;
712 static handler old_segv_handler, old_bus_handler;
716 void GC_set_and_save_fault_handler(handler h)
718 void GC_set_and_save_fault_handler(h)
722 # if defined(SUNOS5SIGS) || defined(IRIX5) \
723 || defined(OSF1) || defined(HURD) || defined(NETBSD) || defined(FREEBSD)
724 struct sigaction act;
727 # if 0 /* Was necessary for Solaris 2.3 and very temporary */
729 act.sa_flags = SA_RESTART | SA_NODEFER;
731 act.sa_flags = SA_RESTART;
734 (void) sigemptyset(&act.sa_mask);
735 # ifdef GC_IRIX_THREADS
736 /* Older versions have a bug related to retrieving and */
737 /* and setting a handler at the same time. */
738 (void) sigaction(SIGSEGV, 0, &old_segv_act);
739 (void) sigaction(SIGSEGV, &act, 0);
741 (void) sigaction(SIGSEGV, &act, &old_segv_act);
742 # if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \
743 || defined(HPUX) || defined(HURD) || defined(NETBSD) || defined(FREEBSD)
744 /* Under Irix 5.x or HP/UX, we may get SIGBUS. */
745 /* Pthreads doesn't exist under Irix 5.x, so we */
746 /* don't have to worry in the threads case. */
747 (void) sigaction(SIGBUS, &act, &old_bus_act);
749 # endif /* GC_IRIX_THREADS */
751 old_segv_handler = signal(SIGSEGV, h);
753 old_bus_handler = signal(SIGBUS, h);
757 # endif /* NEED_FIND_LIMIT || UNIX_LIKE */
759 # ifdef NEED_FIND_LIMIT
760 /* Some tools to implement HEURISTIC2 */
761 # define MIN_PAGE_SIZE 256 /* Smallest conceivable page size, bytes */
762 /* static */ JMP_BUF GC_jmp_buf;
765 void GC_fault_handler(sig)
768 LONGJMP(GC_jmp_buf, 1);
771 void GC_setup_temporary_fault_handler()
773 GC_set_and_save_fault_handler(GC_fault_handler);
776 void GC_reset_fault_handler()
778 # if defined(SUNOS5SIGS) || defined(IRIX5) \
779 || defined(OSF1) || defined(HURD) || defined(NETBSD) || defined(FREEBSD)
780 (void) sigaction(SIGSEGV, &old_segv_act, 0);
781 # if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \
782 || defined(HPUX) || defined(HURD) || defined(NETBSD) || defined(FREEBSD)
783 (void) sigaction(SIGBUS, &old_bus_act, 0);
786 (void) signal(SIGSEGV, old_segv_handler);
788 (void) signal(SIGBUS, old_bus_handler);
793 /* Return the first nonaddressible location > p (up) or */
794 /* the smallest location q s.t. [q,p) is addressable (!up). */
795 /* We assume that p (up) or p-1 (!up) is addressable. */
796 ptr_t GC_find_limit(p, up)
800 static VOLATILE ptr_t result;
801 /* Needs to be static, since otherwise it may not be */
802 /* preserved across the longjmp. Can safely be */
803 /* static since it's only called once, with the */
804 /* allocation lock held. */
807 GC_setup_temporary_fault_handler();
808 if (SETJMP(GC_jmp_buf) == 0) {
809 result = (ptr_t)(((word)(p))
810 & ~(MIN_PAGE_SIZE-1));
813 result += MIN_PAGE_SIZE;
815 result -= MIN_PAGE_SIZE;
817 GC_noop1((word)(*result));
820 GC_reset_fault_handler();
822 result += MIN_PAGE_SIZE;
828 #if defined(ECOS) || defined(NOSYS)
829 ptr_t GC_get_stack_base()
835 #ifdef HPUX_STACKBOTTOM
837 #include <sys/param.h>
838 #include <sys/pstat.h>
840 ptr_t GC_get_register_stack_base(void)
842 struct pst_vm_status vm_status;
845 while (pstat_getprocvm(&vm_status, sizeof(vm_status), 0, i++) == 1) {
846 if (vm_status.pst_type == PS_RSESTACK) {
847 return (ptr_t) vm_status.pst_vaddr;
851 /* old way to get the register stackbottom */
852 return (ptr_t)(((word)GC_stackbottom - BACKING_STORE_DISPLACEMENT - 1)
853 & ~(BACKING_STORE_ALIGNMENT - 1));
856 #endif /* HPUX_STACK_BOTTOM */
858 #ifdef LINUX_STACKBOTTOM
860 #include <sys/types.h>
861 #include <sys/stat.h>
864 # define STAT_SKIP 27 /* Number of fields preceding startstack */
865 /* field in /proc/self/stat */
867 # pragma weak __libc_stack_end
868 extern ptr_t __libc_stack_end;
871 /* Try to read the backing store base from /proc/self/maps. */
872 /* We look for the writable mapping with a 0 major device, */
873 /* which is as close to our frame as possible, but below it.*/
874 static word backing_store_base_from_maps(char *maps)
877 char *buf_ptr = maps;
879 unsigned int maj_dev;
880 word current_best = 0;
884 buf_ptr = GC_parse_map_entry(buf_ptr, &start, &end, prot_buf, &maj_dev);
885 if (buf_ptr == NULL) return current_best;
886 if (prot_buf[1] == 'w' && maj_dev == 0) {
887 if (end < (word)(&dummy) && start > current_best) current_best = start;
893 static word backing_store_base_from_proc(void)
895 return GC_apply_to_maps(backing_store_base_from_maps);
898 # pragma weak __libc_ia64_register_backing_store_base
899 extern ptr_t __libc_ia64_register_backing_store_base;
901 ptr_t GC_get_register_stack_base(void)
903 if (0 != &__libc_ia64_register_backing_store_base
904 && 0 != __libc_ia64_register_backing_store_base) {
905 /* Glibc 2.2.4 has a bug such that for dynamically linked */
906 /* executables __libc_ia64_register_backing_store_base is */
907 /* defined but uninitialized during constructor calls. */
908 /* Hence we check for both nonzero address and value. */
909 return __libc_ia64_register_backing_store_base;
911 word result = backing_store_base_from_proc();
913 /* Use dumb heuristics. Works only for default configuration. */
914 result = (word)GC_stackbottom - BACKING_STORE_DISPLACEMENT;
915 result += BACKING_STORE_ALIGNMENT - 1;
916 result &= ~(BACKING_STORE_ALIGNMENT - 1);
917 /* Verify that it's at least readable. If not, we goofed. */
918 GC_noop1(*(word *)result);
920 return (ptr_t)result;
925 ptr_t GC_linux_stack_base(void)
927 /* We read the stack base value from /proc/self/stat. We do this */
928 /* using direct I/O system calls in order to avoid calling malloc */
929 /* in case REDIRECT_MALLOC is defined. */
930 # define STAT_BUF_SIZE 4096
931 # define STAT_READ read
932 /* Should probably call the real read, if read is wrapped. */
933 char stat_buf[STAT_BUF_SIZE];
937 size_t i, buf_offset = 0;
939 /* First try the easy way. This should work for glibc 2.2 */
940 /* This fails in a prelinked ("prelink" command) executable */
941 /* since the correct value of __libc_stack_end never */
942 /* becomes visible to us. The second test works around */
944 if (0 != &__libc_stack_end && 0 != __libc_stack_end ) {
946 /* Some versions of glibc set the address 16 bytes too */
947 /* low while the initialization code is running. */
948 if (((word)__libc_stack_end & 0xfff) + 0x10 < 0x1000) {
949 return __libc_stack_end + 0x10;
950 } /* Otherwise it's not safe to add 16 bytes and we fall */
951 /* back to using /proc. */
953 return __libc_stack_end;
956 f = open("/proc/self/stat", O_RDONLY);
957 if (f < 0 || STAT_READ(f, stat_buf, STAT_BUF_SIZE) < 2 * STAT_SKIP) {
958 ABORT("Couldn't read /proc/self/stat");
960 c = stat_buf[buf_offset++];
961 /* Skip the required number of fields. This number is hopefully */
962 /* constant across all Linux implementations. */
963 for (i = 0; i < STAT_SKIP; ++i) {
964 while (isspace(c)) c = stat_buf[buf_offset++];
965 while (!isspace(c)) c = stat_buf[buf_offset++];
967 while (isspace(c)) c = stat_buf[buf_offset++];
971 c = stat_buf[buf_offset++];
974 if (result < 0x10000000) ABORT("Absurd stack bottom value");
975 return (ptr_t)result;
978 #endif /* LINUX_STACKBOTTOM */
980 #ifdef FREEBSD_STACKBOTTOM
982 /* This uses an undocumented sysctl call, but at least one expert */
983 /* believes it will stay. */
986 #include <sys/types.h>
987 #include <sys/sysctl.h>
989 ptr_t GC_freebsd_stack_base(void)
991 int nm[2] = {CTL_KERN, KERN_USRSTACK};
993 size_t len = sizeof(ptr_t);
994 int r = sysctl(nm, 2, &base, &len, NULL, 0);
996 if (r) ABORT("Error getting stack base");
1001 #endif /* FREEBSD_STACKBOTTOM */
1003 #if !defined(BEOS) && !defined(AMIGA) && !defined(MSWIN32) \
1004 && !defined(MSWINCE) && !defined(OS2) && !defined(NOSYS) && !defined(ECOS)
1006 ptr_t GC_get_stack_base()
1008 # if defined(HEURISTIC1) || defined(HEURISTIC2) || \
1009 defined(LINUX_STACKBOTTOM) || defined(FREEBSD_STACKBOTTOM)
1014 # define STACKBOTTOM_ALIGNMENT_M1 ((word)STACK_GRAN - 1)
1017 return(STACKBOTTOM);
1020 # ifdef STACK_GROWS_DOWN
1021 result = (ptr_t)((((word)(&dummy))
1022 + STACKBOTTOM_ALIGNMENT_M1)
1023 & ~STACKBOTTOM_ALIGNMENT_M1);
1025 result = (ptr_t)(((word)(&dummy))
1026 & ~STACKBOTTOM_ALIGNMENT_M1);
1028 # endif /* HEURISTIC1 */
1029 # ifdef LINUX_STACKBOTTOM
1030 result = GC_linux_stack_base();
1032 # ifdef FREEBSD_STACKBOTTOM
1033 result = GC_freebsd_stack_base();
1036 # ifdef STACK_GROWS_DOWN
1037 result = GC_find_limit((ptr_t)(&dummy), TRUE);
1038 # ifdef HEURISTIC2_LIMIT
1039 if (result > HEURISTIC2_LIMIT
1040 && (ptr_t)(&dummy) < HEURISTIC2_LIMIT) {
1041 result = HEURISTIC2_LIMIT;
1045 result = GC_find_limit((ptr_t)(&dummy), FALSE);
1046 # ifdef HEURISTIC2_LIMIT
1047 if (result < HEURISTIC2_LIMIT
1048 && (ptr_t)(&dummy) > HEURISTIC2_LIMIT) {
1049 result = HEURISTIC2_LIMIT;
1054 # endif /* HEURISTIC2 */
1055 # ifdef STACK_GROWS_DOWN
1056 if (result == 0) result = (ptr_t)(signed_word)(-sizeof(ptr_t));
1059 # endif /* STACKBOTTOM */
1062 # endif /* ! AMIGA, !OS 2, ! MS Windows, !BEOS, !NOSYS, !ECOS */
1065 * Register static data segment(s) as roots.
1066 * If more data segments are added later then they need to be registered
1067 * add that point (as we do with SunOS dynamic loading),
1068 * or GC_mark_roots needs to check for them (as we do with PCR).
1069 * Called with allocator lock held.
1074 void GC_register_data_segments()
1078 HMODULE module_handle;
1079 # define PBUFSIZ 512
1080 UCHAR path[PBUFSIZ];
1082 struct exe_hdr hdrdos; /* MSDOS header. */
1083 struct e32_exe hdr386; /* Real header for my executable */
1084 struct o32_obj seg; /* Currrent segment */
1088 if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
1089 GC_err_printf0("DosGetInfoBlocks failed\n");
1090 ABORT("DosGetInfoBlocks failed\n");
1092 module_handle = ppib -> pib_hmte;
1093 if (DosQueryModuleName(module_handle, PBUFSIZ, path) != NO_ERROR) {
1094 GC_err_printf0("DosQueryModuleName failed\n");
1095 ABORT("DosGetInfoBlocks failed\n");
1097 myexefile = fopen(path, "rb");
1098 if (myexefile == 0) {
1099 GC_err_puts("Couldn't open executable ");
1100 GC_err_puts(path); GC_err_puts("\n");
1101 ABORT("Failed to open executable\n");
1103 if (fread((char *)(&hdrdos), 1, sizeof hdrdos, myexefile) < sizeof hdrdos) {
1104 GC_err_puts("Couldn't read MSDOS header from ");
1105 GC_err_puts(path); GC_err_puts("\n");
1106 ABORT("Couldn't read MSDOS header");
1108 if (E_MAGIC(hdrdos) != EMAGIC) {
1109 GC_err_puts("Executable has wrong DOS magic number: ");
1110 GC_err_puts(path); GC_err_puts("\n");
1111 ABORT("Bad DOS magic number");
1113 if (fseek(myexefile, E_LFANEW(hdrdos), SEEK_SET) != 0) {
1114 GC_err_puts("Seek to new header failed in ");
1115 GC_err_puts(path); GC_err_puts("\n");
1116 ABORT("Bad DOS magic number");
1118 if (fread((char *)(&hdr386), 1, sizeof hdr386, myexefile) < sizeof hdr386) {
1119 GC_err_puts("Couldn't read MSDOS header from ");
1120 GC_err_puts(path); GC_err_puts("\n");
1121 ABORT("Couldn't read OS/2 header");
1123 if (E32_MAGIC1(hdr386) != E32MAGIC1 || E32_MAGIC2(hdr386) != E32MAGIC2) {
1124 GC_err_puts("Executable has wrong OS/2 magic number:");
1125 GC_err_puts(path); GC_err_puts("\n");
1126 ABORT("Bad OS/2 magic number");
1128 if ( E32_BORDER(hdr386) != E32LEBO || E32_WORDER(hdr386) != E32LEWO) {
1129 GC_err_puts("Executable %s has wrong byte order: ");
1130 GC_err_puts(path); GC_err_puts("\n");
1131 ABORT("Bad byte order");
1133 if ( E32_CPU(hdr386) == E32CPU286) {
1134 GC_err_puts("GC can't handle 80286 executables: ");
1135 GC_err_puts(path); GC_err_puts("\n");
1138 if (fseek(myexefile, E_LFANEW(hdrdos) + E32_OBJTAB(hdr386),
1140 GC_err_puts("Seek to object table failed: ");
1141 GC_err_puts(path); GC_err_puts("\n");
1142 ABORT("Seek to object table failed");
1144 for (nsegs = E32_OBJCNT(hdr386); nsegs > 0; nsegs--) {
1146 if (fread((char *)(&seg), 1, sizeof seg, myexefile) < sizeof seg) {
1147 GC_err_puts("Couldn't read obj table entry from ");
1148 GC_err_puts(path); GC_err_puts("\n");
1149 ABORT("Couldn't read obj table entry");
1151 flags = O32_FLAGS(seg);
1152 if (!(flags & OBJWRITE)) continue;
1153 if (!(flags & OBJREAD)) continue;
1154 if (flags & OBJINVALID) {
1155 GC_err_printf0("Object with invalid pages?\n");
1158 GC_add_roots_inner(O32_BASE(seg), O32_BASE(seg)+O32_SIZE(seg), FALSE);
1164 # if defined(MSWIN32) || defined(MSWINCE)
1167 /* Unfortunately, we have to handle win32s very differently from NT, */
1168 /* Since VirtualQuery has very different semantics. In particular, */
1169 /* under win32s a VirtualQuery call on an unmapped page returns an */
1170 /* invalid result. Under NT, GC_register_data_segments is a noop and */
1171 /* all real work is done by GC_register_dynamic_libraries. Under */
1172 /* win32s, we cannot find the data segments associated with dll's. */
1173 /* We register the main data segment here. */
1174 GC_bool GC_no_win32_dlls = FALSE;
1175 /* This used to be set for gcc, to avoid dealing with */
1176 /* the structured exception handling issues. But we now have */
1177 /* assembly code to do that right. */
1179 void GC_init_win32()
1181 /* if we're running under win32s, assume that no DLLs will be loaded */
1182 DWORD v = GetVersion();
1183 GC_no_win32_dlls |= ((v & 0x80000000) && (v & 0xff) <= 3);
1186 /* Return the smallest address a such that VirtualQuery */
1187 /* returns correct results for all addresses between a and start. */
1188 /* Assumes VirtualQuery returns correct information for start. */
1189 ptr_t GC_least_described_address(ptr_t start)
1191 MEMORY_BASIC_INFORMATION buf;
1197 limit = GC_sysinfo.lpMinimumApplicationAddress;
1198 p = (ptr_t)((word)start & ~(GC_page_size - 1));
1200 q = (LPVOID)(p - GC_page_size);
1201 if ((ptr_t)q > (ptr_t)p /* underflow */ || q < limit) break;
1202 result = VirtualQuery(q, &buf, sizeof(buf));
1203 if (result != sizeof(buf) || buf.AllocationBase == 0) break;
1204 p = (ptr_t)(buf.AllocationBase);
1210 # ifndef REDIRECT_MALLOC
1211 /* We maintain a linked list of AllocationBase values that we know */
1212 /* correspond to malloc heap sections. Currently this is only called */
1213 /* during a GC. But there is some hope that for long running */
1214 /* programs we will eventually see most heap sections. */
1216 /* In the long run, it would be more reliable to occasionally walk */
1217 /* the malloc heap with HeapWalk on the default heap. But that */
1218 /* apparently works only for NT-based Windows. */
1220 /* In the long run, a better data structure would also be nice ... */
1221 struct GC_malloc_heap_list {
1222 void * allocation_base;
1223 struct GC_malloc_heap_list *next;
1224 } *GC_malloc_heap_l = 0;
1226 /* Is p the base of one of the malloc heap sections we already know */
1228 GC_bool GC_is_malloc_heap_base(ptr_t p)
1230 struct GC_malloc_heap_list *q = GC_malloc_heap_l;
1233 if (q -> allocation_base == p) return TRUE;
1239 void *GC_get_allocation_base(void *p)
1241 MEMORY_BASIC_INFORMATION buf;
1242 DWORD result = VirtualQuery(p, &buf, sizeof(buf));
1243 if (result != sizeof(buf)) {
1244 ABORT("Weird VirtualQuery result");
1246 return buf.AllocationBase;
1249 size_t GC_max_root_size = 100000; /* Appr. largest root size. */
1251 void GC_add_current_malloc_heap()
1253 struct GC_malloc_heap_list *new_l =
1254 malloc(sizeof(struct GC_malloc_heap_list));
1255 void * candidate = GC_get_allocation_base(new_l);
1257 if (new_l == 0) return;
1258 if (GC_is_malloc_heap_base(candidate)) {
1259 /* Try a little harder to find malloc heap. */
1260 size_t req_size = 10000;
1262 void *p = malloc(req_size);
1263 if (0 == p) { free(new_l); return; }
1264 candidate = GC_get_allocation_base(p);
1267 } while (GC_is_malloc_heap_base(candidate)
1268 && req_size < GC_max_root_size/10 && req_size < 500000);
1269 if (GC_is_malloc_heap_base(candidate)) {
1270 free(new_l); return;
1275 GC_printf1("Found new system malloc AllocationBase at 0x%lx\n",
1278 new_l -> allocation_base = candidate;
1279 new_l -> next = GC_malloc_heap_l;
1280 GC_malloc_heap_l = new_l;
1282 # endif /* REDIRECT_MALLOC */
1284 /* Is p the start of either the malloc heap, or of one of our */
1285 /* heap sections? */
1286 GC_bool GC_is_heap_base (ptr_t p)
1291 # ifndef REDIRECT_MALLOC
1292 static word last_gc_no = -1;
1294 if (last_gc_no != GC_gc_no) {
1295 GC_add_current_malloc_heap();
1296 last_gc_no = GC_gc_no;
1298 if (GC_root_size > GC_max_root_size) GC_max_root_size = GC_root_size;
1299 if (GC_is_malloc_heap_base(p)) return TRUE;
1301 for (i = 0; i < GC_n_heap_bases; i++) {
1302 if (GC_heap_bases[i] == p) return TRUE;
1308 void GC_register_root_section(ptr_t static_root)
1310 MEMORY_BASIC_INFORMATION buf;
1315 char * limit, * new_limit;
1317 if (!GC_no_win32_dlls) return;
1318 p = base = limit = GC_least_described_address(static_root);
1319 while (p < GC_sysinfo.lpMaximumApplicationAddress) {
1320 result = VirtualQuery(p, &buf, sizeof(buf));
1321 if (result != sizeof(buf) || buf.AllocationBase == 0
1322 || GC_is_heap_base(buf.AllocationBase)) break;
1323 new_limit = (char *)p + buf.RegionSize;
1324 protect = buf.Protect;
1325 if (buf.State == MEM_COMMIT
1326 && is_writable(protect)) {
1327 if ((char *)p == limit) {
1330 if (base != limit) GC_add_roots_inner(base, limit, FALSE);
1335 if (p > (LPVOID)new_limit /* overflow */) break;
1336 p = (LPVOID)new_limit;
1338 if (base != limit) GC_add_roots_inner(base, limit, FALSE);
1342 void GC_register_data_segments()
1346 GC_register_root_section((ptr_t)(&dummy));
1350 # else /* !OS2 && !Windows */
1352 # if (defined(SVR4) || defined(AUX) || defined(DGUX) \
1353 || (defined(LINUX) && defined(SPARC))) && !defined(PCR)
1354 ptr_t GC_SysVGetDataStart(max_page_size, etext_addr)
1358 word text_end = ((word)(etext_addr) + sizeof(word) - 1)
1359 & ~(sizeof(word) - 1);
1360 /* etext rounded to word boundary */
1361 word next_page = ((text_end + (word)max_page_size - 1)
1362 & ~((word)max_page_size - 1));
1363 word page_offset = (text_end & ((word)max_page_size - 1));
1364 VOLATILE char * result = (char *)(next_page + page_offset);
1365 /* Note that this isnt equivalent to just adding */
1366 /* max_page_size to &etext if &etext is at a page boundary */
1368 GC_setup_temporary_fault_handler();
1369 if (SETJMP(GC_jmp_buf) == 0) {
1370 /* Try writing to the address. */
1372 GC_reset_fault_handler();
1374 GC_reset_fault_handler();
1375 /* We got here via a longjmp. The address is not readable. */
1376 /* This is known to happen under Solaris 2.4 + gcc, which place */
1377 /* string constants in the text segment, but after etext. */
1378 /* Use plan B. Note that we now know there is a gap between */
1379 /* text and data segments, so plan A bought us something. */
1380 result = (char *)GC_find_limit((ptr_t)(DATAEND), FALSE);
1382 return((ptr_t)result);
1386 # if defined(FREEBSD) && defined(I386) && !defined(PCR)
1387 /* Its unclear whether this should be identical to the above, or */
1388 /* whether it should apply to non-X86 architectures. */
1389 /* For now we don't assume that there is always an empty page after */
1390 /* etext. But in some cases there actually seems to be slightly more. */
1391 /* This also deals with holes between read-only data and writable data. */
1392 ptr_t GC_FreeBSDGetDataStart(max_page_size, etext_addr)
1396 word text_end = ((word)(etext_addr) + sizeof(word) - 1)
1397 & ~(sizeof(word) - 1);
1398 /* etext rounded to word boundary */
1399 VOLATILE word next_page = (text_end + (word)max_page_size - 1)
1400 & ~((word)max_page_size - 1);
1401 VOLATILE ptr_t result = (ptr_t)text_end;
1402 GC_setup_temporary_fault_handler();
1403 if (SETJMP(GC_jmp_buf) == 0) {
1404 /* Try reading at the address. */
1405 /* This should happen before there is another thread. */
1406 for (; next_page < (word)(DATAEND); next_page += (word)max_page_size)
1407 *(VOLATILE char *)next_page;
1408 GC_reset_fault_handler();
1410 GC_reset_fault_handler();
1411 /* As above, we go to plan B */
1412 result = GC_find_limit((ptr_t)(DATAEND), FALSE);
1422 # define GC_AMIGA_DS
1423 # include "AmigaOS.c"
1426 #else /* !OS2 && !Windows && !AMIGA */
1428 void GC_register_data_segments()
1430 # if !defined(PCR) && !defined(SRC_M3) && !defined(MACOS)
1431 # if defined(REDIRECT_MALLOC) && defined(GC_SOLARIS_THREADS)
1432 /* As of Solaris 2.3, the Solaris threads implementation */
1433 /* allocates the data structure for the initial thread with */
1434 /* sbrk at process startup. It needs to be scanned, so that */
1435 /* we don't lose some malloc allocated data structures */
1436 /* hanging from it. We're on thin ice here ... */
1437 extern caddr_t sbrk();
1439 GC_add_roots_inner(DATASTART, (char *)sbrk(0), FALSE);
1441 GC_add_roots_inner(DATASTART, (char *)(DATAEND), FALSE);
1442 # if defined(DATASTART2)
1443 GC_add_roots_inner(DATASTART2, (char *)(DATAEND2), FALSE);
1449 # if defined(THINK_C)
1450 extern void* GC_MacGetDataStart(void);
1451 /* globals begin above stack and end at a5. */
1452 GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
1453 (ptr_t)LMGetCurrentA5(), FALSE);
1455 # if defined(__MWERKS__)
1457 extern void* GC_MacGetDataStart(void);
1458 /* MATTHEW: Function to handle Far Globals (CW Pro 3) */
1459 # if __option(far_data)
1460 extern void* GC_MacGetDataEnd(void);
1462 /* globals begin above stack and end at a5. */
1463 GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
1464 (ptr_t)LMGetCurrentA5(), FALSE);
1465 /* MATTHEW: Handle Far Globals */
1466 # if __option(far_data)
1467 /* Far globals follow he QD globals: */
1468 GC_add_roots_inner((ptr_t)LMGetCurrentA5(),
1469 (ptr_t)GC_MacGetDataEnd(), FALSE);
1472 extern char __data_start__[], __data_end__[];
1473 GC_add_roots_inner((ptr_t)&__data_start__,
1474 (ptr_t)&__data_end__, FALSE);
1475 # endif /* __POWERPC__ */
1476 # endif /* __MWERKS__ */
1477 # endif /* !THINK_C */
1481 /* Dynamic libraries are added at every collection, since they may */
1485 # endif /* ! AMIGA */
1486 # endif /* ! MSWIN32 && ! MSWINCE*/
1490 * Auxiliary routines for obtaining memory from OS.
1493 # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) \
1494 && !defined(MSWIN32) && !defined(MSWINCE) \
1495 && !defined(MACOS) && !defined(DOS4GW)
1498 extern caddr_t sbrk();
1501 # define SBRK_ARG_T ptrdiff_t
1503 # define SBRK_ARG_T int
1508 /* The compiler seems to generate speculative reads one past the end of */
1509 /* an allocated object. Hence we need to make sure that the page */
1510 /* following the last heap page is also mapped. */
1511 ptr_t GC_unix_get_mem(bytes)
1514 caddr_t cur_brk = (caddr_t)sbrk(0);
1516 SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1);
1517 static caddr_t my_brk_val = 0;
1519 if ((SBRK_ARG_T)bytes < 0) return(0); /* too big */
1521 if((caddr_t)(sbrk(GC_page_size - lsbs)) == (caddr_t)(-1)) return(0);
1523 if (cur_brk == my_brk_val) {
1524 /* Use the extra block we allocated last time. */
1525 result = (ptr_t)sbrk((SBRK_ARG_T)bytes);
1526 if (result == (caddr_t)(-1)) return(0);
1527 result -= GC_page_size;
1529 result = (ptr_t)sbrk(GC_page_size + (SBRK_ARG_T)bytes);
1530 if (result == (caddr_t)(-1)) return(0);
1532 my_brk_val = result + bytes + GC_page_size; /* Always page aligned */
1533 return((ptr_t)result);
1536 #else /* Not RS6000 */
1538 #if defined(USE_MMAP) || defined(USE_MUNMAP) || defined(FALLBACK_TO_MMAP)
1540 #ifdef USE_MMAP_FIXED
1541 # define GC_MMAP_FLAGS MAP_FIXED | MAP_PRIVATE
1542 /* Seems to yield better performance on Solaris 2, but can */
1543 /* be unreliable if something is already mapped at the address. */
1545 # define GC_MMAP_FLAGS MAP_PRIVATE
1548 #ifdef USE_MMAP_ANON
1550 # if defined(MAP_ANONYMOUS)
1551 # define OPT_MAP_ANON MAP_ANONYMOUS
1553 # define OPT_MAP_ANON MAP_ANON
1557 # define OPT_MAP_ANON 0
1560 #endif /* defined(USE_MMAP) || defined(USE_MUNMAP) */
1562 #if defined(USE_MMAP) || defined(FALLBACK_TO_MMAP)
1563 /* Tested only under Linux, IRIX5 and Solaris 2 */
1566 # define HEAP_START 0
1569 #ifdef FALLBACK_TO_MMAP
1570 static ptr_t GC_unix_get_mem_mmap(bytes)
1572 ptr_t GC_unix_get_mem(bytes)
1577 static ptr_t last_addr = HEAP_START;
1579 # ifndef USE_MMAP_ANON
1580 static GC_bool initialized = FALSE;
1583 zero_fd = open("/dev/zero", O_RDONLY);
1584 fcntl(zero_fd, F_SETFD, FD_CLOEXEC);
1589 if (bytes & (GC_page_size -1)) ABORT("Bad GET_MEM arg");
1590 result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC,
1591 GC_MMAP_FLAGS | OPT_MAP_ANON, zero_fd, 0/* offset */);
1592 if (result == MAP_FAILED) return(0);
1593 last_addr = (ptr_t)result + bytes + GC_page_size - 1;
1594 last_addr = (ptr_t)((word)last_addr & ~(GC_page_size - 1));
1595 # if !defined(LINUX)
1596 if (last_addr == 0) {
1597 /* Oops. We got the end of the address space. This isn't */
1598 /* usable by arbitrary C code, since one-past-end pointers */
1599 /* don't work, so we discard it and try again. */
1600 munmap(result, (size_t)(-GC_page_size) - (size_t)result);
1601 /* Leave last page mapped, so we can't repeat. */
1602 return GC_unix_get_mem(bytes);
1605 GC_ASSERT(last_addr != 0);
1607 return((ptr_t)result);
1614 ptr_t GC_unix_get_mem(bytes)
1619 /* Bare sbrk isn't thread safe. Play by malloc rules. */
1620 /* The equivalent may be needed on other systems as well. */
1624 ptr_t cur_brk = (ptr_t)sbrk(0);
1625 SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1);
1627 if ((SBRK_ARG_T)bytes < 0) return(0); /* too big */
1629 if((ptr_t)sbrk(GC_page_size - lsbs) == (ptr_t)(-1)) return(0);
1631 result = (ptr_t)sbrk((SBRK_ARG_T)bytes);
1632 if (result == (ptr_t)(-1)) {
1633 #ifdef FALLBACK_TO_MMAP
1634 result = GC_unix_get_mem_mmap (bytes);
1646 #endif /* Not USE_MMAP */
1647 #endif /* Not RS6000 */
1653 void * os2_alloc(size_t bytes)
1657 if (DosAllocMem(&result, bytes, PAG_EXECUTE | PAG_READ |
1658 PAG_WRITE | PAG_COMMIT)
1662 if (result == 0) return(os2_alloc(bytes));
1669 # if defined(MSWIN32) || defined(MSWINCE)
1670 SYSTEM_INFO GC_sysinfo;
1675 # ifdef USE_GLOBAL_ALLOC
1676 # define GLOBAL_ALLOC_TEST 1
1678 # define GLOBAL_ALLOC_TEST GC_no_win32_dlls
1681 word GC_n_heap_bases = 0;
1683 ptr_t GC_win32_get_mem(bytes)
1688 if (GLOBAL_ALLOC_TEST) {
1689 /* VirtualAlloc doesn't like PAGE_EXECUTE_READWRITE. */
1690 /* There are also unconfirmed rumors of other */
1691 /* problems, so we dodge the issue. */
1692 result = (ptr_t) GlobalAlloc(0, bytes + HBLKSIZE);
1693 result = (ptr_t)(((word)result + HBLKSIZE) & ~(HBLKSIZE-1));
1695 /* VirtualProtect only works on regions returned by a */
1696 /* single VirtualAlloc call. Thus we allocate one */
1697 /* extra page, which will prevent merging of blocks */
1698 /* in separate regions, and eliminate any temptation */
1699 /* to call VirtualProtect on a range spanning regions. */
1700 /* This wastes a small amount of memory, and risks */
1701 /* increased fragmentation. But better alternatives */
1702 /* would require effort. */
1703 result = (ptr_t) VirtualAlloc(NULL, bytes + 1,
1704 MEM_COMMIT | MEM_RESERVE,
1705 PAGE_EXECUTE_READWRITE);
1707 if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
1708 /* If I read the documentation correctly, this can */
1709 /* only happen if HBLKSIZE > 64k or not a power of 2. */
1710 if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
1711 GC_heap_bases[GC_n_heap_bases++] = result;
1715 void GC_win32_free_heap ()
1717 if (GC_no_win32_dlls) {
1718 while (GC_n_heap_bases > 0) {
1719 GlobalFree (GC_heap_bases[--GC_n_heap_bases]);
1720 GC_heap_bases[GC_n_heap_bases] = 0;
1727 # define GC_AMIGA_AM
1728 # include "AmigaOS.c"
1734 word GC_n_heap_bases = 0;
1736 ptr_t GC_wince_get_mem(bytes)
1742 /* Round up allocation size to multiple of page size */
1743 bytes = (bytes + GC_page_size-1) & ~(GC_page_size-1);
1745 /* Try to find reserved, uncommitted pages */
1746 for (i = 0; i < GC_n_heap_bases; i++) {
1747 if (((word)(-(signed_word)GC_heap_lengths[i])
1748 & (GC_sysinfo.dwAllocationGranularity-1))
1750 result = GC_heap_bases[i] + GC_heap_lengths[i];
1755 if (i == GC_n_heap_bases) {
1756 /* Reserve more pages */
1757 word res_bytes = (bytes + GC_sysinfo.dwAllocationGranularity-1)
1758 & ~(GC_sysinfo.dwAllocationGranularity-1);
1759 /* If we ever support MPROTECT_VDB here, we will probably need to */
1760 /* ensure that res_bytes is strictly > bytes, so that VirtualProtect */
1761 /* never spans regions. It seems to be OK for a VirtualFree argument */
1762 /* to span regions, so we should be OK for now. */
1763 result = (ptr_t) VirtualAlloc(NULL, res_bytes,
1764 MEM_RESERVE | MEM_TOP_DOWN,
1765 PAGE_EXECUTE_READWRITE);
1766 if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
1767 /* If I read the documentation correctly, this can */
1768 /* only happen if HBLKSIZE > 64k or not a power of 2. */
1769 if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
1770 GC_heap_bases[GC_n_heap_bases] = result;
1771 GC_heap_lengths[GC_n_heap_bases] = 0;
1776 result = (ptr_t) VirtualAlloc(result, bytes,
1778 PAGE_EXECUTE_READWRITE);
1779 if (result != NULL) {
1780 if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
1781 GC_heap_lengths[i] += bytes;
1790 /* For now, this only works on Win32/WinCE and some Unix-like */
1791 /* systems. If you have something else, don't define */
1793 /* We assume ANSI C to support this feature. */
1795 #if !defined(MSWIN32) && !defined(MSWINCE)
1798 #include <sys/mman.h>
1799 #include <sys/stat.h>
1800 #include <sys/types.h>
1804 /* Compute a page aligned starting address for the unmap */
1805 /* operation on a block of size bytes starting at start. */
1806 /* Return 0 if the block is too small to make this feasible. */
1807 ptr_t GC_unmap_start(ptr_t start, word bytes)
1809 ptr_t result = start;
1810 /* Round start to next page boundary. */
1811 result += GC_page_size - 1;
1812 result = (ptr_t)((word)result & ~(GC_page_size - 1));
1813 if (result + GC_page_size > start + bytes) return 0;
1817 /* Compute end address for an unmap operation on the indicated */
1819 ptr_t GC_unmap_end(ptr_t start, word bytes)
1821 ptr_t end_addr = start + bytes;
1822 end_addr = (ptr_t)((word)end_addr & ~(GC_page_size - 1));
1826 /* Under Win32/WinCE we commit (map) and decommit (unmap) */
1827 /* memory using VirtualAlloc and VirtualFree. These functions */
1828 /* work on individual allocations of virtual memory, made */
1829 /* previously using VirtualAlloc with the MEM_RESERVE flag. */
1830 /* The ranges we need to (de)commit may span several of these */
1831 /* allocations; therefore we use VirtualQuery to check */
1832 /* allocation lengths, and split up the range as necessary. */
1834 /* We assume that GC_remap is called on exactly the same range */
1835 /* as a previous call to GC_unmap. It is safe to consistently */
1836 /* round the endpoints in both places. */
1837 void GC_unmap(ptr_t start, word bytes)
1839 ptr_t start_addr = GC_unmap_start(start, bytes);
1840 ptr_t end_addr = GC_unmap_end(start, bytes);
1841 word len = end_addr - start_addr;
1842 if (0 == start_addr) return;
1843 # if defined(MSWIN32) || defined(MSWINCE)
1845 MEMORY_BASIC_INFORMATION mem_info;
1847 if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
1848 != sizeof(mem_info))
1849 ABORT("Weird VirtualQuery result");
1850 free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
1851 if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT))
1852 ABORT("VirtualFree failed");
1853 GC_unmapped_bytes += free_len;
1854 start_addr += free_len;
1858 /* We immediately remap it to prevent an intervening mmap from */
1859 /* accidentally grabbing the same address space. */
1862 result = mmap(start_addr, len, PROT_NONE,
1863 MAP_PRIVATE | MAP_FIXED | OPT_MAP_ANON,
1864 zero_fd, 0/* offset */);
1865 if (result != (void *)start_addr) ABORT("mmap(...PROT_NONE...) failed");
1867 GC_unmapped_bytes += len;
1872 void GC_remap(ptr_t start, word bytes)
1874 ptr_t start_addr = GC_unmap_start(start, bytes);
1875 ptr_t end_addr = GC_unmap_end(start, bytes);
1876 word len = end_addr - start_addr;
1878 # if defined(MSWIN32) || defined(MSWINCE)
1881 if (0 == start_addr) return;
1883 MEMORY_BASIC_INFORMATION mem_info;
1885 if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
1886 != sizeof(mem_info))
1887 ABORT("Weird VirtualQuery result");
1888 alloc_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
1889 result = VirtualAlloc(start_addr, alloc_len,
1891 PAGE_EXECUTE_READWRITE);
1892 if (result != start_addr) {
1893 ABORT("VirtualAlloc remapping failed");
1895 GC_unmapped_bytes -= alloc_len;
1896 start_addr += alloc_len;
1900 /* It was already remapped with PROT_NONE. */
1903 if (0 == start_addr) return;
1904 result = mprotect(start_addr, len,
1905 PROT_READ | PROT_WRITE | OPT_PROT_EXEC);
1908 "Mprotect failed at 0x%lx (length %ld) with errno %ld\n",
1909 start_addr, len, errno);
1910 ABORT("Mprotect remapping failed");
1912 GC_unmapped_bytes -= len;
1916 /* Two adjacent blocks have already been unmapped and are about to */
1917 /* be merged. Unmap the whole block. This typically requires */
1918 /* that we unmap a small section in the middle that was not previously */
1919 /* unmapped due to alignment constraints. */
1920 void GC_unmap_gap(ptr_t start1, word bytes1, ptr_t start2, word bytes2)
1922 ptr_t start1_addr = GC_unmap_start(start1, bytes1);
1923 ptr_t end1_addr = GC_unmap_end(start1, bytes1);
1924 ptr_t start2_addr = GC_unmap_start(start2, bytes2);
1925 ptr_t end2_addr = GC_unmap_end(start2, bytes2);
1926 ptr_t start_addr = end1_addr;
1927 ptr_t end_addr = start2_addr;
1929 GC_ASSERT(start1 + bytes1 == start2);
1930 if (0 == start1_addr) start_addr = GC_unmap_start(start1, bytes1 + bytes2);
1931 if (0 == start2_addr) end_addr = GC_unmap_end(start1, bytes1 + bytes2);
1932 if (0 == start_addr) return;
1933 len = end_addr - start_addr;
1934 # if defined(MSWIN32) || defined(MSWINCE)
1936 MEMORY_BASIC_INFORMATION mem_info;
1938 if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
1939 != sizeof(mem_info))
1940 ABORT("Weird VirtualQuery result");
1941 free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
1942 if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT))
1943 ABORT("VirtualFree failed");
1944 GC_unmapped_bytes += free_len;
1945 start_addr += free_len;
1949 if (len != 0 && munmap(start_addr, len) != 0) ABORT("munmap failed");
1950 GC_unmapped_bytes += len;
1954 #endif /* USE_MUNMAP */
1956 /* Routine for pushing any additional roots. In THREADS */
1957 /* environment, this is also responsible for marking from */
1958 /* thread stacks. */
1960 void (*GC_push_other_roots)() = 0;
1964 PCR_ERes GC_push_thread_stack(PCR_Th_T *t, PCR_Any dummy)
1966 struct PCR_ThCtl_TInfoRep info;
1969 info.ti_stkLow = info.ti_stkHi = 0;
1970 result = PCR_ThCtl_GetInfo(t, &info);
1971 GC_push_all_stack((ptr_t)(info.ti_stkLow), (ptr_t)(info.ti_stkHi));
1975 /* Push the contents of an old object. We treat this as stack */
1976 /* data only becasue that makes it robust against mark stack */
1978 PCR_ERes GC_push_old_obj(void *p, size_t size, PCR_Any data)
1980 GC_push_all_stack((ptr_t)p, (ptr_t)p + size);
1981 return(PCR_ERes_okay);
1985 void GC_default_push_other_roots GC_PROTO((void))
1987 /* Traverse data allocated by previous memory managers. */
1989 extern struct PCR_MM_ProcsRep * GC_old_allocator;
1991 if ((*(GC_old_allocator->mmp_enumerate))(PCR_Bool_false,
1994 ABORT("Old object enumeration failed");
1997 /* Traverse all thread stacks. */
1999 PCR_ThCtl_ApplyToAllOtherThreads(GC_push_thread_stack,0))
2000 || PCR_ERes_IsErr(GC_push_thread_stack(PCR_Th_CurrThread(), 0))) {
2001 ABORT("Thread stack marking failed\n");
2009 # ifdef ALL_INTERIOR_POINTERS
2013 void GC_push_thread_structures GC_PROTO((void))
2015 /* Not our responsibibility. */
2018 extern void ThreadF__ProcessStacks();
2020 void GC_push_thread_stack(start, stop)
2023 GC_push_all_stack((ptr_t)start, (ptr_t)stop + sizeof(word));
2026 /* Push routine with M3 specific calling convention. */
2027 GC_m3_push_root(dummy1, p, dummy2, dummy3)
2029 ptr_t dummy1, dummy2;
2034 GC_PUSH_ONE_STACK(q, p);
2037 /* M3 set equivalent to RTHeap.TracedRefTypes */
2038 typedef struct { int elts[1]; } RefTypeSet;
2039 RefTypeSet GC_TracedRefTypes = {{0x1}};
2041 void GC_default_push_other_roots GC_PROTO((void))
2043 /* Use the M3 provided routine for finding static roots. */
2044 /* This is a bit dubious, since it presumes no C roots. */
2045 /* We handle the collector roots explicitly in GC_push_roots */
2046 RTMain__GlobalMapProc(GC_m3_push_root, 0, GC_TracedRefTypes);
2047 if (GC_words_allocd > 0) {
2048 ThreadF__ProcessStacks(GC_push_thread_stack);
2050 /* Otherwise this isn't absolutely necessary, and we have */
2051 /* startup ordering problems. */
2054 # endif /* SRC_M3 */
2056 # if defined(GC_SOLARIS_THREADS) || defined(GC_PTHREADS) || \
2057 defined(GC_WIN32_THREADS)
2059 extern void GC_push_all_stacks();
2061 void GC_default_push_other_roots GC_PROTO((void))
2063 GC_push_all_stacks();
2066 # endif /* GC_SOLARIS_THREADS || GC_PTHREADS */
2068 void (*GC_push_other_roots) GC_PROTO((void)) = GC_default_push_other_roots;
2070 #endif /* THREADS */
2073 * Routines for accessing dirty bits on virtual pages.
2074 * We plan to eventually implement four strategies for doing so:
2075 * DEFAULT_VDB: A simple dummy implementation that treats every page
2076 * as possibly dirty. This makes incremental collection
2077 * useless, but the implementation is still correct.
2078 * PCR_VDB: Use PPCRs virtual dirty bit facility.
2079 * PROC_VDB: Use the /proc facility for reading dirty bits. Only
2080 * works under some SVR4 variants. Even then, it may be
2081 * too slow to be entirely satisfactory. Requires reading
2082 * dirty bits for entire address space. Implementations tend
2083 * to assume that the client is a (slow) debugger.
2084 * MPROTECT_VDB:Protect pages and then catch the faults to keep track of
2085 * dirtied pages. The implementation (and implementability)
2086 * is highly system dependent. This usually fails when system
2087 * calls write to a protected page. We prevent the read system
2088 * call from doing so. It is the clients responsibility to
2089 * make sure that other system calls are similarly protected
2090 * or write only to the stack.
2092 GC_bool GC_dirty_maintained = FALSE;
2096 /* All of the following assume the allocation lock is held, and */
2097 /* signals are disabled. */
2099 /* The client asserts that unallocated pages in the heap are never */
2102 /* Initialize virtual dirty bit implementation. */
2103 void GC_dirty_init()
2106 GC_printf0("Initializing DEFAULT_VDB...\n");
2108 GC_dirty_maintained = TRUE;
2111 /* Retrieve system dirty bits for heap to a local buffer. */
2112 /* Restore the systems notion of which pages are dirty. */
2113 void GC_read_dirty()
2116 /* Is the HBLKSIZE sized page at h marked dirty in the local buffer? */
2117 /* If the actual page size is different, this returns TRUE if any */
2118 /* of the pages overlapping h are dirty. This routine may err on the */
2119 /* side of labelling pages as dirty (and this implementation does). */
2121 GC_bool GC_page_was_dirty(h)
2128 * The following two routines are typically less crucial. They matter
2129 * most with large dynamic libraries, or if we can't accurately identify
2130 * stacks, e.g. under Solaris 2.X. Otherwise the following default
2131 * versions are adequate.
2134 /* Could any valid GC heap pointer ever have been written to this page? */
2136 GC_bool GC_page_was_ever_dirty(h)
2142 /* Reset the n pages starting at h to "was never dirty" status. */
2143 void GC_is_fresh(h, n)
2150 /* I) hints that [h, h+nblocks) is about to be written. */
2151 /* II) guarantees that protection is removed. */
2152 /* (I) may speed up some dirty bit implementations. */
2153 /* (II) may be essential if we need to ensure that */
2154 /* pointer-free system call buffers in the heap are */
2155 /* not protected. */
2157 void GC_remove_protection(h, nblocks, is_ptrfree)
2164 # endif /* DEFAULT_VDB */
2167 # ifdef MPROTECT_VDB
2170 * See DEFAULT_VDB for interface descriptions.
2174 * This implementation maintains dirty bits itself by catching write
2175 * faults and keeping track of them. We assume nobody else catches
2176 * SIGBUS or SIGSEGV. We assume no write faults occur in system calls.
2177 * This means that clients must ensure that system calls don't write
2178 * to the write-protected heap. Probably the best way to do this is to
2179 * ensure that system calls write at most to POINTERFREE objects in the
2180 * heap, and do even that only if we are on a platform on which those
2181 * are not protected. Another alternative is to wrap system calls
2182 * (see example for read below), but the current implementation holds
2183 * a lock across blocking calls, making it problematic for multithreaded
2185 * We assume the page size is a multiple of HBLKSIZE.
2186 * We prefer them to be the same. We avoid protecting POINTERFREE
2187 * objects only if they are the same.
2190 # if !defined(MSWIN32) && !defined(MSWINCE) && !defined(DARWIN)
2192 # include <sys/mman.h>
2193 # include <signal.h>
2194 # include <sys/syscall.h>
2196 # define PROTECT(addr, len) \
2197 if (mprotect((caddr_t)(addr), (size_t)(len), \
2198 PROT_READ | OPT_PROT_EXEC) < 0) { \
2199 ABORT("mprotect failed"); \
2201 # define UNPROTECT(addr, len) \
2202 if (mprotect((caddr_t)(addr), (size_t)(len), \
2203 PROT_WRITE | PROT_READ | OPT_PROT_EXEC ) < 0) { \
2204 ABORT("un-mprotect failed"); \
2210 /* Using vm_protect (mach syscall) over mprotect (BSD syscall) seems to
2211 decrease the likelihood of some of the problems described below. */
2212 #include <mach/vm_map.h>
2213 static mach_port_t GC_task_self;
2214 #define PROTECT(addr,len) \
2215 if(vm_protect(GC_task_self,(vm_address_t)(addr),(vm_size_t)(len), \
2216 FALSE,VM_PROT_READ) != KERN_SUCCESS) { \
2217 ABORT("vm_portect failed"); \
2219 #define UNPROTECT(addr,len) \
2220 if(vm_protect(GC_task_self,(vm_address_t)(addr),(vm_size_t)(len), \
2221 FALSE,VM_PROT_READ|VM_PROT_WRITE) != KERN_SUCCESS) { \
2222 ABORT("vm_portect failed"); \
2227 # include <signal.h>
2230 static DWORD protect_junk;
2231 # define PROTECT(addr, len) \
2232 if (!VirtualProtect((addr), (len), PAGE_EXECUTE_READ, \
2234 DWORD last_error = GetLastError(); \
2235 GC_printf1("Last error code: %lx\n", last_error); \
2236 ABORT("VirtualProtect failed"); \
2238 # define UNPROTECT(addr, len) \
2239 if (!VirtualProtect((addr), (len), PAGE_EXECUTE_READWRITE, \
2241 ABORT("un-VirtualProtect failed"); \
2243 # endif /* !DARWIN */
2244 # endif /* MSWIN32 || MSWINCE || DARWIN */
2246 #if defined(SUNOS4) || (defined(FREEBSD) && !defined(SUNOS5SIGS))
2247 typedef void (* SIG_PF)();
2248 #endif /* SUNOS4 || (FREEBSD && !SUNOS5SIGS) */
2250 #if defined(SUNOS5SIGS) || defined(OSF1) || defined(LINUX) \
2253 typedef void (* SIG_PF)(int);
2255 typedef void (* SIG_PF)();
2257 #endif /* SUNOS5SIGS || OSF1 || LINUX || HURD */
2259 #if defined(MSWIN32)
2260 typedef LPTOP_LEVEL_EXCEPTION_FILTER SIG_PF;
2262 # define SIG_DFL (LPTOP_LEVEL_EXCEPTION_FILTER) (-1)
2264 #if defined(MSWINCE)
2265 typedef LONG (WINAPI *SIG_PF)(struct _EXCEPTION_POINTERS *);
2267 # define SIG_DFL (SIG_PF) (-1)
2270 #if defined(IRIX5) || defined(OSF1) || defined(HURD)
2271 typedef void (* REAL_SIG_PF)(int, int, struct sigcontext *);
2272 #endif /* IRIX5 || OSF1 || HURD */
2274 #if defined(SUNOS5SIGS)
2275 # if defined(HPUX) || defined(FREEBSD)
2276 # define SIGINFO_T siginfo_t
2278 # define SIGINFO_T struct siginfo
2281 typedef void (* REAL_SIG_PF)(int, SIGINFO_T *, void *);
2283 typedef void (* REAL_SIG_PF)();
2285 #endif /* SUNOS5SIGS */
2288 # if __GLIBC__ > 2 || __GLIBC__ == 2 && __GLIBC_MINOR__ >= 2
2289 typedef struct sigcontext s_c;
2290 # else /* glibc < 2.2 */
2291 # include <linux/version.h>
2292 # if (LINUX_VERSION_CODE >= 0x20100) && !defined(M68K) || defined(ALPHA) || defined(ARM32)
2293 typedef struct sigcontext s_c;
2295 typedef struct sigcontext_struct s_c;
2297 # endif /* glibc < 2.2 */
2298 # if defined(ALPHA) || defined(M68K)
2299 typedef void (* REAL_SIG_PF)(int, int, s_c *);
2301 # if defined(IA64) || defined(HP_PA)
2302 typedef void (* REAL_SIG_PF)(int, siginfo_t *, s_c *);
2304 typedef void (* REAL_SIG_PF)(int, s_c);
2308 /* Retrieve fault address from sigcontext structure by decoding */
2310 char * get_fault_addr(s_c *sc) {
2314 instr = *((unsigned *)(sc->sc_pc));
2315 faultaddr = sc->sc_regs[(instr >> 16) & 0x1f];
2316 faultaddr += (word) (((int)instr << 16) >> 16);
2317 return (char *)faultaddr;
2319 # endif /* !ALPHA */
2323 SIG_PF GC_old_bus_handler;
2324 SIG_PF GC_old_segv_handler; /* Also old MSWIN32 ACCESS_VIOLATION filter */
2325 #endif /* !DARWIN */
2327 #if defined(THREADS)
2328 /* We need to lock around the bitmap update in the write fault handler */
2329 /* in order to avoid the risk of losing a bit. We do this with a */
2330 /* test-and-set spin lock if we know how to do that. Otherwise we */
2331 /* check whether we are already in the handler and use the dumb but */
2332 /* safe fallback algorithm of setting all bits in the word. */
2333 /* Contention should be very rare, so we do the minimum to handle it */
2335 #ifdef GC_TEST_AND_SET_DEFINED
2336 static VOLATILE unsigned int fault_handler_lock = 0;
2337 void async_set_pht_entry_from_index(VOLATILE page_hash_table db, int index) {
2338 while (GC_test_and_set(&fault_handler_lock)) {}
2339 /* Could also revert to set_pht_entry_from_index_safe if initial */
2340 /* GC_test_and_set fails. */
2341 set_pht_entry_from_index(db, index);
2342 GC_clear(&fault_handler_lock);
2344 #else /* !GC_TEST_AND_SET_DEFINED */
2345 /* THIS IS INCORRECT! The dirty bit vector may be temporarily wrong, */
2346 /* just before we notice the conflict and correct it. We may end up */
2347 /* looking at it while it's wrong. But this requires contention */
2348 /* exactly when a GC is triggered, which seems far less likely to */
2349 /* fail than the old code, which had no reported failures. Thus we */
2350 /* leave it this way while we think of something better, or support */
2351 /* GC_test_and_set on the remaining platforms. */
2352 static VOLATILE word currently_updating = 0;
2353 void async_set_pht_entry_from_index(VOLATILE page_hash_table db, int index) {
2354 unsigned int update_dummy;
2355 currently_updating = (word)(&update_dummy);
2356 set_pht_entry_from_index(db, index);
2357 /* If we get contention in the 10 or so instruction window here, */
2358 /* and we get stopped by a GC between the two updates, we lose! */
2359 if (currently_updating != (word)(&update_dummy)) {
2360 set_pht_entry_from_index_safe(db, index);
2361 /* We claim that if two threads concurrently try to update the */
2362 /* dirty bit vector, the first one to execute UPDATE_START */
2363 /* will see it changed when UPDATE_END is executed. (Note that */
2364 /* &update_dummy must differ in two distinct threads.) It */
2365 /* will then execute set_pht_entry_from_index_safe, thus */
2366 /* returning us to a safe state, though not soon enough. */
2369 #endif /* !GC_TEST_AND_SET_DEFINED */
2370 #else /* !THREADS */
2371 # define async_set_pht_entry_from_index(db, index) \
2372 set_pht_entry_from_index(db, index)
2373 #endif /* !THREADS */
2376 #if !defined(DARWIN)
2377 # if defined (SUNOS4) || (defined(FREEBSD) && !defined(SUNOS5SIGS))
2378 void GC_write_fault_handler(sig, code, scp, addr)
2380 struct sigcontext *scp;
2383 # define SIG_OK (sig == SIGSEGV || sig == SIGBUS)
2384 # define CODE_OK (FC_CODE(code) == FC_PROT \
2385 || (FC_CODE(code) == FC_OBJERR \
2386 && FC_ERRNO(code) == FC_PROT))
2389 # define SIG_OK (sig == SIGBUS)
2390 # define CODE_OK (code == BUS_PAGE_FAULT)
2392 # endif /* SUNOS4 || (FREEBSD && !SUNOS5SIGS) */
2394 # if defined(IRIX5) || defined(OSF1) || defined(HURD)
2396 void GC_write_fault_handler(int sig, int code, struct sigcontext *scp)
2398 # define SIG_OK (sig == SIGSEGV)
2399 # define CODE_OK (code == 2 /* experimentally determined */)
2402 # define SIG_OK (sig == SIGSEGV)
2403 # define CODE_OK (code == EACCES)
2406 # define SIG_OK (sig == SIGBUS || sig == SIGSEGV)
2407 # define CODE_OK TRUE
2409 # endif /* IRIX5 || OSF1 || HURD */
2412 # if defined(ALPHA) || defined(M68K)
2413 void GC_write_fault_handler(int sig, int code, s_c * sc)
2415 # if defined(IA64) || defined(HP_PA)
2416 void GC_write_fault_handler(int sig, siginfo_t * si, s_c * scp)
2419 void GC_write_fault_handler(int sig, int a2, int a3, int a4, s_c sc)
2421 void GC_write_fault_handler(int sig, s_c sc)
2425 # define SIG_OK (sig == SIGSEGV)
2426 # define CODE_OK TRUE
2427 /* Empirically c.trapno == 14, on IA32, but is that useful? */
2428 /* Should probably consider alignment issues on other */
2429 /* architectures. */
2432 # if defined(SUNOS5SIGS)
2434 void GC_write_fault_handler(int sig, SIGINFO_T *scp, void * context)
2436 void GC_write_fault_handler(sig, scp, context)
2442 # define SIG_OK (sig == SIGSEGV || sig == SIGBUS)
2443 # define CODE_OK (scp -> si_code == SEGV_ACCERR) \
2444 || (scp -> si_code == BUS_ADRERR) \
2445 || (scp -> si_code == BUS_UNKNOWN) \
2446 || (scp -> si_code == SEGV_UNKNOWN) \
2447 || (scp -> si_code == BUS_OBJERR)
2450 # define SIG_OK (sig == SIGBUS)
2451 # define CODE_OK (scp -> si_code == BUS_PAGE_FAULT)
2453 # define SIG_OK (sig == SIGSEGV)
2454 # define CODE_OK (scp -> si_code == SEGV_ACCERR)
2457 # endif /* SUNOS5SIGS */
2459 # if defined(MSWIN32) || defined(MSWINCE)
2460 LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info)
2461 # define SIG_OK (exc_info -> ExceptionRecord -> ExceptionCode == \
2462 STATUS_ACCESS_VIOLATION)
2463 # define CODE_OK (exc_info -> ExceptionRecord -> ExceptionInformation[0] == 1)
2465 # endif /* MSWIN32 || MSWINCE */
2467 register unsigned i;
2469 char *addr = (char *) code;
2472 char * addr = (char *) (size_t) (scp -> sc_badvaddr);
2474 # if defined(OSF1) && defined(ALPHA)
2475 char * addr = (char *) (scp -> sc_traparg_a0);
2478 char * addr = (char *) (scp -> si_addr);
2481 # if defined(I386) || defined (X86_64)
2482 char * addr = (char *) (sc.cr2);
2487 struct sigcontext *scp = (struct sigcontext *)(sc);
2489 int format = (scp->sc_formatvec >> 12) & 0xf;
2490 unsigned long *framedata = (unsigned long *)(scp + 1);
2493 if (format == 0xa || format == 0xb) {
2496 } else if (format == 7) {
2499 if (framedata[1] & 0x08000000) {
2500 /* correct addr on misaligned access */
2501 ea = (ea+4095)&(~4095);
2503 } else if (format == 4) {
2506 if (framedata[1] & 0x08000000) {
2507 /* correct addr on misaligned access */
2508 ea = (ea+4095)&(~4095);
2514 char * addr = get_fault_addr(sc);
2516 # if defined(IA64) || defined(HP_PA)
2517 char * addr = si -> si_addr;
2518 /* I believe this is claimed to work on all platforms for */
2519 /* Linux 2.3.47 and later. Hopefully we don't have to */
2520 /* worry about earlier kernels on IA64. */
2522 # if defined(POWERPC)
2523 char * addr = (char *) (sc.regs->dar);
2526 char * addr = (char *)sc.fault_address;
2528 --> architecture not supported
2536 # if defined(MSWIN32) || defined(MSWINCE)
2537 char * addr = (char *) (exc_info -> ExceptionRecord
2538 -> ExceptionInformation[1]);
2539 # define sig SIGSEGV
2542 if (SIG_OK && CODE_OK) {
2543 register struct hblk * h =
2544 (struct hblk *)((word)addr & ~(GC_page_size-1));
2545 GC_bool in_allocd_block;
2548 /* Address is only within the correct physical page. */
2549 in_allocd_block = FALSE;
2550 for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
2551 if (HDR(h+i) != 0) {
2552 in_allocd_block = TRUE;
2556 in_allocd_block = (HDR(addr) != 0);
2558 if (!in_allocd_block) {
2559 /* FIXME - We should make sure that we invoke the */
2560 /* old handler with the appropriate calling */
2561 /* sequence, which often depends on SA_SIGINFO. */
2563 /* Heap blocks now begin and end on page boundaries */
2566 if (sig == SIGSEGV) {
2567 old_handler = GC_old_segv_handler;
2569 old_handler = GC_old_bus_handler;
2571 if (old_handler == SIG_DFL) {
2572 # if !defined(MSWIN32) && !defined(MSWINCE)
2573 GC_err_printf1("Segfault at 0x%lx\n", addr);
2574 ABORT("Unexpected bus error or segmentation fault");
2576 return(EXCEPTION_CONTINUE_SEARCH);
2579 # if defined (SUNOS4) \
2580 || (defined(FREEBSD) && !defined(SUNOS5SIGS))
2581 (*old_handler) (sig, code, scp, addr);
2584 # if defined (SUNOS5SIGS)
2586 * FIXME: For FreeBSD, this code should check if the
2587 * old signal handler used the traditional BSD style and
2588 * if so call it using that style.
2590 (*(REAL_SIG_PF)old_handler) (sig, scp, context);
2593 # if defined (LINUX)
2594 # if defined(ALPHA) || defined(M68K)
2595 (*(REAL_SIG_PF)old_handler) (sig, code, sc);
2597 # if defined(IA64) || defined(HP_PA)
2598 (*(REAL_SIG_PF)old_handler) (sig, si, scp);
2600 (*(REAL_SIG_PF)old_handler) (sig, sc);
2605 # if defined (IRIX5) || defined(OSF1) || defined(HURD)
2606 (*(REAL_SIG_PF)old_handler) (sig, code, scp);
2610 return((*old_handler)(exc_info));
2614 UNPROTECT(h, GC_page_size);
2615 /* We need to make sure that no collection occurs between */
2616 /* the UNPROTECT and the setting of the dirty bit. Otherwise */
2617 /* a write by a third thread might go unnoticed. Reversing */
2618 /* the order is just as bad, since we would end up unprotecting */
2619 /* a page in a GC cycle during which it's not marked. */
2620 /* Currently we do this by disabling the thread stopping */
2621 /* signals while this handler is running. An alternative might */
2622 /* be to record the fact that we're about to unprotect, or */
2623 /* have just unprotected a page in the GC's thread structure, */
2624 /* and then to have the thread stopping code set the dirty */
2625 /* flag, if necessary. */
2626 for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
2627 register int index = PHT_HASH(h+i);
2629 async_set_pht_entry_from_index(GC_dirty_pages, index);
2632 /* These reset the signal handler each time by default. */
2633 signal(SIGSEGV, (SIG_PF) GC_write_fault_handler);
2635 /* The write may not take place before dirty bits are read. */
2636 /* But then we'll fault again ... */
2637 # if defined(MSWIN32) || defined(MSWINCE)
2638 return(EXCEPTION_CONTINUE_EXECUTION);
2643 #if defined(MSWIN32) || defined(MSWINCE)
2644 return EXCEPTION_CONTINUE_SEARCH;
2646 GC_err_printf1("Segfault at 0x%lx\n", addr);
2647 ABORT("Unexpected bus error or segmentation fault");
2650 #endif /* !DARWIN */
2653 * We hold the allocation lock. We expect block h to be written
2654 * shortly. Ensure that all pages containing any part of the n hblks
2655 * starting at h are no longer protected. If is_ptrfree is false,
2656 * also ensure that they will subsequently appear to be dirty.
2658 void GC_remove_protection(h, nblocks, is_ptrfree)
2663 struct hblk * h_trunc; /* Truncated to page boundary */
2664 struct hblk * h_end; /* Page boundary following block end */
2665 struct hblk * current;
2666 GC_bool found_clean;
2668 if (!GC_dirty_maintained) return;
2669 h_trunc = (struct hblk *)((word)h & ~(GC_page_size-1));
2670 h_end = (struct hblk *)(((word)(h + nblocks) + GC_page_size-1)
2671 & ~(GC_page_size-1));
2672 found_clean = FALSE;
2673 for (current = h_trunc; current < h_end; ++current) {
2674 int index = PHT_HASH(current);
2676 if (!is_ptrfree || current < h || current >= h + nblocks) {
2677 async_set_pht_entry_from_index(GC_dirty_pages, index);
2680 UNPROTECT(h_trunc, (ptr_t)h_end - (ptr_t)h_trunc);
2683 #if !defined(DARWIN)
2684 void GC_dirty_init()
2686 # if defined(SUNOS5SIGS) || defined(IRIX5) || defined(LINUX) || \
2687 defined(OSF1) || defined(HURD)
2688 struct sigaction act, oldact;
2689 /* We should probably specify SA_SIGINFO for Linux, and handle */
2690 /* the different architectures more uniformly. */
2691 # if defined(IRIX5) || defined(LINUX) || defined(OSF1) || defined(HURD)
2692 act.sa_flags = SA_RESTART;
2693 act.sa_handler = (SIG_PF)GC_write_fault_handler;
2695 act.sa_flags = SA_RESTART | SA_SIGINFO;
2696 act.sa_sigaction = GC_write_fault_handler;
2698 (void)sigemptyset(&act.sa_mask);
2700 /* Arrange to postpone SIG_SUSPEND while we're in a write fault */
2701 /* handler. This effectively makes the handler atomic w.r.t. */
2702 /* stopping the world for GC. */
2703 (void)sigaddset(&act.sa_mask, SIG_SUSPEND);
2704 # endif /* SIG_SUSPEND */
2707 GC_printf0("Inititalizing mprotect virtual dirty bit implementation\n");
2709 GC_dirty_maintained = TRUE;
2710 if (GC_page_size % HBLKSIZE != 0) {
2711 GC_err_printf0("Page size not multiple of HBLKSIZE\n");
2712 ABORT("Page size not multiple of HBLKSIZE");
2714 # if defined(SUNOS4) || (defined(FREEBSD) && !defined(SUNOS5SIGS))
2715 GC_old_bus_handler = signal(SIGBUS, GC_write_fault_handler);
2716 if (GC_old_bus_handler == SIG_IGN) {
2717 GC_err_printf0("Previously ignored bus error!?");
2718 GC_old_bus_handler = SIG_DFL;
2720 if (GC_old_bus_handler != SIG_DFL) {
2722 GC_err_printf0("Replaced other SIGBUS handler\n");
2726 # if defined(SUNOS4)
2727 GC_old_segv_handler = signal(SIGSEGV, (SIG_PF)GC_write_fault_handler);
2728 if (GC_old_segv_handler == SIG_IGN) {
2729 GC_err_printf0("Previously ignored segmentation violation!?");
2730 GC_old_segv_handler = SIG_DFL;
2732 if (GC_old_segv_handler != SIG_DFL) {
2734 GC_err_printf0("Replaced other SIGSEGV handler\n");
2738 # if (defined(SUNOS5SIGS) && !defined(FREEBSD)) || defined(IRIX5) \
2739 || defined(LINUX) || defined(OSF1) || defined(HURD)
2740 /* SUNOS5SIGS includes HPUX */
2741 # if defined(GC_IRIX_THREADS)
2742 sigaction(SIGSEGV, 0, &oldact);
2743 sigaction(SIGSEGV, &act, 0);
2746 int res = sigaction(SIGSEGV, &act, &oldact);
2747 if (res != 0) ABORT("Sigaction failed");
2750 # if defined(_sigargs) || defined(HURD) || !defined(SA_SIGINFO)
2751 /* This is Irix 5.x, not 6.x. Irix 5.x does not have */
2753 GC_old_segv_handler = oldact.sa_handler;
2754 # else /* Irix 6.x or SUNOS5SIGS or LINUX */
2755 if (oldact.sa_flags & SA_SIGINFO) {
2756 GC_old_segv_handler = (SIG_PF)(oldact.sa_sigaction);
2758 GC_old_segv_handler = oldact.sa_handler;
2761 if (GC_old_segv_handler == SIG_IGN) {
2762 GC_err_printf0("Previously ignored segmentation violation!?");
2763 GC_old_segv_handler = SIG_DFL;
2765 if (GC_old_segv_handler != SIG_DFL) {
2767 GC_err_printf0("Replaced other SIGSEGV handler\n");
2770 # endif /* (SUNOS5SIGS && !FREEBSD) || IRIX5 || LINUX || OSF1 || HURD */
2771 # if defined(HPUX) || defined(LINUX) || defined(HURD) \
2772 || (defined(FREEBSD) && defined(SUNOS5SIGS))
2773 sigaction(SIGBUS, &act, &oldact);
2774 GC_old_bus_handler = oldact.sa_handler;
2775 if (GC_old_bus_handler == SIG_IGN) {
2776 GC_err_printf0("Previously ignored bus error!?");
2777 GC_old_bus_handler = SIG_DFL;
2779 if (GC_old_bus_handler != SIG_DFL) {
2781 GC_err_printf0("Replaced other SIGBUS handler\n");
2784 # endif /* HPUX || LINUX || HURD || (FREEBSD && SUNOS5SIGS) */
2785 # if defined(MSWIN32)
2786 GC_old_segv_handler = SetUnhandledExceptionFilter(GC_write_fault_handler);
2787 if (GC_old_segv_handler != NULL) {
2789 GC_err_printf0("Replaced other UnhandledExceptionFilter\n");
2792 GC_old_segv_handler = SIG_DFL;
2796 #endif /* !DARWIN */
2798 int GC_incremental_protection_needs()
2800 if (GC_page_size == HBLKSIZE) {
2801 return GC_PROTECTS_POINTER_HEAP;
2803 return GC_PROTECTS_POINTER_HEAP | GC_PROTECTS_PTRFREE_HEAP;
2807 #define HAVE_INCREMENTAL_PROTECTION_NEEDS
2809 #define IS_PTRFREE(hhdr) ((hhdr)->hb_descr == 0)
2811 #define PAGE_ALIGNED(x) !((word)(x) & (GC_page_size - 1))
2812 void GC_protect_heap()
2816 struct hblk * current;
2817 struct hblk * current_start; /* Start of block to be protected. */
2818 struct hblk * limit;
2820 GC_bool protect_all =
2821 (0 != (GC_incremental_protection_needs() & GC_PROTECTS_PTRFREE_HEAP));
2822 for (i = 0; i < GC_n_heap_sects; i++) {
2823 start = GC_heap_sects[i].hs_start;
2824 len = GC_heap_sects[i].hs_bytes;
2826 PROTECT(start, len);
2828 GC_ASSERT(PAGE_ALIGNED(len))
2829 GC_ASSERT(PAGE_ALIGNED(start))
2830 current_start = current = (struct hblk *)start;
2831 limit = (struct hblk *)(start + len);
2832 while (current < limit) {
2837 GC_ASSERT(PAGE_ALIGNED(current));
2838 GET_HDR(current, hhdr);
2839 if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
2840 /* This can happen only if we're at the beginning of a */
2841 /* heap segment, and a block spans heap segments. */
2842 /* We will handle that block as part of the preceding */
2844 GC_ASSERT(current_start == current);
2845 current_start = ++current;
2848 if (HBLK_IS_FREE(hhdr)) {
2849 GC_ASSERT(PAGE_ALIGNED(hhdr -> hb_sz));
2850 nhblks = divHBLKSZ(hhdr -> hb_sz);
2851 is_ptrfree = TRUE; /* dirty on alloc */
2853 nhblks = OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz);
2854 is_ptrfree = IS_PTRFREE(hhdr);
2857 if (current_start < current) {
2858 PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
2860 current_start = (current += nhblks);
2865 if (current_start < current) {
2866 PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
2872 /* We assume that either the world is stopped or its OK to lose dirty */
2873 /* bits while this is happenning (as in GC_enable_incremental). */
2874 void GC_read_dirty()
2876 BCOPY((word *)GC_dirty_pages, GC_grungy_pages,
2877 (sizeof GC_dirty_pages));
2878 BZERO((word *)GC_dirty_pages, (sizeof GC_dirty_pages));
2882 GC_bool GC_page_was_dirty(h)
2885 register word index = PHT_HASH(h);
2887 return(HDR(h) == 0 || get_pht_entry_from_index(GC_grungy_pages, index));
2891 * Acquiring the allocation lock here is dangerous, since this
2892 * can be called from within GC_call_with_alloc_lock, and the cord
2893 * package does so. On systems that allow nested lock acquisition, this
2895 * On other systems, SET_LOCK_HOLDER and friends must be suitably defined.
2898 static GC_bool syscall_acquired_lock = FALSE; /* Protected by GC lock. */
2900 void GC_begin_syscall()
2902 if (!I_HOLD_LOCK()) {
2904 syscall_acquired_lock = TRUE;
2908 void GC_end_syscall()
2910 if (syscall_acquired_lock) {
2911 syscall_acquired_lock = FALSE;
2916 void GC_unprotect_range(addr, len)
2920 struct hblk * start_block;
2921 struct hblk * end_block;
2922 register struct hblk *h;
2925 if (!GC_dirty_maintained) return;
2926 obj_start = GC_base(addr);
2927 if (obj_start == 0) return;
2928 if (GC_base(addr + len - 1) != obj_start) {
2929 ABORT("GC_unprotect_range(range bigger than object)");
2931 start_block = (struct hblk *)((word)addr & ~(GC_page_size - 1));
2932 end_block = (struct hblk *)((word)(addr + len - 1) & ~(GC_page_size - 1));
2933 end_block += GC_page_size/HBLKSIZE - 1;
2934 for (h = start_block; h <= end_block; h++) {
2935 register word index = PHT_HASH(h);
2937 async_set_pht_entry_from_index(GC_dirty_pages, index);
2939 UNPROTECT(start_block,
2940 ((ptr_t)end_block - (ptr_t)start_block) + HBLKSIZE);
2945 /* We no longer wrap read by default, since that was causing too many */
2946 /* problems. It is preferred that the client instead avoids writing */
2947 /* to the write-protected heap with a system call. */
2948 /* This still serves as sample code if you do want to wrap system calls.*/
2950 #if !defined(MSWIN32) && !defined(MSWINCE) && !defined(GC_USE_LD_WRAP)
2951 /* Replacement for UNIX system call. */
2952 /* Other calls that write to the heap should be handled similarly. */
2953 /* Note that this doesn't work well for blocking reads: It will hold */
2954 /* the allocation lock for the entire duration of the call. Multithreaded */
2955 /* clients should really ensure that it won't block, either by setting */
2956 /* the descriptor nonblocking, or by calling select or poll first, to */
2957 /* make sure that input is available. */
2958 /* Another, preferred alternative is to ensure that system calls never */
2959 /* write to the protected heap (see above). */
2960 # if defined(__STDC__) && !defined(SUNOS4)
2961 # include <unistd.h>
2962 # include <sys/uio.h>
2963 ssize_t read(int fd, void *buf, size_t nbyte)
2966 int read(fd, buf, nbyte)
2968 int GC_read(fd, buf, nbyte)
2978 GC_unprotect_range(buf, (word)nbyte);
2979 # if defined(IRIX5) || defined(GC_LINUX_THREADS)
2980 /* Indirect system call may not always be easily available. */
2981 /* We could call _read, but that would interfere with the */
2982 /* libpthread interception of read. */
2983 /* On Linux, we have to be careful with the linuxthreads */
2984 /* read interception. */
2989 iov.iov_len = nbyte;
2990 result = readv(fd, &iov, 1);
2994 result = __read(fd, buf, nbyte);
2996 /* The two zero args at the end of this list are because one
2997 IA-64 syscall() implementation actually requires six args
2998 to be passed, even though they aren't always used. */
2999 result = syscall(SYS_read, fd, buf, nbyte, 0, 0);
3005 #endif /* !MSWIN32 && !MSWINCE && !GC_LINUX_THREADS */
3007 #if defined(GC_USE_LD_WRAP) && !defined(THREADS)
3008 /* We use the GNU ld call wrapping facility. */
3009 /* This requires that the linker be invoked with "--wrap read". */
3010 /* This can be done by passing -Wl,"--wrap read" to gcc. */
3011 /* I'm not sure that this actually wraps whatever version of read */
3012 /* is called by stdio. That code also mentions __read. */
3013 # include <unistd.h>
3014 ssize_t __wrap_read(int fd, void *buf, size_t nbyte)
3019 GC_unprotect_range(buf, (word)nbyte);
3020 result = __real_read(fd, buf, nbyte);
3025 /* We should probably also do this for __read, or whatever stdio */
3026 /* actually calls. */
3032 GC_bool GC_page_was_ever_dirty(h)
3038 /* Reset the n pages starting at h to "was never dirty" status. */
3040 void GC_is_fresh(h, n)
3046 # endif /* MPROTECT_VDB */
3051 * See DEFAULT_VDB for interface descriptions.
3055 * This implementaion assumes a Solaris 2.X like /proc pseudo-file-system
3056 * from which we can read page modified bits. This facility is far from
3057 * optimal (e.g. we would like to get the info for only some of the
3058 * address space), but it avoids intercepting system calls.
3062 #include <sys/types.h>
3063 #include <sys/signal.h>
3064 #include <sys/fault.h>
3065 #include <sys/syscall.h>
3066 #include <sys/procfs.h>
3067 #include <sys/stat.h>
3069 #define INITIAL_BUF_SZ 4096
3070 word GC_proc_buf_size = INITIAL_BUF_SZ;
3073 #ifdef GC_SOLARIS_THREADS
3074 /* We don't have exact sp values for threads. So we count on */
3075 /* occasionally declaring stack pages to be fresh. Thus we */
3076 /* need a real implementation of GC_is_fresh. We can't clear */
3077 /* entries in GC_written_pages, since that would declare all */
3078 /* pages with the given hash address to be fresh. */
3079 # define MAX_FRESH_PAGES 8*1024 /* Must be power of 2 */
3080 struct hblk ** GC_fresh_pages; /* A direct mapped cache. */
3081 /* Collisions are dropped. */
3083 # define FRESH_PAGE_SLOT(h) (divHBLKSZ((word)(h)) & (MAX_FRESH_PAGES-1))
3084 # define ADD_FRESH_PAGE(h) \
3085 GC_fresh_pages[FRESH_PAGE_SLOT(h)] = (h)
3086 # define PAGE_IS_FRESH(h) \
3087 (GC_fresh_pages[FRESH_PAGE_SLOT(h)] == (h) && (h) != 0)
3090 /* Add all pages in pht2 to pht1 */
3091 void GC_or_pages(pht1, pht2)
3092 page_hash_table pht1, pht2;
3096 for (i = 0; i < PHT_SIZE; i++) pht1[i] |= pht2[i];
3101 void GC_dirty_init()
3106 GC_dirty_maintained = TRUE;
3107 if (GC_words_allocd != 0 || GC_words_allocd_before_gc != 0) {
3110 for (i = 0; i < PHT_SIZE; i++) GC_written_pages[i] = (word)(-1);
3112 GC_printf1("Allocated words:%lu:all pages may have been written\n",
3114 (GC_words_allocd + GC_words_allocd_before_gc));
3117 sprintf(buf, "/proc/%d", getpid());
3118 fd = open(buf, O_RDONLY);
3120 ABORT("/proc open failed");
3122 GC_proc_fd = syscall(SYS_ioctl, fd, PIOCOPENPD, 0);
3124 syscall(SYS_fcntl, GC_proc_fd, F_SETFD, FD_CLOEXEC);
3125 if (GC_proc_fd < 0) {
3126 ABORT("/proc ioctl failed");
3128 GC_proc_buf = GC_scratch_alloc(GC_proc_buf_size);
3129 # ifdef GC_SOLARIS_THREADS
3130 GC_fresh_pages = (struct hblk **)
3131 GC_scratch_alloc(MAX_FRESH_PAGES * sizeof (struct hblk *));
3132 if (GC_fresh_pages == 0) {
3133 GC_err_printf0("No space for fresh pages\n");
3136 BZERO(GC_fresh_pages, MAX_FRESH_PAGES * sizeof (struct hblk *));
3140 /* Ignore write hints. They don't help us here. */
3142 void GC_remove_protection(h, nblocks, is_ptrfree)
3149 #ifdef GC_SOLARIS_THREADS
3150 # define READ(fd,buf,nbytes) syscall(SYS_read, fd, buf, nbytes)
3152 # define READ(fd,buf,nbytes) read(fd, buf, nbytes)
3155 void GC_read_dirty()
3157 unsigned long ps, np;
3160 struct prasmap * map;
3162 ptr_t current_addr, limit;
3166 BZERO(GC_grungy_pages, (sizeof GC_grungy_pages));
3169 if (READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
3171 GC_printf1("/proc read failed: GC_proc_buf_size = %lu\n",
3175 /* Retry with larger buffer. */
3176 word new_size = 2 * GC_proc_buf_size;
3177 char * new_buf = GC_scratch_alloc(new_size);
3180 GC_proc_buf = bufp = new_buf;
3181 GC_proc_buf_size = new_size;
3183 if (READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
3184 WARN("Insufficient space for /proc read\n", 0);
3186 memset(GC_grungy_pages, 0xff, sizeof (page_hash_table));
3187 memset(GC_written_pages, 0xff, sizeof(page_hash_table));
3188 # ifdef GC_SOLARIS_THREADS
3189 BZERO(GC_fresh_pages,
3190 MAX_FRESH_PAGES * sizeof (struct hblk *));
3196 /* Copy dirty bits into GC_grungy_pages */
3197 nmaps = ((struct prpageheader *)bufp) -> pr_nmap;
3198 /* printf( "nmaps = %d, PG_REFERENCED = %d, PG_MODIFIED = %d\n",
3199 nmaps, PG_REFERENCED, PG_MODIFIED); */
3200 bufp = bufp + sizeof(struct prpageheader);
3201 for (i = 0; i < nmaps; i++) {
3202 map = (struct prasmap *)bufp;
3203 vaddr = (ptr_t)(map -> pr_vaddr);
3204 ps = map -> pr_pagesize;
3205 np = map -> pr_npage;
3206 /* printf("vaddr = 0x%X, ps = 0x%X, np = 0x%X\n", vaddr, ps, np); */
3207 limit = vaddr + ps * np;
3208 bufp += sizeof (struct prasmap);
3209 for (current_addr = vaddr;
3210 current_addr < limit; current_addr += ps){
3211 if ((*bufp++) & PG_MODIFIED) {
3212 register struct hblk * h = (struct hblk *) current_addr;
3214 while ((ptr_t)h < current_addr + ps) {
3215 register word index = PHT_HASH(h);
3217 set_pht_entry_from_index(GC_grungy_pages, index);
3218 # ifdef GC_SOLARIS_THREADS
3220 register int slot = FRESH_PAGE_SLOT(h);
3222 if (GC_fresh_pages[slot] == h) {
3223 GC_fresh_pages[slot] = 0;
3231 bufp += sizeof(long) - 1;
3232 bufp = (char *)((unsigned long)bufp & ~(sizeof(long)-1));
3234 /* Update GC_written_pages. */
3235 GC_or_pages(GC_written_pages, GC_grungy_pages);
3236 # ifdef GC_SOLARIS_THREADS
3237 /* Make sure that old stacks are considered completely clean */
3238 /* unless written again. */
3239 GC_old_stacks_are_fresh();
3245 GC_bool GC_page_was_dirty(h)
3248 register word index = PHT_HASH(h);
3249 register GC_bool result;
3251 result = get_pht_entry_from_index(GC_grungy_pages, index);
3252 # ifdef GC_SOLARIS_THREADS
3253 if (result && PAGE_IS_FRESH(h)) result = FALSE;
3254 /* This happens only if page was declared fresh since */
3255 /* the read_dirty call, e.g. because it's in an unused */
3256 /* thread stack. It's OK to treat it as clean, in */
3257 /* that case. And it's consistent with */
3258 /* GC_page_was_ever_dirty. */
3263 GC_bool GC_page_was_ever_dirty(h)
3266 register word index = PHT_HASH(h);
3267 register GC_bool result;
3269 result = get_pht_entry_from_index(GC_written_pages, index);
3270 # ifdef GC_SOLARIS_THREADS
3271 if (result && PAGE_IS_FRESH(h)) result = FALSE;
3276 /* Caller holds allocation lock. */
3277 void GC_is_fresh(h, n)
3282 register word index;
3284 # ifdef GC_SOLARIS_THREADS
3287 if (GC_fresh_pages != 0) {
3288 for (i = 0; i < n; i++) {
3289 ADD_FRESH_PAGE(h + i);
3295 # endif /* PROC_VDB */
3300 # include "vd/PCR_VD.h"
3302 # define NPAGES (32*1024) /* 128 MB */
3304 PCR_VD_DB GC_grungy_bits[NPAGES];
3306 ptr_t GC_vd_base; /* Address corresponding to GC_grungy_bits[0] */
3307 /* HBLKSIZE aligned. */
3309 void GC_dirty_init()
3311 GC_dirty_maintained = TRUE;
3312 /* For the time being, we assume the heap generally grows up */
3313 GC_vd_base = GC_heap_sects[0].hs_start;
3314 if (GC_vd_base == 0) {
3315 ABORT("Bad initial heap segment");
3317 if (PCR_VD_Start(HBLKSIZE, GC_vd_base, NPAGES*HBLKSIZE)
3319 ABORT("dirty bit initialization failed");
3323 void GC_read_dirty()
3325 /* lazily enable dirty bits on newly added heap sects */
3327 static int onhs = 0;
3328 int nhs = GC_n_heap_sects;
3329 for( ; onhs < nhs; onhs++ ) {
3330 PCR_VD_WriteProtectEnable(
3331 GC_heap_sects[onhs].hs_start,
3332 GC_heap_sects[onhs].hs_bytes );
3337 if (PCR_VD_Clear(GC_vd_base, NPAGES*HBLKSIZE, GC_grungy_bits)
3339 ABORT("dirty bit read failed");
3343 GC_bool GC_page_was_dirty(h)
3346 if((ptr_t)h < GC_vd_base || (ptr_t)h >= GC_vd_base + NPAGES*HBLKSIZE) {
3349 return(GC_grungy_bits[h - (struct hblk *)GC_vd_base] & PCR_VD_DB_dirtyBit);
3353 void GC_remove_protection(h, nblocks, is_ptrfree)
3358 PCR_VD_WriteProtectDisable(h, nblocks*HBLKSIZE);
3359 PCR_VD_WriteProtectEnable(h, nblocks*HBLKSIZE);
3362 # endif /* PCR_VDB */
3364 #if defined(MPROTECT_VDB) && defined(DARWIN)
3365 /* The following sources were used as a *reference* for this exception handling
3367 1. Apple's mach/xnu documentation
3368 2. Timothy J. Wood's "Mach Exception Handlers 101" post to the
3369 omnigroup's macosx-dev list.
3370 www.omnigroup.com/mailman/archive/macosx-dev/2000-June/002030.html
3371 3. macosx-nat.c from Apple's GDB source code.
3374 /* The bug that caused all this trouble should now be fixed. This should
3375 eventually be removed if all goes well. */
3376 /* define BROKEN_EXCEPTION_HANDLING */
3378 #include <mach/mach.h>
3379 #include <mach/mach_error.h>
3380 #include <mach/thread_status.h>
3381 #include <mach/exception.h>
3382 #include <mach/task.h>
3383 #include <pthread.h>
3385 /* These are not defined in any header, although they are documented */
3386 extern boolean_t exc_server(mach_msg_header_t *,mach_msg_header_t *);
3387 extern kern_return_t exception_raise(
3388 mach_port_t,mach_port_t,mach_port_t,
3389 exception_type_t,exception_data_t,mach_msg_type_number_t);
3390 extern kern_return_t exception_raise_state(
3391 mach_port_t,mach_port_t,mach_port_t,
3392 exception_type_t,exception_data_t,mach_msg_type_number_t,
3393 thread_state_flavor_t*,thread_state_t,mach_msg_type_number_t,
3394 thread_state_t,mach_msg_type_number_t*);
3395 extern kern_return_t exception_raise_state_identity(
3396 mach_port_t,mach_port_t,mach_port_t,
3397 exception_type_t,exception_data_t,mach_msg_type_number_t,
3398 thread_state_flavor_t*,thread_state_t,mach_msg_type_number_t,
3399 thread_state_t,mach_msg_type_number_t*);
3402 #define MAX_EXCEPTION_PORTS 16
3404 static mach_port_t GC_task_self;
3407 mach_msg_type_number_t count;
3408 exception_mask_t masks[MAX_EXCEPTION_PORTS];
3409 exception_handler_t ports[MAX_EXCEPTION_PORTS];
3410 exception_behavior_t behaviors[MAX_EXCEPTION_PORTS];
3411 thread_state_flavor_t flavors[MAX_EXCEPTION_PORTS];
3415 mach_port_t exception;
3416 #if defined(THREADS)
3422 mach_msg_header_t head;
3426 GC_MP_NORMAL, GC_MP_DISCARDING, GC_MP_STOPPED
3427 } GC_mprotect_state_t;
3429 /* FIXME: 1 and 2 seem to be safe to use in the msgh_id field,
3430 but it isn't documented. Use the source and see if they
3435 /* These values are only used on the reply port */
3438 #if defined(THREADS)
3440 GC_mprotect_state_t GC_mprotect_state;
3442 /* The following should ONLY be called when the world is stopped */
3443 static void GC_mprotect_thread_notify(mach_msg_id_t id) {
3446 mach_msg_trailer_t trailer;
3448 mach_msg_return_t r;
3450 buf.msg.head.msgh_bits =
3451 MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND,0);
3452 buf.msg.head.msgh_size = sizeof(buf.msg);
3453 buf.msg.head.msgh_remote_port = GC_ports.exception;
3454 buf.msg.head.msgh_local_port = MACH_PORT_NULL;
3455 buf.msg.head.msgh_id = id;
3459 MACH_SEND_MSG|MACH_RCV_MSG|MACH_RCV_LARGE,
3463 MACH_MSG_TIMEOUT_NONE,
3465 if(r != MACH_MSG_SUCCESS)
3466 ABORT("mach_msg failed in GC_mprotect_thread_notify");
3467 if(buf.msg.head.msgh_id != ID_ACK)
3468 ABORT("invalid ack in GC_mprotect_thread_notify");
3471 /* Should only be called by the mprotect thread */
3472 static void GC_mprotect_thread_reply() {
3474 mach_msg_return_t r;
3476 msg.head.msgh_bits =
3477 MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND,0);
3478 msg.head.msgh_size = sizeof(msg);
3479 msg.head.msgh_remote_port = GC_ports.reply;
3480 msg.head.msgh_local_port = MACH_PORT_NULL;
3481 msg.head.msgh_id = ID_ACK;
3489 MACH_MSG_TIMEOUT_NONE,
3491 if(r != MACH_MSG_SUCCESS)
3492 ABORT("mach_msg failed in GC_mprotect_thread_reply");
3495 void GC_mprotect_stop() {
3496 GC_mprotect_thread_notify(ID_STOP);
3498 void GC_mprotect_resume() {
3499 GC_mprotect_thread_notify(ID_RESUME);
3502 #else /* !THREADS */
3503 /* The compiler should optimize away any GC_mprotect_state computations */
3504 #define GC_mprotect_state GC_MP_NORMAL
3507 static void *GC_mprotect_thread(void *arg) {
3508 mach_msg_return_t r;
3509 /* These two structures contain some private kernel data. We don't need to
3510 access any of it so we don't bother defining a proper struct. The
3511 correct definitions are in the xnu source code. */
3513 mach_msg_header_t head;
3517 mach_msg_header_t head;
3518 mach_msg_body_t msgh_body;
3524 GC_darwin_register_mach_handler_thread(mach_thread_self());
3529 MACH_RCV_MSG|MACH_RCV_LARGE|
3530 (GC_mprotect_state == GC_MP_DISCARDING ? MACH_RCV_TIMEOUT : 0),
3534 GC_mprotect_state == GC_MP_DISCARDING ? 0 : MACH_MSG_TIMEOUT_NONE,
3537 id = r == MACH_MSG_SUCCESS ? msg.head.msgh_id : -1;
3539 #if defined(THREADS)
3540 if(GC_mprotect_state == GC_MP_DISCARDING) {
3541 if(r == MACH_RCV_TIMED_OUT) {
3542 GC_mprotect_state = GC_MP_STOPPED;
3543 GC_mprotect_thread_reply();
3546 if(r == MACH_MSG_SUCCESS && (id == ID_STOP || id == ID_RESUME))
3547 ABORT("out of order mprotect thread request");
3551 if(r != MACH_MSG_SUCCESS) {
3552 GC_err_printf2("mach_msg failed with %d %s\n",
3553 (int)r,mach_error_string(r));
3554 ABORT("mach_msg failed");
3558 #if defined(THREADS)
3560 if(GC_mprotect_state != GC_MP_NORMAL)
3561 ABORT("Called mprotect_stop when state wasn't normal");
3562 GC_mprotect_state = GC_MP_DISCARDING;
3565 if(GC_mprotect_state != GC_MP_STOPPED)
3566 ABORT("Called mprotect_resume when state wasn't stopped");
3567 GC_mprotect_state = GC_MP_NORMAL;
3568 GC_mprotect_thread_reply();
3570 #endif /* THREADS */
3572 /* Handle the message (calls catch_exception_raise) */
3573 if(!exc_server(&msg.head,&reply.head))
3574 ABORT("exc_server failed");
3575 /* Send the reply */
3579 reply.head.msgh_size,
3582 MACH_MSG_TIMEOUT_NONE,
3584 if(r != MACH_MSG_SUCCESS) {
3585 /* This will fail if the thread dies, but the thread shouldn't
3587 #ifdef BROKEN_EXCEPTION_HANDLING
3589 "mach_msg failed with %d %s while sending exc reply\n",
3590 (int)r,mach_error_string(r));
3592 ABORT("mach_msg failed while sending exception reply");
3601 /* All this SIGBUS code shouldn't be necessary. All protection faults should
3602 be going throught the mach exception handler. However, it seems a SIGBUS is
3603 occasionally sent for some unknown reason. Even more odd, it seems to be
3604 meaningless and safe to ignore. */
3605 #ifdef BROKEN_EXCEPTION_HANDLING
3607 typedef void (* SIG_PF)();
3608 static SIG_PF GC_old_bus_handler;
3610 /* Updates to this aren't atomic, but the SIGBUSs seem pretty rare.
3611 Even if this doesn't get updated property, it isn't really a problem */
3612 static int GC_sigbus_count;
3614 static void GC_darwin_sigbus(int num,siginfo_t *sip,void *context) {
3615 if(num != SIGBUS) ABORT("Got a non-sigbus signal in the sigbus handler");
3617 /* Ugh... some seem safe to ignore, but too many in a row probably means
3618 trouble. GC_sigbus_count is reset for each mach exception that is
3620 if(GC_sigbus_count >= 8) {
3621 ABORT("Got more than 8 SIGBUSs in a row!");
3624 GC_err_printf0("GC: WARNING: Ignoring SIGBUS.\n");
3627 #endif /* BROKEN_EXCEPTION_HANDLING */
3629 void GC_dirty_init() {
3633 pthread_attr_t attr;
3634 exception_mask_t mask;
3637 GC_printf0("Inititalizing mach/darwin mprotect virtual dirty bit "
3638 "implementation\n");
3640 # ifdef BROKEN_EXCEPTION_HANDLING
3641 GC_err_printf0("GC: WARNING: Enabling workarounds for various darwin "
3642 "exception handling bugs.\n");
3644 GC_dirty_maintained = TRUE;
3645 if (GC_page_size % HBLKSIZE != 0) {
3646 GC_err_printf0("Page size not multiple of HBLKSIZE\n");
3647 ABORT("Page size not multiple of HBLKSIZE");
3650 GC_task_self = me = mach_task_self();
3652 r = mach_port_allocate(me,MACH_PORT_RIGHT_RECEIVE,&GC_ports.exception);
3653 if(r != KERN_SUCCESS) ABORT("mach_port_allocate failed (exception port)");
3655 r = mach_port_insert_right(me,GC_ports.exception,GC_ports.exception,
3656 MACH_MSG_TYPE_MAKE_SEND);
3657 if(r != KERN_SUCCESS)
3658 ABORT("mach_port_insert_right failed (exception port)");
3660 #if defined(THREADS)
3661 r = mach_port_allocate(me,MACH_PORT_RIGHT_RECEIVE,&GC_ports.reply);
3662 if(r != KERN_SUCCESS) ABORT("mach_port_allocate failed (reply port)");
3665 /* The exceptions we want to catch */
3666 mask = EXC_MASK_BAD_ACCESS;
3668 r = task_get_exception_ports(
3671 GC_old_exc_ports.masks,
3672 &GC_old_exc_ports.count,
3673 GC_old_exc_ports.ports,
3674 GC_old_exc_ports.behaviors,
3675 GC_old_exc_ports.flavors
3677 if(r != KERN_SUCCESS) ABORT("task_get_exception_ports failed");
3679 r = task_set_exception_ports(
3684 MACHINE_THREAD_STATE
3686 if(r != KERN_SUCCESS) ABORT("task_set_exception_ports failed");
3688 if(pthread_attr_init(&attr) != 0) ABORT("pthread_attr_init failed");
3689 if(pthread_attr_setdetachstate(&attr,PTHREAD_CREATE_DETACHED) != 0)
3690 ABORT("pthread_attr_setdetachedstate failed");
3692 # undef pthread_create
3693 /* This will call the real pthread function, not our wrapper */
3694 if(pthread_create(&thread,&attr,GC_mprotect_thread,NULL) != 0)
3695 ABORT("pthread_create failed");
3696 pthread_attr_destroy(&attr);
3698 /* Setup the sigbus handler for ignoring the meaningless SIGBUSs */
3699 #ifdef BROKEN_EXCEPTION_HANDLING
3701 struct sigaction sa, oldsa;
3702 sa.sa_handler = (SIG_PF)GC_darwin_sigbus;
3703 sigemptyset(&sa.sa_mask);
3704 sa.sa_flags = SA_RESTART|SA_SIGINFO;
3705 if(sigaction(SIGBUS,&sa,&oldsa) < 0) ABORT("sigaction");
3706 GC_old_bus_handler = (SIG_PF)oldsa.sa_handler;
3707 if (GC_old_bus_handler != SIG_DFL) {
3709 GC_err_printf0("Replaced other SIGBUS handler\n");
3713 #endif /* BROKEN_EXCEPTION_HANDLING */
3716 /* The source code for Apple's GDB was used as a reference for the exception
3717 forwarding code. This code is similar to be GDB code only because there is
3718 only one way to do it. */
3719 static kern_return_t GC_forward_exception(
3722 exception_type_t exception,
3723 exception_data_t data,
3724 mach_msg_type_number_t data_count
3729 exception_behavior_t behavior;
3730 thread_state_flavor_t flavor;
3732 thread_state_data_t thread_state;
3733 mach_msg_type_number_t thread_state_count = THREAD_STATE_MAX;
3735 for(i=0;i<GC_old_exc_ports.count;i++)
3736 if(GC_old_exc_ports.masks[i] & (1 << exception))
3738 if(i==GC_old_exc_ports.count) ABORT("No handler for exception!");
3740 port = GC_old_exc_ports.ports[i];
3741 behavior = GC_old_exc_ports.behaviors[i];
3742 flavor = GC_old_exc_ports.flavors[i];
3744 if(behavior != EXCEPTION_DEFAULT) {
3745 r = thread_get_state(thread,flavor,thread_state,&thread_state_count);
3746 if(r != KERN_SUCCESS)
3747 ABORT("thread_get_state failed in forward_exception");
3751 case EXCEPTION_DEFAULT:
3752 r = exception_raise(port,thread,task,exception,data,data_count);
3754 case EXCEPTION_STATE:
3755 r = exception_raise_state(port,thread,task,exception,data,
3756 data_count,&flavor,thread_state,thread_state_count,
3757 thread_state,&thread_state_count);
3759 case EXCEPTION_STATE_IDENTITY:
3760 r = exception_raise_state_identity(port,thread,task,exception,data,
3761 data_count,&flavor,thread_state,thread_state_count,
3762 thread_state,&thread_state_count);
3765 r = KERN_FAILURE; /* make gcc happy */
3766 ABORT("forward_exception: unknown behavior");
3770 if(behavior != EXCEPTION_DEFAULT) {
3771 r = thread_set_state(thread,flavor,thread_state,thread_state_count);
3772 if(r != KERN_SUCCESS)
3773 ABORT("thread_set_state failed in forward_exception");
3779 #define FWD() GC_forward_exception(thread,task,exception,code,code_count)
3781 /* This violates the namespace rules but there isn't anything that can be done
3782 about it. The exception handling stuff is hard coded to call this */
3784 catch_exception_raise(
3785 mach_port_t exception_port,mach_port_t thread,mach_port_t task,
3786 exception_type_t exception,exception_data_t code,
3787 mach_msg_type_number_t code_count
3794 thread_state_flavor_t flavor = PPC_EXCEPTION_STATE;
3795 mach_msg_type_number_t exc_state_count = PPC_EXCEPTION_STATE_COUNT;
3796 ppc_exception_state_t exc_state;
3798 # error FIXME for non-ppc darwin
3802 if(exception != EXC_BAD_ACCESS || code[0] != KERN_PROTECTION_FAILURE) {
3803 #ifdef DEBUG_EXCEPTION_HANDLING
3804 /* We aren't interested, pass it on to the old handler */
3805 GC_printf3("Exception: 0x%x Code: 0x%x 0x%x in catch....\n",
3807 code_count > 0 ? code[0] : -1,
3808 code_count > 1 ? code[1] : -1);
3813 r = thread_get_state(thread,flavor,
3814 (natural_t*)&exc_state,&exc_state_count);
3815 if(r != KERN_SUCCESS) {
3816 /* The thread is supposed to be suspended while the exception handler
3817 is called. This shouldn't fail. */
3818 #ifdef BROKEN_EXCEPTION_HANDLING
3819 GC_err_printf0("thread_get_state failed in "
3820 "catch_exception_raise\n");
3821 return KERN_SUCCESS;
3823 ABORT("thread_get_state failed in catch_exception_raise");
3827 /* This is the address that caused the fault */
3828 addr = (char*) exc_state.dar;
3830 if((HDR(addr)) == 0) {
3831 /* Ugh... just like the SIGBUS problem above, it seems we get a bogus
3832 KERN_PROTECTION_FAILURE every once and a while. We wait till we get
3833 a bunch in a row before doing anything about it. If a "real" fault
3834 ever occurres it'll just keep faulting over and over and we'll hit
3835 the limit pretty quickly. */
3836 #ifdef BROKEN_EXCEPTION_HANDLING
3837 static char *last_fault;
3838 static int last_fault_count;
3840 if(addr != last_fault) {
3842 last_fault_count = 0;
3844 if(++last_fault_count < 32) {
3845 if(last_fault_count == 1)
3847 "GC: WARNING: Ignoring KERN_PROTECTION_FAILURE at %p\n",
3849 return KERN_SUCCESS;
3852 GC_err_printf1("Unexpected KERN_PROTECTION_FAILURE at %p\n",addr);
3853 /* Can't pass it along to the signal handler because that is
3854 ignoring SIGBUS signals. We also shouldn't call ABORT here as
3855 signals don't always work too well from the exception handler. */
3856 GC_err_printf0("Aborting\n");
3858 #else /* BROKEN_EXCEPTION_HANDLING */
3859 /* Pass it along to the next exception handler
3860 (which should call SIGBUS/SIGSEGV) */
3862 #endif /* !BROKEN_EXCEPTION_HANDLING */
3865 #ifdef BROKEN_EXCEPTION_HANDLING
3866 /* Reset the number of consecutive SIGBUSs */
3867 GC_sigbus_count = 0;
3870 if(GC_mprotect_state == GC_MP_NORMAL) { /* common case */
3871 h = (struct hblk*)((word)addr & ~(GC_page_size-1));
3872 UNPROTECT(h, GC_page_size);
3873 for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
3874 register int index = PHT_HASH(h+i);
3875 async_set_pht_entry_from_index(GC_dirty_pages, index);
3877 } else if(GC_mprotect_state == GC_MP_DISCARDING) {
3878 /* Lie to the thread for now. No sense UNPROTECT()ing the memory
3879 when we're just going to PROTECT() it again later. The thread
3880 will just fault again once it resumes */
3882 /* Shouldn't happen, i don't think */
3883 GC_printf0("KERN_PROTECTION_FAILURE while world is stopped\n");
3886 return KERN_SUCCESS;
3890 /* These should never be called, but just in case... */
3891 kern_return_t catch_exception_raise_state(mach_port_name_t exception_port,
3892 int exception, exception_data_t code, mach_msg_type_number_t codeCnt,
3893 int flavor, thread_state_t old_state, int old_stateCnt,
3894 thread_state_t new_state, int new_stateCnt)
3896 ABORT("catch_exception_raise_state");
3897 return(KERN_INVALID_ARGUMENT);
3899 kern_return_t catch_exception_raise_state_identity(
3900 mach_port_name_t exception_port, mach_port_t thread, mach_port_t task,
3901 int exception, exception_data_t code, mach_msg_type_number_t codeCnt,
3902 int flavor, thread_state_t old_state, int old_stateCnt,
3903 thread_state_t new_state, int new_stateCnt)
3905 ABORT("catch_exception_raise_state_identity");
3906 return(KERN_INVALID_ARGUMENT);
3910 #endif /* DARWIN && MPROTECT_VDB */
3912 # ifndef HAVE_INCREMENTAL_PROTECTION_NEEDS
3913 int GC_incremental_protection_needs()
3915 return GC_PROTECTS_NONE;
3917 # endif /* !HAVE_INCREMENTAL_PROTECTION_NEEDS */
3920 * Call stack save code for debugging.
3921 * Should probably be in mach_dep.c, but that requires reorganization.
3924 /* I suspect the following works for most X86 *nix variants, so */
3925 /* long as the frame pointer is explicitly stored. In the case of gcc, */
3926 /* compiler flags (e.g. -fomit-frame-pointer) determine whether it is. */
3927 #if defined(I386) && defined(LINUX) && defined(SAVE_CALL_CHAIN)
3928 # include <features.h>
3931 struct frame *fr_savfp;
3933 long fr_arg[NARGS]; /* All the arguments go here. */
3939 # include <features.h>
3944 struct frame *fr_savfp;
3953 # if defined(SUNOS4)
3954 # include <machine/frame.h>
3956 # if defined (DRSNX)
3957 # include <sys/sparc/frame.h>
3959 # if defined(OPENBSD) || defined(NETBSD)
3962 # include <sys/frame.h>
3968 --> We only know how to to get the first 6 arguments
3972 #ifdef NEED_CALLINFO
3973 /* Fill in the pc and argument information for up to NFRAMES of my */
3974 /* callers. Ignore my frame and my callers frame. */
3977 # include <unistd.h>
3980 #endif /* NEED_CALLINFO */
3982 #if defined(GC_HAVE_BUILTIN_BACKTRACE)
3983 # include <execinfo.h>
3986 #ifdef SAVE_CALL_CHAIN
3988 #if NARGS == 0 && NFRAMES % 2 == 0 /* No padding */ \
3989 && defined(GC_HAVE_BUILTIN_BACKTRACE)
3991 void GC_save_callers (info)
3992 struct callinfo info[NFRAMES];
3994 void * tmp_info[NFRAMES + 1];
3996 # define IGNORE_FRAMES 1
3998 /* We retrieve NFRAMES+1 pc values, but discard the first, since it */
3999 /* points to our own frame. */
4000 GC_ASSERT(sizeof(struct callinfo) == sizeof(void *));
4001 npcs = backtrace((void **)tmp_info, NFRAMES + IGNORE_FRAMES);
4002 BCOPY(tmp_info+IGNORE_FRAMES, info, (npcs - IGNORE_FRAMES) * sizeof(void *));
4003 for (i = npcs - IGNORE_FRAMES; i < NFRAMES; ++i) info[i].ci_pc = 0;
4006 #else /* No builtin backtrace; do it ourselves */
4008 #if (defined(OPENBSD) || defined(NETBSD)) && defined(SPARC)
4009 # define FR_SAVFP fr_fp
4010 # define FR_SAVPC fr_pc
4012 # define FR_SAVFP fr_savfp
4013 # define FR_SAVPC fr_savpc
4016 #if defined(SPARC) && (defined(__arch64__) || defined(__sparcv9))
4022 void GC_save_callers (info)
4023 struct callinfo info[NFRAMES];
4025 struct frame *frame;
4029 /* We assume this is turned on only with gcc as the compiler. */
4030 asm("movl %%ebp,%0" : "=r"(frame));
4033 frame = (struct frame *) GC_save_regs_in_stack ();
4034 fp = (struct frame *)((long) frame -> FR_SAVFP + BIAS);
4037 for (; (!(fp HOTTER_THAN frame) && !(GC_stackbottom HOTTER_THAN (ptr_t)fp)
4038 && (nframes < NFRAMES));
4039 fp = (struct frame *)((long) fp -> FR_SAVFP + BIAS), nframes++) {
4042 info[nframes].ci_pc = fp->FR_SAVPC;
4044 for (i = 0; i < NARGS; i++) {
4045 info[nframes].ci_arg[i] = ~(fp->fr_arg[i]);
4047 # endif /* NARGS > 0 */
4049 if (nframes < NFRAMES) info[nframes].ci_pc = 0;
4052 #endif /* No builtin backtrace */
4054 #endif /* SAVE_CALL_CHAIN */
4056 #ifdef NEED_CALLINFO
4058 /* Print info to stderr. We do NOT hold the allocation lock */
4059 void GC_print_callers (info)
4060 struct callinfo info[NFRAMES];
4063 static int reentry_count = 0;
4064 GC_bool stop = FALSE;
4066 /* FIXME: This should probably use a different lock, so that we */
4067 /* become callable with or without the allocation lock. */
4073 GC_err_printf0("\tCaller at allocation:\n");
4075 GC_err_printf0("\tCall chain at allocation:\n");
4077 for (i = 0; i < NFRAMES && !stop ; i++) {
4078 if (info[i].ci_pc == 0) break;
4083 GC_err_printf0("\t\targs: ");
4084 for (j = 0; j < NARGS; j++) {
4085 if (j != 0) GC_err_printf0(", ");
4086 GC_err_printf2("%d (0x%X)", ~(info[i].ci_arg[j]),
4087 ~(info[i].ci_arg[j]));
4089 GC_err_printf0("\n");
4092 if (reentry_count > 1) {
4093 /* We were called during an allocation during */
4094 /* a previous GC_print_callers call; punt. */
4095 GC_err_printf1("\t\t##PC##= 0x%lx\n", info[i].ci_pc);
4102 # if defined(GC_HAVE_BUILTIN_BACKTRACE) \
4103 && !defined(GC_BACKTRACE_SYMBOLS_BROKEN)
4105 backtrace_symbols((void **)(&(info[i].ci_pc)), 1);
4106 char *name = sym_name[0];
4110 sprintf(buf, "##PC##= 0x%lx", info[i].ci_pc);
4112 # if defined(LINUX) && !defined(SMALL_CONFIG)
4113 /* Try for a line number. */
4116 static char exe_name[EXE_SZ];
4118 char cmd_buf[CMD_SZ];
4119 # define RESULT_SZ 200
4120 static char result_buf[RESULT_SZ];
4123 # define PRELOAD_SZ 200
4124 char preload_buf[PRELOAD_SZ];
4125 static GC_bool found_exe_name = FALSE;
4126 static GC_bool will_fail = FALSE;
4128 /* Try to get it via a hairy and expensive scheme. */
4129 /* First we get the name of the executable: */
4130 if (will_fail) goto out;
4131 if (!found_exe_name) {
4132 ret_code = readlink("/proc/self/exe", exe_name, EXE_SZ);
4133 if (ret_code < 0 || ret_code >= EXE_SZ
4134 || exe_name[0] != '/') {
4135 will_fail = TRUE; /* Dont try again. */
4138 exe_name[ret_code] = '\0';
4139 found_exe_name = TRUE;
4141 /* Then we use popen to start addr2line -e <exe> <addr> */
4142 /* There are faster ways to do this, but hopefully this */
4143 /* isn't time critical. */
4144 sprintf(cmd_buf, "/usr/bin/addr2line -f -e %s 0x%lx", exe_name,
4145 (unsigned long)info[i].ci_pc);
4146 old_preload = getenv ("LD_PRELOAD");
4147 if (0 != old_preload) {
4148 if (strlen (old_preload) >= PRELOAD_SZ) {
4152 strcpy (preload_buf, old_preload);
4153 unsetenv ("LD_PRELOAD");
4155 pipe = popen(cmd_buf, "r");
4156 if (0 != old_preload
4157 && 0 != setenv ("LD_PRELOAD", preload_buf, 0)) {
4158 WARN("Failed to reset LD_PRELOAD\n", 0);
4161 || (result_len = fread(result_buf, 1, RESULT_SZ - 1, pipe))
4163 if (pipe != NULL) pclose(pipe);
4167 if (result_buf[result_len - 1] == '\n') --result_len;
4168 result_buf[result_len] = 0;
4169 if (result_buf[0] == '?'
4170 || result_buf[result_len-2] == ':'
4171 && result_buf[result_len-1] == '0') {
4175 /* Get rid of embedded newline, if any. Test for "main" */
4177 char * nl = strchr(result_buf, '\n');
4178 if (nl != NULL && nl < result_buf + result_len) {
4181 if (strncmp(result_buf, "main", nl - result_buf) == 0) {
4185 if (result_len < RESULT_SZ - 25) {
4186 /* Add in hex address */
4187 sprintf(result_buf + result_len, " [0x%lx]",
4188 (unsigned long)info[i].ci_pc);
4195 GC_err_printf1("\t\t%s\n", name);
4196 # if defined(GC_HAVE_BUILTIN_BACKTRACE) \
4197 && !defined(GC_BACKTRACE_SYMBOLS_BROKEN)
4198 free(sym_name); /* May call GC_free; that's OK */
4207 #endif /* NEED_CALLINFO */
4211 #if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG)
4213 /* Dump /proc/self/maps to GC_stderr, to enable looking up names for
4214 addresses in FIND_LEAK output. */
4216 static word dump_maps(char *maps)
4218 GC_err_write(maps, strlen(maps));
4222 void GC_print_address_map()
4224 GC_err_printf0("---------- Begin address map ----------\n");
4225 GC_apply_to_maps(dump_maps);
4226 GC_err_printf0("---------- End address map ----------\n");