source: trunk/gc6.8/os_dep.c@ 360

Last change on this file since 360 was 239, checked in by cinc, 19 years ago

Synching before applying WC2007 patches
File size: 131.6 KB
Line 
1/*
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.
6 *
7 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
8 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
9 *
10 * Permission is hereby granted to use or copy this program
11 * for any purpose, provided the above notices are retained on all copies.
12 * Permission to modify the code and to distribute modified code is granted,
13 * provided the above notices are retained, and a notice that the code was
14 * modified is included with the above copyright notice.
15 */
16
17# include "private/gc_priv.h"
18
19# if defined(LINUX) && !defined(POWERPC)
20# include <linux/version.h>
21# if (LINUX_VERSION_CODE <= 0x10400)
22 /* Ugly hack to get struct sigcontext_struct definition. Required */
23 /* for some early 1.3.X releases. Will hopefully go away soon. */
24 /* in some later Linux releases, asm/sigcontext.h may have to */
25 /* be included instead. */
26# define __KERNEL__
27# include <asm/signal.h>
28# undef __KERNEL__
29# else
30 /* Kernels prior to 2.1.1 defined struct sigcontext_struct instead of */
31 /* struct sigcontext. libc6 (glibc2) uses "struct sigcontext" in */
32 /* prototypes, so we have to include the top-level sigcontext.h to */
33 /* make sure the former gets defined to be the latter if appropriate. */
34# include <features.h>
35# if 2 <= __GLIBC__
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__ */
46# endif
47# endif
48# if !defined(OS2) && !defined(PCR) && !defined(AMIGA) && !defined(MACOS) \
49 && !defined(MSWINCE)
50# include <sys/types.h>
51# if !defined(MSWIN32) && !defined(SUNOS4)
52# include <unistd.h>
53# endif
54# endif
55
56# include <stdio.h>
57# if defined(MSWINCE)
58# define SIGSEGV 0 /* value is irrelevant */
59# else
60# include <signal.h>
61# endif
62
63#if defined(LINUX) || defined(LINUX_STACKBOTTOM)
64# include <ctype.h>
65#endif
66
67/* Blatantly OS dependent routines, except for those that are related */
68/* to dynamic loading. */
69
70# if defined(HEURISTIC2) || defined(SEARCH_FOR_DATA_START)
71# define NEED_FIND_LIMIT
72# endif
73
74# if !defined(STACKBOTTOM) && defined(HEURISTIC2)
75# define NEED_FIND_LIMIT
76# endif
77
78# if (defined(SUNOS4) && defined(DYNAMIC_LOADING)) && !defined(PCR)
79# define NEED_FIND_LIMIT
80# endif
81
82# if (defined(SVR4) || defined(AUX) || defined(DGUX) \
83 || (defined(LINUX) && defined(SPARC))) && !defined(PCR)
84# define NEED_FIND_LIMIT
85# endif
86
87#if defined(FREEBSD) && (defined(I386) || defined(powerpc) || defined(__powerpc__))
88# include <machine/trap.h>
89# if !defined(PCR)
90# define NEED_FIND_LIMIT
91# endif
92#endif
93
94#if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__) \
95 && !defined(NEED_FIND_LIMIT)
96 /* Used by GC_init_netbsd_elf() below. */
97# define NEED_FIND_LIMIT
98#endif
99
100#ifdef NEED_FIND_LIMIT
101# include <setjmp.h>
102#endif
103
104#ifdef AMIGA
105# define GC_AMIGA_DEF
106# include "AmigaOS.c"
107# undef GC_AMIGA_DEF
108#endif
109
110#if defined(MSWIN32) || defined(MSWINCE)
111# define WIN32_LEAN_AND_MEAN
112# define NOSERVICE
113# include <windows.h>
114#endif
115
116#ifdef MACOS
117# include <Processes.h>
118#endif
119
120#ifdef IRIX5
121# include <sys/uio.h>
122# include <malloc.h> /* for locking */
123#endif
124#if defined(USE_MMAP) || defined(USE_MUNMAP)
125# ifndef USE_MMAP
126 --> USE_MUNMAP requires USE_MMAP
127# endif
128# include <sys/types.h>
129# include <sys/mman.h>
130# include <sys/stat.h>
131# include <errno.h>
132#endif
133
134#ifdef UNIX_LIKE
135# include <fcntl.h>
136# if defined(SUNOS5SIGS) && !defined(FREEBSD)
137# include <sys/siginfo.h>
138# endif
139 /* Define SETJMP and friends to be the version that restores */
140 /* the signal mask. */
141# define SETJMP(env) sigsetjmp(env, 1)
142# define LONGJMP(env, val) siglongjmp(env, val)
143# define JMP_BUF sigjmp_buf
144#else
145# define SETJMP(env) setjmp(env)
146# define LONGJMP(env, val) longjmp(env, val)
147# define JMP_BUF jmp_buf
148#endif
149
150#ifdef DARWIN
151/* for get_etext and friends */
152#include <mach-o/getsect.h>
153#endif
154
155#ifdef DJGPP
156 /* Apparently necessary for djgpp 2.01. May cause problems with */
157 /* other versions. */
158 typedef long unsigned int caddr_t;
159#endif
160
161#ifdef PCR
162# include "il/PCR_IL.h"
163# include "th/PCR_ThCtl.h"
164# include "mm/PCR_MM.h"
165#endif
166
167#if !defined(NO_EXECUTE_PERMISSION)
168# define OPT_PROT_EXEC PROT_EXEC
169#else
170# define OPT_PROT_EXEC 0
171#endif
172
173#if defined(LINUX) && \
174 (defined(USE_PROC_FOR_LIBRARIES) || defined(IA64) || !defined(SMALL_CONFIG))
175
176/* We need to parse /proc/self/maps, either to find dynamic libraries, */
177/* and/or to find the register backing store base (IA64). Do it once */
178/* here. */
179
180#define READ read
181
182/* Repeatedly perform a read call until the buffer is filled or */
183/* we encounter EOF. */
184ssize_t GC_repeat_read(int fd, char *buf, size_t count)
185{
186 ssize_t num_read = 0;
187 ssize_t result;
188
189 while (num_read < count) {
190 result = READ(fd, buf + num_read, count - num_read);
191 if (result < 0) return result;
192 if (result == 0) break;
193 num_read += result;
194 }
195 return num_read;
196}
197
198/*
199 * Apply fn to a buffer containing the contents of /proc/self/maps.
200 * Return the result of fn or, if we failed, 0.
201 * We currently do nothing to /proc/self/maps other than simply read
202 * it. This code could be simplified if we could determine its size
203 * ahead of time.
204 */
205
206word GC_apply_to_maps(word (*fn)(char *))
207{
208 int f;
209 int result;
210 size_t maps_size = 4000; /* Initial guess. */
211 static char init_buf[1];
212 static char *maps_buf = init_buf;
213 static size_t maps_buf_sz = 1;
214
215 /* Read /proc/self/maps, growing maps_buf as necessary. */
216 /* Note that we may not allocate conventionally, and */
217 /* thus can't use stdio. */
218 do {
219 if (maps_size >= maps_buf_sz) {
220 /* Grow only by powers of 2, since we leak "too small" buffers. */
221 while (maps_size >= maps_buf_sz) maps_buf_sz *= 2;
222 maps_buf = GC_scratch_alloc(maps_buf_sz);
223 if (maps_buf == 0) return 0;
224 }
225 f = open("/proc/self/maps", O_RDONLY);
226 if (-1 == f) return 0;
227 maps_size = 0;
228 do {
229 result = GC_repeat_read(f, maps_buf, maps_buf_sz-1);
230 if (result <= 0) return 0;
231 maps_size += result;
232 } while (result == maps_buf_sz-1);
233 close(f);
234 } while (maps_size >= maps_buf_sz);
235 maps_buf[maps_size] = '\0';
236
237 /* Apply fn to result. */
238 return fn(maps_buf);
239}
240
241#endif /* Need GC_apply_to_maps */
242
243#if defined(LINUX) && (defined(USE_PROC_FOR_LIBRARIES) || defined(IA64))
244//
245// GC_parse_map_entry parses an entry from /proc/self/maps so we can
246// locate all writable data segments that belong to shared libraries.
247// The format of one of these entries and the fields we care about
248// is as follows:
249// XXXXXXXX-XXXXXXXX r-xp 00000000 30:05 260537 name of mapping...\n
250// ^^^^^^^^ ^^^^^^^^ ^^^^ ^^
251// start end prot maj_dev
252//
253// Note that since about auguat 2003 kernels, the columns no longer have
254// fixed offsets on 64-bit kernels. Hence we no longer rely on fixed offsets
255// anywhere, which is safer anyway.
256//
257
258/*
259 * Assign various fields of the first line in buf_ptr to *start, *end,
260 * *prot_buf and *maj_dev. Only *prot_buf may be set for unwritable maps.
261 */
262char *GC_parse_map_entry(char *buf_ptr, word *start, word *end,
263 char *prot_buf, unsigned int *maj_dev)
264{
265 char *start_start, *end_start, *prot_start, *maj_dev_start;
266 char *p;
267 char *endp;
268
269 if (buf_ptr == NULL || *buf_ptr == '\0') {
270 return NULL;
271 }
272
273 p = buf_ptr;
274 while (isspace(*p)) ++p;
275 start_start = p;
276 GC_ASSERT(isxdigit(*start_start));
277 *start = strtoul(start_start, &endp, 16); p = endp;
278 GC_ASSERT(*p=='-');
279
280 ++p;
281 end_start = p;
282 GC_ASSERT(isxdigit(*end_start));
283 *end = strtoul(end_start, &endp, 16); p = endp;
284 GC_ASSERT(isspace(*p));
285
286 while (isspace(*p)) ++p;
287 prot_start = p;
288 GC_ASSERT(*prot_start == 'r' || *prot_start == '-');
289 memcpy(prot_buf, prot_start, 4);
290 prot_buf[4] = '\0';
291 if (prot_buf[1] == 'w') {/* we can skip the rest if it's not writable. */
292 /* Skip past protection field to offset field */
293 while (!isspace(*p)) ++p; while (isspace(*p)) ++p;
294 GC_ASSERT(isxdigit(*p));
295 /* Skip past offset field, which we ignore */
296 while (!isspace(*p)) ++p; while (isspace(*p)) ++p;
297 maj_dev_start = p;
298 GC_ASSERT(isxdigit(*maj_dev_start));
299 *maj_dev = strtoul(maj_dev_start, NULL, 16);
300 }
301
302 while (*p && *p++ != '\n');
303
304 return p;
305}
306
307#endif /* Need to parse /proc/self/maps. */
308
309#if defined(SEARCH_FOR_DATA_START)
310 /* The I386 case can be handled without a search. The Alpha case */
311 /* used to be handled differently as well, but the rules changed */
312 /* for recent Linux versions. This seems to be the easiest way to */
313 /* cover all versions. */
314
315# ifdef LINUX
316 /* Some Linux distributions arrange to define __data_start. Some */
317 /* define data_start as a weak symbol. The latter is technically */
318 /* broken, since the user program may define data_start, in which */
319 /* case we lose. Nonetheless, we try both, prefering __data_start. */
320 /* We assume gcc-compatible pragmas. */
321# pragma weak __data_start
322 extern int __data_start[];
323# pragma weak data_start
324 extern int data_start[];
325# endif /* LINUX */
326 extern int _end[];
327
328 ptr_t GC_data_start;
329
330 void GC_init_linux_data_start()
331 {
332 extern ptr_t GC_find_limit();
333
334# ifdef LINUX
335 /* Try the easy approaches first: */
336 if ((ptr_t)__data_start != 0) {
337 GC_data_start = (ptr_t)(__data_start);
338 return;
339 }
340 if ((ptr_t)data_start != 0) {
341 GC_data_start = (ptr_t)(data_start);
342 return;
343 }
344# endif /* LINUX */
345 GC_data_start = GC_find_limit((ptr_t)(_end), FALSE);
346 }
347#endif
348
349# ifdef ECOS
350
351# ifndef ECOS_GC_MEMORY_SIZE
352# define ECOS_GC_MEMORY_SIZE (448 * 1024)
353# endif /* ECOS_GC_MEMORY_SIZE */
354
355// setjmp() function, as described in ANSI para 7.6.1.1
356#undef SETJMP
357#define SETJMP( __env__ ) hal_setjmp( __env__ )
358
359// FIXME: This is a simple way of allocating memory which is
360// compatible with ECOS early releases. Later releases use a more
361// sophisticated means of allocating memory than this simple static
362// allocator, but this method is at least bound to work.
363static char memory[ECOS_GC_MEMORY_SIZE];
364static char *brk = memory;
365
366static void *tiny_sbrk(ptrdiff_t increment)
367{
368 void *p = brk;
369
370 brk += increment;
371
372 if (brk > memory + sizeof memory)
373 {
374 brk -= increment;
375 return NULL;
376 }
377
378 return p;
379}
380#define sbrk tiny_sbrk
381# endif /* ECOS */
382
383#if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__)
384 ptr_t GC_data_start;
385
386 void GC_init_netbsd_elf()
387 {
388 extern ptr_t GC_find_limit();
389 extern char **environ;
390 /* This may need to be environ, without the underscore, for */
391 /* some versions. */
392 GC_data_start = GC_find_limit((ptr_t)&environ, FALSE);
393 }
394#endif
395
396# ifdef OS2
397
398# include <stddef.h>
399
400# if !defined(__IBMC__) && !defined(__WATCOMC__) /* e.g. EMX */
401
402struct exe_hdr {
403 unsigned short magic_number;
404 unsigned short padding[29];
405 long new_exe_offset;
406};
407
408#define E_MAGIC(x) (x).magic_number
409#define EMAGIC 0x5A4D
410#define E_LFANEW(x) (x).new_exe_offset
411
412struct e32_exe {
413 unsigned char magic_number[2];
414 unsigned char byte_order;
415 unsigned char word_order;
416 unsigned long exe_format_level;
417 unsigned short cpu;
418 unsigned short os;
419 unsigned long padding1[13];
420 unsigned long object_table_offset;
421 unsigned long object_count;
422 unsigned long padding2[31];
423};
424
425#define E32_MAGIC1(x) (x).magic_number[0]
426#define E32MAGIC1 'L'
427#define E32_MAGIC2(x) (x).magic_number[1]
428#define E32MAGIC2 'X'
429#define E32_BORDER(x) (x).byte_order
430#define E32LEBO 0
431#define E32_WORDER(x) (x).word_order
432#define E32LEWO 0
433#define E32_CPU(x) (x).cpu
434#define E32CPU286 1
435#define E32_OBJTAB(x) (x).object_table_offset
436#define E32_OBJCNT(x) (x).object_count
437
438struct o32_obj {
439 unsigned long size;
440 unsigned long base;
441 unsigned long flags;
442 unsigned long pagemap;
443 unsigned long mapsize;
444 unsigned long reserved;
445};
446
447#define O32_FLAGS(x) (x).flags
448#define OBJREAD 0x0001L
449#define OBJWRITE 0x0002L
450#define OBJINVALID 0x0080L
451#define O32_SIZE(x) (x).size
452#define O32_BASE(x) (x).base
453
454# else /* IBM's compiler */
455
456/* A kludge to get around what appears to be a header file bug */
457# ifndef WORD
458# define WORD unsigned short
459# endif
460# ifndef DWORD
461# define DWORD unsigned long
462# endif
463
464# define EXE386 1
465# include <newexe.h>
466# include <exe386.h>
467
468# endif /* __IBMC__ */
469
470# define INCL_DOSEXCEPTIONS
471# define INCL_DOSPROCESS
472# define INCL_DOSERRORS
473# define INCL_DOSMODULEMGR
474# define INCL_DOSMEMMGR
475# include <os2.h>
476
477
478/* Disable and enable signals during nontrivial allocations */
479
480void GC_disable_signals(void)
481{
482 ULONG nest;
483
484 DosEnterMustComplete(&nest);
485 if (nest != 1) ABORT("nested GC_disable_signals");
486}
487
488void GC_enable_signals(void)
489{
490 ULONG nest;
491
492 DosExitMustComplete(&nest);
493 if (nest != 0) ABORT("GC_enable_signals");
494}
495
496
497# else
498
499# if !defined(PCR) && !defined(AMIGA) && !defined(MSWIN32) \
500 && !defined(MSWINCE) \
501 && !defined(MACOS) && !defined(DJGPP) && !defined(DOS4GW) \
502 && !defined(NOSYS) && !defined(ECOS)
503
504# if defined(sigmask) && !defined(UTS4) && !defined(HURD)
505 /* Use the traditional BSD interface */
506# define SIGSET_T int
507# define SIG_DEL(set, signal) (set) &= ~(sigmask(signal))
508# define SIG_FILL(set) (set) = 0x7fffffff
509 /* Setting the leading bit appears to provoke a bug in some */
510 /* longjmp implementations. Most systems appear not to have */
511 /* a signal 32. */
512# define SIGSETMASK(old, new) (old) = sigsetmask(new)
513# else
514 /* Use POSIX/SYSV interface */
515# define SIGSET_T sigset_t
516# define SIG_DEL(set, signal) sigdelset(&(set), (signal))
517# define SIG_FILL(set) sigfillset(&set)
518# define SIGSETMASK(old, new) sigprocmask(SIG_SETMASK, &(new), &(old))
519# endif
520
521static GC_bool mask_initialized = FALSE;
522
523static SIGSET_T new_mask;
524
525static SIGSET_T old_mask;
526
527static SIGSET_T dummy;
528
529#if defined(PRINTSTATS) && !defined(THREADS)
530# define CHECK_SIGNALS
531 int GC_sig_disabled = 0;
532#endif
533
534void GC_disable_signals()
535{
536 if (!mask_initialized) {
537 SIG_FILL(new_mask);
538
539 SIG_DEL(new_mask, SIGSEGV);
540 SIG_DEL(new_mask, SIGILL);
541 SIG_DEL(new_mask, SIGQUIT);
542# ifdef SIGBUS
543 SIG_DEL(new_mask, SIGBUS);
544# endif
545# ifdef SIGIOT
546 SIG_DEL(new_mask, SIGIOT);
547# endif
548# ifdef SIGEMT
549 SIG_DEL(new_mask, SIGEMT);
550# endif
551# ifdef SIGTRAP
552 SIG_DEL(new_mask, SIGTRAP);
553# endif
554 mask_initialized = TRUE;
555 }
556# ifdef CHECK_SIGNALS
557 if (GC_sig_disabled != 0) ABORT("Nested disables");
558 GC_sig_disabled++;
559# endif
560 SIGSETMASK(old_mask,new_mask);
561}
562
563void GC_enable_signals()
564{
565# ifdef CHECK_SIGNALS
566 if (GC_sig_disabled != 1) ABORT("Unmatched enable");
567 GC_sig_disabled--;
568# endif
569 SIGSETMASK(dummy,old_mask);
570}
571
572# endif /* !PCR */
573
574# endif /*!OS/2 */
575
576/* Ivan Demakov: simplest way (to me) */
577#if defined (DOS4GW)
578 void GC_disable_signals() { }
579 void GC_enable_signals() { }
580#endif
581
582/* Find the page size */
583word GC_page_size;
584
585# if defined(MSWIN32) || defined(MSWINCE)
586 void GC_setpagesize()
587 {
588 GetSystemInfo(&GC_sysinfo);
589 GC_page_size = GC_sysinfo.dwPageSize;
590 }
591
592# else
593# if defined(MPROTECT_VDB) || defined(PROC_VDB) || defined(USE_MMAP) \
594 || defined(USE_MUNMAP)
595 void GC_setpagesize()
596 {
597 GC_page_size = GETPAGESIZE();
598 }
599# else
600 /* It's acceptable to fake it. */
601 void GC_setpagesize()
602 {
603 GC_page_size = HBLKSIZE;
604 }
605# endif
606# endif
607
608/*
609 * Find the base of the stack.
610 * Used only in single-threaded environment.
611 * With threads, GC_mark_roots needs to know how to do this.
612 * Called with allocator lock held.
613 */
614# if defined(MSWIN32) || defined(MSWINCE)
615# define is_writable(prot) ((prot) == PAGE_READWRITE \
616 || (prot) == PAGE_WRITECOPY \
617 || (prot) == PAGE_EXECUTE_READWRITE \
618 || (prot) == PAGE_EXECUTE_WRITECOPY)
619/* Return the number of bytes that are writable starting at p. */
620/* The pointer p is assumed to be page aligned. */
621/* If base is not 0, *base becomes the beginning of the */
622/* allocation region containing p. */
623word GC_get_writable_length(ptr_t p, ptr_t *base)
624{
625 MEMORY_BASIC_INFORMATION buf;
626 word result;
627 word protect;
628
629 result = VirtualQuery(p, &buf, sizeof(buf));
630 if (result != sizeof(buf)) ABORT("Weird VirtualQuery result");
631 if (base != 0) *base = (ptr_t)(buf.AllocationBase);
632 protect = (buf.Protect & ~(PAGE_GUARD | PAGE_NOCACHE));
633 if (!is_writable(protect)) {
634 return(0);
635 }
636 if (buf.State != MEM_COMMIT) return(0);
637 return(buf.RegionSize);
638}
639
640ptr_t GC_get_stack_base()
641{
642 int dummy;
643 ptr_t sp = (ptr_t)(&dummy);
644 ptr_t trunc_sp = (ptr_t)((word)sp & ~(GC_page_size - 1));
645 word size = GC_get_writable_length(trunc_sp, 0);
646
647 return(trunc_sp + size);
648}
649
650
651# endif /* MS Windows */
652
653# ifdef BEOS
654# include <kernel/OS.h>
655ptr_t GC_get_stack_base(){
656 thread_info th;
657 get_thread_info(find_thread(NULL),&th);
658 return th.stack_end;
659}
660# endif /* BEOS */
661
662
663# ifdef OS2
664
665ptr_t GC_get_stack_base()
666{
667 PTIB ptib;
668 PPIB ppib;
669
670 if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
671 GC_err_printf0("DosGetInfoBlocks failed\n");
672 ABORT("DosGetInfoBlocks failed\n");
673 }
674 return((ptr_t)(ptib -> tib_pstacklimit));
675}
676
677# endif /* OS2 */
678
679# ifdef AMIGA
680# define GC_AMIGA_SB
681# include "AmigaOS.c"
682# undef GC_AMIGA_SB
683# endif /* AMIGA */
684
685# if defined(NEED_FIND_LIMIT) || defined(UNIX_LIKE)
686
687# ifdef __STDC__
688 typedef void (*handler)(int);
689# else
690 typedef void (*handler)();
691# endif
692
693# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) \
694 || defined(HURD) || defined(NETBSD)
695 static struct sigaction old_segv_act;
696# if defined(IRIX5) || defined(HPUX) \
697 || defined(HURD) || defined(NETBSD)
698 static struct sigaction old_bus_act;
699# endif
700# else
701 static handler old_segv_handler, old_bus_handler;
702# endif
703
704# ifdef __STDC__
705 void GC_set_and_save_fault_handler(handler h)
706# else
707 void GC_set_and_save_fault_handler(h)
708 handler h;
709# endif
710 {
711# if defined(SUNOS5SIGS) || defined(IRIX5) \
712 || defined(OSF1) || defined(HURD) || defined(NETBSD)
713 struct sigaction act;
714
715 act.sa_handler = h;
716# if 0 /* Was necessary for Solaris 2.3 and very temporary */
717 /* NetBSD bugs. */
718 act.sa_flags = SA_RESTART | SA_NODEFER;
719# else
720 act.sa_flags = SA_RESTART;
721# endif
722
723 (void) sigemptyset(&act.sa_mask);
724# ifdef GC_IRIX_THREADS
725 /* Older versions have a bug related to retrieving and */
726 /* and setting a handler at the same time. */
727 (void) sigaction(SIGSEGV, 0, &old_segv_act);
728 (void) sigaction(SIGSEGV, &act, 0);
729 (void) sigaction(SIGBUS, 0, &old_bus_act);
730 (void) sigaction(SIGBUS, &act, 0);
731# else
732 (void) sigaction(SIGSEGV, &act, &old_segv_act);
733# if defined(IRIX5) \
734 || defined(HPUX) || defined(HURD) || defined(NETBSD)
735 /* Under Irix 5.x or HP/UX, we may get SIGBUS. */
736 /* Pthreads doesn't exist under Irix 5.x, so we */
737 /* don't have to worry in the threads case. */
738 (void) sigaction(SIGBUS, &act, &old_bus_act);
739# endif
740# endif /* GC_IRIX_THREADS */
741# else
742 old_segv_handler = signal(SIGSEGV, h);
743# ifdef SIGBUS
744 old_bus_handler = signal(SIGBUS, h);
745# endif
746# endif
747 }
748# endif /* NEED_FIND_LIMIT || UNIX_LIKE */
749
750# ifdef NEED_FIND_LIMIT
751 /* Some tools to implement HEURISTIC2 */
752# define MIN_PAGE_SIZE 256 /* Smallest conceivable page size, bytes */
753 /* static */ JMP_BUF GC_jmp_buf;
754
755 /*ARGSUSED*/
756 void GC_fault_handler(sig)
757 int sig;
758 {
759 LONGJMP(GC_jmp_buf, 1);
760 }
761
762 void GC_setup_temporary_fault_handler()
763 {
764 GC_set_and_save_fault_handler(GC_fault_handler);
765 }
766
767 void GC_reset_fault_handler()
768 {
769# if defined(SUNOS5SIGS) || defined(IRIX5) \
770 || defined(OSF1) || defined(HURD) || defined(NETBSD)
771 (void) sigaction(SIGSEGV, &old_segv_act, 0);
772# if defined(IRIX5) \
773 || defined(HPUX) || defined(HURD) || defined(NETBSD)
774 (void) sigaction(SIGBUS, &old_bus_act, 0);
775# endif
776# else
777 (void) signal(SIGSEGV, old_segv_handler);
778# ifdef SIGBUS
779 (void) signal(SIGBUS, old_bus_handler);
780# endif
781# endif
782 }
783
784 /* Return the first nonaddressible location > p (up) or */
785 /* the smallest location q s.t. [q,p) is addressable (!up). */
786 /* We assume that p (up) or p-1 (!up) is addressable. */
787 ptr_t GC_find_limit(p, up)
788 ptr_t p;
789 GC_bool up;
790 {
791 static VOLATILE ptr_t result;
792 /* Needs to be static, since otherwise it may not be */
793 /* preserved across the longjmp. Can safely be */
794 /* static since it's only called once, with the */
795 /* allocation lock held. */
796
797
798 GC_setup_temporary_fault_handler();
799 if (SETJMP(GC_jmp_buf) == 0) {
800 result = (ptr_t)(((word)(p))
801 & ~(MIN_PAGE_SIZE-1));
802 for (;;) {
803 if (up) {
804 result += MIN_PAGE_SIZE;
805 } else {
806 result -= MIN_PAGE_SIZE;
807 }
808 GC_noop1((word)(*result));
809 }
810 }
811 GC_reset_fault_handler();
812 if (!up) {
813 result += MIN_PAGE_SIZE;
814 }
815 return(result);
816 }
817# endif
818
819#if defined(ECOS) || defined(NOSYS)
820 ptr_t GC_get_stack_base()
821 {
822 return STACKBOTTOM;
823 }
824#endif
825
826#ifdef HPUX_STACKBOTTOM
827
828#include <sys/param.h>
829#include <sys/pstat.h>
830
831 ptr_t GC_get_register_stack_base(void)
832 {
833 struct pst_vm_status vm_status;
834
835 int i = 0;
836 while (pstat_getprocvm(&vm_status, sizeof(vm_status), 0, i++) == 1) {
837 if (vm_status.pst_type == PS_RSESTACK) {
838 return (ptr_t) vm_status.pst_vaddr;
839 }
840 }
841
842 /* old way to get the register stackbottom */
843 return (ptr_t)(((word)GC_stackbottom - BACKING_STORE_DISPLACEMENT - 1)
844 & ~(BACKING_STORE_ALIGNMENT - 1));
845 }
846
847#endif /* HPUX_STACK_BOTTOM */
848
849#ifdef LINUX_STACKBOTTOM
850
851#include <sys/types.h>
852#include <sys/stat.h>
853
854# define STAT_SKIP 27 /* Number of fields preceding startstack */
855 /* field in /proc/self/stat */
856
857#ifdef USE_LIBC_PRIVATES
858# pragma weak __libc_stack_end
859 extern ptr_t __libc_stack_end;
860#endif
861
862# ifdef IA64
863 /* Try to read the backing store base from /proc/self/maps. */
864 /* We look for the writable mapping with a 0 major device, */
865 /* which is as close to our frame as possible, but below it.*/
866 static word backing_store_base_from_maps(char *maps)
867 {
868 char prot_buf[5];
869 char *buf_ptr = maps;
870 word start, end;
871 unsigned int maj_dev;
872 word current_best = 0;
873 word dummy;
874
875 for (;;) {
876 buf_ptr = GC_parse_map_entry(buf_ptr, &start, &end, prot_buf, &maj_dev);
877 if (buf_ptr == NULL) return current_best;
878 if (prot_buf[1] == 'w' && maj_dev == 0) {
879 if (end < (word)(&dummy) && start > current_best) current_best = start;
880 }
881 }
882 return current_best;
883 }
884
885 static word backing_store_base_from_proc(void)
886 {
887 return GC_apply_to_maps(backing_store_base_from_maps);
888 }
889
890# ifdef USE_LIBC_PRIVATES
891# pragma weak __libc_ia64_register_backing_store_base
892 extern ptr_t __libc_ia64_register_backing_store_base;
893# endif
894
895 ptr_t GC_get_register_stack_base(void)
896 {
897# ifdef USE_LIBC_PRIVATES
898 if (0 != &__libc_ia64_register_backing_store_base
899 && 0 != __libc_ia64_register_backing_store_base) {
900 /* Glibc 2.2.4 has a bug such that for dynamically linked */
901 /* executables __libc_ia64_register_backing_store_base is */
902 /* defined but uninitialized during constructor calls. */
903 /* Hence we check for both nonzero address and value. */
904 return __libc_ia64_register_backing_store_base;
905 }
906# endif
907 word result = backing_store_base_from_proc();
908 if (0 == result) {
909 /* Use dumb heuristics. Works only for default configuration. */
910 result = (word)GC_stackbottom - BACKING_STORE_DISPLACEMENT;
911 result += BACKING_STORE_ALIGNMENT - 1;
912 result &= ~(BACKING_STORE_ALIGNMENT - 1);
913 /* Verify that it's at least readable. If not, we goofed. */
914 GC_noop1(*(word *)result);
915 }
916 return (ptr_t)result;
917 }
918# endif
919
920 ptr_t GC_linux_stack_base(void)
921 {
922 /* We read the stack base value from /proc/self/stat. We do this */
923 /* using direct I/O system calls in order to avoid calling malloc */
924 /* in case REDIRECT_MALLOC is defined. */
925# define STAT_BUF_SIZE 4096
926# define STAT_READ read
927 /* Should probably call the real read, if read is wrapped. */
928 char stat_buf[STAT_BUF_SIZE];
929 int f;
930 char c;
931 word result = 0;
932 size_t i, buf_offset = 0;
933
934 /* First try the easy way. This should work for glibc 2.2 */
935 /* This fails in a prelinked ("prelink" command) executable */
936 /* since the correct value of __libc_stack_end never */
937 /* becomes visible to us. The second test works around */
938 /* this. */
939# ifdef USE_LIBC_PRIVATES
940 if (0 != &__libc_stack_end && 0 != __libc_stack_end ) {
941# ifdef IA64
942 /* Some versions of glibc set the address 16 bytes too */
943 /* low while the initialization code is running. */
944 if (((word)__libc_stack_end & 0xfff) + 0x10 < 0x1000) {
945 return __libc_stack_end + 0x10;
946 } /* Otherwise it's not safe to add 16 bytes and we fall */
947 /* back to using /proc. */
948# else
949# ifdef SPARC
950 /* Older versions of glibc for 64-bit Sparc do not set
951 * this variable correctly, it gets set to either zero
952 * or one.
953 */
954 if (__libc_stack_end != (ptr_t) (unsigned long)0x1)
955 return __libc_stack_end;
956# else
957 return __libc_stack_end;
958# endif
959# endif
960 }
961# endif
962 f = open("/proc/self/stat", O_RDONLY);
963 if (f < 0 || STAT_READ(f, stat_buf, STAT_BUF_SIZE) < 2 * STAT_SKIP) {
964 ABORT("Couldn't read /proc/self/stat");
965 }
966 c = stat_buf[buf_offset++];
967 /* Skip the required number of fields. This number is hopefully */
968 /* constant across all Linux implementations. */
969 for (i = 0; i < STAT_SKIP; ++i) {
970 while (isspace(c)) c = stat_buf[buf_offset++];
971 while (!isspace(c)) c = stat_buf[buf_offset++];
972 }
973 while (isspace(c)) c = stat_buf[buf_offset++];
974 while (isdigit(c)) {
975 result *= 10;
976 result += c - '0';
977 c = stat_buf[buf_offset++];
978 }
979 close(f);
980 if (result < 0x10000000) ABORT("Absurd stack bottom value");
981 return (ptr_t)result;
982 }
983
984#endif /* LINUX_STACKBOTTOM */
985
986#ifdef FREEBSD_STACKBOTTOM
987
988/* This uses an undocumented sysctl call, but at least one expert */
989/* believes it will stay. */
990
991#include <unistd.h>
992#include <sys/types.h>
993#include <sys/sysctl.h>
994
995 ptr_t GC_freebsd_stack_base(void)
996 {
997 int nm[2] = {CTL_KERN, KERN_USRSTACK};
998 ptr_t base;
999 size_t len = sizeof(ptr_t);
1000 int r = sysctl(nm, 2, &base, &len, NULL, 0);
1001
1002 if (r) ABORT("Error getting stack base");
1003
1004 return base;
1005 }
1006
1007#endif /* FREEBSD_STACKBOTTOM */
1008
1009#if !defined(BEOS) && !defined(AMIGA) && !defined(MSWIN32) \
1010 && !defined(MSWINCE) && !defined(OS2) && !defined(NOSYS) && !defined(ECOS)
1011
1012ptr_t GC_get_stack_base()
1013{
1014# if defined(HEURISTIC1) || defined(HEURISTIC2) || \
1015 defined(LINUX_STACKBOTTOM) || defined(FREEBSD_STACKBOTTOM)
1016 word dummy;
1017 ptr_t result;
1018# endif
1019
1020# define STACKBOTTOM_ALIGNMENT_M1 ((word)STACK_GRAN - 1)
1021
1022# ifdef STACKBOTTOM
1023 return(STACKBOTTOM);
1024# else
1025# ifdef HEURISTIC1
1026# ifdef STACK_GROWS_DOWN
1027 result = (ptr_t)((((word)(&dummy))
1028 + STACKBOTTOM_ALIGNMENT_M1)
1029 & ~STACKBOTTOM_ALIGNMENT_M1);
1030# else
1031 result = (ptr_t)(((word)(&dummy))
1032 & ~STACKBOTTOM_ALIGNMENT_M1);
1033# endif
1034# endif /* HEURISTIC1 */
1035# ifdef LINUX_STACKBOTTOM
1036 result = GC_linux_stack_base();
1037# endif
1038# ifdef FREEBSD_STACKBOTTOM
1039 result = GC_freebsd_stack_base();
1040# endif
1041# ifdef HEURISTIC2
1042# ifdef STACK_GROWS_DOWN
1043 result = GC_find_limit((ptr_t)(&dummy), TRUE);
1044# ifdef HEURISTIC2_LIMIT
1045 if (result > HEURISTIC2_LIMIT
1046 && (ptr_t)(&dummy) < HEURISTIC2_LIMIT) {
1047 result = HEURISTIC2_LIMIT;
1048 }
1049# endif
1050# else
1051 result = GC_find_limit((ptr_t)(&dummy), FALSE);
1052# ifdef HEURISTIC2_LIMIT
1053 if (result < HEURISTIC2_LIMIT
1054 && (ptr_t)(&dummy) > HEURISTIC2_LIMIT) {
1055 result = HEURISTIC2_LIMIT;
1056 }
1057# endif
1058# endif
1059
1060# endif /* HEURISTIC2 */
1061# ifdef STACK_GROWS_DOWN
1062 if (result == 0) result = (ptr_t)(signed_word)(-sizeof(ptr_t));
1063# endif
1064 return(result);
1065# endif /* STACKBOTTOM */
1066}
1067
1068# endif /* ! AMIGA, !OS 2, ! MS Windows, !BEOS, !NOSYS, !ECOS */
1069
1070/*
1071 * Register static data segment(s) as roots.
1072 * If more data segments are added later then they need to be registered
1073 * add that point (as we do with SunOS dynamic loading),
1074 * or GC_mark_roots needs to check for them (as we do with PCR).
1075 * Called with allocator lock held.
1076 */
1077
1078# ifdef OS2
1079
1080void GC_register_data_segments()
1081{
1082 PTIB ptib;
1083 PPIB ppib;
1084 HMODULE module_handle;
1085# define PBUFSIZ 512
1086 UCHAR path[PBUFSIZ];
1087 FILE * myexefile;
1088 struct exe_hdr hdrdos; /* MSDOS header. */
1089 struct e32_exe hdr386; /* Real header for my executable */
1090 struct o32_obj seg; /* Currrent segment */
1091 int nsegs;
1092
1093
1094 if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
1095 GC_err_printf0("DosGetInfoBlocks failed\n");
1096 ABORT("DosGetInfoBlocks failed\n");
1097 }
1098 module_handle = ppib -> pib_hmte;
1099 if (DosQueryModuleName(module_handle, PBUFSIZ, path) != NO_ERROR) {
1100 GC_err_printf0("DosQueryModuleName failed\n");
1101 ABORT("DosGetInfoBlocks failed\n");
1102 }
1103 myexefile = fopen(path, "rb");
1104 if (myexefile == 0) {
1105 GC_err_puts("Couldn't open executable ");
1106 GC_err_puts(path); GC_err_puts("\n");
1107 ABORT("Failed to open executable\n");
1108 }
1109 if (fread((char *)(&hdrdos), 1, sizeof hdrdos, myexefile) < sizeof hdrdos) {
1110 GC_err_puts("Couldn't read MSDOS header from ");
1111 GC_err_puts(path); GC_err_puts("\n");
1112 ABORT("Couldn't read MSDOS header");
1113 }
1114 if (E_MAGIC(hdrdos) != EMAGIC) {
1115 GC_err_puts("Executable has wrong DOS magic number: ");
1116 GC_err_puts(path); GC_err_puts("\n");
1117 ABORT("Bad DOS magic number");
1118 }
1119 if (fseek(myexefile, E_LFANEW(hdrdos), SEEK_SET) != 0) {
1120 GC_err_puts("Seek to new header failed in ");
1121 GC_err_puts(path); GC_err_puts("\n");
1122 ABORT("Bad DOS magic number");
1123 }
1124 if (fread((char *)(&hdr386), 1, sizeof hdr386, myexefile) < sizeof hdr386) {
1125 GC_err_puts("Couldn't read MSDOS header from ");
1126 GC_err_puts(path); GC_err_puts("\n");
1127 ABORT("Couldn't read OS/2 header");
1128 }
1129 if (E32_MAGIC1(hdr386) != E32MAGIC1 || E32_MAGIC2(hdr386) != E32MAGIC2) {
1130 GC_err_puts("Executable has wrong OS/2 magic number:");
1131 GC_err_puts(path); GC_err_puts("\n");
1132 ABORT("Bad OS/2 magic number");
1133 }
1134 if ( E32_BORDER(hdr386) != E32LEBO || E32_WORDER(hdr386) != E32LEWO) {
1135 GC_err_puts("Executable %s has wrong byte order: ");
1136 GC_err_puts(path); GC_err_puts("\n");
1137 ABORT("Bad byte order");
1138 }
1139 if ( E32_CPU(hdr386) == E32CPU286) {
1140 GC_err_puts("GC can't handle 80286 executables: ");
1141 GC_err_puts(path); GC_err_puts("\n");
1142 EXIT();
1143 }
1144 if (fseek(myexefile, E_LFANEW(hdrdos) + E32_OBJTAB(hdr386),
1145 SEEK_SET) != 0) {
1146 GC_err_puts("Seek to object table failed: ");
1147 GC_err_puts(path); GC_err_puts("\n");
1148 ABORT("Seek to object table failed");
1149 }
1150 for (nsegs = E32_OBJCNT(hdr386); nsegs > 0; nsegs--) {
1151 int flags;
1152 if (fread((char *)(&seg), 1, sizeof seg, myexefile) < sizeof seg) {
1153 GC_err_puts("Couldn't read obj table entry from ");
1154 GC_err_puts(path); GC_err_puts("\n");
1155 ABORT("Couldn't read obj table entry");
1156 }
1157 flags = O32_FLAGS(seg);
1158 if (!(flags & OBJWRITE)) continue;
1159 if (!(flags & OBJREAD)) continue;
1160 if (flags & OBJINVALID) {
1161 GC_err_printf0("Object with invalid pages?\n");
1162 printf(" ----> %s: %x %x \n", path, O32_BASE(seg), O32_BASE(seg)+O32_SIZE(seg));
1163 continue;
1164 }
1165 printf("----> %s: %x %x \n", path, O32_BASE(seg), O32_BASE(seg)+O32_SIZE(seg));
1166 GC_add_roots_inner(O32_BASE(seg), O32_BASE(seg)+O32_SIZE(seg), FALSE);
1167 }
1168}
1169
1170# else /* !OS2 */
1171
1172# if defined(MSWIN32) || defined(MSWINCE)
1173
1174# ifdef MSWIN32
1175 /* Unfortunately, we have to handle win32s very differently from NT, */
1176 /* Since VirtualQuery has very different semantics. In particular, */
1177 /* under win32s a VirtualQuery call on an unmapped page returns an */
1178 /* invalid result. Under NT, GC_register_data_segments is a noop and */
1179 /* all real work is done by GC_register_dynamic_libraries. Under */
1180 /* win32s, we cannot find the data segments associated with dll's. */
1181 /* We register the main data segment here. */
1182 GC_bool GC_no_win32_dlls = FALSE;
1183 /* This used to be set for gcc, to avoid dealing with */
1184 /* the structured exception handling issues. But we now have */
1185 /* assembly code to do that right. */
1186 GC_bool GC_wnt = FALSE;
1187 /* This is a Windows NT derivative, i.e. NT, W2K, XP or later. */
1188
1189 void GC_init_win32()
1190 {
1191 /* if we're running under win32s, assume that no DLLs will be loaded */
1192 DWORD v = GetVersion();
1193 GC_wnt = !(v & 0x80000000);
1194 GC_no_win32_dlls |= ((!GC_wnt) && (v & 0xff) <= 3);
1195 }
1196
1197 /* Return the smallest address a such that VirtualQuery */
1198 /* returns correct results for all addresses between a and start. */
1199 /* Assumes VirtualQuery returns correct information for start. */
1200 ptr_t GC_least_described_address(ptr_t start)
1201 {
1202 MEMORY_BASIC_INFORMATION buf;
1203 DWORD result;
1204 LPVOID limit;
1205 ptr_t p;
1206 LPVOID q;
1207
1208 limit = GC_sysinfo.lpMinimumApplicationAddress;
1209 p = (ptr_t)((word)start & ~(GC_page_size - 1));
1210 for (;;) {
1211 q = (LPVOID)(p - GC_page_size);
1212 if ((ptr_t)q > (ptr_t)p /* underflow */ || q < limit) break;
1213 result = VirtualQuery(q, &buf, sizeof(buf));
1214 if (result != sizeof(buf) || buf.AllocationBase == 0) break;
1215 p = (ptr_t)(buf.AllocationBase);
1216 }
1217 return(p);
1218 }
1219# endif
1220
1221# ifndef REDIRECT_MALLOC
1222 /* We maintain a linked list of AllocationBase values that we know */
1223 /* correspond to malloc heap sections. Currently this is only called */
1224 /* during a GC. But there is some hope that for long running */
1225 /* programs we will eventually see most heap sections. */
1226
1227 /* In the long run, it would be more reliable to occasionally walk */
1228 /* the malloc heap with HeapWalk on the default heap. But that */
1229 /* apparently works only for NT-based Windows. */
1230
1231 /* In the long run, a better data structure would also be nice ... */
1232 struct GC_malloc_heap_list {
1233 void * allocation_base;
1234 struct GC_malloc_heap_list *next;
1235 } *GC_malloc_heap_l = 0;
1236
1237 /* Is p the base of one of the malloc heap sections we already know */
1238 /* about? */
1239 GC_bool GC_is_malloc_heap_base(ptr_t p)
1240 {
1241 struct GC_malloc_heap_list *q = GC_malloc_heap_l;
1242
1243 while (0 != q) {
1244 if (q -> allocation_base == p) return TRUE;
1245 q = q -> next;
1246 }
1247 return FALSE;
1248 }
1249
1250 void *GC_get_allocation_base(void *p)
1251 {
1252 MEMORY_BASIC_INFORMATION buf;
1253 DWORD result = VirtualQuery(p, &buf, sizeof(buf));
1254 if (result != sizeof(buf)) {
1255 ABORT("Weird VirtualQuery result");
1256 }
1257 return buf.AllocationBase;
1258 }
1259
1260 size_t GC_max_root_size = 100000; /* Appr. largest root size. */
1261
1262 void GC_add_current_malloc_heap()
1263 {
1264 struct GC_malloc_heap_list *new_l =
1265 malloc(sizeof(struct GC_malloc_heap_list));
1266 void * candidate = GC_get_allocation_base(new_l);
1267
1268 if (new_l == 0) return;
1269 if (GC_is_malloc_heap_base(candidate)) {
1270 /* Try a little harder to find malloc heap. */
1271 size_t req_size = 10000;
1272 do {
1273 void *p = malloc(req_size);
1274 if (0 == p) { free(new_l); return; }
1275 candidate = GC_get_allocation_base(p);
1276 free(p);
1277 req_size *= 2;
1278 } while (GC_is_malloc_heap_base(candidate)
1279 && req_size < GC_max_root_size/10 && req_size < 500000);
1280 if (GC_is_malloc_heap_base(candidate)) {
1281 free(new_l); return;
1282 }
1283 }
1284# ifdef CONDPRINT
1285 if (GC_print_stats)
1286 GC_printf1("Found new system malloc AllocationBase at 0x%lx\n",
1287 candidate);
1288# endif
1289 new_l -> allocation_base = candidate;
1290 new_l -> next = GC_malloc_heap_l;
1291 GC_malloc_heap_l = new_l;
1292 }
1293# endif /* REDIRECT_MALLOC */
1294
1295 /* Is p the start of either the malloc heap, or of one of our */
1296 /* heap sections? */
1297 GC_bool GC_is_heap_base (ptr_t p)
1298 {
1299
1300 unsigned i;
1301
1302# ifndef REDIRECT_MALLOC
1303 static word last_gc_no = -1;
1304
1305 if (last_gc_no != GC_gc_no) {
1306 GC_add_current_malloc_heap();
1307 last_gc_no = GC_gc_no;
1308 }
1309 if (GC_root_size > GC_max_root_size) GC_max_root_size = GC_root_size;
1310 if (GC_is_malloc_heap_base(p)) return TRUE;
1311# endif
1312 for (i = 0; i < GC_n_heap_bases; i++) {
1313 if (GC_heap_bases[i] == p) return TRUE;
1314 }
1315 return FALSE ;
1316 }
1317
1318# ifdef MSWIN32
1319 void GC_register_root_section(ptr_t static_root)
1320 {
1321 MEMORY_BASIC_INFORMATION buf;
1322 DWORD result;
1323 DWORD protect;
1324 LPVOID p;
1325 char * base;
1326 char * limit, * new_limit;
1327
1328 if (!GC_no_win32_dlls) return;
1329 p = base = limit = GC_least_described_address(static_root);
1330 while (p < GC_sysinfo.lpMaximumApplicationAddress) {
1331 result = VirtualQuery(p, &buf, sizeof(buf));
1332 if (result != sizeof(buf) || buf.AllocationBase == 0
1333 || GC_is_heap_base(buf.AllocationBase)) break;
1334 new_limit = (char *)p + buf.RegionSize;
1335 protect = buf.Protect;
1336 if (buf.State == MEM_COMMIT
1337 && is_writable(protect)) {
1338 if ((char *)p == limit) {
1339 limit = new_limit;
1340 } else {
1341 if (base != limit) GC_add_roots_inner(base, limit, FALSE);
1342 base = p;
1343 limit = new_limit;
1344 }
1345 }
1346 if (p > (LPVOID)new_limit /* overflow */) break;
1347 p = (LPVOID)new_limit;
1348 }
1349 if (base != limit) GC_add_roots_inner(base, limit, FALSE);
1350 }
1351#endif
1352
1353 void GC_register_data_segments()
1354 {
1355# ifdef MSWIN32
1356 static char dummy;
1357 GC_register_root_section((ptr_t)(&dummy));
1358# endif
1359 }
1360
1361# else /* !OS2 && !Windows */
1362
1363# if (defined(SVR4) || defined(AUX) || defined(DGUX) \
1364 || (defined(LINUX) && defined(SPARC))) && !defined(PCR)
1365ptr_t GC_SysVGetDataStart(max_page_size, etext_addr)
1366int max_page_size;
1367int * etext_addr;
1368{
1369 word text_end = ((word)(etext_addr) + sizeof(word) - 1)
1370 & ~(sizeof(word) - 1);
1371 /* etext rounded to word boundary */
1372 word next_page = ((text_end + (word)max_page_size - 1)
1373 & ~((word)max_page_size - 1));
1374 word page_offset = (text_end & ((word)max_page_size - 1));
1375 VOLATILE char * result = (char *)(next_page + page_offset);
1376 /* Note that this isnt equivalent to just adding */
1377 /* max_page_size to &etext if &etext is at a page boundary */
1378
1379 GC_setup_temporary_fault_handler();
1380 if (SETJMP(GC_jmp_buf) == 0) {
1381 /* Try writing to the address. */
1382 *result = *result;
1383 GC_reset_fault_handler();
1384 } else {
1385 GC_reset_fault_handler();
1386 /* We got here via a longjmp. The address is not readable. */
1387 /* This is known to happen under Solaris 2.4 + gcc, which place */
1388 /* string constants in the text segment, but after etext. */
1389 /* Use plan B. Note that we now know there is a gap between */
1390 /* text and data segments, so plan A bought us something. */
1391 result = (char *)GC_find_limit((ptr_t)(DATAEND), FALSE);
1392 }
1393 return((ptr_t)result);
1394}
1395# endif
1396
1397# if defined(FREEBSD) && (defined(I386) || defined(powerpc) || defined(__powerpc__)) && !defined(PCR)
1398/* Its unclear whether this should be identical to the above, or */
1399/* whether it should apply to non-X86 architectures. */
1400/* For now we don't assume that there is always an empty page after */
1401/* etext. But in some cases there actually seems to be slightly more. */
1402/* This also deals with holes between read-only data and writable data. */
1403ptr_t GC_FreeBSDGetDataStart(max_page_size, etext_addr)
1404int max_page_size;
1405int * etext_addr;
1406{
1407 word text_end = ((word)(etext_addr) + sizeof(word) - 1)
1408 & ~(sizeof(word) - 1);
1409 /* etext rounded to word boundary */
1410 VOLATILE word next_page = (text_end + (word)max_page_size - 1)
1411 & ~((word)max_page_size - 1);
1412 VOLATILE ptr_t result = (ptr_t)text_end;
1413 GC_setup_temporary_fault_handler();
1414 if (SETJMP(GC_jmp_buf) == 0) {
1415 /* Try reading at the address. */
1416 /* This should happen before there is another thread. */
1417 for (; next_page < (word)(DATAEND); next_page += (word)max_page_size)
1418 *(VOLATILE char *)next_page;
1419 GC_reset_fault_handler();
1420 } else {
1421 GC_reset_fault_handler();
1422 /* As above, we go to plan B */
1423 result = GC_find_limit((ptr_t)(DATAEND), FALSE);
1424 }
1425 return(result);
1426}
1427
1428# endif
1429
1430
1431#ifdef AMIGA
1432
1433# define GC_AMIGA_DS
1434# include "AmigaOS.c"
1435# undef GC_AMIGA_DS
1436
1437#else /* !OS2 && !Windows && !AMIGA */
1438
1439void GC_register_data_segments()
1440{
1441# if !defined(PCR) && !defined(SRC_M3) && !defined(MACOS)
1442# if defined(REDIRECT_MALLOC) && defined(GC_SOLARIS_THREADS)
1443 /* As of Solaris 2.3, the Solaris threads implementation */
1444 /* allocates the data structure for the initial thread with */
1445 /* sbrk at process startup. It needs to be scanned, so that */
1446 /* we don't lose some malloc allocated data structures */
1447 /* hanging from it. We're on thin ice here ... */
1448 extern caddr_t sbrk();
1449
1450 GC_add_roots_inner(DATASTART, (char *)sbrk(0), FALSE);
1451# else
1452 GC_add_roots_inner(DATASTART, (char *)(DATAEND), FALSE);
1453# if defined(DATASTART2)
1454 GC_add_roots_inner(DATASTART2, (char *)(DATAEND2), FALSE);
1455# endif
1456# endif
1457# endif
1458# if defined(MACOS)
1459 {
1460# if defined(THINK_C)
1461 extern void* GC_MacGetDataStart(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# else
1466# if defined(__MWERKS__)
1467# if !__POWERPC__
1468 extern void* GC_MacGetDataStart(void);
1469 /* MATTHEW: Function to handle Far Globals (CW Pro 3) */
1470# if __option(far_data)
1471 extern void* GC_MacGetDataEnd(void);
1472# endif
1473 /* globals begin above stack and end at a5. */
1474 GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
1475 (ptr_t)LMGetCurrentA5(), FALSE);
1476 /* MATTHEW: Handle Far Globals */
1477# if __option(far_data)
1478 /* Far globals follow he QD globals: */
1479 GC_add_roots_inner((ptr_t)LMGetCurrentA5(),
1480 (ptr_t)GC_MacGetDataEnd(), FALSE);
1481# endif
1482# else
1483 extern char __data_start__[], __data_end__[];
1484 GC_add_roots_inner((ptr_t)&__data_start__,
1485 (ptr_t)&__data_end__, FALSE);
1486# endif /* __POWERPC__ */
1487# endif /* __MWERKS__ */
1488# endif /* !THINK_C */
1489 }
1490# endif /* MACOS */
1491
1492 /* Dynamic libraries are added at every collection, since they may */
1493 /* change. */
1494}
1495
1496# endif /* ! AMIGA */
1497# endif /* ! MSWIN32 && ! MSWINCE*/
1498# endif /* ! OS2 */
1499
1500/*
1501 * Auxiliary routines for obtaining memory from OS.
1502 */
1503
1504# if !defined(OS2) && !defined(PCR) && !defined(AMIGA) \
1505 && !defined(MSWIN32) && !defined(MSWINCE) \
1506 && !defined(MACOS) && !defined(DOS4GW) && !defined(NONSTOP)
1507
1508# ifdef SUNOS4
1509 extern caddr_t sbrk();
1510# endif
1511# ifdef __STDC__
1512# define SBRK_ARG_T ptrdiff_t
1513# else
1514# define SBRK_ARG_T int
1515# endif
1516
1517
1518# if 0 && defined(RS6000) /* We now use mmap */
1519/* The compiler seems to generate speculative reads one past the end of */
1520/* an allocated object. Hence we need to make sure that the page */
1521/* following the last heap page is also mapped. */
1522ptr_t GC_unix_get_mem(bytes)
1523word bytes;
1524{
1525 caddr_t cur_brk = (caddr_t)sbrk(0);
1526 caddr_t result;
1527 SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1);
1528 static caddr_t my_brk_val = 0;
1529
1530 if ((SBRK_ARG_T)bytes < 0) return(0); /* too big */
1531 if (lsbs != 0) {
1532 if((caddr_t)(sbrk(GC_page_size - lsbs)) == (caddr_t)(-1)) return(0);
1533 }
1534 if (cur_brk == my_brk_val) {
1535 /* Use the extra block we allocated last time. */
1536 result = (ptr_t)sbrk((SBRK_ARG_T)bytes);
1537 if (result == (caddr_t)(-1)) return(0);
1538 result -= GC_page_size;
1539 } else {
1540 result = (ptr_t)sbrk(GC_page_size + (SBRK_ARG_T)bytes);
1541 if (result == (caddr_t)(-1)) return(0);
1542 }
1543 my_brk_val = result + bytes + GC_page_size; /* Always page aligned */
1544 return((ptr_t)result);
1545}
1546
1547#else /* Not RS6000 */
1548
1549#if defined(USE_MMAP) || defined(USE_MUNMAP)
1550
1551#ifdef USE_MMAP_FIXED
1552# define GC_MMAP_FLAGS MAP_FIXED | MAP_PRIVATE
1553 /* Seems to yield better performance on Solaris 2, but can */
1554 /* be unreliable if something is already mapped at the address. */
1555#else
1556# define GC_MMAP_FLAGS MAP_PRIVATE
1557#endif
1558
1559#ifdef USE_MMAP_ANON
1560# define zero_fd -1
1561# if defined(MAP_ANONYMOUS)
1562# define OPT_MAP_ANON MAP_ANONYMOUS
1563# else
1564# define OPT_MAP_ANON MAP_ANON
1565# endif
1566#else
1567 static int zero_fd;
1568# define OPT_MAP_ANON 0
1569#endif
1570
1571#endif /* defined(USE_MMAP) || defined(USE_MUNMAP) */
1572
1573#if defined(USE_MMAP)
1574/* Tested only under Linux, IRIX5 and Solaris 2 */
1575
1576#ifndef HEAP_START
1577# define HEAP_START 0
1578#endif
1579
1580ptr_t GC_unix_get_mem(bytes)
1581word bytes;
1582{
1583 void *result;
1584 static ptr_t last_addr = HEAP_START;
1585
1586# ifndef USE_MMAP_ANON
1587 static GC_bool initialized = FALSE;
1588
1589 if (!initialized) {
1590 zero_fd = open("/dev/zero", O_RDONLY);
1591 fcntl(zero_fd, F_SETFD, FD_CLOEXEC);
1592 initialized = TRUE;
1593 }
1594# endif
1595
1596 if (bytes & (GC_page_size -1)) ABORT("Bad GET_MEM arg");
1597 result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC,
1598 GC_MMAP_FLAGS | OPT_MAP_ANON, zero_fd, 0/* offset */);
1599 if (result == MAP_FAILED) return(0);
1600 last_addr = (ptr_t)result + bytes + GC_page_size - 1;
1601 last_addr = (ptr_t)((word)last_addr & ~(GC_page_size - 1));
1602# if !defined(LINUX)
1603 if (last_addr == 0) {
1604 /* Oops. We got the end of the address space. This isn't */
1605 /* usable by arbitrary C code, since one-past-end pointers */
1606 /* don't work, so we discard it and try again. */
1607 munmap(result, (size_t)(-GC_page_size) - (size_t)result);
1608 /* Leave last page mapped, so we can't repeat. */
1609 return GC_unix_get_mem(bytes);
1610 }
1611# else
1612 GC_ASSERT(last_addr != 0);
1613# endif
1614 return((ptr_t)result);
1615}
1616
1617#else /* Not RS6000, not USE_MMAP */
1618ptr_t GC_unix_get_mem(bytes)
1619word bytes;
1620{
1621 ptr_t result;
1622# ifdef IRIX5
1623 /* Bare sbrk isn't thread safe. Play by malloc rules. */
1624 /* The equivalent may be needed on other systems as well. */
1625 __LOCK_MALLOC();
1626# endif
1627 {
1628 ptr_t cur_brk = (ptr_t)sbrk(0);
1629 SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1);
1630
1631 if ((SBRK_ARG_T)bytes < 0) {
1632 result = 0; /* too big */
1633 goto out;
1634 }
1635 if (lsbs != 0) {
1636 if((ptr_t)sbrk(GC_page_size - lsbs) == (ptr_t)(-1)) {
1637 result = 0;
1638 goto out;
1639 }
1640 }
1641 result = (ptr_t)sbrk((SBRK_ARG_T)bytes);
1642 if (result == (ptr_t)(-1)) result = 0;
1643 }
1644 out:
1645# ifdef IRIX5
1646 __UNLOCK_MALLOC();
1647# endif
1648 return(result);
1649}
1650
1651#endif /* Not USE_MMAP */
1652#endif /* Not RS6000 */
1653
1654# endif /* UN*X */
1655
1656# ifdef OS2
1657
1658void * os2_alloc(size_t bytes)
1659{
1660 void * result;
1661
1662 if (DosAllocMem(&result, bytes, PAG_EXECUTE | PAG_READ |
1663 PAG_WRITE | PAG_COMMIT)
1664 != NO_ERROR) {
1665 return(0);
1666 }
1667 if (result == 0) return(os2_alloc(bytes));
1668 return(result);
1669}
1670
1671# endif /* OS2 */
1672
1673
1674# if defined(MSWIN32) || defined(MSWINCE)
1675SYSTEM_INFO GC_sysinfo;
1676# endif
1677
1678# ifdef MSWIN32
1679
1680# ifdef USE_GLOBAL_ALLOC
1681# define GLOBAL_ALLOC_TEST 1
1682# else
1683# define GLOBAL_ALLOC_TEST GC_no_win32_dlls
1684# endif
1685
1686word GC_n_heap_bases = 0;
1687
1688ptr_t GC_win32_get_mem(bytes)
1689word bytes;
1690{
1691 ptr_t result;
1692
1693 if (GLOBAL_ALLOC_TEST) {
1694 /* VirtualAlloc doesn't like PAGE_EXECUTE_READWRITE. */
1695 /* There are also unconfirmed rumors of other */
1696 /* problems, so we dodge the issue. */
1697 result = (ptr_t) GlobalAlloc(0, bytes + HBLKSIZE);
1698 result = (ptr_t)(((word)result + HBLKSIZE) & ~(HBLKSIZE-1));
1699 } else {
1700 /* VirtualProtect only works on regions returned by a */
1701 /* single VirtualAlloc call. Thus we allocate one */
1702 /* extra page, which will prevent merging of blocks */
1703 /* in separate regions, and eliminate any temptation */
1704 /* to call VirtualProtect on a range spanning regions. */
1705 /* This wastes a small amount of memory, and risks */
1706 /* increased fragmentation. But better alternatives */
1707 /* would require effort. */
1708 result = (ptr_t) VirtualAlloc(NULL, bytes + 1,
1709 MEM_COMMIT | MEM_RESERVE,
1710 PAGE_EXECUTE_READWRITE);
1711 }
1712 if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
1713 /* If I read the documentation correctly, this can */
1714 /* only happen if HBLKSIZE > 64k or not a power of 2. */
1715 if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
1716 GC_heap_bases[GC_n_heap_bases++] = result;
1717 return(result);
1718}
1719
1720void GC_win32_free_heap ()
1721{
1722 if (GC_no_win32_dlls) {
1723 while (GC_n_heap_bases > 0) {
1724 GlobalFree (GC_heap_bases[--GC_n_heap_bases]);
1725 GC_heap_bases[GC_n_heap_bases] = 0;
1726 }
1727 }
1728}
1729# endif
1730
1731#ifdef AMIGA
1732# define GC_AMIGA_AM
1733# include "AmigaOS.c"
1734# undef GC_AMIGA_AM
1735#endif
1736
1737
1738# ifdef MSWINCE
1739word GC_n_heap_bases = 0;
1740
1741ptr_t GC_wince_get_mem(bytes)
1742word bytes;
1743{
1744 ptr_t result;
1745 word i;
1746
1747 /* Round up allocation size to multiple of page size */
1748 bytes = (bytes + GC_page_size-1) & ~(GC_page_size-1);
1749
1750 /* Try to find reserved, uncommitted pages */
1751 for (i = 0; i < GC_n_heap_bases; i++) {
1752 if (((word)(-(signed_word)GC_heap_lengths[i])
1753 & (GC_sysinfo.dwAllocationGranularity-1))
1754 >= bytes) {
1755 result = GC_heap_bases[i] + GC_heap_lengths[i];
1756 break;
1757 }
1758 }
1759
1760 if (i == GC_n_heap_bases) {
1761 /* Reserve more pages */
1762 word res_bytes = (bytes + GC_sysinfo.dwAllocationGranularity-1)
1763 & ~(GC_sysinfo.dwAllocationGranularity-1);
1764 /* If we ever support MPROTECT_VDB here, we will probably need to */
1765 /* ensure that res_bytes is strictly > bytes, so that VirtualProtect */
1766 /* never spans regions. It seems to be OK for a VirtualFree argument */
1767 /* to span regions, so we should be OK for now. */
1768 result = (ptr_t) VirtualAlloc(NULL, res_bytes,
1769 MEM_RESERVE | MEM_TOP_DOWN,
1770 PAGE_EXECUTE_READWRITE);
1771 if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
1772 /* If I read the documentation correctly, this can */
1773 /* only happen if HBLKSIZE > 64k or not a power of 2. */
1774 if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
1775 GC_heap_bases[GC_n_heap_bases] = result;
1776 GC_heap_lengths[GC_n_heap_bases] = 0;
1777 GC_n_heap_bases++;
1778 }
1779
1780 /* Commit pages */
1781 result = (ptr_t) VirtualAlloc(result, bytes,
1782 MEM_COMMIT,
1783 PAGE_EXECUTE_READWRITE);
1784 if (result != NULL) {
1785 if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
1786 GC_heap_lengths[i] += bytes;
1787 }
1788
1789 return(result);
1790}
1791# endif
1792
1793#ifdef USE_MUNMAP
1794
1795/* For now, this only works on Win32/WinCE and some Unix-like */
1796/* systems. If you have something else, don't define */
1797/* USE_MUNMAP. */
1798/* We assume ANSI C to support this feature. */
1799
1800#if !defined(MSWIN32) && !defined(MSWINCE)
1801
1802#include <unistd.h>
1803#include <sys/mman.h>
1804#include <sys/stat.h>
1805#include <sys/types.h>
1806
1807#endif
1808
1809/* Compute a page aligned starting address for the unmap */
1810/* operation on a block of size bytes starting at start. */
1811/* Return 0 if the block is too small to make this feasible. */
1812ptr_t GC_unmap_start(ptr_t start, word bytes)
1813{
1814 ptr_t result = start;
1815 /* Round start to next page boundary. */
1816 result += GC_page_size - 1;
1817 result = (ptr_t)((word)result & ~(GC_page_size - 1));
1818 if (result + GC_page_size > start + bytes) return 0;
1819 return result;
1820}
1821
1822/* Compute end address for an unmap operation on the indicated */
1823/* block. */
1824ptr_t GC_unmap_end(ptr_t start, word bytes)
1825{
1826 ptr_t end_addr = start + bytes;
1827 end_addr = (ptr_t)((word)end_addr & ~(GC_page_size - 1));
1828 return end_addr;
1829}
1830
1831/* Under Win32/WinCE we commit (map) and decommit (unmap) */
1832/* memory using VirtualAlloc and VirtualFree. These functions */
1833/* work on individual allocations of virtual memory, made */
1834/* previously using VirtualAlloc with the MEM_RESERVE flag. */
1835/* The ranges we need to (de)commit may span several of these */
1836/* allocations; therefore we use VirtualQuery to check */
1837/* allocation lengths, and split up the range as necessary. */
1838
1839/* We assume that GC_remap is called on exactly the same range */
1840/* as a previous call to GC_unmap. It is safe to consistently */
1841/* round the endpoints in both places. */
1842void GC_unmap(ptr_t start, word bytes)
1843{
1844 ptr_t start_addr = GC_unmap_start(start, bytes);
1845 ptr_t end_addr = GC_unmap_end(start, bytes);
1846 word len = end_addr - start_addr;
1847 if (0 == start_addr) return;
1848# if defined(MSWIN32) || defined(MSWINCE)
1849 while (len != 0) {
1850 MEMORY_BASIC_INFORMATION mem_info;
1851 GC_word free_len;
1852 if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
1853 != sizeof(mem_info))
1854 ABORT("Weird VirtualQuery result");
1855 free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
1856 if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT))
1857 ABORT("VirtualFree failed");
1858 GC_unmapped_bytes += free_len;
1859 start_addr += free_len;
1860 len -= free_len;
1861 }
1862# else
1863 /* We immediately remap it to prevent an intervening mmap from */
1864 /* accidentally grabbing the same address space. */
1865 {
1866 void * result;
1867 result = mmap(start_addr, len, PROT_NONE,
1868 MAP_PRIVATE | MAP_FIXED | OPT_MAP_ANON,
1869 zero_fd, 0/* offset */);
1870 if (result != (void *)start_addr) ABORT("mmap(...PROT_NONE...) failed");
1871 }
1872 GC_unmapped_bytes += len;
1873# endif
1874}
1875
1876
1877void GC_remap(ptr_t start, word bytes)
1878{
1879 ptr_t start_addr = GC_unmap_start(start, bytes);
1880 ptr_t end_addr = GC_unmap_end(start, bytes);
1881 word len = end_addr - start_addr;
1882
1883# if defined(MSWIN32) || defined(MSWINCE)
1884 ptr_t result;
1885
1886 if (0 == start_addr) return;
1887 while (len != 0) {
1888 MEMORY_BASIC_INFORMATION mem_info;
1889 GC_word alloc_len;
1890 if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
1891 != sizeof(mem_info))
1892 ABORT("Weird VirtualQuery result");
1893 alloc_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
1894 result = VirtualAlloc(start_addr, alloc_len,
1895 MEM_COMMIT,
1896 PAGE_EXECUTE_READWRITE);
1897 if (result != start_addr) {
1898 ABORT("VirtualAlloc remapping failed");
1899 }
1900 GC_unmapped_bytes -= alloc_len;
1901 start_addr += alloc_len;
1902 len -= alloc_len;
1903 }
1904# else
1905 /* It was already remapped with PROT_NONE. */
1906 int result;
1907
1908 if (0 == start_addr) return;
1909 result = mprotect(start_addr, len,
1910 PROT_READ | PROT_WRITE | OPT_PROT_EXEC);
1911 if (result != 0) {
1912 GC_err_printf3(
1913 "Mprotect failed at 0x%lx (length %ld) with errno %ld\n",
1914 start_addr, len, errno);
1915 ABORT("Mprotect remapping failed");
1916 }
1917 GC_unmapped_bytes -= len;
1918# endif
1919}
1920
1921/* Two adjacent blocks have already been unmapped and are about to */
1922/* be merged. Unmap the whole block. This typically requires */
1923/* that we unmap a small section in the middle that was not previously */
1924/* unmapped due to alignment constraints. */
1925void GC_unmap_gap(ptr_t start1, word bytes1, ptr_t start2, word bytes2)
1926{
1927 ptr_t start1_addr = GC_unmap_start(start1, bytes1);
1928 ptr_t end1_addr = GC_unmap_end(start1, bytes1);
1929 ptr_t start2_addr = GC_unmap_start(start2, bytes2);
1930 ptr_t end2_addr = GC_unmap_end(start2, bytes2);
1931 ptr_t start_addr = end1_addr;
1932 ptr_t end_addr = start2_addr;
1933 word len;
1934 GC_ASSERT(start1 + bytes1 == start2);
1935 if (0 == start1_addr) start_addr = GC_unmap_start(start1, bytes1 + bytes2);
1936 if (0 == start2_addr) end_addr = GC_unmap_end(start1, bytes1 + bytes2);
1937 if (0 == start_addr) return;
1938 len = end_addr - start_addr;
1939# if defined(MSWIN32) || defined(MSWINCE)
1940 while (len != 0) {
1941 MEMORY_BASIC_INFORMATION mem_info;
1942 GC_word free_len;
1943 if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
1944 != sizeof(mem_info))
1945 ABORT("Weird VirtualQuery result");
1946 free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
1947 if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT))
1948 ABORT("VirtualFree failed");
1949 GC_unmapped_bytes += free_len;
1950 start_addr += free_len;
1951 len -= free_len;
1952 }
1953# else
1954 if (len != 0 && munmap(start_addr, len) != 0) ABORT("munmap failed");
1955 GC_unmapped_bytes += len;
1956# endif
1957}
1958
1959#endif /* USE_MUNMAP */
1960
1961/* Routine for pushing any additional roots. In THREADS */
1962/* environment, this is also responsible for marking from */
1963/* thread stacks. */
1964#ifndef THREADS
1965void (*GC_push_other_roots)() = 0;
1966#else /* THREADS */
1967
1968# ifdef PCR
1969PCR_ERes GC_push_thread_stack(PCR_Th_T *t, PCR_Any dummy)
1970{
1971 struct PCR_ThCtl_TInfoRep info;
1972 PCR_ERes result;
1973
1974 info.ti_stkLow = info.ti_stkHi = 0;
1975 result = PCR_ThCtl_GetInfo(t, &info);
1976 GC_push_all_stack((ptr_t)(info.ti_stkLow), (ptr_t)(info.ti_stkHi));
1977 return(result);
1978}
1979
1980/* Push the contents of an old object. We treat this as stack */
1981/* data only becasue that makes it robust against mark stack */
1982/* overflow. */
1983PCR_ERes GC_push_old_obj(void *p, size_t size, PCR_Any data)
1984{
1985 GC_push_all_stack((ptr_t)p, (ptr_t)p + size);
1986 return(PCR_ERes_okay);
1987}
1988
1989
1990void GC_default_push_other_roots GC_PROTO((void))
1991{
1992 /* Traverse data allocated by previous memory managers. */
1993 {
1994 extern struct PCR_MM_ProcsRep * GC_old_allocator;
1995
1996 if ((*(GC_old_allocator->mmp_enumerate))(PCR_Bool_false,
1997 GC_push_old_obj, 0)
1998 != PCR_ERes_okay) {
1999 ABORT("Old object enumeration failed");
2000 }
2001 }
2002 /* Traverse all thread stacks. */
2003 if (PCR_ERes_IsErr(
2004 PCR_ThCtl_ApplyToAllOtherThreads(GC_push_thread_stack,0))
2005 || PCR_ERes_IsErr(GC_push_thread_stack(PCR_Th_CurrThread(), 0))) {
2006 ABORT("Thread stack marking failed\n");
2007 }
2008}
2009
2010# endif /* PCR */
2011
2012# ifdef SRC_M3
2013
2014# ifdef ALL_INTERIOR_POINTERS
2015 --> misconfigured
2016# endif
2017
2018void GC_push_thread_structures GC_PROTO((void))
2019{
2020 /* Not our responsibibility. */
2021}
2022
2023extern void ThreadF__ProcessStacks();
2024
2025void GC_push_thread_stack(start, stop)
2026word start, stop;
2027{
2028 GC_push_all_stack((ptr_t)start, (ptr_t)stop + sizeof(word));
2029}
2030
2031/* Push routine with M3 specific calling convention. */
2032GC_m3_push_root(dummy1, p, dummy2, dummy3)
2033word *p;
2034ptr_t dummy1, dummy2;
2035int dummy3;
2036{
2037 word q = *p;
2038
2039 GC_PUSH_ONE_STACK(q, p);
2040}
2041
2042/* M3 set equivalent to RTHeap.TracedRefTypes */
2043typedef struct { int elts[1]; } RefTypeSet;
2044RefTypeSet GC_TracedRefTypes = {{0x1}};
2045
2046void GC_default_push_other_roots GC_PROTO((void))
2047{
2048 /* Use the M3 provided routine for finding static roots. */
2049 /* This is a bit dubious, since it presumes no C roots. */
2050 /* We handle the collector roots explicitly in GC_push_roots */
2051 RTMain__GlobalMapProc(GC_m3_push_root, 0, GC_TracedRefTypes);
2052 if (GC_words_allocd > 0) {
2053 ThreadF__ProcessStacks(GC_push_thread_stack);
2054 }
2055 /* Otherwise this isn't absolutely necessary, and we have */
2056 /* startup ordering problems. */
2057}
2058
2059# endif /* SRC_M3 */
2060
2061# if defined(GC_SOLARIS_THREADS) || defined(GC_PTHREADS) || \
2062 defined(GC_WIN32_THREADS)
2063
2064extern void GC_push_all_stacks();
2065
2066void GC_default_push_other_roots GC_PROTO((void))
2067{
2068 GC_push_all_stacks();
2069}
2070
2071# endif /* GC_SOLARIS_THREADS || GC_PTHREADS */
2072
2073void (*GC_push_other_roots) GC_PROTO((void)) = GC_default_push_other_roots;
2074
2075#endif /* THREADS */
2076
2077/*
2078 * Routines for accessing dirty bits on virtual pages.
2079 * We plan to eventually implement four strategies for doing so:
2080 * DEFAULT_VDB: A simple dummy implementation that treats every page
2081 * as possibly dirty. This makes incremental collection
2082 * useless, but the implementation is still correct.
2083 * PCR_VDB: Use PPCRs virtual dirty bit facility.
2084 * PROC_VDB: Use the /proc facility for reading dirty bits. Only
2085 * works under some SVR4 variants. Even then, it may be
2086 * too slow to be entirely satisfactory. Requires reading
2087 * dirty bits for entire address space. Implementations tend
2088 * to assume that the client is a (slow) debugger.
2089 * MPROTECT_VDB:Protect pages and then catch the faults to keep track of
2090 * dirtied pages. The implementation (and implementability)
2091 * is highly system dependent. This usually fails when system
2092 * calls write to a protected page. We prevent the read system
2093 * call from doing so. It is the clients responsibility to
2094 * make sure that other system calls are similarly protected
2095 * or write only to the stack.
2096 */
2097GC_bool GC_dirty_maintained = FALSE;
2098
2099# ifdef DEFAULT_VDB
2100
2101/* All of the following assume the allocation lock is held, and */
2102/* signals are disabled. */
2103
2104/* The client asserts that unallocated pages in the heap are never */
2105/* written. */
2106
2107/* Initialize virtual dirty bit implementation. */
2108void GC_dirty_init()
2109{
2110# ifdef PRINTSTATS
2111 GC_printf0("Initializing DEFAULT_VDB...\n");
2112# endif
2113 GC_dirty_maintained = TRUE;
2114}
2115
2116/* Retrieve system dirty bits for heap to a local buffer. */
2117/* Restore the systems notion of which pages are dirty. */
2118void GC_read_dirty()
2119{}
2120
2121/* Is the HBLKSIZE sized page at h marked dirty in the local buffer? */
2122/* If the actual page size is different, this returns TRUE if any */
2123/* of the pages overlapping h are dirty. This routine may err on the */
2124/* side of labelling pages as dirty (and this implementation does). */
2125/*ARGSUSED*/
2126GC_bool GC_page_was_dirty(h)
2127struct hblk *h;
2128{
2129 return(TRUE);
2130}
2131
2132/*
2133 * The following two routines are typically less crucial. They matter
2134 * most with large dynamic libraries, or if we can't accurately identify
2135 * stacks, e.g. under Solaris 2.X. Otherwise the following default
2136 * versions are adequate.
2137 */
2138
2139/* Could any valid GC heap pointer ever have been written to this page? */
2140/*ARGSUSED*/
2141GC_bool GC_page_was_ever_dirty(h)
2142struct hblk *h;
2143{
2144 return(TRUE);
2145}
2146
2147/* Reset the n pages starting at h to "was never dirty" status. */
2148void GC_is_fresh(h, n)
2149struct hblk *h;
2150word n;
2151{
2152}
2153
2154/* A call that: */
2155/* I) hints that [h, h+nblocks) is about to be written. */
2156/* II) guarantees that protection is removed. */
2157/* (I) may speed up some dirty bit implementations. */
2158/* (II) may be essential if we need to ensure that */
2159/* pointer-free system call buffers in the heap are */
2160/* not protected. */
2161/*ARGSUSED*/
2162void GC_remove_protection(h, nblocks, is_ptrfree)
2163struct hblk *h;
2164word nblocks;
2165GC_bool is_ptrfree;
2166{
2167}
2168
2169# endif /* DEFAULT_VDB */
2170
2171
2172# ifdef MPROTECT_VDB
2173
2174/*
2175 * See DEFAULT_VDB for interface descriptions.
2176 */
2177
2178/*
2179 * This implementation maintains dirty bits itself by catching write
2180 * faults and keeping track of them. We assume nobody else catches
2181 * SIGBUS or SIGSEGV. We assume no write faults occur in system calls.
2182 * This means that clients must ensure that system calls don't write
2183 * to the write-protected heap. Probably the best way to do this is to
2184 * ensure that system calls write at most to POINTERFREE objects in the
2185 * heap, and do even that only if we are on a platform on which those
2186 * are not protected. Another alternative is to wrap system calls
2187 * (see example for read below), but the current implementation holds
2188 * a lock across blocking calls, making it problematic for multithreaded
2189 * applications.
2190 * We assume the page size is a multiple of HBLKSIZE.
2191 * We prefer them to be the same. We avoid protecting POINTERFREE
2192 * objects only if they are the same.
2193 */
2194
2195# if !defined(MSWIN32) && !defined(MSWINCE) && !defined(DARWIN)
2196
2197# include <sys/mman.h>
2198# include <signal.h>
2199# include <sys/syscall.h>
2200
2201# define PROTECT(addr, len) \
2202 if (mprotect((caddr_t)(addr), (size_t)(len), \
2203 PROT_READ | OPT_PROT_EXEC) < 0) { \
2204 ABORT("mprotect failed"); \
2205 }
2206# define UNPROTECT(addr, len) \
2207 if (mprotect((caddr_t)(addr), (size_t)(len), \
2208 PROT_WRITE | PROT_READ | OPT_PROT_EXEC ) < 0) { \
2209 ABORT("un-mprotect failed"); \
2210 }
2211
2212# else
2213
2214# ifdef DARWIN
2215 /* Using vm_protect (mach syscall) over mprotect (BSD syscall) seems to
2216 decrease the likelihood of some of the problems described below. */
2217 #include <mach/vm_map.h>
2218 static mach_port_t GC_task_self;
2219 #define PROTECT(addr,len) \
2220 if(vm_protect(GC_task_self,(vm_address_t)(addr),(vm_size_t)(len), \
2221 FALSE,VM_PROT_READ) != KERN_SUCCESS) { \
2222 ABORT("vm_portect failed"); \
2223 }
2224 #define UNPROTECT(addr,len) \
2225 if(vm_protect(GC_task_self,(vm_address_t)(addr),(vm_size_t)(len), \
2226 FALSE,VM_PROT_READ|VM_PROT_WRITE) != KERN_SUCCESS) { \
2227 ABORT("vm_portect failed"); \
2228 }
2229# else
2230
2231# ifndef MSWINCE
2232# include <signal.h>
2233# endif
2234
2235 static DWORD protect_junk;
2236# define PROTECT(addr, len) \
2237 if (!VirtualProtect((addr), (len), PAGE_EXECUTE_READ, \
2238 &protect_junk)) { \
2239 DWORD last_error = GetLastError(); \
2240 GC_printf1("Last error code: %lx\n", last_error); \
2241 ABORT("VirtualProtect failed"); \
2242 }
2243# define UNPROTECT(addr, len) \
2244 if (!VirtualProtect((addr), (len), PAGE_EXECUTE_READWRITE, \
2245 &protect_junk)) { \
2246 ABORT("un-VirtualProtect failed"); \
2247 }
2248# endif /* !DARWIN */
2249# endif /* MSWIN32 || MSWINCE || DARWIN */
2250
2251#if defined(SUNOS4) || (defined(FREEBSD) && !defined(SUNOS5SIGS))
2252 typedef void (* SIG_PF)();
2253#endif /* SUNOS4 || (FREEBSD && !SUNOS5SIGS) */
2254
2255#if defined(SUNOS5SIGS) || defined(OSF1) || defined(LINUX) \
2256 || defined(HURD)
2257# ifdef __STDC__
2258 typedef void (* SIG_PF)(int);
2259# else
2260 typedef void (* SIG_PF)();
2261# endif
2262#endif /* SUNOS5SIGS || OSF1 || LINUX || HURD */
2263
2264#if defined(MSWIN32)
2265 typedef LPTOP_LEVEL_EXCEPTION_FILTER SIG_PF;
2266# undef SIG_DFL
2267# define SIG_DFL (LPTOP_LEVEL_EXCEPTION_FILTER) (-1)
2268#endif
2269#if defined(MSWINCE)
2270 typedef LONG (WINAPI *SIG_PF)(struct _EXCEPTION_POINTERS *);
2271# undef SIG_DFL
2272# define SIG_DFL (SIG_PF) (-1)
2273#endif
2274
2275#if defined(IRIX5) || defined(OSF1) || defined(HURD)
2276 typedef void (* REAL_SIG_PF)(int, int, struct sigcontext *);
2277#endif /* IRIX5 || OSF1 || HURD */
2278
2279#if defined(SUNOS5SIGS)
2280# if defined(HPUX) || defined(FREEBSD)
2281# define SIGINFO_T siginfo_t
2282# else
2283# define SIGINFO_T struct siginfo
2284# endif
2285# ifdef __STDC__
2286 typedef void (* REAL_SIG_PF)(int, SIGINFO_T *, void *);
2287# else
2288 typedef void (* REAL_SIG_PF)();
2289# endif
2290#endif /* SUNOS5SIGS */
2291
2292#if defined(LINUX)
2293# if __GLIBC__ > 2 || __GLIBC__ == 2 && __GLIBC_MINOR__ >= 2
2294 typedef struct sigcontext s_c;
2295# else /* glibc < 2.2 */
2296# include <linux/version.h>
2297# if (LINUX_VERSION_CODE >= 0x20100) && !defined(M68K) || defined(ALPHA) || defined(ARM32)
2298 typedef struct sigcontext s_c;
2299# else
2300 typedef struct sigcontext_struct s_c;
2301# endif
2302# endif /* glibc < 2.2 */
2303# if defined(ALPHA) || defined(M68K)
2304 typedef void (* REAL_SIG_PF)(int, int, s_c *);
2305# else
2306# if defined(IA64) || defined(HP_PA) || defined(X86_64)
2307 typedef void (* REAL_SIG_PF)(int, siginfo_t *, s_c *);
2308 /* FIXME: */
2309 /* According to SUSV3, the last argument should have type */
2310 /* void * or ucontext_t * */
2311# else
2312 typedef void (* REAL_SIG_PF)(int, s_c);
2313# endif
2314# endif
2315# ifdef ALPHA
2316 /* Retrieve fault address from sigcontext structure by decoding */
2317 /* instruction. */
2318 char * get_fault_addr(s_c *sc) {
2319 unsigned instr;
2320 word faultaddr;
2321
2322 instr = *((unsigned *)(sc->sc_pc));
2323 faultaddr = sc->sc_regs[(instr >> 16) & 0x1f];
2324 faultaddr += (word) (((int)instr << 16) >> 16);
2325 return (char *)faultaddr;
2326 }
2327# endif /* !ALPHA */
2328# endif /* LINUX */
2329
2330#ifndef DARWIN
2331SIG_PF GC_old_bus_handler;
2332SIG_PF GC_old_segv_handler; /* Also old MSWIN32 ACCESS_VIOLATION filter */
2333#endif /* !DARWIN */
2334
2335#if defined(THREADS)
2336/* We need to lock around the bitmap update in the write fault handler */
2337/* in order to avoid the risk of losing a bit. We do this with a */
2338/* test-and-set spin lock if we know how to do that. Otherwise we */
2339/* check whether we are already in the handler and use the dumb but */
2340/* safe fallback algorithm of setting all bits in the word. */
2341/* Contention should be very rare, so we do the minimum to handle it */
2342/* correctly. */
2343#ifdef GC_TEST_AND_SET_DEFINED
2344 static VOLATILE unsigned int fault_handler_lock = 0;
2345 void async_set_pht_entry_from_index(VOLATILE page_hash_table db, int index) {
2346 while (GC_test_and_set(&fault_handler_lock)) {}
2347 /* Could also revert to set_pht_entry_from_index_safe if initial */
2348 /* GC_test_and_set fails. */
2349 set_pht_entry_from_index(db, index);
2350 GC_clear(&fault_handler_lock);
2351 }
2352#else /* !GC_TEST_AND_SET_DEFINED */
2353 /* THIS IS INCORRECT! The dirty bit vector may be temporarily wrong, */
2354 /* just before we notice the conflict and correct it. We may end up */
2355 /* looking at it while it's wrong. But this requires contention */
2356 /* exactly when a GC is triggered, which seems far less likely to */
2357 /* fail than the old code, which had no reported failures. Thus we */
2358 /* leave it this way while we think of something better, or support */
2359 /* GC_test_and_set on the remaining platforms. */
2360 static VOLATILE word currently_updating = 0;
2361 void async_set_pht_entry_from_index(VOLATILE page_hash_table db, int index) {
2362 unsigned int update_dummy;
2363 currently_updating = (word)(&update_dummy);
2364 set_pht_entry_from_index(db, index);
2365 /* If we get contention in the 10 or so instruction window here, */
2366 /* and we get stopped by a GC between the two updates, we lose! */
2367 if (currently_updating != (word)(&update_dummy)) {
2368 set_pht_entry_from_index_safe(db, index);
2369 /* We claim that if two threads concurrently try to update the */
2370 /* dirty bit vector, the first one to execute UPDATE_START */
2371 /* will see it changed when UPDATE_END is executed. (Note that */
2372 /* &update_dummy must differ in two distinct threads.) It */
2373 /* will then execute set_pht_entry_from_index_safe, thus */
2374 /* returning us to a safe state, though not soon enough. */
2375 }
2376 }
2377#endif /* !GC_TEST_AND_SET_DEFINED */
2378#else /* !THREADS */
2379# define async_set_pht_entry_from_index(db, index) \
2380 set_pht_entry_from_index(db, index)
2381#endif /* !THREADS */
2382
2383/*ARGSUSED*/
2384#if !defined(DARWIN)
2385# if defined (SUNOS4) || (defined(FREEBSD) && !defined(SUNOS5SIGS))
2386 void GC_write_fault_handler(sig, code, scp, addr)
2387 int sig, code;
2388 struct sigcontext *scp;
2389 char * addr;
2390# ifdef SUNOS4
2391# define SIG_OK (sig == SIGSEGV || sig == SIGBUS)
2392# define CODE_OK (FC_CODE(code) == FC_PROT \
2393 || (FC_CODE(code) == FC_OBJERR \
2394 && FC_ERRNO(code) == FC_PROT))
2395# endif
2396# ifdef FREEBSD
2397# define SIG_OK (sig == SIGBUS)
2398# define CODE_OK TRUE
2399# endif
2400# endif /* SUNOS4 || (FREEBSD && !SUNOS5SIGS) */
2401
2402# if defined(IRIX5) || defined(OSF1) || defined(HURD)
2403# include <errno.h>
2404 void GC_write_fault_handler(int sig, int code, struct sigcontext *scp)
2405# ifdef OSF1
2406# define SIG_OK (sig == SIGSEGV)
2407# define CODE_OK (code == 2 /* experimentally determined */)
2408# endif
2409# ifdef IRIX5
2410# define SIG_OK (sig == SIGSEGV)
2411# define CODE_OK (code == EACCES)
2412# endif
2413# ifdef HURD
2414# define SIG_OK (sig == SIGBUS || sig == SIGSEGV)
2415# define CODE_OK TRUE
2416# endif
2417# endif /* IRIX5 || OSF1 || HURD */
2418
2419# if defined(LINUX)
2420# if defined(ALPHA) || defined(M68K)
2421 void GC_write_fault_handler(int sig, int code, s_c * sc)
2422# else
2423# if defined(IA64) || defined(HP_PA) || defined(X86_64)
2424 void GC_write_fault_handler(int sig, siginfo_t * si, s_c * scp)
2425# else
2426# if defined(ARM32)
2427 void GC_write_fault_handler(int sig, int a2, int a3, int a4, s_c sc)
2428# else
2429 void GC_write_fault_handler(int sig, s_c sc)
2430# endif
2431# endif
2432# endif
2433# define SIG_OK (sig == SIGSEGV)
2434# define CODE_OK TRUE
2435 /* Empirically c.trapno == 14, on IA32, but is that useful? */
2436 /* Should probably consider alignment issues on other */
2437 /* architectures. */
2438# endif /* LINUX */
2439
2440# if defined(SUNOS5SIGS)
2441# ifdef __STDC__
2442 void GC_write_fault_handler(int sig, SIGINFO_T *scp, void * context)
2443# else
2444 void GC_write_fault_handler(sig, scp, context)
2445 int sig;
2446 SIGINFO_T *scp;
2447 void * context;
2448# endif
2449# ifdef HPUX
2450# define SIG_OK (sig == SIGSEGV || sig == SIGBUS)
2451# define CODE_OK (scp -> si_code == SEGV_ACCERR) \
2452 || (scp -> si_code == BUS_ADRERR) \
2453 || (scp -> si_code == BUS_UNKNOWN) \
2454 || (scp -> si_code == SEGV_UNKNOWN) \
2455 || (scp -> si_code == BUS_OBJERR)
2456# else
2457# ifdef FREEBSD
2458# define SIG_OK (sig == SIGBUS)
2459# define CODE_OK (scp -> si_code == BUS_PAGE_FAULT)
2460# else
2461# define SIG_OK (sig == SIGSEGV)
2462# define CODE_OK (scp -> si_code == SEGV_ACCERR)
2463# endif
2464# endif
2465# endif /* SUNOS5SIGS */
2466
2467# if defined(MSWIN32) || defined(MSWINCE)
2468 LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info)
2469# define SIG_OK (exc_info -> ExceptionRecord -> ExceptionCode == \
2470 STATUS_ACCESS_VIOLATION)
2471# define CODE_OK (exc_info -> ExceptionRecord -> ExceptionInformation[0] == 1)
2472 /* Write fault */
2473# endif /* MSWIN32 || MSWINCE */
2474{
2475 register unsigned i;
2476# if defined(HURD)
2477 char *addr = (char *) code;
2478# endif
2479# ifdef IRIX5
2480 char * addr = (char *) (size_t) (scp -> sc_badvaddr);
2481# endif
2482# if defined(OSF1) && defined(ALPHA)
2483 char * addr = (char *) (scp -> sc_traparg_a0);
2484# endif
2485# ifdef SUNOS5SIGS
2486 char * addr = (char *) (scp -> si_addr);
2487# endif
2488# ifdef LINUX
2489# if defined(I386)
2490 char * addr = (char *) (sc.cr2);
2491# else
2492# if defined(M68K)
2493 char * addr = NULL;
2494
2495 struct sigcontext *scp = (struct sigcontext *)(sc);
2496
2497 int format = (scp->sc_formatvec >> 12) & 0xf;
2498 unsigned long *framedata = (unsigned long *)(scp + 1);
2499 unsigned long ea;
2500
2501 if (format == 0xa || format == 0xb) {
2502 /* 68020/030 */
2503 ea = framedata[2];
2504 } else if (format == 7) {
2505 /* 68040 */
2506 ea = framedata[3];
2507 if (framedata[1] & 0x08000000) {
2508 /* correct addr on misaligned access */
2509 ea = (ea+4095)&(~4095);
2510 }
2511 } else if (format == 4) {
2512 /* 68060 */
2513 ea = framedata[0];
2514 if (framedata[1] & 0x08000000) {
2515 /* correct addr on misaligned access */
2516 ea = (ea+4095)&(~4095);
2517 }
2518 }
2519 addr = (char *)ea;
2520# else
2521# ifdef ALPHA
2522 char * addr = get_fault_addr(sc);
2523# else
2524# if defined(IA64) || defined(HP_PA) || defined(X86_64)
2525 char * addr = si -> si_addr;
2526 /* I believe this is claimed to work on all platforms for */
2527 /* Linux 2.3.47 and later. Hopefully we don't have to */
2528 /* worry about earlier kernels on IA64. */
2529# else
2530# if defined(POWERPC)
2531 char * addr = (char *) (sc.regs->dar);
2532# else
2533# if defined(ARM32)
2534 char * addr = (char *)sc.fault_address;
2535# else
2536# if defined(CRIS)
2537 char * addr = (char *)sc.regs.csraddr;
2538# else
2539 --> architecture not supported
2540# endif
2541# endif
2542# endif
2543# endif
2544# endif
2545# endif
2546# endif
2547# endif
2548# if defined(MSWIN32) || defined(MSWINCE)
2549 char * addr = (char *) (exc_info -> ExceptionRecord
2550 -> ExceptionInformation[1]);
2551# define sig SIGSEGV
2552# endif
2553
2554 if (SIG_OK && CODE_OK) {
2555 register struct hblk * h =
2556 (struct hblk *)((word)addr & ~(GC_page_size-1));
2557 GC_bool in_allocd_block;
2558
2559# ifdef SUNOS5SIGS
2560 /* Address is only within the correct physical page. */
2561 in_allocd_block = FALSE;
2562 for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
2563 if (HDR(h+i) != 0) {
2564 in_allocd_block = TRUE;
2565 }
2566 }
2567# else
2568 in_allocd_block = (HDR(addr) != 0);
2569# endif
2570 if (!in_allocd_block) {
2571 /* FIXME - We should make sure that we invoke the */
2572 /* old handler with the appropriate calling */
2573 /* sequence, which often depends on SA_SIGINFO. */
2574
2575 /* Heap blocks now begin and end on page boundaries */
2576 SIG_PF old_handler;
2577
2578 if (sig == SIGSEGV) {
2579 old_handler = GC_old_segv_handler;
2580 } else {
2581 old_handler = GC_old_bus_handler;
2582 }
2583 if (old_handler == SIG_DFL) {
2584# if !defined(MSWIN32) && !defined(MSWINCE)
2585 GC_err_printf1("Segfault at 0x%lx\n", addr);
2586 ABORT("Unexpected bus error or segmentation fault");
2587# else
2588 return(EXCEPTION_CONTINUE_SEARCH);
2589# endif
2590 } else {
2591# if defined (SUNOS4) \
2592 || (defined(FREEBSD) && !defined(SUNOS5SIGS))
2593 (*old_handler) (sig, code, scp, addr);
2594 return;
2595# endif
2596# if defined (SUNOS5SIGS)
2597 /*
2598 * FIXME: For FreeBSD, this code should check if the
2599 * old signal handler used the traditional BSD style and
2600 * if so call it using that style.
2601 */
2602 (*(REAL_SIG_PF)old_handler) (sig, scp, context);
2603 return;
2604# endif
2605# if defined (LINUX)
2606# if defined(ALPHA) || defined(M68K)
2607 (*(REAL_SIG_PF)old_handler) (sig, code, sc);
2608# else
2609# if defined(IA64) || defined(HP_PA) || defined(X86_64)
2610 (*(REAL_SIG_PF)old_handler) (sig, si, scp);
2611# else
2612 (*(REAL_SIG_PF)old_handler) (sig, sc);
2613# endif
2614# endif
2615 return;
2616# endif
2617# if defined (IRIX5) || defined(OSF1) || defined(HURD)
2618 (*(REAL_SIG_PF)old_handler) (sig, code, scp);
2619 return;
2620# endif
2621# ifdef MSWIN32
2622 return((*old_handler)(exc_info));
2623# endif
2624 }
2625 }
2626 UNPROTECT(h, GC_page_size);
2627 /* We need to make sure that no collection occurs between */
2628 /* the UNPROTECT and the setting of the dirty bit. Otherwise */
2629 /* a write by a third thread might go unnoticed. Reversing */
2630 /* the order is just as bad, since we would end up unprotecting */
2631 /* a page in a GC cycle during which it's not marked. */
2632 /* Currently we do this by disabling the thread stopping */
2633 /* signals while this handler is running. An alternative might */
2634 /* be to record the fact that we're about to unprotect, or */
2635 /* have just unprotected a page in the GC's thread structure, */
2636 /* and then to have the thread stopping code set the dirty */
2637 /* flag, if necessary. */
2638 for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
2639 register int index = PHT_HASH(h+i);
2640
2641 async_set_pht_entry_from_index(GC_dirty_pages, index);
2642 }
2643# if defined(OSF1)
2644 /* These reset the signal handler each time by default. */
2645 signal(SIGSEGV, (SIG_PF) GC_write_fault_handler);
2646# endif
2647 /* The write may not take place before dirty bits are read. */
2648 /* But then we'll fault again ... */
2649# if defined(MSWIN32) || defined(MSWINCE)
2650 return(EXCEPTION_CONTINUE_EXECUTION);
2651# else
2652 return;
2653# endif
2654 }
2655#if defined(MSWIN32) || defined(MSWINCE)
2656 return EXCEPTION_CONTINUE_SEARCH;
2657#else
2658 GC_err_printf1("Segfault at 0x%lx\n", addr);
2659 ABORT("Unexpected bus error or segmentation fault");
2660#endif
2661}
2662#endif /* !DARWIN */
2663
2664/*
2665 * We hold the allocation lock. We expect block h to be written
2666 * shortly. Ensure that all pages containing any part of the n hblks
2667 * starting at h are no longer protected. If is_ptrfree is false,
2668 * also ensure that they will subsequently appear to be dirty.
2669 */
2670void GC_remove_protection(h, nblocks, is_ptrfree)
2671struct hblk *h;
2672word nblocks;
2673GC_bool is_ptrfree;
2674{
2675 struct hblk * h_trunc; /* Truncated to page boundary */
2676 struct hblk * h_end; /* Page boundary following block end */
2677 struct hblk * current;
2678 GC_bool found_clean;
2679
2680 if (!GC_dirty_maintained) return;
2681 h_trunc = (struct hblk *)((word)h & ~(GC_page_size-1));
2682 h_end = (struct hblk *)(((word)(h + nblocks) + GC_page_size-1)
2683 & ~(GC_page_size-1));
2684 found_clean = FALSE;
2685 for (current = h_trunc; current < h_end; ++current) {
2686 int index = PHT_HASH(current);
2687
2688 if (!is_ptrfree || current < h || current >= h + nblocks) {
2689 async_set_pht_entry_from_index(GC_dirty_pages, index);
2690 }
2691 }
2692 UNPROTECT(h_trunc, (ptr_t)h_end - (ptr_t)h_trunc);
2693}
2694
2695#if !defined(DARWIN)
2696void GC_dirty_init()
2697{
2698# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(LINUX) || \
2699 defined(OSF1) || defined(HURD)
2700 struct sigaction act, oldact;
2701 /* We should probably specify SA_SIGINFO for Linux, and handle */
2702 /* the different architectures more uniformly. */
2703# if defined(IRIX5) || defined(LINUX) && !defined(X86_64) \
2704 || defined(OSF1) || defined(HURD)
2705 act.sa_flags = SA_RESTART;
2706 act.sa_handler = (SIG_PF)GC_write_fault_handler;
2707# else
2708 act.sa_flags = SA_RESTART | SA_SIGINFO;
2709 act.sa_sigaction = GC_write_fault_handler;
2710# endif
2711 (void)sigemptyset(&act.sa_mask);
2712# ifdef SIG_SUSPEND
2713 /* Arrange to postpone SIG_SUSPEND while we're in a write fault */
2714 /* handler. This effectively makes the handler atomic w.r.t. */
2715 /* stopping the world for GC. */
2716 (void)sigaddset(&act.sa_mask, SIG_SUSPEND);
2717# endif /* SIG_SUSPEND */
2718# endif
2719# ifdef PRINTSTATS
2720 GC_printf0("Inititalizing mprotect virtual dirty bit implementation\n");
2721# endif
2722 GC_dirty_maintained = TRUE;
2723 if (GC_page_size % HBLKSIZE != 0) {
2724 GC_err_printf0("Page size not multiple of HBLKSIZE\n");
2725 ABORT("Page size not multiple of HBLKSIZE");
2726 }
2727# if defined(SUNOS4) || (defined(FREEBSD) && !defined(SUNOS5SIGS))
2728 GC_old_bus_handler = signal(SIGBUS, GC_write_fault_handler);
2729 if (GC_old_bus_handler == SIG_IGN) {
2730 GC_err_printf0("Previously ignored bus error!?");
2731 GC_old_bus_handler = SIG_DFL;
2732 }
2733 if (GC_old_bus_handler != SIG_DFL) {
2734# ifdef PRINTSTATS
2735 GC_err_printf0("Replaced other SIGBUS handler\n");
2736# endif
2737 }
2738# endif
2739# if defined(SUNOS4)
2740 GC_old_segv_handler = signal(SIGSEGV, (SIG_PF)GC_write_fault_handler);
2741 if (GC_old_segv_handler == SIG_IGN) {
2742 GC_err_printf0("Previously ignored segmentation violation!?");
2743 GC_old_segv_handler = SIG_DFL;
2744 }
2745 if (GC_old_segv_handler != SIG_DFL) {
2746# ifdef PRINTSTATS
2747 GC_err_printf0("Replaced other SIGSEGV handler\n");
2748# endif
2749 }
2750# endif
2751# if (defined(SUNOS5SIGS) && !defined(FREEBSD)) || defined(IRIX5) \
2752 || defined(LINUX) || defined(OSF1) || defined(HURD)
2753 /* SUNOS5SIGS includes HPUX */
2754# if defined(GC_IRIX_THREADS)
2755 sigaction(SIGSEGV, 0, &oldact);
2756 sigaction(SIGSEGV, &act, 0);
2757# else
2758 {
2759 int res = sigaction(SIGSEGV, &act, &oldact);
2760 if (res != 0) ABORT("Sigaction failed");
2761 }
2762# endif
2763# if defined(_sigargs) || defined(HURD) || !defined(SA_SIGINFO)
2764 /* This is Irix 5.x, not 6.x. Irix 5.x does not have */
2765 /* sa_sigaction. */
2766 GC_old_segv_handler = oldact.sa_handler;
2767# else /* Irix 6.x or SUNOS5SIGS or LINUX */
2768 if (oldact.sa_flags & SA_SIGINFO) {
2769 GC_old_segv_handler = (SIG_PF)(oldact.sa_sigaction);
2770 } else {
2771 GC_old_segv_handler = oldact.sa_handler;
2772 }
2773# endif
2774 if (GC_old_segv_handler == SIG_IGN) {
2775 GC_err_printf0("Previously ignored segmentation violation!?");
2776 GC_old_segv_handler = SIG_DFL;
2777 }
2778 if (GC_old_segv_handler != SIG_DFL) {
2779# ifdef PRINTSTATS
2780 GC_err_printf0("Replaced other SIGSEGV handler\n");
2781# endif
2782 }
2783# endif /* (SUNOS5SIGS && !FREEBSD) || IRIX5 || LINUX || OSF1 || HURD */
2784# if defined(HPUX) || defined(LINUX) || defined(HURD) \
2785 || (defined(FREEBSD) && defined(SUNOS5SIGS))
2786 sigaction(SIGBUS, &act, &oldact);
2787 GC_old_bus_handler = oldact.sa_handler;
2788 if (GC_old_bus_handler == SIG_IGN) {
2789 GC_err_printf0("Previously ignored bus error!?");
2790 GC_old_bus_handler = SIG_DFL;
2791 }
2792 if (GC_old_bus_handler != SIG_DFL) {
2793# ifdef PRINTSTATS
2794 GC_err_printf0("Replaced other SIGBUS handler\n");
2795# endif
2796 }
2797# endif /* HPUX || LINUX || HURD || (FREEBSD && SUNOS5SIGS) */
2798# if defined(MSWIN32)
2799 GC_old_segv_handler = SetUnhandledExceptionFilter(GC_write_fault_handler);
2800 if (GC_old_segv_handler != NULL) {
2801# ifdef PRINTSTATS
2802 GC_err_printf0("Replaced other UnhandledExceptionFilter\n");
2803# endif
2804 } else {
2805 GC_old_segv_handler = SIG_DFL;
2806 }
2807# endif
2808}
2809#endif /* !DARWIN */
2810
2811int GC_incremental_protection_needs()
2812{
2813 if (GC_page_size == HBLKSIZE) {
2814 return GC_PROTECTS_POINTER_HEAP;
2815 } else {
2816 return GC_PROTECTS_POINTER_HEAP | GC_PROTECTS_PTRFREE_HEAP;
2817 }
2818}
2819
2820#define HAVE_INCREMENTAL_PROTECTION_NEEDS
2821
2822#define IS_PTRFREE(hhdr) ((hhdr)->hb_descr == 0)
2823
2824#define PAGE_ALIGNED(x) !((word)(x) & (GC_page_size - 1))
2825void GC_protect_heap()
2826{
2827 ptr_t start;
2828 word len;
2829 struct hblk * current;
2830 struct hblk * current_start; /* Start of block to be protected. */
2831 struct hblk * limit;
2832 unsigned i;
2833 GC_bool protect_all =
2834 (0 != (GC_incremental_protection_needs() & GC_PROTECTS_PTRFREE_HEAP));
2835 for (i = 0; i < GC_n_heap_sects; i++) {
2836 start = GC_heap_sects[i].hs_start;
2837 len = GC_heap_sects[i].hs_bytes;
2838 if (protect_all) {
2839 PROTECT(start, len);
2840 } else {
2841 GC_ASSERT(PAGE_ALIGNED(len))
2842 GC_ASSERT(PAGE_ALIGNED(start))
2843 current_start = current = (struct hblk *)start;
2844 limit = (struct hblk *)(start + len);
2845 while (current < limit) {
2846 hdr * hhdr;
2847 word nhblks;
2848 GC_bool is_ptrfree;
2849
2850 GC_ASSERT(PAGE_ALIGNED(current));
2851 GET_HDR(current, hhdr);
2852 if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
2853 /* This can happen only if we're at the beginning of a */
2854 /* heap segment, and a block spans heap segments. */
2855 /* We will handle that block as part of the preceding */
2856 /* segment. */
2857 GC_ASSERT(current_start == current);
2858 current_start = ++current;
2859 continue;
2860 }
2861 if (HBLK_IS_FREE(hhdr)) {
2862 GC_ASSERT(PAGE_ALIGNED(hhdr -> hb_sz));
2863 nhblks = divHBLKSZ(hhdr -> hb_sz);
2864 is_ptrfree = TRUE; /* dirty on alloc */
2865 } else {
2866 nhblks = OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz);
2867 is_ptrfree = IS_PTRFREE(hhdr);
2868 }
2869 if (is_ptrfree) {
2870 if (current_start < current) {
2871 PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
2872 }
2873 current_start = (current += nhblks);
2874 } else {
2875 current += nhblks;
2876 }
2877 }
2878 if (current_start < current) {
2879 PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
2880 }
2881 }
2882 }
2883}
2884
2885/* We assume that either the world is stopped or its OK to lose dirty */
2886/* bits while this is happenning (as in GC_enable_incremental). */
2887void GC_read_dirty()
2888{
2889 BCOPY((word *)GC_dirty_pages, GC_grungy_pages,
2890 (sizeof GC_dirty_pages));
2891 BZERO((word *)GC_dirty_pages, (sizeof GC_dirty_pages));
2892 GC_protect_heap();
2893}
2894
2895GC_bool GC_page_was_dirty(h)
2896struct hblk * h;
2897{
2898 register word index = PHT_HASH(h);
2899
2900 return(HDR(h) == 0 || get_pht_entry_from_index(GC_grungy_pages, index));
2901}
2902
2903/*
2904 * Acquiring the allocation lock here is dangerous, since this
2905 * can be called from within GC_call_with_alloc_lock, and the cord
2906 * package does so. On systems that allow nested lock acquisition, this
2907 * happens to work.
2908 * On other systems, SET_LOCK_HOLDER and friends must be suitably defined.
2909 */
2910
2911static GC_bool syscall_acquired_lock = FALSE; /* Protected by GC lock. */
2912
2913void GC_begin_syscall()
2914{
2915 if (!I_HOLD_LOCK()) {
2916 LOCK();
2917 syscall_acquired_lock = TRUE;
2918 }
2919}
2920
2921void GC_end_syscall()
2922{
2923 if (syscall_acquired_lock) {
2924 syscall_acquired_lock = FALSE;
2925 UNLOCK();
2926 }
2927}
2928
2929void GC_unprotect_range(addr, len)
2930ptr_t addr;
2931word len;
2932{
2933 struct hblk * start_block;
2934 struct hblk * end_block;
2935 register struct hblk *h;
2936 ptr_t obj_start;
2937
2938 if (!GC_dirty_maintained) return;
2939 obj_start = GC_base(addr);
2940 if (obj_start == 0) return;
2941 if (GC_base(addr + len - 1) != obj_start) {
2942 ABORT("GC_unprotect_range(range bigger than object)");
2943 }
2944 start_block = (struct hblk *)((word)addr & ~(GC_page_size - 1));
2945 end_block = (struct hblk *)((word)(addr + len - 1) & ~(GC_page_size - 1));
2946 end_block += GC_page_size/HBLKSIZE - 1;
2947 for (h = start_block; h <= end_block; h++) {
2948 register word index = PHT_HASH(h);
2949
2950 async_set_pht_entry_from_index(GC_dirty_pages, index);
2951 }
2952 UNPROTECT(start_block,
2953 ((ptr_t)end_block - (ptr_t)start_block) + HBLKSIZE);
2954}
2955
2956#if 0
2957
2958/* We no longer wrap read by default, since that was causing too many */
2959/* problems. It is preferred that the client instead avoids writing */
2960/* to the write-protected heap with a system call. */
2961/* This still serves as sample code if you do want to wrap system calls.*/
2962
2963#if !defined(MSWIN32) && !defined(MSWINCE) && !defined(GC_USE_LD_WRAP)
2964/* Replacement for UNIX system call. */
2965/* Other calls that write to the heap should be handled similarly. */
2966/* Note that this doesn't work well for blocking reads: It will hold */
2967/* the allocation lock for the entire duration of the call. Multithreaded */
2968/* clients should really ensure that it won't block, either by setting */
2969/* the descriptor nonblocking, or by calling select or poll first, to */
2970/* make sure that input is available. */
2971/* Another, preferred alternative is to ensure that system calls never */
2972/* write to the protected heap (see above). */
2973# if defined(__STDC__) && !defined(SUNOS4)
2974# include <unistd.h>
2975# include <sys/uio.h>
2976 ssize_t read(int fd, void *buf, size_t nbyte)
2977# else
2978# ifndef LINT
2979 int read(fd, buf, nbyte)
2980# else
2981 int GC_read(fd, buf, nbyte)
2982# endif
2983 int fd;
2984 char *buf;
2985 int nbyte;
2986# endif
2987{
2988 int result;
2989
2990 GC_begin_syscall();
2991 GC_unprotect_range(buf, (word)nbyte);
2992# if defined(IRIX5) || defined(GC_LINUX_THREADS)
2993 /* Indirect system call may not always be easily available. */
2994 /* We could call _read, but that would interfere with the */
2995 /* libpthread interception of read. */
2996 /* On Linux, we have to be careful with the linuxthreads */
2997 /* read interception. */
2998 {
2999 struct iovec iov;
3000
3001 iov.iov_base = buf;
3002 iov.iov_len = nbyte;
3003 result = readv(fd, &iov, 1);
3004 }
3005# else
3006# if defined(HURD)
3007 result = __read(fd, buf, nbyte);
3008# else
3009 /* The two zero args at the end of this list are because one
3010 IA-64 syscall() implementation actually requires six args
3011 to be passed, even though they aren't always used. */
3012 result = syscall(SYS_read, fd, buf, nbyte, 0, 0);
3013# endif /* !HURD */
3014# endif
3015 GC_end_syscall();
3016 return(result);
3017}
3018#endif /* !MSWIN32 && !MSWINCE && !GC_LINUX_THREADS */
3019
3020#if defined(GC_USE_LD_WRAP) && !defined(THREADS)
3021 /* We use the GNU ld call wrapping facility. */
3022 /* This requires that the linker be invoked with "--wrap read". */
3023 /* This can be done by passing -Wl,"--wrap read" to gcc. */
3024 /* I'm not sure that this actually wraps whatever version of read */
3025 /* is called by stdio. That code also mentions __read. */
3026# include <unistd.h>
3027 ssize_t __wrap_read(int fd, void *buf, size_t nbyte)
3028 {
3029 int result;
3030
3031 GC_begin_syscall();
3032 GC_unprotect_range(buf, (word)nbyte);
3033 result = __real_read(fd, buf, nbyte);
3034 GC_end_syscall();
3035 return(result);
3036 }
3037
3038 /* We should probably also do this for __read, or whatever stdio */
3039 /* actually calls. */
3040#endif
3041
3042#endif /* 0 */
3043
3044/*ARGSUSED*/
3045GC_bool GC_page_was_ever_dirty(h)
3046struct hblk *h;
3047{
3048 return(TRUE);
3049}
3050
3051/* Reset the n pages starting at h to "was never dirty" status. */
3052/*ARGSUSED*/
3053void GC_is_fresh(h, n)
3054struct hblk *h;
3055word n;
3056{
3057}
3058
3059# endif /* MPROTECT_VDB */
3060
3061# ifdef PROC_VDB
3062
3063/*
3064 * See DEFAULT_VDB for interface descriptions.
3065 */
3066
3067/*
3068 * This implementaion assumes a Solaris 2.X like /proc pseudo-file-system
3069 * from which we can read page modified bits. This facility is far from
3070 * optimal (e.g. we would like to get the info for only some of the
3071 * address space), but it avoids intercepting system calls.
3072 */
3073
3074#include <errno.h>
3075#include <sys/types.h>
3076#include <sys/signal.h>
3077#include <sys/fault.h>
3078#include <sys/syscall.h>
3079#include <sys/procfs.h>
3080#include <sys/stat.h>
3081
3082#define INITIAL_BUF_SZ 16384
3083word GC_proc_buf_size = INITIAL_BUF_SZ;
3084char *GC_proc_buf;
3085
3086#ifdef GC_SOLARIS_THREADS
3087/* We don't have exact sp values for threads. So we count on */
3088/* occasionally declaring stack pages to be fresh. Thus we */
3089/* need a real implementation of GC_is_fresh. We can't clear */
3090/* entries in GC_written_pages, since that would declare all */
3091/* pages with the given hash address to be fresh. */
3092# define MAX_FRESH_PAGES 8*1024 /* Must be power of 2 */
3093 struct hblk ** GC_fresh_pages; /* A direct mapped cache. */
3094 /* Collisions are dropped. */
3095
3096# define FRESH_PAGE_SLOT(h) (divHBLKSZ((word)(h)) & (MAX_FRESH_PAGES-1))
3097# define ADD_FRESH_PAGE(h) \
3098 GC_fresh_pages[FRESH_PAGE_SLOT(h)] = (h)
3099# define PAGE_IS_FRESH(h) \
3100 (GC_fresh_pages[FRESH_PAGE_SLOT(h)] == (h) && (h) != 0)
3101#endif
3102
3103/* Add all pages in pht2 to pht1 */
3104void GC_or_pages(pht1, pht2)
3105page_hash_table pht1, pht2;
3106{
3107 register int i;
3108
3109 for (i = 0; i < PHT_SIZE; i++) pht1[i] |= pht2[i];
3110}
3111
3112int GC_proc_fd;
3113
3114void GC_dirty_init()
3115{
3116 int fd;
3117 char buf[30];
3118
3119 GC_dirty_maintained = TRUE;
3120 if (GC_words_allocd != 0 || GC_words_allocd_before_gc != 0) {
3121 register int i;
3122
3123 for (i = 0; i < PHT_SIZE; i++) GC_written_pages[i] = (word)(-1);
3124# ifdef PRINTSTATS
3125 GC_printf1("Allocated words:%lu:all pages may have been written\n",
3126 (unsigned long)
3127 (GC_words_allocd + GC_words_allocd_before_gc));
3128# endif
3129 }
3130 sprintf(buf, "/proc/%d", getpid());
3131 fd = open(buf, O_RDONLY);
3132 if (fd < 0) {
3133 ABORT("/proc open failed");
3134 }
3135 GC_proc_fd = syscall(SYS_ioctl, fd, PIOCOPENPD, 0);
3136 close(fd);
3137 syscall(SYS_fcntl, GC_proc_fd, F_SETFD, FD_CLOEXEC);
3138 if (GC_proc_fd < 0) {
3139 ABORT("/proc ioctl failed");
3140 }
3141 GC_proc_buf = GC_scratch_alloc(GC_proc_buf_size);
3142# ifdef GC_SOLARIS_THREADS
3143 GC_fresh_pages = (struct hblk **)
3144 GC_scratch_alloc(MAX_FRESH_PAGES * sizeof (struct hblk *));
3145 if (GC_fresh_pages == 0) {
3146 GC_err_printf0("No space for fresh pages\n");
3147 EXIT();
3148 }
3149 BZERO(GC_fresh_pages, MAX_FRESH_PAGES * sizeof (struct hblk *));
3150# endif
3151}
3152
3153/* Ignore write hints. They don't help us here. */
3154/*ARGSUSED*/
3155void GC_remove_protection(h, nblocks, is_ptrfree)
3156struct hblk *h;
3157word nblocks;
3158GC_bool is_ptrfree;
3159{
3160}
3161
3162#ifdef GC_SOLARIS_THREADS
3163# define READ(fd,buf,nbytes) syscall(SYS_read, fd, buf, nbytes)
3164#else
3165# define READ(fd,buf,nbytes) read(fd, buf, nbytes)
3166#endif
3167
3168void GC_read_dirty()
3169{
3170 unsigned long ps, np;
3171 int nmaps;
3172 ptr_t vaddr;
3173 struct prasmap * map;
3174 char * bufp;
3175 ptr_t current_addr, limit;
3176 int i;
3177int dummy;
3178
3179 BZERO(GC_grungy_pages, (sizeof GC_grungy_pages));
3180
3181 bufp = GC_proc_buf;
3182 if (READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
3183# ifdef PRINTSTATS
3184 GC_printf1("/proc read failed: GC_proc_buf_size = %lu\n",
3185 GC_proc_buf_size);
3186# endif
3187 {
3188 /* Retry with larger buffer. */
3189 word new_size = 2 * GC_proc_buf_size;
3190 char * new_buf = GC_scratch_alloc(new_size);
3191
3192 if (new_buf != 0) {
3193 GC_proc_buf = bufp = new_buf;
3194 GC_proc_buf_size = new_size;
3195 }
3196 if (READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
3197 WARN("Insufficient space for /proc read\n", 0);
3198 /* Punt: */
3199 memset(GC_grungy_pages, 0xff, sizeof (page_hash_table));
3200 memset(GC_written_pages, 0xff, sizeof(page_hash_table));
3201# ifdef GC_SOLARIS_THREADS
3202 BZERO(GC_fresh_pages,
3203 MAX_FRESH_PAGES * sizeof (struct hblk *));
3204# endif
3205 return;
3206 }
3207 }
3208 }
3209 /* Copy dirty bits into GC_grungy_pages */
3210 nmaps = ((struct prpageheader *)bufp) -> pr_nmap;
3211 /* printf( "nmaps = %d, PG_REFERENCED = %d, PG_MODIFIED = %d\n",
3212 nmaps, PG_REFERENCED, PG_MODIFIED); */
3213 bufp = bufp + sizeof(struct prpageheader);
3214 for (i = 0; i < nmaps; i++) {
3215 map = (struct prasmap *)bufp;
3216 vaddr = (ptr_t)(map -> pr_vaddr);
3217 ps = map -> pr_pagesize;
3218 np = map -> pr_npage;
3219 /* printf("vaddr = 0x%X, ps = 0x%X, np = 0x%X\n", vaddr, ps, np); */
3220 limit = vaddr + ps * np;
3221 bufp += sizeof (struct prasmap);
3222 for (current_addr = vaddr;
3223 current_addr < limit; current_addr += ps){
3224 if ((*bufp++) & PG_MODIFIED) {
3225 register struct hblk * h = (struct hblk *) current_addr;
3226
3227 while ((ptr_t)h < current_addr + ps) {
3228 register word index = PHT_HASH(h);
3229
3230 set_pht_entry_from_index(GC_grungy_pages, index);
3231# ifdef GC_SOLARIS_THREADS
3232 {
3233 register int slot = FRESH_PAGE_SLOT(h);
3234
3235 if (GC_fresh_pages[slot] == h) {
3236 GC_fresh_pages[slot] = 0;
3237 }
3238 }
3239# endif
3240 h++;
3241 }
3242 }
3243 }
3244 bufp += sizeof(long) - 1;
3245 bufp = (char *)((unsigned long)bufp & ~(sizeof(long)-1));
3246 }
3247 /* Update GC_written_pages. */
3248 GC_or_pages(GC_written_pages, GC_grungy_pages);
3249# ifdef GC_SOLARIS_THREADS
3250 /* Make sure that old stacks are considered completely clean */
3251 /* unless written again. */
3252 GC_old_stacks_are_fresh();
3253# endif
3254}
3255
3256#undef READ
3257
3258GC_bool GC_page_was_dirty(h)
3259struct hblk *h;
3260{
3261 register word index = PHT_HASH(h);
3262 register GC_bool result;
3263
3264 result = get_pht_entry_from_index(GC_grungy_pages, index);
3265# ifdef GC_SOLARIS_THREADS
3266 if (result && PAGE_IS_FRESH(h)) result = FALSE;
3267 /* This happens only if page was declared fresh since */
3268 /* the read_dirty call, e.g. because it's in an unused */
3269 /* thread stack. It's OK to treat it as clean, in */
3270 /* that case. And it's consistent with */
3271 /* GC_page_was_ever_dirty. */
3272# endif
3273 return(result);
3274}
3275
3276GC_bool GC_page_was_ever_dirty(h)
3277struct hblk *h;
3278{
3279 register word index = PHT_HASH(h);
3280 register GC_bool result;
3281
3282 result = get_pht_entry_from_index(GC_written_pages, index);
3283# ifdef GC_SOLARIS_THREADS
3284 if (result && PAGE_IS_FRESH(h)) result = FALSE;
3285# endif
3286 return(result);
3287}
3288
3289/* Caller holds allocation lock. */
3290void GC_is_fresh(h, n)
3291struct hblk *h;
3292word n;
3293{
3294
3295 register word index;
3296
3297# ifdef GC_SOLARIS_THREADS
3298 register word i;
3299
3300 if (GC_fresh_pages != 0) {
3301 for (i = 0; i < n; i++) {
3302 ADD_FRESH_PAGE(h + i);
3303 }
3304 }
3305# endif
3306}
3307
3308# endif /* PROC_VDB */
3309
3310
3311# ifdef PCR_VDB
3312
3313# include "vd/PCR_VD.h"
3314
3315# define NPAGES (32*1024) /* 128 MB */
3316
3317PCR_VD_DB GC_grungy_bits[NPAGES];
3318
3319ptr_t GC_vd_base; /* Address corresponding to GC_grungy_bits[0] */
3320 /* HBLKSIZE aligned. */
3321
3322void GC_dirty_init()
3323{
3324 GC_dirty_maintained = TRUE;
3325 /* For the time being, we assume the heap generally grows up */
3326 GC_vd_base = GC_heap_sects[0].hs_start;
3327 if (GC_vd_base == 0) {
3328 ABORT("Bad initial heap segment");
3329 }
3330 if (PCR_VD_Start(HBLKSIZE, GC_vd_base, NPAGES*HBLKSIZE)
3331 != PCR_ERes_okay) {
3332 ABORT("dirty bit initialization failed");
3333 }
3334}
3335
3336void GC_read_dirty()
3337{
3338 /* lazily enable dirty bits on newly added heap sects */
3339 {
3340 static int onhs = 0;
3341 int nhs = GC_n_heap_sects;
3342 for( ; onhs < nhs; onhs++ ) {
3343 PCR_VD_WriteProtectEnable(
3344 GC_heap_sects[onhs].hs_start,
3345 GC_heap_sects[onhs].hs_bytes );
3346 }
3347 }
3348
3349
3350 if (PCR_VD_Clear(GC_vd_base, NPAGES*HBLKSIZE, GC_grungy_bits)
3351 != PCR_ERes_okay) {
3352 ABORT("dirty bit read failed");
3353 }
3354}
3355
3356GC_bool GC_page_was_dirty(h)
3357struct hblk *h;
3358{
3359 if((ptr_t)h < GC_vd_base || (ptr_t)h >= GC_vd_base + NPAGES*HBLKSIZE) {
3360 return(TRUE);
3361 }
3362 return(GC_grungy_bits[h - (struct hblk *)GC_vd_base] & PCR_VD_DB_dirtyBit);
3363}
3364
3365/*ARGSUSED*/
3366void GC_remove_protection(h, nblocks, is_ptrfree)
3367struct hblk *h;
3368word nblocks;
3369GC_bool is_ptrfree;
3370{
3371 PCR_VD_WriteProtectDisable(h, nblocks*HBLKSIZE);
3372 PCR_VD_WriteProtectEnable(h, nblocks*HBLKSIZE);
3373}
3374
3375# endif /* PCR_VDB */
3376
3377#if defined(MPROTECT_VDB) && defined(DARWIN)
3378/* The following sources were used as a *reference* for this exception handling
3379 code:
3380 1. Apple's mach/xnu documentation
3381 2. Timothy J. Wood's "Mach Exception Handlers 101" post to the
3382 omnigroup's macosx-dev list.
3383 www.omnigroup.com/mailman/archive/macosx-dev/2000-June/002030.html
3384 3. macosx-nat.c from Apple's GDB source code.
3385*/
3386
3387/* The bug that caused all this trouble should now be fixed. This should
3388 eventually be removed if all goes well. */
3389/* define BROKEN_EXCEPTION_HANDLING */
3390
3391#include <mach/mach.h>
3392#include <mach/mach_error.h>
3393#include <mach/thread_status.h>
3394#include <mach/exception.h>
3395#include <mach/task.h>
3396#include <pthread.h>
3397
3398/* These are not defined in any header, although they are documented */
3399extern boolean_t exc_server(mach_msg_header_t *,mach_msg_header_t *);
3400extern kern_return_t exception_raise(
3401 mach_port_t,mach_port_t,mach_port_t,
3402 exception_type_t,exception_data_t,mach_msg_type_number_t);
3403extern kern_return_t exception_raise_state(
3404 mach_port_t,mach_port_t,mach_port_t,
3405 exception_type_t,exception_data_t,mach_msg_type_number_t,
3406 thread_state_flavor_t*,thread_state_t,mach_msg_type_number_t,
3407 thread_state_t,mach_msg_type_number_t*);
3408extern kern_return_t exception_raise_state_identity(
3409 mach_port_t,mach_port_t,mach_port_t,
3410 exception_type_t,exception_data_t,mach_msg_type_number_t,
3411 thread_state_flavor_t*,thread_state_t,mach_msg_type_number_t,
3412 thread_state_t,mach_msg_type_number_t*);
3413
3414
3415#define MAX_EXCEPTION_PORTS 16
3416
3417static struct {
3418 mach_msg_type_number_t count;
3419 exception_mask_t masks[MAX_EXCEPTION_PORTS];
3420 exception_handler_t ports[MAX_EXCEPTION_PORTS];
3421 exception_behavior_t behaviors[MAX_EXCEPTION_PORTS];
3422 thread_state_flavor_t flavors[MAX_EXCEPTION_PORTS];
3423} GC_old_exc_ports;
3424
3425static struct {
3426 mach_port_t exception;
3427#if defined(THREADS)
3428 mach_port_t reply;
3429#endif
3430} GC_ports;
3431
3432typedef struct {
3433 mach_msg_header_t head;
3434} GC_msg_t;
3435
3436typedef enum {
3437 GC_MP_NORMAL, GC_MP_DISCARDING, GC_MP_STOPPED
3438} GC_mprotect_state_t;
3439
3440/* FIXME: 1 and 2 seem to be safe to use in the msgh_id field,
3441 but it isn't documented. Use the source and see if they
3442 should be ok. */
3443#define ID_STOP 1
3444#define ID_RESUME 2
3445
3446/* These values are only used on the reply port */
3447#define ID_ACK 3
3448
3449#if defined(THREADS)
3450
3451GC_mprotect_state_t GC_mprotect_state;
3452
3453/* The following should ONLY be called when the world is stopped */
3454static void GC_mprotect_thread_notify(mach_msg_id_t id) {
3455 struct {
3456 GC_msg_t msg;
3457 mach_msg_trailer_t trailer;
3458 } buf;
3459 mach_msg_return_t r;
3460 /* remote, local */
3461 buf.msg.head.msgh_bits =
3462 MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND,0);
3463 buf.msg.head.msgh_size = sizeof(buf.msg);
3464 buf.msg.head.msgh_remote_port = GC_ports.exception;
3465 buf.msg.head.msgh_local_port = MACH_PORT_NULL;
3466 buf.msg.head.msgh_id = id;
3467
3468 r = mach_msg(
3469 &buf.msg.head,
3470 MACH_SEND_MSG|MACH_RCV_MSG|MACH_RCV_LARGE,
3471 sizeof(buf.msg),
3472 sizeof(buf),
3473 GC_ports.reply,
3474 MACH_MSG_TIMEOUT_NONE,
3475 MACH_PORT_NULL);
3476 if(r != MACH_MSG_SUCCESS)
3477 ABORT("mach_msg failed in GC_mprotect_thread_notify");
3478 if(buf.msg.head.msgh_id != ID_ACK)
3479 ABORT("invalid ack in GC_mprotect_thread_notify");
3480}
3481
3482/* Should only be called by the mprotect thread */
3483static void GC_mprotect_thread_reply() {
3484 GC_msg_t msg;
3485 mach_msg_return_t r;
3486 /* remote, local */
3487 msg.head.msgh_bits =
3488 MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND,0);
3489 msg.head.msgh_size = sizeof(msg);
3490 msg.head.msgh_remote_port = GC_ports.reply;
3491 msg.head.msgh_local_port = MACH_PORT_NULL;
3492 msg.head.msgh_id = ID_ACK;
3493
3494 r = mach_msg(
3495 &msg.head,
3496 MACH_SEND_MSG,
3497 sizeof(msg),
3498 0,
3499 MACH_PORT_NULL,
3500 MACH_MSG_TIMEOUT_NONE,
3501 MACH_PORT_NULL);
3502 if(r != MACH_MSG_SUCCESS)
3503 ABORT("mach_msg failed in GC_mprotect_thread_reply");
3504}
3505
3506void GC_mprotect_stop() {
3507 GC_mprotect_thread_notify(ID_STOP);
3508}
3509void GC_mprotect_resume() {
3510 GC_mprotect_thread_notify(ID_RESUME);
3511}
3512
3513#else /* !THREADS */
3514/* The compiler should optimize away any GC_mprotect_state computations */
3515#define GC_mprotect_state GC_MP_NORMAL
3516#endif
3517
3518static void *GC_mprotect_thread(void *arg) {
3519 mach_msg_return_t r;
3520 /* These two structures contain some private kernel data. We don't need to
3521 access any of it so we don't bother defining a proper struct. The
3522 correct definitions are in the xnu source code. */
3523 struct {
3524 mach_msg_header_t head;
3525 char data[256];
3526 } reply;
3527 struct {
3528 mach_msg_header_t head;
3529 mach_msg_body_t msgh_body;
3530 char data[1024];
3531 } msg;
3532
3533 mach_msg_id_t id;
3534
3535 GC_darwin_register_mach_handler_thread(mach_thread_self());
3536
3537 for(;;) {
3538 r = mach_msg(
3539 &msg.head,
3540 MACH_RCV_MSG|MACH_RCV_LARGE|
3541 (GC_mprotect_state == GC_MP_DISCARDING ? MACH_RCV_TIMEOUT : 0),
3542 0,
3543 sizeof(msg),
3544 GC_ports.exception,
3545 GC_mprotect_state == GC_MP_DISCARDING ? 0 : MACH_MSG_TIMEOUT_NONE,
3546 MACH_PORT_NULL);
3547
3548 id = r == MACH_MSG_SUCCESS ? msg.head.msgh_id : -1;
3549
3550#if defined(THREADS)
3551 if(GC_mprotect_state == GC_MP_DISCARDING) {
3552 if(r == MACH_RCV_TIMED_OUT) {
3553 GC_mprotect_state = GC_MP_STOPPED;
3554 GC_mprotect_thread_reply();
3555 continue;
3556 }
3557 if(r == MACH_MSG_SUCCESS && (id == ID_STOP || id == ID_RESUME))
3558 ABORT("out of order mprotect thread request");
3559 }
3560#endif
3561
3562 if(r != MACH_MSG_SUCCESS) {
3563 GC_err_printf2("mach_msg failed with %d %s\n",
3564 (int)r,mach_error_string(r));
3565 ABORT("mach_msg failed");
3566 }
3567
3568 switch(id) {
3569#if defined(THREADS)
3570 case ID_STOP:
3571 if(GC_mprotect_state != GC_MP_NORMAL)
3572 ABORT("Called mprotect_stop when state wasn't normal");
3573 GC_mprotect_state = GC_MP_DISCARDING;
3574 break;
3575 case ID_RESUME:
3576 if(GC_mprotect_state != GC_MP_STOPPED)
3577 ABORT("Called mprotect_resume when state wasn't stopped");
3578 GC_mprotect_state = GC_MP_NORMAL;
3579 GC_mprotect_thread_reply();
3580 break;
3581#endif /* THREADS */
3582 default:
3583 /* Handle the message (calls catch_exception_raise) */
3584 if(!exc_server(&msg.head,&reply.head))
3585 ABORT("exc_server failed");
3586 /* Send the reply */
3587 r = mach_msg(
3588 &reply.head,
3589 MACH_SEND_MSG,
3590 reply.head.msgh_size,
3591 0,
3592 MACH_PORT_NULL,
3593 MACH_MSG_TIMEOUT_NONE,
3594 MACH_PORT_NULL);
3595 if(r != MACH_MSG_SUCCESS) {
3596 /* This will fail if the thread dies, but the thread shouldn't
3597 die... */
3598 #ifdef BROKEN_EXCEPTION_HANDLING
3599 GC_err_printf2(
3600 "mach_msg failed with %d %s while sending exc reply\n",
3601 (int)r,mach_error_string(r));
3602 #else
3603 ABORT("mach_msg failed while sending exception reply");
3604 #endif
3605 }
3606 } /* switch */
3607 } /* for(;;) */
3608 /* NOT REACHED */
3609 return NULL;
3610}
3611
3612/* All this SIGBUS code shouldn't be necessary. All protection faults should
3613 be going throught the mach exception handler. However, it seems a SIGBUS is
3614 occasionally sent for some unknown reason. Even more odd, it seems to be
3615 meaningless and safe to ignore. */
3616#ifdef BROKEN_EXCEPTION_HANDLING
3617
3618typedef void (* SIG_PF)();
3619static SIG_PF GC_old_bus_handler;
3620
3621/* Updates to this aren't atomic, but the SIGBUSs seem pretty rare.
3622 Even if this doesn't get updated property, it isn't really a problem */
3623static int GC_sigbus_count;
3624
3625static void GC_darwin_sigbus(int num,siginfo_t *sip,void *context) {
3626 if(num != SIGBUS) ABORT("Got a non-sigbus signal in the sigbus handler");
3627
3628 /* Ugh... some seem safe to ignore, but too many in a row probably means
3629 trouble. GC_sigbus_count is reset for each mach exception that is
3630 handled */
3631 if(GC_sigbus_count >= 8) {
3632 ABORT("Got more than 8 SIGBUSs in a row!");
3633 } else {
3634 GC_sigbus_count++;
3635 GC_err_printf0("GC: WARNING: Ignoring SIGBUS.\n");
3636 }
3637}
3638#endif /* BROKEN_EXCEPTION_HANDLING */
3639
3640void GC_dirty_init() {
3641 kern_return_t r;
3642 mach_port_t me;
3643 pthread_t thread;
3644 pthread_attr_t attr;
3645 exception_mask_t mask;
3646
3647# ifdef PRINTSTATS
3648 GC_printf0("Inititalizing mach/darwin mprotect virtual dirty bit "
3649 "implementation\n");
3650# endif
3651# ifdef BROKEN_EXCEPTION_HANDLING
3652 GC_err_printf0("GC: WARNING: Enabling workarounds for various darwin "
3653 "exception handling bugs.\n");
3654# endif
3655 GC_dirty_maintained = TRUE;
3656 if (GC_page_size % HBLKSIZE != 0) {
3657 GC_err_printf0("Page size not multiple of HBLKSIZE\n");
3658 ABORT("Page size not multiple of HBLKSIZE");
3659 }
3660
3661 GC_task_self = me = mach_task_self();
3662
3663 r = mach_port_allocate(me,MACH_PORT_RIGHT_RECEIVE,&GC_ports.exception);
3664 if(r != KERN_SUCCESS) ABORT("mach_port_allocate failed (exception port)");
3665
3666 r = mach_port_insert_right(me,GC_ports.exception,GC_ports.exception,
3667 MACH_MSG_TYPE_MAKE_SEND);
3668 if(r != KERN_SUCCESS)
3669 ABORT("mach_port_insert_right failed (exception port)");
3670
3671 #if defined(THREADS)
3672 r = mach_port_allocate(me,MACH_PORT_RIGHT_RECEIVE,&GC_ports.reply);
3673 if(r != KERN_SUCCESS) ABORT("mach_port_allocate failed (reply port)");
3674 #endif
3675
3676 /* The exceptions we want to catch */
3677 mask = EXC_MASK_BAD_ACCESS;
3678
3679 r = task_get_exception_ports(
3680 me,
3681 mask,
3682 GC_old_exc_ports.masks,
3683 &GC_old_exc_ports.count,
3684 GC_old_exc_ports.ports,
3685 GC_old_exc_ports.behaviors,
3686 GC_old_exc_ports.flavors
3687 );
3688 if(r != KERN_SUCCESS) ABORT("task_get_exception_ports failed");
3689
3690 r = task_set_exception_ports(
3691 me,
3692 mask,
3693 GC_ports.exception,
3694 EXCEPTION_DEFAULT,
3695 MACHINE_THREAD_STATE
3696 );
3697 if(r != KERN_SUCCESS) ABORT("task_set_exception_ports failed");
3698
3699 if(pthread_attr_init(&attr) != 0) ABORT("pthread_attr_init failed");
3700 if(pthread_attr_setdetachstate(&attr,PTHREAD_CREATE_DETACHED) != 0)
3701 ABORT("pthread_attr_setdetachedstate failed");
3702
3703# undef pthread_create
3704 /* This will call the real pthread function, not our wrapper */
3705 if(pthread_create(&thread,&attr,GC_mprotect_thread,NULL) != 0)
3706 ABORT("pthread_create failed");
3707 pthread_attr_destroy(&attr);
3708
3709 /* Setup the sigbus handler for ignoring the meaningless SIGBUSs */
3710 #ifdef BROKEN_EXCEPTION_HANDLING
3711 {
3712 struct sigaction sa, oldsa;
3713 sa.sa_handler = (SIG_PF)GC_darwin_sigbus;
3714 sigemptyset(&sa.sa_mask);
3715 sa.sa_flags = SA_RESTART|SA_SIGINFO;
3716 if(sigaction(SIGBUS,&sa,&oldsa) < 0) ABORT("sigaction");
3717 GC_old_bus_handler = (SIG_PF)oldsa.sa_handler;
3718 if (GC_old_bus_handler != SIG_DFL) {
3719# ifdef PRINTSTATS
3720 GC_err_printf0("Replaced other SIGBUS handler\n");
3721# endif
3722 }
3723 }
3724 #endif /* BROKEN_EXCEPTION_HANDLING */
3725}
3726
3727/* The source code for Apple's GDB was used as a reference for the exception
3728 forwarding code. This code is similar to be GDB code only because there is
3729 only one way to do it. */
3730static kern_return_t GC_forward_exception(
3731 mach_port_t thread,
3732 mach_port_t task,
3733 exception_type_t exception,
3734 exception_data_t data,
3735 mach_msg_type_number_t data_count
3736) {
3737 int i;
3738 kern_return_t r;
3739 mach_port_t port;
3740 exception_behavior_t behavior;
3741 thread_state_flavor_t flavor;
3742
3743 thread_state_t thread_state;
3744 mach_msg_type_number_t thread_state_count = THREAD_STATE_MAX;
3745
3746 for(i=0;i<GC_old_exc_ports.count;i++)
3747 if(GC_old_exc_ports.masks[i] & (1 << exception))
3748 break;
3749 if(i==GC_old_exc_ports.count) ABORT("No handler for exception!");
3750
3751 port = GC_old_exc_ports.ports[i];
3752 behavior = GC_old_exc_ports.behaviors[i];
3753 flavor = GC_old_exc_ports.flavors[i];
3754
3755 if(behavior != EXCEPTION_DEFAULT) {
3756 r = thread_get_state(thread,flavor,thread_state,&thread_state_count);
3757 if(r != KERN_SUCCESS)
3758 ABORT("thread_get_state failed in forward_exception");
3759 }
3760
3761 switch(behavior) {
3762 case EXCEPTION_DEFAULT:
3763 r = exception_raise(port,thread,task,exception,data,data_count);
3764 break;
3765 case EXCEPTION_STATE:
3766 r = exception_raise_state(port,thread,task,exception,data,
3767 data_count,&flavor,thread_state,thread_state_count,
3768 thread_state,&thread_state_count);
3769 break;
3770 case EXCEPTION_STATE_IDENTITY:
3771 r = exception_raise_state_identity(port,thread,task,exception,data,
3772 data_count,&flavor,thread_state,thread_state_count,
3773 thread_state,&thread_state_count);
3774 break;
3775 default:
3776 r = KERN_FAILURE; /* make gcc happy */
3777 ABORT("forward_exception: unknown behavior");
3778 break;
3779 }
3780
3781 if(behavior != EXCEPTION_DEFAULT) {
3782 r = thread_set_state(thread,flavor,thread_state,thread_state_count);
3783 if(r != KERN_SUCCESS)
3784 ABORT("thread_set_state failed in forward_exception");
3785 }
3786
3787 return r;
3788}
3789
3790#define FWD() GC_forward_exception(thread,task,exception,code,code_count)
3791
3792/* This violates the namespace rules but there isn't anything that can be done
3793 about it. The exception handling stuff is hard coded to call this */
3794kern_return_t
3795catch_exception_raise(
3796 mach_port_t exception_port,mach_port_t thread,mach_port_t task,
3797 exception_type_t exception,exception_data_t code,
3798 mach_msg_type_number_t code_count
3799) {
3800 kern_return_t r;
3801 char *addr;
3802 struct hblk *h;
3803 int i;
3804# if defined(POWERPC)
3805# if CPP_WORDSZ == 32
3806 thread_state_flavor_t flavor = PPC_EXCEPTION_STATE;
3807 mach_msg_type_number_t exc_state_count = PPC_EXCEPTION_STATE_COUNT;
3808 ppc_exception_state_t exc_state;
3809# else
3810 thread_state_flavor_t flavor = PPC_EXCEPTION_STATE64;
3811 mach_msg_type_number_t exc_state_count = PPC_EXCEPTION_STATE64_COUNT;
3812 ppc_exception_state64_t exc_state;
3813# endif
3814# elif defined(I386)
3815 thread_state_flavor_t flavor = i386_EXCEPTION_STATE;
3816 mach_msg_type_number_t exc_state_count = i386_EXCEPTION_STATE_COUNT;
3817 i386_exception_state_t exc_state;
3818# else
3819# error FIXME for non-ppc/x86 darwin
3820# endif
3821
3822
3823 if(exception != EXC_BAD_ACCESS || code[0] != KERN_PROTECTION_FAILURE) {
3824 #ifdef DEBUG_EXCEPTION_HANDLING
3825 /* We aren't interested, pass it on to the old handler */
3826 GC_printf3("Exception: 0x%x Code: 0x%x 0x%x in catch....\n",
3827 exception,
3828 code_count > 0 ? code[0] : -1,
3829 code_count > 1 ? code[1] : -1);
3830 #endif
3831 return FWD();
3832 }
3833
3834 r = thread_get_state(thread,flavor,
3835 (natural_t*)&exc_state,&exc_state_count);
3836 if(r != KERN_SUCCESS) {
3837 /* The thread is supposed to be suspended while the exception handler
3838 is called. This shouldn't fail. */
3839 #ifdef BROKEN_EXCEPTION_HANDLING
3840 GC_err_printf0("thread_get_state failed in "
3841 "catch_exception_raise\n");
3842 return KERN_SUCCESS;
3843 #else
3844 ABORT("thread_get_state failed in catch_exception_raise");
3845 #endif
3846 }
3847
3848 /* This is the address that caused the fault */
3849#if defined(POWERPC)
3850 addr = (char*) exc_state.dar;
3851#elif defined (I386)
3852 addr = (char*) exc_state.faultvaddr;
3853#else
3854# error FIXME for non POWERPC/I386
3855#endif
3856
3857 if((HDR(addr)) == 0) {
3858 /* Ugh... just like the SIGBUS problem above, it seems we get a bogus
3859 KERN_PROTECTION_FAILURE every once and a while. We wait till we get
3860 a bunch in a row before doing anything about it. If a "real" fault
3861 ever occurres it'll just keep faulting over and over and we'll hit
3862 the limit pretty quickly. */
3863 #ifdef BROKEN_EXCEPTION_HANDLING
3864 static char *last_fault;
3865 static int last_fault_count;
3866
3867 if(addr != last_fault) {
3868 last_fault = addr;
3869 last_fault_count = 0;
3870 }
3871 if(++last_fault_count < 32) {
3872 if(last_fault_count == 1)
3873 GC_err_printf1(
3874 "GC: WARNING: Ignoring KERN_PROTECTION_FAILURE at %p\n",
3875 addr);
3876 return KERN_SUCCESS;
3877 }
3878
3879 GC_err_printf1("Unexpected KERN_PROTECTION_FAILURE at %p\n",addr);
3880 /* Can't pass it along to the signal handler because that is
3881 ignoring SIGBUS signals. We also shouldn't call ABORT here as
3882 signals don't always work too well from the exception handler. */
3883 GC_err_printf0("Aborting\n");
3884 exit(EXIT_FAILURE);
3885 #else /* BROKEN_EXCEPTION_HANDLING */
3886 /* Pass it along to the next exception handler
3887 (which should call SIGBUS/SIGSEGV) */
3888 return FWD();
3889 #endif /* !BROKEN_EXCEPTION_HANDLING */
3890 }
3891
3892 #ifdef BROKEN_EXCEPTION_HANDLING
3893 /* Reset the number of consecutive SIGBUSs */
3894 GC_sigbus_count = 0;
3895 #endif
3896
3897 if(GC_mprotect_state == GC_MP_NORMAL) { /* common case */
3898 h = (struct hblk*)((word)addr & ~(GC_page_size-1));
3899 UNPROTECT(h, GC_page_size);
3900 for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
3901 register int index = PHT_HASH(h+i);
3902 async_set_pht_entry_from_index(GC_dirty_pages, index);
3903 }
3904 } else if(GC_mprotect_state == GC_MP_DISCARDING) {
3905 /* Lie to the thread for now. No sense UNPROTECT()ing the memory
3906 when we're just going to PROTECT() it again later. The thread
3907 will just fault again once it resumes */
3908 } else {
3909 /* Shouldn't happen, i don't think */
3910 GC_printf0("KERN_PROTECTION_FAILURE while world is stopped\n");
3911 return FWD();
3912 }
3913 return KERN_SUCCESS;
3914}
3915#undef FWD
3916
3917/* These should never be called, but just in case... */
3918kern_return_t catch_exception_raise_state(mach_port_name_t exception_port,
3919 int exception, exception_data_t code, mach_msg_type_number_t codeCnt,
3920 int flavor, thread_state_t old_state, int old_stateCnt,
3921 thread_state_t new_state, int new_stateCnt)
3922{
3923 ABORT("catch_exception_raise_state");
3924 return(KERN_INVALID_ARGUMENT);
3925}
3926kern_return_t catch_exception_raise_state_identity(
3927 mach_port_name_t exception_port, mach_port_t thread, mach_port_t task,
3928 int exception, exception_data_t code, mach_msg_type_number_t codeCnt,
3929 int flavor, thread_state_t old_state, int old_stateCnt,
3930 thread_state_t new_state, int new_stateCnt)
3931{
3932 ABORT("catch_exception_raise_state_identity");
3933 return(KERN_INVALID_ARGUMENT);
3934}
3935
3936
3937#endif /* DARWIN && MPROTECT_VDB */
3938
3939# ifndef HAVE_INCREMENTAL_PROTECTION_NEEDS
3940 int GC_incremental_protection_needs()
3941 {
3942 return GC_PROTECTS_NONE;
3943 }
3944# endif /* !HAVE_INCREMENTAL_PROTECTION_NEEDS */
3945
3946/*
3947 * Call stack save code for debugging.
3948 * Should probably be in mach_dep.c, but that requires reorganization.
3949 */
3950
3951/* I suspect the following works for most X86 *nix variants, so */
3952/* long as the frame pointer is explicitly stored. In the case of gcc, */
3953/* compiler flags (e.g. -fomit-frame-pointer) determine whether it is. */
3954#if defined(I386) && defined(LINUX) && defined(SAVE_CALL_CHAIN)
3955# include <features.h>
3956
3957 struct frame {
3958 struct frame *fr_savfp;
3959 long fr_savpc;
3960 long fr_arg[NARGS]; /* All the arguments go here. */
3961 };
3962#endif
3963
3964#if defined(SPARC)
3965# if defined(LINUX)
3966# include <features.h>
3967
3968 struct frame {
3969 long fr_local[8];
3970 long fr_arg[6];
3971 struct frame *fr_savfp;
3972 long fr_savpc;
3973# ifndef __arch64__
3974 char *fr_stret;
3975# endif
3976 long fr_argd[6];
3977 long fr_argx[0];
3978 };
3979# else
3980# if defined(SUNOS4)
3981# include <machine/frame.h>
3982# else
3983# if defined (DRSNX)
3984# include <sys/sparc/frame.h>
3985# else
3986# if defined(OPENBSD)
3987# include <frame.h>
3988# else
3989# if defined(FREEBSD) || defined(NETBSD)
3990# include <machine/frame.h>
3991# else
3992# include <sys/frame.h>
3993# endif
3994# endif
3995# endif
3996# endif
3997# endif
3998# if NARGS > 6
3999 --> We only know how to to get the first 6 arguments
4000# endif
4001#endif /* SPARC */
4002
4003#ifdef NEED_CALLINFO
4004/* Fill in the pc and argument information for up to NFRAMES of my */
4005/* callers. Ignore my frame and my callers frame. */
4006
4007#ifdef LINUX
4008# include <unistd.h>
4009#endif
4010
4011#endif /* NEED_CALLINFO */
4012
4013#if defined(GC_HAVE_BUILTIN_BACKTRACE)
4014# include <execinfo.h>
4015#endif
4016
4017#ifdef SAVE_CALL_CHAIN
4018
4019#if NARGS == 0 && NFRAMES % 2 == 0 /* No padding */ \
4020 && defined(GC_HAVE_BUILTIN_BACKTRACE)
4021
4022#ifdef REDIRECT_MALLOC
4023 /* Deal with possible malloc calls in backtrace by omitting */
4024 /* the infinitely recursing backtrace. */
4025# ifdef THREADS
4026 __thread /* If your compiler doesn't understand this */
4027 /* you could use something like pthread_getspecific. */
4028# endif
4029 GC_in_save_callers = FALSE;
4030#endif
4031
4032void GC_save_callers (info)
4033struct callinfo info[NFRAMES];
4034{
4035 void * tmp_info[NFRAMES + 1];
4036 int npcs, i;
4037# define IGNORE_FRAMES 1
4038
4039 /* We retrieve NFRAMES+1 pc values, but discard the first, since it */
4040 /* points to our own frame. */
4041# ifdef REDIRECT_MALLOC
4042 if (GC_in_save_callers) {
4043 info[0].ci_pc = (word)(&GC_save_callers);
4044 for (i = 1; i < NFRAMES; ++i) info[i].ci_pc = 0;
4045 return;
4046 }
4047 GC_in_save_callers = TRUE;
4048# endif
4049 GC_ASSERT(sizeof(struct callinfo) == sizeof(void *));
4050 npcs = backtrace((void **)tmp_info, NFRAMES + IGNORE_FRAMES);
4051 BCOPY(tmp_info+IGNORE_FRAMES, info, (npcs - IGNORE_FRAMES) * sizeof(void *));
4052 for (i = npcs - IGNORE_FRAMES; i < NFRAMES; ++i) info[i].ci_pc = 0;
4053# ifdef REDIRECT_MALLOC
4054 GC_in_save_callers = FALSE;
4055# endif
4056}
4057
4058#else /* No builtin backtrace; do it ourselves */
4059
4060#if (defined(OPENBSD) || defined(NETBSD) || defined(FREEBSD)) && defined(SPARC)
4061# define FR_SAVFP fr_fp
4062# define FR_SAVPC fr_pc
4063#else
4064# define FR_SAVFP fr_savfp
4065# define FR_SAVPC fr_savpc
4066#endif
4067
4068#if defined(SPARC) && (defined(__arch64__) || defined(__sparcv9))
4069# define BIAS 2047
4070#else
4071# define BIAS 0
4072#endif
4073
4074void GC_save_callers (info)
4075struct callinfo info[NFRAMES];
4076{
4077 struct frame *frame;
4078 struct frame *fp;
4079 int nframes = 0;
4080# ifdef I386
4081 /* We assume this is turned on only with gcc as the compiler. */
4082 asm("movl %%ebp,%0" : "=r"(frame));
4083 fp = frame;
4084# else
4085 frame = (struct frame *) GC_save_regs_in_stack ();
4086 fp = (struct frame *)((long) frame -> FR_SAVFP + BIAS);
4087#endif
4088
4089 for (; (!(fp HOTTER_THAN frame) && !(GC_stackbottom HOTTER_THAN (ptr_t)fp)
4090 && (nframes < NFRAMES));
4091 fp = (struct frame *)((long) fp -> FR_SAVFP + BIAS), nframes++) {
4092 register int i;
4093
4094 info[nframes].ci_pc = fp->FR_SAVPC;
4095# if NARGS > 0
4096 for (i = 0; i < NARGS; i++) {
4097 info[nframes].ci_arg[i] = ~(fp->fr_arg[i]);
4098 }
4099# endif /* NARGS > 0 */
4100 }
4101 if (nframes < NFRAMES) info[nframes].ci_pc = 0;
4102}
4103
4104#endif /* No builtin backtrace */
4105
4106#endif /* SAVE_CALL_CHAIN */
4107
4108#ifdef NEED_CALLINFO
4109
4110/* Print info to stderr. We do NOT hold the allocation lock */
4111void GC_print_callers (info)
4112struct callinfo info[NFRAMES];
4113{
4114 register int i;
4115 static int reentry_count = 0;
4116 GC_bool stop = FALSE;
4117
4118 /* FIXME: This should probably use a different lock, so that we */
4119 /* become callable with or without the allocation lock. */
4120 LOCK();
4121 ++reentry_count;
4122 UNLOCK();
4123
4124# if NFRAMES == 1
4125 GC_err_printf0("\tCaller at allocation:\n");
4126# else
4127 GC_err_printf0("\tCall chain at allocation:\n");
4128# endif
4129 for (i = 0; i < NFRAMES && !stop ; i++) {
4130 if (info[i].ci_pc == 0) break;
4131# if NARGS > 0
4132 {
4133 int j;
4134
4135 GC_err_printf0("\t\targs: ");
4136 for (j = 0; j < NARGS; j++) {
4137 if (j != 0) GC_err_printf0(", ");
4138 GC_err_printf2("%d (0x%X)", ~(info[i].ci_arg[j]),
4139 ~(info[i].ci_arg[j]));
4140 }
4141 GC_err_printf0("\n");
4142 }
4143# endif
4144 if (reentry_count > 1) {
4145 /* We were called during an allocation during */
4146 /* a previous GC_print_callers call; punt. */
4147 GC_err_printf1("\t\t##PC##= 0x%lx\n", info[i].ci_pc);
4148 continue;
4149 }
4150 {
4151# ifdef LINUX
4152 FILE *pipe;
4153# endif
4154# if defined(GC_HAVE_BUILTIN_BACKTRACE) \
4155 && !defined(GC_BACKTRACE_SYMBOLS_BROKEN)
4156 char **sym_name =
4157 backtrace_symbols((void **)(&(info[i].ci_pc)), 1);
4158 char *name = sym_name[0];
4159# else
4160 char buf[40];
4161 char *name = buf;
4162 sprintf(buf, "##PC##= 0x%lx", info[i].ci_pc);
4163# endif
4164# if defined(LINUX) && !defined(SMALL_CONFIG)
4165 /* Try for a line number. */
4166 {
4167# define EXE_SZ 100
4168 static char exe_name[EXE_SZ];
4169# define CMD_SZ 200
4170 char cmd_buf[CMD_SZ];
4171# define RESULT_SZ 200
4172 static char result_buf[RESULT_SZ];
4173 size_t result_len;
4174 char *old_preload;
4175# define PRELOAD_SZ 200
4176 char preload_buf[PRELOAD_SZ];
4177 static GC_bool found_exe_name = FALSE;
4178 static GC_bool will_fail = FALSE;
4179 int ret_code;
4180 /* Try to get it via a hairy and expensive scheme. */
4181 /* First we get the name of the executable: */
4182 if (will_fail) goto out;
4183 if (!found_exe_name) {
4184 ret_code = readlink("/proc/self/exe", exe_name, EXE_SZ);
4185 if (ret_code < 0 || ret_code >= EXE_SZ
4186 || exe_name[0] != '/') {
4187 will_fail = TRUE; /* Dont try again. */
4188 goto out;
4189 }
4190 exe_name[ret_code] = '\0';
4191 found_exe_name = TRUE;
4192 }
4193 /* Then we use popen to start addr2line -e <exe> <addr> */
4194 /* There are faster ways to do this, but hopefully this */
4195 /* isn't time critical. */
4196 sprintf(cmd_buf, "/usr/bin/addr2line -f -e %s 0x%lx", exe_name,
4197 (unsigned long)info[i].ci_pc);
4198 old_preload = getenv ("LD_PRELOAD");
4199 if (0 != old_preload) {
4200 if (strlen (old_preload) >= PRELOAD_SZ) {
4201 will_fail = TRUE;
4202 goto out;
4203 }
4204 strcpy (preload_buf, old_preload);
4205 unsetenv ("LD_PRELOAD");
4206 }
4207 pipe = popen(cmd_buf, "r");
4208 if (0 != old_preload
4209 && 0 != setenv ("LD_PRELOAD", preload_buf, 0)) {
4210 WARN("Failed to reset LD_PRELOAD\n", 0);
4211 }
4212 if (pipe == NULL
4213 || (result_len = fread(result_buf, 1, RESULT_SZ - 1, pipe))
4214 == 0) {
4215 if (pipe != NULL) pclose(pipe);
4216 will_fail = TRUE;
4217 goto out;
4218 }
4219 if (result_buf[result_len - 1] == '\n') --result_len;
4220 result_buf[result_len] = 0;
4221 if (result_buf[0] == '?'
4222 || result_buf[result_len-2] == ':'
4223 && result_buf[result_len-1] == '0') {
4224 pclose(pipe);
4225 goto out;
4226 }
4227 /* Get rid of embedded newline, if any. Test for "main" */
4228 {
4229 char * nl = strchr(result_buf, '\n');
4230 if (nl != NULL && nl < result_buf + result_len) {
4231 *nl = ':';
4232 }
4233 if (strncmp(result_buf, "main", nl - result_buf) == 0) {
4234 stop = TRUE;
4235 }
4236 }
4237 if (result_len < RESULT_SZ - 25) {
4238 /* Add in hex address */
4239 sprintf(result_buf + result_len, " [0x%lx]",
4240 (unsigned long)info[i].ci_pc);
4241 }
4242 name = result_buf;
4243 pclose(pipe);
4244 out:;
4245 }
4246# endif /* LINUX */
4247 GC_err_printf1("\t\t%s\n", name);
4248# if defined(GC_HAVE_BUILTIN_BACKTRACE) \
4249 && !defined(GC_BACKTRACE_SYMBOLS_BROKEN)
4250 free(sym_name); /* May call GC_free; that's OK */
4251# endif
4252 }
4253 }
4254 LOCK();
4255 --reentry_count;
4256 UNLOCK();
4257}
4258
4259#endif /* NEED_CALLINFO */
4260
4261
4262
4263#if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG)
4264
4265/* Dump /proc/self/maps to GC_stderr, to enable looking up names for
4266 addresses in FIND_LEAK output. */
4267
4268static word dump_maps(char *maps)
4269{
4270 GC_err_write(maps, strlen(maps));
4271 return 1;
4272}
4273
4274void GC_print_address_map()
4275{
4276 GC_err_printf0("---------- Begin address map ----------\n");
4277 GC_apply_to_maps(dump_maps);
4278 GC_err_printf0("---------- End address map ----------\n");
4279}
4280
4281#endif
4282
4283
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