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PR other/2873
[official-gcc.git] / boehm-gc / os_dep.c
blob82386ec4fba1bfc93259793ea388faf016e283be
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 /* Blatantly OS dependent routines, except for those that are related */
64 /* to dynamic loading. */
65
66 # if defined(HEURISTIC2) || defined(SEARCH_FOR_DATA_START)
67 # define NEED_FIND_LIMIT
68 # endif
69
70 # if !defined(STACKBOTTOM) && defined(HEURISTIC2)
71 # define NEED_FIND_LIMIT
72 # endif
73
74 # if (defined(SUNOS4) && defined(DYNAMIC_LOADING)) && !defined(PCR)
75 # define NEED_FIND_LIMIT
76 # endif
77
78 # if (defined(SVR4) || defined(AUX) || defined(DGUX) \
79 || (defined(LINUX) && defined(SPARC))) && !defined(PCR)
80 # define NEED_FIND_LIMIT
81 # endif
82
83 #ifdef NEED_FIND_LIMIT
84 # include <setjmp.h>
85 #endif
86
87 #if defined(FREEBSD) && defined(I386)
88 # include <machine/trap.h>
89 #endif
90
91 #ifdef AMIGA
92 # define GC_AMIGA_DEF
93 # include "AmigaOS.c"
94 # undef GC_AMIGA_DEF
95 #endif
96
97 #if defined(MSWIN32) || defined(MSWINCE)
98 # define WIN32_LEAN_AND_MEAN
99 # define NOSERVICE
100 # include <windows.h>
101 #endif
102
103 #ifdef MACOS
104 # include <Processes.h>
105 #endif
106
107 #ifdef IRIX5
108 # include <sys/uio.h>
109 # include <malloc.h> /* for locking */
110 #endif
111 #ifdef USE_MMAP
112 # include <sys/types.h>
113 # include <sys/mman.h>
114 # include <sys/stat.h>
115 #endif
116
117 #ifdef UNIX_LIKE
118 # include <fcntl.h>
119 #endif
120
121 #if defined(SUNOS5SIGS) || defined (HURD) || defined(LINUX)
122 # ifdef SUNOS5SIGS
123 # include <sys/siginfo.h>
124 # endif
125 # undef setjmp
126 # undef longjmp
127 # define setjmp(env) sigsetjmp(env, 1)
128 # define longjmp(env, val) siglongjmp(env, val)
129 # define jmp_buf sigjmp_buf
130 #endif
131
132 #ifdef DJGPP
133 /* Apparently necessary for djgpp 2.01. May cause problems with */
134 /* other versions. */
135 typedef long unsigned int caddr_t;
136 #endif
137
138 #ifdef PCR
139 # include "il/PCR_IL.h"
140 # include "th/PCR_ThCtl.h"
141 # include "mm/PCR_MM.h"
142 #endif
143
144 #if !defined(NO_EXECUTE_PERMISSION)
145 # define OPT_PROT_EXEC PROT_EXEC
146 #else
147 # define OPT_PROT_EXEC 0
148 #endif
149
150 #if defined(SEARCH_FOR_DATA_START)
151 /* The I386 case can be handled without a search. The Alpha case */
152 /* used to be handled differently as well, but the rules changed */
153 /* for recent Linux versions. This seems to be the easiest way to */
154 /* cover all versions. */
155
156 # ifdef LINUX
157 # pragma weak __data_start
158 extern int __data_start[];
159 # pragma weak data_start
160 extern int data_start[];
161 # endif /* LINUX */
162 extern int _end[];
163
164 ptr_t GC_data_start;
165
166 void GC_init_linux_data_start()
167 {
168 extern ptr_t GC_find_limit();
169
170 # ifdef LINUX
171 /* Try the easy approaches first: */
172 if (__data_start != 0) {
173 GC_data_start = (ptr_t)__data_start;
174 return;
175 }
176 if (data_start != 0) {
177 GC_data_start = (ptr_t)data_start;
178 return;
179 }
180 # endif /* LINUX */
181 GC_data_start = GC_find_limit((ptr_t)_end, FALSE);
182 }
183 #endif
184
185 # ifdef ECOS
186
187 # ifndef ECOS_GC_MEMORY_SIZE
188 # define ECOS_GC_MEMORY_SIZE (448 * 1024)
189 # endif /* ECOS_GC_MEMORY_SIZE */
190
191 // setjmp() function, as described in ANSI para 7.6.1.1
192 #define setjmp( __env__ ) hal_setjmp( __env__ )
193
194 // FIXME: This is a simple way of allocating memory which is
195 // compatible with ECOS early releases. Later releases use a more
196 // sophisticated means of allocating memory than this simple static
197 // allocator, but this method is at least bound to work.
198 static char memory[ECOS_GC_MEMORY_SIZE];
199 static char *brk = memory;
200
201 static void *tiny_sbrk(ptrdiff_t increment)
202 {
203 void *p = brk;
204
205 brk += increment;
206
207 if (brk > memory + sizeof memory)
208 {
209 brk -= increment;
210 return NULL;
211 }
212
213 return p;
214 }
215 #define sbrk tiny_sbrk
216 # endif /* ECOS */
217
218 #if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__)
219 ptr_t GC_data_start;
220
221 void GC_init_netbsd_elf()
222 {
223 extern ptr_t GC_find_limit();
224 extern char **environ;
225 /* This may need to be environ, without the underscore, for */
226 /* some versions. */
227 GC_data_start = GC_find_limit((ptr_t)&environ, FALSE);
228 }
229 #endif
230
231 # ifdef OS2
232
233 # include <stddef.h>
234
235 # if !defined(__IBMC__) && !defined(__WATCOMC__) /* e.g. EMX */
236
237 struct exe_hdr {
238 unsigned short magic_number;
239 unsigned short padding[29];
240 long new_exe_offset;
241 };
242
243 #define E_MAGIC(x) (x).magic_number
244 #define EMAGIC 0x5A4D
245 #define E_LFANEW(x) (x).new_exe_offset
246
247 struct e32_exe {
248 unsigned char magic_number[2];
249 unsigned char byte_order;
250 unsigned char word_order;
251 unsigned long exe_format_level;
252 unsigned short cpu;
253 unsigned short os;
254 unsigned long padding1[13];
255 unsigned long object_table_offset;
256 unsigned long object_count;
257 unsigned long padding2[31];
258 };
259
260 #define E32_MAGIC1(x) (x).magic_number[0]
261 #define E32MAGIC1 'L'
262 #define E32_MAGIC2(x) (x).magic_number[1]
263 #define E32MAGIC2 'X'
264 #define E32_BORDER(x) (x).byte_order
265 #define E32LEBO 0
266 #define E32_WORDER(x) (x).word_order
267 #define E32LEWO 0
268 #define E32_CPU(x) (x).cpu
269 #define E32CPU286 1
270 #define E32_OBJTAB(x) (x).object_table_offset
271 #define E32_OBJCNT(x) (x).object_count
272
273 struct o32_obj {
274 unsigned long size;
275 unsigned long base;
276 unsigned long flags;
277 unsigned long pagemap;
278 unsigned long mapsize;
279 unsigned long reserved;
280 };
281
282 #define O32_FLAGS(x) (x).flags
283 #define OBJREAD 0x0001L
284 #define OBJWRITE 0x0002L
285 #define OBJINVALID 0x0080L
286 #define O32_SIZE(x) (x).size
287 #define O32_BASE(x) (x).base
288
289 # else /* IBM's compiler */
290
291 /* A kludge to get around what appears to be a header file bug */
292 # ifndef WORD
293 # define WORD unsigned short
294 # endif
295 # ifndef DWORD
296 # define DWORD unsigned long
297 # endif
298
299 # define EXE386 1
300 # include <newexe.h>
301 # include <exe386.h>
302
303 # endif /* __IBMC__ */
304
305 # define INCL_DOSEXCEPTIONS
306 # define INCL_DOSPROCESS
307 # define INCL_DOSERRORS
308 # define INCL_DOSMODULEMGR
309 # define INCL_DOSMEMMGR
310 # include <os2.h>
311
312
313 /* Disable and enable signals during nontrivial allocations */
314
315 void GC_disable_signals(void)
316 {
317 ULONG nest;
318
319 DosEnterMustComplete(&nest);
320 if (nest != 1) ABORT("nested GC_disable_signals");
321 }
322
323 void GC_enable_signals(void)
324 {
325 ULONG nest;
326
327 DosExitMustComplete(&nest);
328 if (nest != 0) ABORT("GC_enable_signals");
329 }
330
331
332 # else
333
334 # if !defined(PCR) && !defined(AMIGA) && !defined(MSWIN32) \
335 && !defined(MSWINCE) \
336 && !defined(MACOS) && !defined(DJGPP) && !defined(DOS4GW) \
337 && !defined(NOSYS) && !defined(ECOS)
338
339 # if defined(sigmask) && !defined(UTS4) && !defined(HURD)
340 /* Use the traditional BSD interface */
341 # define SIGSET_T int
342 # define SIG_DEL(set, signal) (set) &= ~(sigmask(signal))
343 # define SIG_FILL(set) (set) = 0x7fffffff
344 /* Setting the leading bit appears to provoke a bug in some */
345 /* longjmp implementations. Most systems appear not to have */
346 /* a signal 32. */
347 # define SIGSETMASK(old, new) (old) = sigsetmask(new)
348 # else
349 /* Use POSIX/SYSV interface */
350 # define SIGSET_T sigset_t
351 # define SIG_DEL(set, signal) sigdelset(&(set), (signal))
352 # define SIG_FILL(set) sigfillset(&set)
353 # define SIGSETMASK(old, new) sigprocmask(SIG_SETMASK, &(new), &(old))
354 # endif
355
356 static GC_bool mask_initialized = FALSE;
357
358 static SIGSET_T new_mask;
359
360 static SIGSET_T old_mask;
361
362 static SIGSET_T dummy;
363
364 #if defined(PRINTSTATS) && !defined(THREADS)
365 # define CHECK_SIGNALS
366 int GC_sig_disabled = 0;
367 #endif
368
369 void GC_disable_signals()
370 {
371 if (!mask_initialized) {
372 SIG_FILL(new_mask);
373
374 SIG_DEL(new_mask, SIGSEGV);
375 SIG_DEL(new_mask, SIGILL);
376 SIG_DEL(new_mask, SIGQUIT);
377 # ifdef SIGBUS
378 SIG_DEL(new_mask, SIGBUS);
379 # endif
380 # ifdef SIGIOT
381 SIG_DEL(new_mask, SIGIOT);
382 # endif
383 # ifdef SIGEMT
384 SIG_DEL(new_mask, SIGEMT);
385 # endif
386 # ifdef SIGTRAP
387 SIG_DEL(new_mask, SIGTRAP);
388 # endif
389 mask_initialized = TRUE;
390 }
391 # ifdef CHECK_SIGNALS
392 if (GC_sig_disabled != 0) ABORT("Nested disables");
393 GC_sig_disabled++;
394 # endif
395 SIGSETMASK(old_mask,new_mask);
396 }
397
398 void GC_enable_signals()
399 {
400 # ifdef CHECK_SIGNALS
401 if (GC_sig_disabled != 1) ABORT("Unmatched enable");
402 GC_sig_disabled--;
403 # endif
404 SIGSETMASK(dummy,old_mask);
405 }
406
407 # endif /* !PCR */
408
409 # endif /*!OS/2 */
410
411 /* Ivan Demakov: simplest way (to me) */
412 #if defined (DOS4GW)
413 void GC_disable_signals() { }
414 void GC_enable_signals() { }
415 #endif
416
417 /* Find the page size */
418 word GC_page_size;
419
420 # if defined(MSWIN32) || defined(MSWINCE)
421 void GC_setpagesize()
422 {
423 GetSystemInfo(&GC_sysinfo);
424 GC_page_size = GC_sysinfo.dwPageSize;
425 }
426
427 # else
428 # if defined(MPROTECT_VDB) || defined(PROC_VDB) || defined(USE_MMAP) \
429 || defined(USE_MUNMAP)
430 void GC_setpagesize()
431 {
432 GC_page_size = GETPAGESIZE();
433 }
434 # else
435 /* It's acceptable to fake it. */
436 void GC_setpagesize()
437 {
438 GC_page_size = HBLKSIZE;
439 }
440 # endif
441 # endif
442
443 /*
444 * Find the base of the stack.
445 * Used only in single-threaded environment.
446 * With threads, GC_mark_roots needs to know how to do this.
447 * Called with allocator lock held.
448 */
449 # if defined(MSWIN32) || defined(MSWINCE)
450 # define is_writable(prot) ((prot) == PAGE_READWRITE \
451 || (prot) == PAGE_WRITECOPY \
452 || (prot) == PAGE_EXECUTE_READWRITE \
453 || (prot) == PAGE_EXECUTE_WRITECOPY)
454 /* Return the number of bytes that are writable starting at p. */
455 /* The pointer p is assumed to be page aligned. */
456 /* If base is not 0, *base becomes the beginning of the */
457 /* allocation region containing p. */
458 word GC_get_writable_length(ptr_t p, ptr_t *base)
459 {
460 MEMORY_BASIC_INFORMATION buf;
461 word result;
462 word protect;
463
464 result = VirtualQuery(p, &buf, sizeof(buf));
465 if (result != sizeof(buf)) ABORT("Weird VirtualQuery result");
466 if (base != 0) *base = (ptr_t)(buf.AllocationBase);
467 protect = (buf.Protect & ~(PAGE_GUARD | PAGE_NOCACHE));
468 if (!is_writable(protect)) {
469 return(0);
470 }
471 if (buf.State != MEM_COMMIT) return(0);
472 return(buf.RegionSize);
473 }
474
475 ptr_t GC_get_stack_base()
476 {
477 int dummy;
478 ptr_t sp = (ptr_t)(&dummy);
479 ptr_t trunc_sp = (ptr_t)((word)sp & ~(GC_page_size - 1));
480 word size = GC_get_writable_length(trunc_sp, 0);
481
482 return(trunc_sp + size);
483 }
484
485
486 # endif /* MS Windows */
487
488 # ifdef BEOS
489 # include <kernel/OS.h>
490 ptr_t GC_get_stack_base(){
491 thread_info th;
492 get_thread_info(find_thread(NULL),&th);
493 return th.stack_end;
494 }
495 # endif /* BEOS */
496
497
498 # ifdef OS2
499
500 ptr_t GC_get_stack_base()
501 {
502 PTIB ptib;
503 PPIB ppib;
504
505 if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
506 GC_err_printf0("DosGetInfoBlocks failed\n");
507 ABORT("DosGetInfoBlocks failed\n");
508 }
509 return((ptr_t)(ptib -> tib_pstacklimit));
510 }
511
512 # endif /* OS2 */
513
514 # ifdef AMIGA
515 # define GC_AMIGA_SB
516 # include "AmigaOS.c"
517 # undef GC_AMIGA_SB
518 # endif /* AMIGA */
519
520 # if defined(NEED_FIND_LIMIT) || defined(UNIX_LIKE)
521
522 # ifdef __STDC__
523 typedef void (*handler)(int);
524 # else
525 typedef void (*handler)();
526 # endif
527
528 # if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) || defined(HURD)
529 static struct sigaction old_segv_act;
530 # if defined(_sigargs) /* !Irix6.x */ || defined(HPUX) || defined(HURD)
531 static struct sigaction old_bus_act;
532 # endif
533 # else
534 static handler old_segv_handler, old_bus_handler;
535 # endif
536
537 # ifdef __STDC__
538 void GC_set_and_save_fault_handler(handler h)
539 # else
540 void GC_set_and_save_fault_handler(h)
541 handler h;
542 # endif
543 {
544 # if defined(SUNOS5SIGS) || defined(IRIX5) \
545 || defined(OSF1) || defined(HURD)
546 struct sigaction act;
547
548 act.sa_handler = h;
549 # ifdef SUNOS5SIGS
550 act.sa_flags = SA_RESTART | SA_NODEFER;
551 # else
552 act.sa_flags = SA_RESTART;
553 # endif
554 /* The presence of SA_NODEFER represents yet another gross */
555 /* hack. Under Solaris 2.3, siglongjmp doesn't appear to */
556 /* interact correctly with -lthread. We hide the confusion */
557 /* by making sure that signal handling doesn't affect the */
558 /* signal mask. */
559
560 (void) sigemptyset(&act.sa_mask);
561 # ifdef GC_IRIX_THREADS
562 /* Older versions have a bug related to retrieving and */
563 /* and setting a handler at the same time. */
564 (void) sigaction(SIGSEGV, 0, &old_segv_act);
565 (void) sigaction(SIGSEGV, &act, 0);
566 # else
567 (void) sigaction(SIGSEGV, &act, &old_segv_act);
568 # if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \
569 || defined(HPUX) || defined(HURD)
570 /* Under Irix 5.x or HP/UX, we may get SIGBUS. */
571 /* Pthreads doesn't exist under Irix 5.x, so we */
572 /* don't have to worry in the threads case. */
573 (void) sigaction(SIGBUS, &act, &old_bus_act);
574 # endif
575 # endif /* GC_IRIX_THREADS */
576 # else
577 old_segv_handler = signal(SIGSEGV, h);
578 # ifdef SIGBUS
579 old_bus_handler = signal(SIGBUS, h);
580 # endif
581 # endif
582 }
583 # endif /* NEED_FIND_LIMIT || UNIX_LIKE */
584
585 # ifdef NEED_FIND_LIMIT
586 /* Some tools to implement HEURISTIC2 */
587 # define MIN_PAGE_SIZE 256 /* Smallest conceivable page size, bytes */
588 /* static */ jmp_buf GC_jmp_buf;
589
590 /*ARGSUSED*/
591 void GC_fault_handler(sig)
592 int sig;
593 {
594 longjmp(GC_jmp_buf, 1);
595 }
596
597 void GC_setup_temporary_fault_handler()
598 {
599 GC_set_and_save_fault_handler(GC_fault_handler);
600 }
601
602 void GC_reset_fault_handler()
603 {
604 # if defined(SUNOS5SIGS) || defined(IRIX5) \
605 || defined(OSF1) || defined(HURD)
606 (void) sigaction(SIGSEGV, &old_segv_act, 0);
607 # if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \
608 || defined(HPUX) || defined(HURD)
609 (void) sigaction(SIGBUS, &old_bus_act, 0);
610 # endif
611 # else
612 (void) signal(SIGSEGV, old_segv_handler);
613 # ifdef SIGBUS
614 (void) signal(SIGBUS, old_bus_handler);
615 # endif
616 # endif
617 }
618
619 /* Return the first nonaddressible location > p (up) or */
620 /* the smallest location q s.t. [q,p] is addressible (!up). */
621 ptr_t GC_find_limit(p, up)
622 ptr_t p;
623 GC_bool up;
624 {
625 static VOLATILE ptr_t result;
626 /* Needs to be static, since otherwise it may not be */
627 /* preserved across the longjmp. Can safely be */
628 /* static since it's only called once, with the */
629 /* allocation lock held. */
630
631
632 GC_setup_temporary_fault_handler();
633 if (setjmp(GC_jmp_buf) == 0) {
634 result = (ptr_t)(((word)(p))
635 & ~(MIN_PAGE_SIZE-1));
636 for (;;) {
637 if (up) {
638 result += MIN_PAGE_SIZE;
639 } else {
640 result -= MIN_PAGE_SIZE;
641 }
642 GC_noop1((word)(*result));
643 }
644 }
645 GC_reset_fault_handler();
646 if (!up) {
647 result += MIN_PAGE_SIZE;
648 }
649 return(result);
650 }
651 # endif
652
653 # if defined(ECOS) || defined(NOSYS)
654 ptr_t GC_get_stack_base()
655 {
656 return STACKBOTTOM;
657 }
658
659 #else
660
661 #ifdef LINUX_STACKBOTTOM
662
663 #include <sys/types.h>
664 #include <sys/stat.h>
665
666 # define STAT_SKIP 27 /* Number of fields preceding startstack */
667 /* field in /proc/self/stat */
668
669 # pragma weak __libc_stack_end
670 extern ptr_t __libc_stack_end;
671
672 # ifdef IA64
673 # pragma weak __libc_ia64_register_backing_store_base
674 extern ptr_t __libc_ia64_register_backing_store_base;
675
676 ptr_t GC_get_register_stack_base(void)
677 {
678 if (0 != &__libc_ia64_register_backing_store_base
679 && 0 != __libc_ia64_register_backing_store_base) {
680 /* Glibc 2.2.4 has a bug such that for dynamically linked */
681 /* executables __libc_ia64_register_backing_store_base is */
682 /* defined but ininitialized during constructor calls. */
683 /* Hence we check for both nonzero address and value. */
684 return __libc_ia64_register_backing_store_base;
685 } else {
686 word result = (word)GC_stackbottom - BACKING_STORE_DISPLACEMENT;
687 result += BACKING_STORE_ALIGNMENT - 1;
688 result &= ~(BACKING_STORE_ALIGNMENT - 1);
689 return (ptr_t)result;
690 }
691 }
692 # endif
693
694 ptr_t GC_linux_stack_base(void)
695 {
696 /* We read the stack base value from /proc/self/stat. We do this */
697 /* using direct I/O system calls in order to avoid calling malloc */
698 /* in case REDIRECT_MALLOC is defined. */
699 # define STAT_BUF_SIZE 4096
700 # if defined(GC_USE_LD_WRAP)
701 # define STAT_READ __real_read
702 # else
703 # define STAT_READ read
704 # endif
705 char stat_buf[STAT_BUF_SIZE];
706 int f;
707 char c;
708 word result = 0;
709 size_t i, buf_offset = 0;
710
711 /* First try the easy way. This should work for glibc 2.2 */
712 if (0 != &__libc_stack_end) {
713 return __libc_stack_end;
714 }
715 f = open("/proc/self/stat", O_RDONLY);
716 if (f < 0 || STAT_READ(f, stat_buf, STAT_BUF_SIZE) < 2 * STAT_SKIP) {
717 ABORT("Couldn't read /proc/self/stat");
718 }
719 c = stat_buf[buf_offset++];
720 /* Skip the required number of fields. This number is hopefully */
721 /* constant across all Linux implementations. */
722 for (i = 0; i < STAT_SKIP; ++i) {
723 while (isspace(c)) c = stat_buf[buf_offset++];
724 while (!isspace(c)) c = stat_buf[buf_offset++];
725 }
726 while (isspace(c)) c = stat_buf[buf_offset++];
727 while (isdigit(c)) {
728 result *= 10;
729 result += c - '0';
730 c = stat_buf[buf_offset++];
731 }
732 close(f);
733 if (result < 0x10000000) ABORT("Absurd stack bottom value");
734 return (ptr_t)result;
735 }
736
737 #endif /* LINUX_STACKBOTTOM */
738
739 #ifdef FREEBSD_STACKBOTTOM
740
741 /* This uses an undocumented sysctl call, but at least one expert */
742 /* believes it will stay. */
743
744 #include <unistd.h>
745 #include <sys/types.h>
746 #include <sys/sysctl.h>
747
748 ptr_t GC_freebsd_stack_base(void)
749 {
750 int nm[2] = {CTL_KERN, KERN_USRSTACK};
751 ptr_t base;
752 size_t len = sizeof(ptr_t);
753 int r = sysctl(nm, 2, &base, &len, NULL, 0);
754
755 if (r) ABORT("Error getting stack base");
756
757 return base;
758 }
759
760 #endif /* FREEBSD_STACKBOTTOM */
761
762 #if !defined(BEOS) && !defined(AMIGA) && !defined(MSWIN32) \
763 && !defined(MSWINCE) && !defined(OS2)
764
765 ptr_t GC_get_stack_base()
766 {
767 word dummy;
768 ptr_t result;
769
770 # define STACKBOTTOM_ALIGNMENT_M1 ((word)STACK_GRAN - 1)
771
772 # ifdef STACKBOTTOM
773 return(STACKBOTTOM);
774 # else
775 # ifdef HEURISTIC1
776 # ifdef STACK_GROWS_DOWN
777 result = (ptr_t)((((word)(&dummy))
778 + STACKBOTTOM_ALIGNMENT_M1)
779 & ~STACKBOTTOM_ALIGNMENT_M1);
780 # else
781 result = (ptr_t)(((word)(&dummy))
782 & ~STACKBOTTOM_ALIGNMENT_M1);
783 # endif
784 # endif /* HEURISTIC1 */
785 # ifdef LINUX_STACKBOTTOM
786 result = GC_linux_stack_base();
787 # endif
788 # ifdef FREEBSD_STACKBOTTOM
789 result = GC_freebsd_stack_base();
790 # endif
791 # ifdef HEURISTIC2
792 # ifdef STACK_GROWS_DOWN
793 result = GC_find_limit((ptr_t)(&dummy), TRUE);
794 # ifdef HEURISTIC2_LIMIT
795 if (result > HEURISTIC2_LIMIT
796 && (ptr_t)(&dummy) < HEURISTIC2_LIMIT) {
797 result = HEURISTIC2_LIMIT;
798 }
799 # endif
800 # else
801 result = GC_find_limit((ptr_t)(&dummy), FALSE);
802 # ifdef HEURISTIC2_LIMIT
803 if (result < HEURISTIC2_LIMIT
804 && (ptr_t)(&dummy) > HEURISTIC2_LIMIT) {
805 result = HEURISTIC2_LIMIT;
806 }
807 # endif
808 # endif
809
810 # endif /* HEURISTIC2 */
811 # ifdef STACK_GROWS_DOWN
812 if (result == 0) result = (ptr_t)(signed_word)(-sizeof(ptr_t));
813 # endif
814 return(result);
815 # endif /* STACKBOTTOM */
816 }
817 # endif /* NOSYS ECOS */
818
819 # endif /* ! AMIGA, !OS 2, ! MS Windows, !BEOS */
820
821 /*
822 * Register static data segment(s) as roots.
823 * If more data segments are added later then they need to be registered
824 * add that point (as we do with SunOS dynamic loading),
825 * or GC_mark_roots needs to check for them (as we do with PCR).
826 * Called with allocator lock held.
827 */
828
829 # ifdef OS2
830
831 void GC_register_data_segments()
832 {
833 PTIB ptib;
834 PPIB ppib;
835 HMODULE module_handle;
836 # define PBUFSIZ 512
837 UCHAR path[PBUFSIZ];
838 FILE * myexefile;
839 struct exe_hdr hdrdos; /* MSDOS header. */
840 struct e32_exe hdr386; /* Real header for my executable */
841 struct o32_obj seg; /* Currrent segment */
842 int nsegs;
843
844
845 if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
846 GC_err_printf0("DosGetInfoBlocks failed\n");
847 ABORT("DosGetInfoBlocks failed\n");
848 }
849 module_handle = ppib -> pib_hmte;
850 if (DosQueryModuleName(module_handle, PBUFSIZ, path) != NO_ERROR) {
851 GC_err_printf0("DosQueryModuleName failed\n");
852 ABORT("DosGetInfoBlocks failed\n");
853 }
854 myexefile = fopen(path, "rb");
855 if (myexefile == 0) {
856 GC_err_puts("Couldn't open executable ");
857 GC_err_puts(path); GC_err_puts("\n");
858 ABORT("Failed to open executable\n");
859 }
860 if (fread((char *)(&hdrdos), 1, sizeof hdrdos, myexefile) < sizeof hdrdos) {
861 GC_err_puts("Couldn't read MSDOS header from ");
862 GC_err_puts(path); GC_err_puts("\n");
863 ABORT("Couldn't read MSDOS header");
864 }
865 if (E_MAGIC(hdrdos) != EMAGIC) {
866 GC_err_puts("Executable has wrong DOS magic number: ");
867 GC_err_puts(path); GC_err_puts("\n");
868 ABORT("Bad DOS magic number");
869 }
870 if (fseek(myexefile, E_LFANEW(hdrdos), SEEK_SET) != 0) {
871 GC_err_puts("Seek to new header failed in ");
872 GC_err_puts(path); GC_err_puts("\n");
873 ABORT("Bad DOS magic number");
874 }
875 if (fread((char *)(&hdr386), 1, sizeof hdr386, myexefile) < sizeof hdr386) {
876 GC_err_puts("Couldn't read MSDOS header from ");
877 GC_err_puts(path); GC_err_puts("\n");
878 ABORT("Couldn't read OS/2 header");
879 }
880 if (E32_MAGIC1(hdr386) != E32MAGIC1 || E32_MAGIC2(hdr386) != E32MAGIC2) {
881 GC_err_puts("Executable has wrong OS/2 magic number:");
882 GC_err_puts(path); GC_err_puts("\n");
883 ABORT("Bad OS/2 magic number");
884 }
885 if ( E32_BORDER(hdr386) != E32LEBO || E32_WORDER(hdr386) != E32LEWO) {
886 GC_err_puts("Executable %s has wrong byte order: ");
887 GC_err_puts(path); GC_err_puts("\n");
888 ABORT("Bad byte order");
889 }
890 if ( E32_CPU(hdr386) == E32CPU286) {
891 GC_err_puts("GC can't handle 80286 executables: ");
892 GC_err_puts(path); GC_err_puts("\n");
893 EXIT();
894 }
895 if (fseek(myexefile, E_LFANEW(hdrdos) + E32_OBJTAB(hdr386),
896 SEEK_SET) != 0) {
897 GC_err_puts("Seek to object table failed: ");
898 GC_err_puts(path); GC_err_puts("\n");
899 ABORT("Seek to object table failed");
900 }
901 for (nsegs = E32_OBJCNT(hdr386); nsegs > 0; nsegs--) {
902 int flags;
903 if (fread((char *)(&seg), 1, sizeof seg, myexefile) < sizeof seg) {
904 GC_err_puts("Couldn't read obj table entry from ");
905 GC_err_puts(path); GC_err_puts("\n");
906 ABORT("Couldn't read obj table entry");
907 }
908 flags = O32_FLAGS(seg);
909 if (!(flags & OBJWRITE)) continue;
910 if (!(flags & OBJREAD)) continue;
911 if (flags & OBJINVALID) {
912 GC_err_printf0("Object with invalid pages?\n");
913 continue;
914 }
915 GC_add_roots_inner(O32_BASE(seg), O32_BASE(seg)+O32_SIZE(seg), FALSE);
916 }
917 }
918
919 # else /* !OS2 */
920
921 # if defined(MSWIN32) || defined(MSWINCE)
922
923 # ifdef MSWIN32
924 /* Unfortunately, we have to handle win32s very differently from NT, */
925 /* Since VirtualQuery has very different semantics. In particular, */
926 /* under win32s a VirtualQuery call on an unmapped page returns an */
927 /* invalid result. Under GC_register_data_segments is a noop and */
928 /* all real work is done by GC_register_dynamic_libraries. Under */
929 /* win32s, we cannot find the data segments associated with dll's. */
930 /* We rgister the main data segment here. */
931 # ifdef __GCC__
932 GC_bool GC_no_win32_dlls = TRUE; /* GCC can't do SEH, so we can't use VirtualQuery */
933 # else
934 GC_bool GC_no_win32_dlls = FALSE;
935 # endif
936
937 void GC_init_win32()
938 {
939 /* if we're running under win32s, assume that no DLLs will be loaded */
940 DWORD v = GetVersion();
941 GC_no_win32_dlls |= ((v & 0x80000000) && (v & 0xff) <= 3);
942 }
943
944 /* Return the smallest address a such that VirtualQuery */
945 /* returns correct results for all addresses between a and start. */
946 /* Assumes VirtualQuery returns correct information for start. */
947 ptr_t GC_least_described_address(ptr_t start)
948 {
949 MEMORY_BASIC_INFORMATION buf;
950 DWORD result;
951 LPVOID limit;
952 ptr_t p;
953 LPVOID q;
954
955 limit = GC_sysinfo.lpMinimumApplicationAddress;
956 p = (ptr_t)((word)start & ~(GC_page_size - 1));
957 for (;;) {
958 q = (LPVOID)(p - GC_page_size);
959 if ((ptr_t)q > (ptr_t)p /* underflow */ || q < limit) break;
960 result = VirtualQuery(q, &buf, sizeof(buf));
961 if (result != sizeof(buf) || buf.AllocationBase == 0) break;
962 p = (ptr_t)(buf.AllocationBase);
963 }
964 return(p);
965 }
966 # endif
967
968 /* Is p the start of either the malloc heap, or of one of our */
969 /* heap sections? */
970 GC_bool GC_is_heap_base (ptr_t p)
971 {
972
973 register unsigned i;
974
975 # ifndef REDIRECT_MALLOC
976 static ptr_t malloc_heap_pointer = 0;
977
978 if (0 == malloc_heap_pointer) {
979 MEMORY_BASIC_INFORMATION buf;
980 void *pTemp = malloc( 1 );
981 register DWORD result = VirtualQuery(pTemp, &buf, sizeof(buf));
982
983 free( pTemp );
984
985
986 if (result != sizeof(buf)) {
987 ABORT("Weird VirtualQuery result");
988 }
989 malloc_heap_pointer = (ptr_t)(buf.AllocationBase);
990 }
991 if (p == malloc_heap_pointer) return(TRUE);
992 # endif
993 for (i = 0; i < GC_n_heap_bases; i++) {
994 if (GC_heap_bases[i] == p) return(TRUE);
995 }
996 return(FALSE);
997 }
998
999 # ifdef MSWIN32
1000 void GC_register_root_section(ptr_t static_root)
1001 {
1002 MEMORY_BASIC_INFORMATION buf;
1003 DWORD result;
1004 DWORD protect;
1005 LPVOID p;
1006 char * base;
1007 char * limit, * new_limit;
1008
1009 if (!GC_no_win32_dlls) return;
1010 p = base = limit = GC_least_described_address(static_root);
1011 while (p < GC_sysinfo.lpMaximumApplicationAddress) {
1012 result = VirtualQuery(p, &buf, sizeof(buf));
1013 if (result != sizeof(buf) || buf.AllocationBase == 0
1014 || GC_is_heap_base(buf.AllocationBase)) break;
1015 new_limit = (char *)p + buf.RegionSize;
1016 protect = buf.Protect;
1017 if (buf.State == MEM_COMMIT
1018 && is_writable(protect)) {
1019 if ((char *)p == limit) {
1020 limit = new_limit;
1021 } else {
1022 if (base != limit) GC_add_roots_inner(base, limit, FALSE);
1023 base = p;
1024 limit = new_limit;
1025 }
1026 }
1027 if (p > (LPVOID)new_limit /* overflow */) break;
1028 p = (LPVOID)new_limit;
1029 }
1030 if (base != limit) GC_add_roots_inner(base, limit, FALSE);
1031 }
1032 #endif
1033
1034 void GC_register_data_segments()
1035 {
1036 # ifdef MSWIN32
1037 static char dummy;
1038 GC_register_root_section((ptr_t)(&dummy));
1039 # endif
1040 }
1041
1042 # else /* !OS2 && !Windows */
1043
1044 # if (defined(SVR4) || defined(AUX) || defined(DGUX) \
1045 || (defined(LINUX) && defined(SPARC))) && !defined(PCR)
1046 char * GC_SysVGetDataStart(max_page_size, etext_addr)
1047 int max_page_size;
1048 int * etext_addr;
1049 {
1050 word text_end = ((word)(etext_addr) + sizeof(word) - 1)
1051 & ~(sizeof(word) - 1);
1052 /* etext rounded to word boundary */
1053 word next_page = ((text_end + (word)max_page_size - 1)
1054 & ~((word)max_page_size - 1));
1055 word page_offset = (text_end & ((word)max_page_size - 1));
1056 VOLATILE char * result = (char *)(next_page + page_offset);
1057 /* Note that this isnt equivalent to just adding */
1058 /* max_page_size to &etext if &etext is at a page boundary */
1059
1060 GC_setup_temporary_fault_handler();
1061 if (setjmp(GC_jmp_buf) == 0) {
1062 /* Try writing to the address. */
1063 *result = *result;
1064 GC_reset_fault_handler();
1065 } else {
1066 GC_reset_fault_handler();
1067 /* We got here via a longjmp. The address is not readable. */
1068 /* This is known to happen under Solaris 2.4 + gcc, which place */
1069 /* string constants in the text segment, but after etext. */
1070 /* Use plan B. Note that we now know there is a gap between */
1071 /* text and data segments, so plan A bought us something. */
1072 result = (char *)GC_find_limit((ptr_t)(DATAEND) - MIN_PAGE_SIZE, FALSE);
1073 }
1074 return((char *)result);
1075 }
1076 # endif
1077
1078
1079 #ifdef AMIGA
1080
1081 # define GC_AMIGA_DS
1082 # include "AmigaOS.c"
1083 # undef GC_AMIGA_DS
1084
1085 #else /* !OS2 && !Windows && !AMIGA */
1086
1087 void GC_register_data_segments()
1088 {
1089 # if !defined(PCR) && !defined(SRC_M3) && !defined(NEXT) && !defined(MACOS) \
1090 && !defined(MACOSX)
1091 # if defined(REDIRECT_MALLOC) && defined(GC_SOLARIS_THREADS)
1092 /* As of Solaris 2.3, the Solaris threads implementation */
1093 /* allocates the data structure for the initial thread with */
1094 /* sbrk at process startup. It needs to be scanned, so that */
1095 /* we don't lose some malloc allocated data structures */
1096 /* hanging from it. We're on thin ice here ... */
1097 extern caddr_t sbrk();
1098
1099 GC_add_roots_inner(DATASTART, (char *)sbrk(0), FALSE);
1100 # else
1101 GC_add_roots_inner(DATASTART, (char *)(DATAEND), FALSE);
1102 # if defined(DATASTART2)
1103 GC_add_roots_inner(DATASTART2, (char *)(DATAEND2), FALSE);
1104 # endif
1105 # endif
1106 # endif
1107 # if !defined(PCR) && (defined(NEXT) || defined(MACOSX))
1108 GC_add_roots_inner(DATASTART, (char *) get_end(), FALSE);
1109 # endif
1110 # if defined(MACOS)
1111 {
1112 # if defined(THINK_C)
1113 extern void* GC_MacGetDataStart(void);
1114 /* globals begin above stack and end at a5. */
1115 GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
1116 (ptr_t)LMGetCurrentA5(), FALSE);
1117 # else
1118 # if defined(__MWERKS__)
1119 # if !__POWERPC__
1120 extern void* GC_MacGetDataStart(void);
1121 /* MATTHEW: Function to handle Far Globals (CW Pro 3) */
1122 # if __option(far_data)
1123 extern void* GC_MacGetDataEnd(void);
1124 # endif
1125 /* globals begin above stack and end at a5. */
1126 GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
1127 (ptr_t)LMGetCurrentA5(), FALSE);
1128 /* MATTHEW: Handle Far Globals */
1129 # if __option(far_data)
1130 /* Far globals follow he QD globals: */
1131 GC_add_roots_inner((ptr_t)LMGetCurrentA5(),
1132 (ptr_t)GC_MacGetDataEnd(), FALSE);
1133 # endif
1134 # else
1135 extern char __data_start__[], __data_end__[];
1136 GC_add_roots_inner((ptr_t)&__data_start__,
1137 (ptr_t)&__data_end__, FALSE);
1138 # endif /* __POWERPC__ */
1139 # endif /* __MWERKS__ */
1140 # endif /* !THINK_C */
1141 }
1142 # endif /* MACOS */
1143
1144 /* Dynamic libraries are added at every collection, since they may */
1145 /* change. */
1146 }
1147
1148 # endif /* ! AMIGA */
1149 # endif /* ! MSWIN32 && ! MSWINCE*/
1150 # endif /* ! OS2 */
1151
1152 /*
1153 * Auxiliary routines for obtaining memory from OS.
1154 */
1155
1156 # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) \
1157 && !defined(MSWIN32) && !defined(MSWINCE) \
1158 && !defined(MACOS) && !defined(DOS4GW)
1159
1160 # ifdef SUNOS4
1161 extern caddr_t sbrk();
1162 # endif
1163 # ifdef __STDC__
1164 # define SBRK_ARG_T ptrdiff_t
1165 # else
1166 # define SBRK_ARG_T int
1167 # endif
1168
1169
1170 # ifdef RS6000
1171 /* The compiler seems to generate speculative reads one past the end of */
1172 /* an allocated object. Hence we need to make sure that the page */
1173 /* following the last heap page is also mapped. */
1174 ptr_t GC_unix_get_mem(bytes)
1175 word bytes;
1176 {
1177 caddr_t cur_brk = (caddr_t)sbrk(0);
1178 caddr_t result;
1179 SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1);
1180 static caddr_t my_brk_val = 0;
1181
1182 if ((SBRK_ARG_T)bytes < 0) return(0); /* too big */
1183 if (lsbs != 0) {
1184 if((caddr_t)(sbrk(GC_page_size - lsbs)) == (caddr_t)(-1)) return(0);
1185 }
1186 if (cur_brk == my_brk_val) {
1187 /* Use the extra block we allocated last time. */
1188 result = (ptr_t)sbrk((SBRK_ARG_T)bytes);
1189 if (result == (caddr_t)(-1)) return(0);
1190 result -= GC_page_size;
1191 } else {
1192 result = (ptr_t)sbrk(GC_page_size + (SBRK_ARG_T)bytes);
1193 if (result == (caddr_t)(-1)) return(0);
1194 }
1195 my_brk_val = result + bytes + GC_page_size; /* Always page aligned */
1196 return((ptr_t)result);
1197 }
1198
1199 #else /* Not RS6000 */
1200
1201 #if defined(USE_MMAP)
1202 /* Tested only under Linux, IRIX5 and Solaris 2 */
1203
1204 #ifdef USE_MMAP_FIXED
1205 # define GC_MMAP_FLAGS MAP_FIXED | MAP_PRIVATE
1206 /* Seems to yield better performance on Solaris 2, but can */
1207 /* be unreliable if something is already mapped at the address. */
1208 #else
1209 # define GC_MMAP_FLAGS MAP_PRIVATE
1210 #endif
1211
1212 #ifndef HEAP_START
1213 # define HEAP_START 0
1214 #endif
1215
1216 ptr_t GC_unix_get_mem(bytes)
1217 word bytes;
1218 {
1219 static GC_bool initialized = FALSE;
1220 static int fd;
1221 void *result;
1222 static ptr_t last_addr = HEAP_START;
1223
1224 if (!initialized) {
1225 fd = open("/dev/zero", O_RDONLY);
1226 initialized = TRUE;
1227 }
1228 if (bytes & (GC_page_size -1)) ABORT("Bad GET_MEM arg");
1229 result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC,
1230 GC_MMAP_FLAGS, fd, 0/* offset */);
1231 if (result == MAP_FAILED) return(0);
1232 last_addr = (ptr_t)result + bytes + GC_page_size - 1;
1233 last_addr = (ptr_t)((word)last_addr & ~(GC_page_size - 1));
1234 # if !defined(LINUX)
1235 if (last_addr == 0) {
1236 /* Oops. We got the end of the address space. This isn't */
1237 /* usable by arbitrary C code, since one-past-end pointers */
1238 /* don't work, so we discard it and try again. */
1239 munmap(result, (size_t)(-GC_page_size) - (size_t)result);
1240 /* Leave last page mapped, so we can't repeat. */
1241 return GC_unix_get_mem(bytes);
1242 }
1243 # else
1244 GC_ASSERT(last_addr != 0);
1245 # endif
1246 return((ptr_t)result);
1247 }
1248
1249 #else /* Not RS6000, not USE_MMAP */
1250 ptr_t GC_unix_get_mem(bytes)
1251 word bytes;
1252 {
1253 ptr_t result;
1254 # ifdef IRIX5
1255 /* Bare sbrk isn't thread safe. Play by malloc rules. */
1256 /* The equivalent may be needed on other systems as well. */
1257 __LOCK_MALLOC();
1258 # endif
1259 {
1260 ptr_t cur_brk = (ptr_t)sbrk(0);
1261 SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1);
1262
1263 if ((SBRK_ARG_T)bytes < 0) return(0); /* too big */
1264 if (lsbs != 0) {
1265 if((ptr_t)sbrk(GC_page_size - lsbs) == (ptr_t)(-1)) return(0);
1266 }
1267 result = (ptr_t)sbrk((SBRK_ARG_T)bytes);
1268 if (result == (ptr_t)(-1)) result = 0;
1269 }
1270 # ifdef IRIX5
1271 __UNLOCK_MALLOC();
1272 # endif
1273 return(result);
1274 }
1275
1276 #endif /* Not USE_MMAP */
1277 #endif /* Not RS6000 */
1278
1279 # endif /* UN*X */
1280
1281 # ifdef OS2
1282
1283 void * os2_alloc(size_t bytes)
1284 {
1285 void * result;
1286
1287 if (DosAllocMem(&result, bytes, PAG_EXECUTE | PAG_READ |
1288 PAG_WRITE | PAG_COMMIT)
1289 != NO_ERROR) {
1290 return(0);
1291 }
1292 if (result == 0) return(os2_alloc(bytes));
1293 return(result);
1294 }
1295
1296 # endif /* OS2 */
1297
1298
1299 # if defined(MSWIN32) || defined(MSWINCE)
1300 SYSTEM_INFO GC_sysinfo;
1301 # endif
1302
1303 # ifdef MSWIN32
1304
1305 # ifdef USE_GLOBAL_ALLOC
1306 # define GLOBAL_ALLOC_TEST 1
1307 # else
1308 # define GLOBAL_ALLOC_TEST GC_no_win32_dlls
1309 # endif
1310
1311 word GC_n_heap_bases = 0;
1312
1313 ptr_t GC_win32_get_mem(bytes)
1314 word bytes;
1315 {
1316 ptr_t result;
1317
1318 if (GLOBAL_ALLOC_TEST) {
1319 /* VirtualAlloc doesn't like PAGE_EXECUTE_READWRITE. */
1320 /* There are also unconfirmed rumors of other */
1321 /* problems, so we dodge the issue. */
1322 result = (ptr_t) GlobalAlloc(0, bytes + HBLKSIZE);
1323 result = (ptr_t)(((word)result + HBLKSIZE) & ~(HBLKSIZE-1));
1324 } else {
1325 result = (ptr_t) VirtualAlloc(NULL, bytes,
1326 MEM_COMMIT | MEM_RESERVE,
1327 PAGE_EXECUTE_READWRITE);
1328 }
1329 if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
1330 /* If I read the documentation correctly, this can */
1331 /* only happen if HBLKSIZE > 64k or not a power of 2. */
1332 if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
1333 GC_heap_bases[GC_n_heap_bases++] = result;
1334 return(result);
1335 }
1336
1337 void GC_win32_free_heap ()
1338 {
1339 if (GC_no_win32_dlls) {
1340 while (GC_n_heap_bases > 0) {
1341 GlobalFree (GC_heap_bases[--GC_n_heap_bases]);
1342 GC_heap_bases[GC_n_heap_bases] = 0;
1343 }
1344 }
1345 }
1346 # endif
1347
1348 #ifdef AMIGA
1349 # define GC_AMIGA_AM
1350 # include "AmigaOS.c"
1351 # undef GC_AMIGA_AM
1352 #endif
1353
1354
1355 # ifdef MSWINCE
1356 word GC_n_heap_bases = 0;
1357
1358 ptr_t GC_wince_get_mem(bytes)
1359 word bytes;
1360 {
1361 ptr_t result;
1362 word i;
1363
1364 /* Round up allocation size to multiple of page size */
1365 bytes = (bytes + GC_page_size-1) & ~(GC_page_size-1);
1366
1367 /* Try to find reserved, uncommitted pages */
1368 for (i = 0; i < GC_n_heap_bases; i++) {
1369 if (((word)(-(signed_word)GC_heap_lengths[i])
1370 & (GC_sysinfo.dwAllocationGranularity-1))
1371 >= bytes) {
1372 result = GC_heap_bases[i] + GC_heap_lengths[i];
1373 break;
1374 }
1375 }
1376
1377 if (i == GC_n_heap_bases) {
1378 /* Reserve more pages */
1379 word res_bytes = (bytes + GC_sysinfo.dwAllocationGranularity-1)
1380 & ~(GC_sysinfo.dwAllocationGranularity-1);
1381 result = (ptr_t) VirtualAlloc(NULL, res_bytes,
1382 MEM_RESERVE | MEM_TOP_DOWN,
1383 PAGE_EXECUTE_READWRITE);
1384 if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
1385 /* If I read the documentation correctly, this can */
1386 /* only happen if HBLKSIZE > 64k or not a power of 2. */
1387 if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
1388 GC_heap_bases[GC_n_heap_bases] = result;
1389 GC_heap_lengths[GC_n_heap_bases] = 0;
1390 GC_n_heap_bases++;
1391 }
1392
1393 /* Commit pages */
1394 result = (ptr_t) VirtualAlloc(result, bytes,
1395 MEM_COMMIT,
1396 PAGE_EXECUTE_READWRITE);
1397 if (result != NULL) {
1398 if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
1399 GC_heap_lengths[i] += bytes;
1400 }
1401
1402 return(result);
1403 }
1404 # endif
1405
1406 #ifdef USE_MUNMAP
1407
1408 /* For now, this only works on Win32/WinCE and some Unix-like */
1409 /* systems. If you have something else, don't define */
1410 /* USE_MUNMAP. */
1411 /* We assume ANSI C to support this feature. */
1412
1413 #if !defined(MSWIN32) && !defined(MSWINCE)
1414
1415 #include <unistd.h>
1416 #include <sys/mman.h>
1417 #include <sys/stat.h>
1418 #include <sys/types.h>
1419
1420 #endif
1421
1422 /* Compute a page aligned starting address for the unmap */
1423 /* operation on a block of size bytes starting at start. */
1424 /* Return 0 if the block is too small to make this feasible. */
1425 ptr_t GC_unmap_start(ptr_t start, word bytes)
1426 {
1427 ptr_t result = start;
1428 /* Round start to next page boundary. */
1429 result += GC_page_size - 1;
1430 result = (ptr_t)((word)result & ~(GC_page_size - 1));
1431 if (result + GC_page_size > start + bytes) return 0;
1432 return result;
1433 }
1434
1435 /* Compute end address for an unmap operation on the indicated */
1436 /* block. */
1437 ptr_t GC_unmap_end(ptr_t start, word bytes)
1438 {
1439 ptr_t end_addr = start + bytes;
1440 end_addr = (ptr_t)((word)end_addr & ~(GC_page_size - 1));
1441 return end_addr;
1442 }
1443
1444 /* Under Win32/WinCE we commit (map) and decommit (unmap) */
1445 /* memory using VirtualAlloc and VirtualFree. These functions */
1446 /* work on individual allocations of virtual memory, made */
1447 /* previously using VirtualAlloc with the MEM_RESERVE flag. */
1448 /* The ranges we need to (de)commit may span several of these */
1449 /* allocations; therefore we use VirtualQuery to check */
1450 /* allocation lengths, and split up the range as necessary. */
1451
1452 /* We assume that GC_remap is called on exactly the same range */
1453 /* as a previous call to GC_unmap. It is safe to consistently */
1454 /* round the endpoints in both places. */
1455 void GC_unmap(ptr_t start, word bytes)
1456 {
1457 ptr_t start_addr = GC_unmap_start(start, bytes);
1458 ptr_t end_addr = GC_unmap_end(start, bytes);
1459 word len = end_addr - start_addr;
1460 if (0 == start_addr) return;
1461 # if defined(MSWIN32) || defined(MSWINCE)
1462 while (len != 0) {
1463 MEMORY_BASIC_INFORMATION mem_info;
1464 GC_word free_len;
1465 if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
1466 != sizeof(mem_info))
1467 ABORT("Weird VirtualQuery result");
1468 free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
1469 if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT))
1470 ABORT("VirtualFree failed");
1471 GC_unmapped_bytes += free_len;
1472 start_addr += free_len;
1473 len -= free_len;
1474 }
1475 # else
1476 if (munmap(start_addr, len) != 0) ABORT("munmap failed");
1477 GC_unmapped_bytes += len;
1478 # endif
1479 }
1480
1481
1482 void GC_remap(ptr_t start, word bytes)
1483 {
1484 static int zero_descr = -1;
1485 ptr_t start_addr = GC_unmap_start(start, bytes);
1486 ptr_t end_addr = GC_unmap_end(start, bytes);
1487 word len = end_addr - start_addr;
1488 ptr_t result;
1489
1490 # if defined(MSWIN32) || defined(MSWINCE)
1491 if (0 == start_addr) return;
1492 while (len != 0) {
1493 MEMORY_BASIC_INFORMATION mem_info;
1494 GC_word alloc_len;
1495 if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
1496 != sizeof(mem_info))
1497 ABORT("Weird VirtualQuery result");
1498 alloc_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
1499 result = VirtualAlloc(start_addr, alloc_len,
1500 MEM_COMMIT,
1501 PAGE_EXECUTE_READWRITE);
1502 if (result != start_addr) {
1503 ABORT("VirtualAlloc remapping failed");
1504 }
1505 GC_unmapped_bytes -= alloc_len;
1506 start_addr += alloc_len;
1507 len -= alloc_len;
1508 }
1509 # else
1510 if (-1 == zero_descr) zero_descr = open("/dev/zero", O_RDWR);
1511 if (0 == start_addr) return;
1512 result = mmap(start_addr, len, PROT_READ | PROT_WRITE | OPT_PROT_EXEC,
1513 MAP_FIXED | MAP_PRIVATE, zero_descr, 0);
1514 if (result != start_addr) {
1515 ABORT("mmap remapping failed");
1516 }
1517 GC_unmapped_bytes -= len;
1518 # endif
1519 }
1520
1521 /* Two adjacent blocks have already been unmapped and are about to */
1522 /* be merged. Unmap the whole block. This typically requires */
1523 /* that we unmap a small section in the middle that was not previously */
1524 /* unmapped due to alignment constraints. */
1525 void GC_unmap_gap(ptr_t start1, word bytes1, ptr_t start2, word bytes2)
1526 {
1527 ptr_t start1_addr = GC_unmap_start(start1, bytes1);
1528 ptr_t end1_addr = GC_unmap_end(start1, bytes1);
1529 ptr_t start2_addr = GC_unmap_start(start2, bytes2);
1530 ptr_t end2_addr = GC_unmap_end(start2, bytes2);
1531 ptr_t start_addr = end1_addr;
1532 ptr_t end_addr = start2_addr;
1533 word len;
1534 GC_ASSERT(start1 + bytes1 == start2);
1535 if (0 == start1_addr) start_addr = GC_unmap_start(start1, bytes1 + bytes2);
1536 if (0 == start2_addr) end_addr = GC_unmap_end(start1, bytes1 + bytes2);
1537 if (0 == start_addr) return;
1538 len = end_addr - start_addr;
1539 # if defined(MSWIN32) || defined(MSWINCE)
1540 while (len != 0) {
1541 MEMORY_BASIC_INFORMATION mem_info;
1542 GC_word free_len;
1543 if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
1544 != sizeof(mem_info))
1545 ABORT("Weird VirtualQuery result");
1546 free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
1547 if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT))
1548 ABORT("VirtualFree failed");
1549 GC_unmapped_bytes += free_len;
1550 start_addr += free_len;
1551 len -= free_len;
1552 }
1553 # else
1554 if (len != 0 && munmap(start_addr, len) != 0) ABORT("munmap failed");
1555 GC_unmapped_bytes += len;
1556 # endif
1557 }
1558
1559 #endif /* USE_MUNMAP */
1560
1561 /* Routine for pushing any additional roots. In THREADS */
1562 /* environment, this is also responsible for marking from */
1563 /* thread stacks. */
1564 #ifndef THREADS
1565 void (*GC_push_other_roots)() = 0;
1566 #else /* THREADS */
1567
1568 # ifdef PCR
1569 PCR_ERes GC_push_thread_stack(PCR_Th_T *t, PCR_Any dummy)
1570 {
1571 struct PCR_ThCtl_TInfoRep info;
1572 PCR_ERes result;
1573
1574 info.ti_stkLow = info.ti_stkHi = 0;
1575 result = PCR_ThCtl_GetInfo(t, &info);
1576 GC_push_all_stack((ptr_t)(info.ti_stkLow), (ptr_t)(info.ti_stkHi));
1577 return(result);
1578 }
1579
1580 /* Push the contents of an old object. We treat this as stack */
1581 /* data only becasue that makes it robust against mark stack */
1582 /* overflow. */
1583 PCR_ERes GC_push_old_obj(void *p, size_t size, PCR_Any data)
1584 {
1585 GC_push_all_stack((ptr_t)p, (ptr_t)p + size);
1586 return(PCR_ERes_okay);
1587 }
1588
1589
1590 void GC_default_push_other_roots GC_PROTO((void))
1591 {
1592 /* Traverse data allocated by previous memory managers. */
1593 {
1594 extern struct PCR_MM_ProcsRep * GC_old_allocator;
1595
1596 if ((*(GC_old_allocator->mmp_enumerate))(PCR_Bool_false,
1597 GC_push_old_obj, 0)
1598 != PCR_ERes_okay) {
1599 ABORT("Old object enumeration failed");
1600 }
1601 }
1602 /* Traverse all thread stacks. */
1603 if (PCR_ERes_IsErr(
1604 PCR_ThCtl_ApplyToAllOtherThreads(GC_push_thread_stack,0))
1605 || PCR_ERes_IsErr(GC_push_thread_stack(PCR_Th_CurrThread(), 0))) {
1606 ABORT("Thread stack marking failed\n");
1607 }
1608 }
1609
1610 # endif /* PCR */
1611
1612 # ifdef SRC_M3
1613
1614 # ifdef ALL_INTERIOR_POINTERS
1615 --> misconfigured
1616 # endif
1617
1618 void GC_push_thread_structures GC_PROTO((void))
1619 {
1620 /* Not our responsibibility. */
1621 }
1622
1623 extern void ThreadF__ProcessStacks();
1624
1625 void GC_push_thread_stack(start, stop)
1626 word start, stop;
1627 {
1628 GC_push_all_stack((ptr_t)start, (ptr_t)stop + sizeof(word));
1629 }
1630
1631 /* Push routine with M3 specific calling convention. */
1632 GC_m3_push_root(dummy1, p, dummy2, dummy3)
1633 word *p;
1634 ptr_t dummy1, dummy2;
1635 int dummy3;
1636 {
1637 word q = *p;
1638
1639 GC_PUSH_ONE_STACK(q, p);
1640 }
1641
1642 /* M3 set equivalent to RTHeap.TracedRefTypes */
1643 typedef struct { int elts[1]; } RefTypeSet;
1644 RefTypeSet GC_TracedRefTypes = {{0x1}};
1645
1646 void GC_default_push_other_roots GC_PROTO((void))
1647 {
1648 /* Use the M3 provided routine for finding static roots. */
1649 /* This is a bit dubious, since it presumes no C roots. */
1650 /* We handle the collector roots explicitly in GC_push_roots */
1651 RTMain__GlobalMapProc(GC_m3_push_root, 0, GC_TracedRefTypes);
1652 if (GC_words_allocd > 0) {
1653 ThreadF__ProcessStacks(GC_push_thread_stack);
1654 }
1655 /* Otherwise this isn't absolutely necessary, and we have */
1656 /* startup ordering problems. */
1657 }
1658
1659 # endif /* SRC_M3 */
1660
1661 # if defined(GC_SOLARIS_THREADS) || defined(GC_PTHREADS) || \
1662 defined(GC_WIN32_THREADS)
1663
1664 extern void GC_push_all_stacks();
1665
1666 void GC_default_push_other_roots GC_PROTO((void))
1667 {
1668 GC_push_all_stacks();
1669 }
1670
1671 # endif /* GC_SOLARIS_THREADS || GC_PTHREADS */
1672
1673 void (*GC_push_other_roots) GC_PROTO((void)) = GC_default_push_other_roots;
1674
1675 #endif /* THREADS */
1676
1677 /*
1678 * Routines for accessing dirty bits on virtual pages.
1679 * We plan to eventually implement four strategies for doing so:
1680 * DEFAULT_VDB: A simple dummy implementation that treats every page
1681 * as possibly dirty. This makes incremental collection
1682 * useless, but the implementation is still correct.
1683 * PCR_VDB: Use PPCRs virtual dirty bit facility.
1684 * PROC_VDB: Use the /proc facility for reading dirty bits. Only
1685 * works under some SVR4 variants. Even then, it may be
1686 * too slow to be entirely satisfactory. Requires reading
1687 * dirty bits for entire address space. Implementations tend
1688 * to assume that the client is a (slow) debugger.
1689 * MPROTECT_VDB:Protect pages and then catch the faults to keep track of
1690 * dirtied pages. The implementation (and implementability)
1691 * is highly system dependent. This usually fails when system
1692 * calls write to a protected page. We prevent the read system
1693 * call from doing so. It is the clients responsibility to
1694 * make sure that other system calls are similarly protected
1695 * or write only to the stack.
1696 */
1697
1698 GC_bool GC_dirty_maintained = FALSE;
1699
1700 # ifdef DEFAULT_VDB
1701
1702 /* All of the following assume the allocation lock is held, and */
1703 /* signals are disabled. */
1704
1705 /* The client asserts that unallocated pages in the heap are never */
1706 /* written. */
1707
1708 /* Initialize virtual dirty bit implementation. */
1709 void GC_dirty_init()
1710 {
1711 GC_dirty_maintained = TRUE;
1712 }
1713
1714 /* Retrieve system dirty bits for heap to a local buffer. */
1715 /* Restore the systems notion of which pages are dirty. */
1716 void GC_read_dirty()
1717 {}
1718
1719 /* Is the HBLKSIZE sized page at h marked dirty in the local buffer? */
1720 /* If the actual page size is different, this returns TRUE if any */
1721 /* of the pages overlapping h are dirty. This routine may err on the */
1722 /* side of labelling pages as dirty (and this implementation does). */
1723 /*ARGSUSED*/
1724 GC_bool GC_page_was_dirty(h)
1725 struct hblk *h;
1726 {
1727 return(TRUE);
1728 }
1729
1730 /*
1731 * The following two routines are typically less crucial. They matter
1732 * most with large dynamic libraries, or if we can't accurately identify
1733 * stacks, e.g. under Solaris 2.X. Otherwise the following default
1734 * versions are adequate.
1735 */
1736
1737 /* Could any valid GC heap pointer ever have been written to this page? */
1738 /*ARGSUSED*/
1739 GC_bool GC_page_was_ever_dirty(h)
1740 struct hblk *h;
1741 {
1742 return(TRUE);
1743 }
1744
1745 /* Reset the n pages starting at h to "was never dirty" status. */
1746 void GC_is_fresh(h, n)
1747 struct hblk *h;
1748 word n;
1749 {
1750 }
1751
1752 /* A call that: */
1753 /* I) hints that [h, h+nblocks) is about to be written. */
1754 /* II) guarantees that protection is removed. */
1755 /* (I) may speed up some dirty bit implementations. */
1756 /* (II) may be essential if we need to ensure that */
1757 /* pointer-free system call buffers in the heap are */
1758 /* not protected. */
1759 /*ARGSUSED*/
1760 void GC_remove_protection(h, nblocks, is_ptrfree)
1761 struct hblk *h;
1762 word nblocks;
1763 GC_bool is_ptrfree;
1764 {
1765 }
1766
1767 # endif /* DEFAULT_VDB */
1768
1769
1770 # ifdef MPROTECT_VDB
1771
1772 /*
1773 * See DEFAULT_VDB for interface descriptions.
1774 */
1775
1776 /*
1777 * This implementation maintains dirty bits itself by catching write
1778 * faults and keeping track of them. We assume nobody else catches
1779 * SIGBUS or SIGSEGV. We assume no write faults occur in system calls
1780 * except as a result of a read system call. This means clients must
1781 * either ensure that system calls do not touch the heap, or must
1782 * provide their own wrappers analogous to the one for read.
1783 * We assume the page size is a multiple of HBLKSIZE.
1784 * This implementation is currently SunOS 4.X and IRIX 5.X specific, though we
1785 * tried to use portable code where easily possible. It is known
1786 * not to work under a number of other systems.
1787 */
1788
1789 # if !defined(MSWIN32) && !defined(MSWINCE)
1790
1791 # include <sys/mman.h>
1792 # include <signal.h>
1793 # include <sys/syscall.h>
1794
1795 # define PROTECT(addr, len) \
1796 if (mprotect((caddr_t)(addr), (size_t)(len), \
1797 PROT_READ | OPT_PROT_EXEC) < 0) { \
1798 ABORT("mprotect failed"); \
1799 }
1800 # define UNPROTECT(addr, len) \
1801 if (mprotect((caddr_t)(addr), (size_t)(len), \
1802 PROT_WRITE | PROT_READ | OPT_PROT_EXEC ) < 0) { \
1803 ABORT("un-mprotect failed"); \
1804 }
1805
1806 # else
1807
1808 # ifndef MSWINCE
1809 # include <signal.h>
1810 # endif
1811
1812 static DWORD protect_junk;
1813 # define PROTECT(addr, len) \
1814 if (!VirtualProtect((addr), (len), PAGE_EXECUTE_READ, \
1815 &protect_junk)) { \
1816 DWORD last_error = GetLastError(); \
1817 GC_printf1("Last error code: %lx\n", last_error); \
1818 ABORT("VirtualProtect failed"); \
1819 }
1820 # define UNPROTECT(addr, len) \
1821 if (!VirtualProtect((addr), (len), PAGE_EXECUTE_READWRITE, \
1822 &protect_junk)) { \
1823 ABORT("un-VirtualProtect failed"); \
1824 }
1825
1826 # endif
1827
1828 #if defined(SUNOS4) || defined(FREEBSD)
1829 typedef void (* SIG_PF)();
1830 #endif
1831 #if defined(SUNOS5SIGS) || defined(OSF1) || defined(LINUX) \
1832 || defined(MACOSX) || defined(HURD)
1833 # ifdef __STDC__
1834 typedef void (* SIG_PF)(int);
1835 # else
1836 typedef void (* SIG_PF)();
1837 # endif
1838 #endif
1839 #if defined(MSWIN32)
1840 typedef LPTOP_LEVEL_EXCEPTION_FILTER SIG_PF;
1841 # undef SIG_DFL
1842 # define SIG_DFL (LPTOP_LEVEL_EXCEPTION_FILTER) (-1)
1843 #endif
1844 #if defined(MSWINCE)
1845 typedef LONG (WINAPI *SIG_PF)(struct _EXCEPTION_POINTERS *);
1846 # undef SIG_DFL
1847 # define SIG_DFL (SIG_PF) (-1)
1848 #endif
1849
1850 #if defined(IRIX5) || defined(OSF1) || defined(HURD)
1851 typedef void (* REAL_SIG_PF)(int, int, struct sigcontext *);
1852 #endif
1853 #if defined(SUNOS5SIGS)
1854 # ifdef HPUX
1855 # define SIGINFO __siginfo
1856 # else
1857 # define SIGINFO siginfo
1858 # endif
1859 # ifdef __STDC__
1860 typedef void (* REAL_SIG_PF)(int, struct SIGINFO *, void *);
1861 # else
1862 typedef void (* REAL_SIG_PF)();
1863 # endif
1864 #endif
1865 #if defined(LINUX)
1866 # if __GLIBC__ > 2 || __GLIBC__ == 2 && __GLIBC_MINOR__ >= 2
1867 typedef struct sigcontext s_c;
1868 # else /* glibc < 2.2 */
1869 # include <linux/version.h>
1870 # if (LINUX_VERSION_CODE >= 0x20100) && !defined(M68K) || defined(ALPHA)
1871 typedef struct sigcontext s_c;
1872 # else
1873 typedef struct sigcontext_struct s_c;
1874 # endif
1875 # endif /* glibc < 2.2 */
1876 # if defined(ALPHA) || defined(M68K)
1877 typedef void (* REAL_SIG_PF)(int, int, s_c *);
1878 # else
1879 # if defined(IA64) || defined(HP_PA)
1880 typedef void (* REAL_SIG_PF)(int, siginfo_t *, s_c *);
1881 # else
1882 typedef void (* REAL_SIG_PF)(int, s_c);
1883 # endif
1884 # endif
1885 # ifdef ALPHA
1886 /* Retrieve fault address from sigcontext structure by decoding */
1887 /* instruction. */
1888 char * get_fault_addr(s_c *sc) {
1889 unsigned instr;
1890 word faultaddr;
1891
1892 instr = *((unsigned *)(sc->sc_pc));
1893 faultaddr = sc->sc_regs[(instr >> 16) & 0x1f];
1894 faultaddr += (word) (((int)instr << 16) >> 16);
1895 return (char *)faultaddr;
1896 }
1897 # endif /* !ALPHA */
1898 # endif
1899
1900 # if defined(MACOSX) /* Should also test for PowerPC? */
1901 typedef void (* REAL_SIG_PF)(int, int, struct sigcontext *);
1902
1903 /* Decodes the machine instruction which was responsible for the sending of the
1904 SIGBUS signal. Sadly this is the only way to find the faulting address because
1905 the signal handler doesn't get it directly from the kernel (although it is
1906 available on the Mach level, but droppped by the BSD personality before it
1907 calls our signal handler...)
1908 This code should be able to deal correctly with all PPCs starting from the
1909 601 up to and including the G4s (including Velocity Engine). */
1910 #define EXTRACT_OP1(iw) (((iw) & 0xFC000000) >> 26)
1911 #define EXTRACT_OP2(iw) (((iw) & 0x000007FE) >> 1)
1912 #define EXTRACT_REGA(iw) (((iw) & 0x001F0000) >> 16)
1913 #define EXTRACT_REGB(iw) (((iw) & 0x03E00000) >> 21)
1914 #define EXTRACT_REGC(iw) (((iw) & 0x0000F800) >> 11)
1915 #define EXTRACT_DISP(iw) ((short *) &(iw))[1]
1916
1917 static char *get_fault_addr(struct sigcontext *scp)
1918 {
1919 unsigned int instr = *((unsigned int *) scp->sc_ir);
1920 unsigned int * regs = &((unsigned int *) scp->sc_regs)[2];
1921 int disp = 0, tmp;
1922 unsigned int baseA = 0, baseB = 0;
1923 unsigned int addr, alignmask = 0xFFFFFFFF;
1924
1925 #ifdef GC_DEBUG_DECODER
1926 GC_err_printf1("Instruction: 0x%lx\n", instr);
1927 GC_err_printf1("Opcode 1: d\n", (int)EXTRACT_OP1(instr));
1928 #endif
1929 switch(EXTRACT_OP1(instr)) {
1930 case 38: /* stb */
1931 case 39: /* stbu */
1932 case 54: /* stfd */
1933 case 55: /* stfdu */
1934 case 52: /* stfs */
1935 case 53: /* stfsu */
1936 case 44: /* sth */
1937 case 45: /* sthu */
1938 case 47: /* stmw */
1939 case 36: /* stw */
1940 case 37: /* stwu */
1941 tmp = EXTRACT_REGA(instr);
1942 if(tmp > 0)
1943 baseA = regs[tmp];
1944 disp = EXTRACT_DISP(instr);
1945 break;
1946 case 31:
1947 #ifdef GC_DEBUG_DECODER
1948 GC_err_printf1("Opcode 2: %d\n", (int)EXTRACT_OP2(instr));
1949 #endif
1950 switch(EXTRACT_OP2(instr)) {
1951 case 86: /* dcbf */
1952 case 54: /* dcbst */
1953 case 1014: /* dcbz */
1954 case 247: /* stbux */
1955 case 215: /* stbx */
1956 case 759: /* stfdux */
1957 case 727: /* stfdx */
1958 case 983: /* stfiwx */
1959 case 695: /* stfsux */
1960 case 663: /* stfsx */
1961 case 918: /* sthbrx */
1962 case 439: /* sthux */
1963 case 407: /* sthx */
1964 case 661: /* stswx */
1965 case 662: /* stwbrx */
1966 case 150: /* stwcx. */
1967 case 183: /* stwux */
1968 case 151: /* stwx */
1969 case 135: /* stvebx */
1970 case 167: /* stvehx */
1971 case 199: /* stvewx */
1972 case 231: /* stvx */
1973 case 487: /* stvxl */
1974 tmp = EXTRACT_REGA(instr);
1975 if(tmp > 0)
1976 baseA = regs[tmp];
1977 baseB = regs[EXTRACT_REGC(instr)];
1978 /* determine Altivec alignment mask */
1979 switch(EXTRACT_OP2(instr)) {
1980 case 167: /* stvehx */
1981 alignmask = 0xFFFFFFFE;
1982 break;
1983 case 199: /* stvewx */
1984 alignmask = 0xFFFFFFFC;
1985 break;
1986 case 231: /* stvx */
1987 alignmask = 0xFFFFFFF0;
1988 break;
1989 case 487: /* stvxl */
1990 alignmask = 0xFFFFFFF0;
1991 break;
1992 }
1993 break;
1994 case 725: /* stswi */
1995 tmp = EXTRACT_REGA(instr);
1996 if(tmp > 0)
1997 baseA = regs[tmp];
1998 break;
1999 default: /* ignore instruction */
2000 #ifdef GC_DEBUG_DECODER
2001 GC_err_printf("Ignored by inner handler\n");
2002 #endif
2003 return NULL;
2004 break;
2005 }
2006 break;
2007 default: /* ignore instruction */
2008 #ifdef GC_DEBUG_DECODER
2009 GC_err_printf("Ignored by main handler\n");
2010 #endif
2011 return NULL;
2012 break;
2013 }
2014
2015 addr = (baseA + baseB) + disp;
2016 addr &= alignmask;
2017 #ifdef GC_DEBUG_DECODER
2018 GC_err_printf1("BaseA: %d\n", baseA);
2019 GC_err_printf1("BaseB: %d\n", baseB);
2020 GC_err_printf1("Disp: %d\n", disp);
2021 GC_err_printf1("Address: %d\n", addr);
2022 #endif
2023 return (char *)addr;
2024 }
2025 #endif /* MACOSX */
2026
2027 SIG_PF GC_old_bus_handler;
2028 SIG_PF GC_old_segv_handler; /* Also old MSWIN32 ACCESS_VIOLATION filter */
2029
2030 #ifdef THREADS
2031 /* We need to lock around the bitmap update in the write fault handler */
2032 /* in order to avoid the risk of losing a bit. We do this with a */
2033 /* test-and-set spin lock if we know how to do that. Otherwise we */
2034 /* check whether we are already in the handler and use the dumb but */
2035 /* safe fallback algorithm of setting all bits in the word. */
2036 /* Contention should be very rare, so we do the minimum to handle it */
2037 /* correctly. */
2038 #ifdef GC_TEST_AND_SET_DEFINED
2039 static VOLATILE unsigned int fault_handler_lock = 0;
2040 void async_set_pht_entry_from_index(VOLATILE page_hash_table db, int index) {
2041 while (GC_test_and_set(&fault_handler_lock)) {}
2042 /* Could also revert to set_pht_entry_from_index_safe if initial */
2043 /* GC_test_and_set fails. */
2044 set_pht_entry_from_index(db, index);
2045 GC_clear(&fault_handler_lock);
2046 }
2047 #else /* !GC_TEST_AND_SET_DEFINED */
2048 /* THIS IS INCORRECT! The dirty bit vector may be temporarily wrong, */
2049 /* just before we notice the conflict and correct it. We may end up */
2050 /* looking at it while it's wrong. But this requires contention */
2051 /* exactly when a GC is triggered, which seems far less likely to */
2052 /* fail than the old code, which had no reported failures. Thus we */
2053 /* leave it this way while we think of something better, or support */
2054 /* GC_test_and_set on the remaining platforms. */
2055 static VOLATILE word currently_updating = 0;
2056 void async_set_pht_entry_from_index(VOLATILE page_hash_table db, int index) {
2057 unsigned int update_dummy;
2058 currently_updating = (word)(&update_dummy);
2059 set_pht_entry_from_index(db, index);
2060 /* If we get contention in the 10 or so instruction window here, */
2061 /* and we get stopped by a GC between the two updates, we lose! */
2062 if (currently_updating != (word)(&update_dummy)) {
2063 set_pht_entry_from_index_safe(db, index);
2064 /* We claim that if two threads concurrently try to update the */
2065 /* dirty bit vector, the first one to execute UPDATE_START */
2066 /* will see it changed when UPDATE_END is executed. (Note that */
2067 /* &update_dummy must differ in two distinct threads.) It */
2068 /* will then execute set_pht_entry_from_index_safe, thus */
2069 /* returning us to a safe state, though not soon enough. */
2070 }
2071 }
2072 #endif /* !GC_TEST_AND_SET_DEFINED */
2073 #else /* !THREADS */
2074 # define async_set_pht_entry_from_index(db, index) \
2075 set_pht_entry_from_index(db, index)
2076 #endif /* !THREADS */
2077
2078 /*ARGSUSED*/
2079 # if defined (SUNOS4) || defined(FREEBSD)
2080 void GC_write_fault_handler(sig, code, scp, addr)
2081 int sig, code;
2082 struct sigcontext *scp;
2083 char * addr;
2084 # ifdef SUNOS4
2085 # define SIG_OK (sig == SIGSEGV || sig == SIGBUS)
2086 # define CODE_OK (FC_CODE(code) == FC_PROT \
2087 || (FC_CODE(code) == FC_OBJERR \
2088 && FC_ERRNO(code) == FC_PROT))
2089 # endif
2090 # ifdef FREEBSD
2091 # define SIG_OK (sig == SIGBUS)
2092 # define CODE_OK (code == BUS_PAGE_FAULT)
2093 # endif
2094 # endif
2095 # if defined(IRIX5) || defined(OSF1) || defined(HURD)
2096 # include <errno.h>
2097 void GC_write_fault_handler(int sig, int code, struct sigcontext *scp)
2098 # ifdef OSF1
2099 # define SIG_OK (sig == SIGSEGV)
2100 # define CODE_OK (code == 2 /* experimentally determined */)
2101 # endif
2102 # ifdef IRIX5
2103 # define SIG_OK (sig == SIGSEGV)
2104 # define CODE_OK (code == EACCES)
2105 # endif
2106 # ifdef HURD
2107 # define SIG_OK (sig == SIGBUS || sig == SIGSEGV)
2108 # define CODE_OK TRUE
2109 # endif
2110 # endif
2111 # if defined(LINUX)
2112 # if defined(ALPHA) || defined(M68K)
2113 void GC_write_fault_handler(int sig, int code, s_c * sc)
2114 # else
2115 # if defined(IA64) || defined(HP_PA)
2116 void GC_write_fault_handler(int sig, siginfo_t * si, s_c * scp)
2117 # else
2118 void GC_write_fault_handler(int sig, s_c sc)
2119 # endif
2120 # endif
2121 # define SIG_OK (sig == SIGSEGV)
2122 # define CODE_OK TRUE
2123 /* Empirically c.trapno == 14, on IA32, but is that useful? */
2124 /* Should probably consider alignment issues on other */
2125 /* architectures. */
2126 # endif
2127 # if defined(SUNOS5SIGS)
2128 # ifdef __STDC__
2129 void GC_write_fault_handler(int sig, struct SIGINFO *scp, void * context)
2130 # else
2131 void GC_write_fault_handler(sig, scp, context)
2132 int sig;
2133 struct SIGINFO *scp;
2134 void * context;
2135 # endif
2136 # ifdef HPUX
2137 # define SIG_OK (sig == SIGSEGV || sig == SIGBUS)
2138 # define CODE_OK (scp -> si_code == SEGV_ACCERR) \
2139 || (scp -> si_code == BUS_ADRERR) \
2140 || (scp -> si_code == BUS_UNKNOWN) \
2141 || (scp -> si_code == SEGV_UNKNOWN) \
2142 || (scp -> si_code == BUS_OBJERR)
2143 # else
2144 # define SIG_OK (sig == SIGSEGV)
2145 # define CODE_OK (scp -> si_code == SEGV_ACCERR)
2146 # endif
2147 # endif
2148
2149 # if defined(MACOSX)
2150 void GC_write_fault_handler(int sig, int code, struct sigcontext *scp)
2151 # define SIG_OK (sig == SIGBUS)
2152 # define CODE_OK (code == 0 /* experimentally determined */)
2153 # endif
2154
2155 # if defined(MSWIN32) || defined(MSWINCE)
2156 LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info)
2157 # define SIG_OK (exc_info -> ExceptionRecord -> ExceptionCode == \
2158 STATUS_ACCESS_VIOLATION)
2159 # define CODE_OK (exc_info -> ExceptionRecord -> ExceptionInformation[0] == 1)
2160 /* Write fault */
2161 # endif
2162 {
2163 register unsigned i;
2164 # if defined(HURD)
2165 char *addr = (char *) code;
2166 # endif
2167 # ifdef IRIX5
2168 char * addr = (char *) (size_t) (scp -> sc_badvaddr);
2169 # endif
2170 # if defined(OSF1) && defined(ALPHA)
2171 char * addr = (char *) (scp -> sc_traparg_a0);
2172 # endif
2173 # ifdef SUNOS5SIGS
2174 char * addr = (char *) (scp -> si_addr);
2175 # endif
2176 # ifdef LINUX
2177 # if defined(I386) || defined (X86_64)
2178 char * addr = (char *) (sc.cr2);
2179 # else
2180 # if defined(M68K)
2181 char * addr = NULL;
2182
2183 struct sigcontext *scp = (struct sigcontext *)(sc);
2184
2185 int format = (scp->sc_formatvec >> 12) & 0xf;
2186 unsigned long *framedata = (unsigned long *)(scp + 1);
2187 unsigned long ea;
2188
2189 if (format == 0xa || format == 0xb) {
2190 /* 68020/030 */
2191 ea = framedata[2];
2192 } else if (format == 7) {
2193 /* 68040 */
2194 ea = framedata[3];
2195 if (framedata[1] & 0x08000000) {
2196 /* correct addr on misaligned access */
2197 ea = (ea+4095)&(~4095);
2198 }
2199 } else if (format == 4) {
2200 /* 68060 */
2201 ea = framedata[0];
2202 if (framedata[1] & 0x08000000) {
2203 /* correct addr on misaligned access */
2204 ea = (ea+4095)&(~4095);
2205 }
2206 }
2207 addr = (char *)ea;
2208 # else
2209 # ifdef ALPHA
2210 char * addr = get_fault_addr(sc);
2211 # else
2212 # if defined(IA64) || defined(HP_PA)
2213 char * addr = si -> si_addr;
2214 /* I believe this is claimed to work on all platforms for */
2215 /* Linux 2.3.47 and later. Hopefully we don't have to */
2216 /* worry about earlier kernels on IA64. */
2217 # else
2218 # if defined(POWERPC)
2219 char * addr = (char *) (sc.regs->dar);
2220 # else
2221 --> architecture not supported
2222 # endif
2223 # endif
2224 # endif
2225 # endif
2226 # endif
2227 # endif
2228 # if defined(MACOSX)
2229 char * addr = get_fault_addr(scp);
2230 # endif
2231 # if defined(MSWIN32) || defined(MSWINCE)
2232 char * addr = (char *) (exc_info -> ExceptionRecord
2233 -> ExceptionInformation[1]);
2234 # define sig SIGSEGV
2235 # endif
2236
2237 if (SIG_OK && CODE_OK) {
2238 register struct hblk * h =
2239 (struct hblk *)((word)addr & ~(GC_page_size-1));
2240 GC_bool in_allocd_block;
2241
2242 # ifdef SUNOS5SIGS
2243 /* Address is only within the correct physical page. */
2244 in_allocd_block = FALSE;
2245 for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
2246 if (HDR(h+i) != 0) {
2247 in_allocd_block = TRUE;
2248 }
2249 }
2250 # else
2251 in_allocd_block = (HDR(addr) != 0);
2252 # endif
2253 if (!in_allocd_block) {
2254 /* Heap blocks now begin and end on page boundaries */
2255 SIG_PF old_handler;
2256
2257 if (sig == SIGSEGV) {
2258 old_handler = GC_old_segv_handler;
2259 } else {
2260 old_handler = GC_old_bus_handler;
2261 }
2262 if (old_handler == SIG_DFL) {
2263 # if !defined(MSWIN32) && !defined(MSWINCE)
2264 GC_err_printf1("Segfault at 0x%lx\n", addr);
2265 ABORT("Unexpected bus error or segmentation fault");
2266 # else
2267 return(EXCEPTION_CONTINUE_SEARCH);
2268 # endif
2269 } else {
2270 # if defined (SUNOS4) || defined(FREEBSD)
2271 (*old_handler) (sig, code, scp, addr);
2272 return;
2273 # endif
2274 # if defined (SUNOS5SIGS)
2275 (*(REAL_SIG_PF)old_handler) (sig, scp, context);
2276 return;
2277 # endif
2278 # if defined (LINUX)
2279 # if defined(ALPHA) || defined(M68K)
2280 (*(REAL_SIG_PF)old_handler) (sig, code, sc);
2281 # else
2282 # if defined(IA64) || defined(HP_PA)
2283 (*(REAL_SIG_PF)old_handler) (sig, si, scp);
2284 # else
2285 (*(REAL_SIG_PF)old_handler) (sig, sc);
2286 # endif
2287 # endif
2288 return;
2289 # endif
2290 # if defined (IRIX5) || defined(OSF1) || defined(HURD)
2291 (*(REAL_SIG_PF)old_handler) (sig, code, scp);
2292 return;
2293 # endif
2294 # ifdef MACOSX
2295 (*(REAL_SIG_PF)old_handler) (sig, code, scp);
2296 # endif
2297 # ifdef MSWIN32
2298 return((*old_handler)(exc_info));
2299 # endif
2300 }
2301 }
2302 UNPROTECT(h, GC_page_size);
2303 /* We need to make sure that no collection occurs between */
2304 /* the UNPROTECT and the setting of the dirty bit. Otherwise */
2305 /* a write by a third thread might go unnoticed. Reversing */
2306 /* the order is just as bad, since we would end up unprotecting */
2307 /* a page in a GC cycle during which it's not marked. */
2308 /* Currently we do this by disabling the thread stopping */
2309 /* signals while this handler is running. An alternative might */
2310 /* be to record the fact that we're about to unprotect, or */
2311 /* have just unprotected a page in the GC's thread structure, */
2312 /* and then to have the thread stopping code set the dirty */
2313 /* flag, if necessary. */
2314 for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
2315 register int index = PHT_HASH(h+i);
2316
2317 async_set_pht_entry_from_index(GC_dirty_pages, index);
2318 }
2319 # if defined(OSF1)
2320 /* These reset the signal handler each time by default. */
2321 signal(SIGSEGV, (SIG_PF) GC_write_fault_handler);
2322 # endif
2323 /* The write may not take place before dirty bits are read. */
2324 /* But then we'll fault again ... */
2325 # if defined(MSWIN32) || defined(MSWINCE)
2326 return(EXCEPTION_CONTINUE_EXECUTION);
2327 # else
2328 return;
2329 # endif
2330 }
2331 #if defined(MSWIN32) || defined(MSWINCE)
2332 return EXCEPTION_CONTINUE_SEARCH;
2333 #else
2334 GC_err_printf1("Segfault at 0x%lx\n", addr);
2335 ABORT("Unexpected bus error or segmentation fault");
2336 #endif
2337 }
2338
2339 /*
2340 * We hold the allocation lock. We expect block h to be written
2341 * shortly. Ensure that all pages cvontaining any part of the n hblks
2342 * starting at h are no longer protected. If is_ptrfree is false,
2343 * also ensure that they will subsequently appear to be dirty.
2344 */
2345 void GC_remove_protection(h, nblocks, is_ptrfree)
2346 struct hblk *h;
2347 word nblocks;
2348 GC_bool is_ptrfree;
2349 {
2350 struct hblk * h_trunc; /* Truncated to page boundary */
2351 struct hblk * h_end; /* Page boundary following block end */
2352 struct hblk * current;
2353 GC_bool found_clean;
2354
2355 if (!GC_dirty_maintained) return;
2356 h_trunc = (struct hblk *)((word)h & ~(GC_page_size-1));
2357 h_end = (struct hblk *)(((word)(h + nblocks) + GC_page_size-1)
2358 & ~(GC_page_size-1));
2359 found_clean = FALSE;
2360 for (current = h_trunc; current < h_end; ++current) {
2361 int index = PHT_HASH(current);
2362
2363 if (!is_ptrfree || current < h || current >= h + nblocks) {
2364 async_set_pht_entry_from_index(GC_dirty_pages, index);
2365 }
2366 }
2367 UNPROTECT(h_trunc, (ptr_t)h_end - (ptr_t)h_trunc);
2368 }
2369
2370 void GC_dirty_init()
2371 {
2372 # if defined(SUNOS5SIGS) || defined(IRIX5) || defined(LINUX) || \
2373 defined(OSF1) || defined(HURD)
2374 struct sigaction act, oldact;
2375 /* We should probably specify SA_SIGINFO for Linux, and handle */
2376 /* the different architectures more uniformly. */
2377 # if defined(IRIX5) || defined(LINUX) || defined(OSF1) || defined(HURD)
2378 act.sa_flags = SA_RESTART;
2379 act.sa_handler = (SIG_PF)GC_write_fault_handler;
2380 # else
2381 act.sa_flags = SA_RESTART | SA_SIGINFO;
2382 act.sa_sigaction = GC_write_fault_handler;
2383 # endif
2384 (void)sigemptyset(&act.sa_mask);
2385 # ifdef SIG_SUSPEND
2386 /* Arrange to postpone SIG_SUSPEND while we're in a write fault */
2387 /* handler. This effectively makes the handler atomic w.r.t. */
2388 /* stopping the world for GC. */
2389 (void)sigaddset(&act.sa_mask, SIG_SUSPEND);
2390 # endif /* SIG_SUSPEND */
2391 # endif
2392 # if defined(MACOSX)
2393 struct sigaction act, oldact;
2394
2395 act.sa_flags = SA_RESTART;
2396 act.sa_handler = GC_write_fault_handler;
2397 sigemptyset(&act.sa_mask);
2398 # endif
2399 # ifdef PRINTSTATS
2400 GC_printf0("Inititalizing mprotect virtual dirty bit implementation\n");
2401 # endif
2402 GC_dirty_maintained = TRUE;
2403 if (GC_page_size % HBLKSIZE != 0) {
2404 GC_err_printf0("Page size not multiple of HBLKSIZE\n");
2405 ABORT("Page size not multiple of HBLKSIZE");
2406 }
2407 # if defined(SUNOS4) || defined(FREEBSD)
2408 GC_old_bus_handler = signal(SIGBUS, GC_write_fault_handler);
2409 if (GC_old_bus_handler == SIG_IGN) {
2410 GC_err_printf0("Previously ignored bus error!?");
2411 GC_old_bus_handler = SIG_DFL;
2412 }
2413 if (GC_old_bus_handler != SIG_DFL) {
2414 # ifdef PRINTSTATS
2415 GC_err_printf0("Replaced other SIGBUS handler\n");
2416 # endif
2417 }
2418 # endif
2419 # if defined(SUNOS4)
2420 GC_old_segv_handler = signal(SIGSEGV, (SIG_PF)GC_write_fault_handler);
2421 if (GC_old_segv_handler == SIG_IGN) {
2422 GC_err_printf0("Previously ignored segmentation violation!?");
2423 GC_old_segv_handler = SIG_DFL;
2424 }
2425 if (GC_old_segv_handler != SIG_DFL) {
2426 # ifdef PRINTSTATS
2427 GC_err_printf0("Replaced other SIGSEGV handler\n");
2428 # endif
2429 }
2430 # endif
2431 # if defined(SUNOS5SIGS) || defined(IRIX5) || defined(LINUX) \
2432 || defined(OSF1) || defined(HURD)
2433 /* SUNOS5SIGS includes HPUX */
2434 # if defined(GC_IRIX_THREADS)
2435 sigaction(SIGSEGV, 0, &oldact);
2436 sigaction(SIGSEGV, &act, 0);
2437 # else
2438 sigaction(SIGSEGV, &act, &oldact);
2439 # endif
2440 # if defined(_sigargs) || defined(HURD)
2441 /* This is Irix 5.x, not 6.x. Irix 5.x does not have */
2442 /* sa_sigaction. */
2443 GC_old_segv_handler = oldact.sa_handler;
2444 # else /* Irix 6.x or SUNOS5SIGS or LINUX */
2445 if (oldact.sa_flags & SA_SIGINFO) {
2446 GC_old_segv_handler = (SIG_PF)(oldact.sa_sigaction);
2447 } else {
2448 GC_old_segv_handler = oldact.sa_handler;
2449 }
2450 # endif
2451 if (GC_old_segv_handler == SIG_IGN) {
2452 GC_err_printf0("Previously ignored segmentation violation!?");
2453 GC_old_segv_handler = SIG_DFL;
2454 }
2455 if (GC_old_segv_handler != SIG_DFL) {
2456 # ifdef PRINTSTATS
2457 GC_err_printf0("Replaced other SIGSEGV handler\n");
2458 # endif
2459 }
2460 # endif
2461 # if defined(MACOSX) || defined(HPUX) || defined(LINUX) || defined(HURD)
2462 sigaction(SIGBUS, &act, &oldact);
2463 GC_old_bus_handler = oldact.sa_handler;
2464 if (GC_old_bus_handler == SIG_IGN) {
2465 GC_err_printf0("Previously ignored bus error!?");
2466 GC_old_bus_handler = SIG_DFL;
2467 }
2468 if (GC_old_bus_handler != SIG_DFL) {
2469 # ifdef PRINTSTATS
2470 GC_err_printf0("Replaced other SIGBUS handler\n");
2471 # endif
2472 }
2473 # endif /* MACOS || HPUX || LINUX */
2474 # if defined(MSWIN32)
2475 GC_old_segv_handler = SetUnhandledExceptionFilter(GC_write_fault_handler);
2476 if (GC_old_segv_handler != NULL) {
2477 # ifdef PRINTSTATS
2478 GC_err_printf0("Replaced other UnhandledExceptionFilter\n");
2479 # endif
2480 } else {
2481 GC_old_segv_handler = SIG_DFL;
2482 }
2483 # endif
2484 }
2485
2486 int GC_incremental_protection_needs()
2487 {
2488 if (GC_page_size == HBLKSIZE) {
2489 return GC_PROTECTS_POINTER_HEAP;
2490 } else {
2491 return GC_PROTECTS_POINTER_HEAP | GC_PROTECTS_PTRFREE_HEAP;
2492 }
2493 }
2494
2495 #define HAVE_INCREMENTAL_PROTECTION_NEEDS
2496
2497 #define IS_PTRFREE(hhdr) ((hhdr)->hb_descr == 0)
2498
2499 #define PAGE_ALIGNED(x) !((word)(x) & (GC_page_size - 1))
2500 void GC_protect_heap()
2501 {
2502 ptr_t start;
2503 word len;
2504 struct hblk * current;
2505 struct hblk * current_start; /* Start of block to be protected. */
2506 struct hblk * limit;
2507 unsigned i;
2508 GC_bool protect_all =
2509 (0 != (GC_incremental_protection_needs() & GC_PROTECTS_PTRFREE_HEAP));
2510 for (i = 0; i < GC_n_heap_sects; i++) {
2511 start = GC_heap_sects[i].hs_start;
2512 len = GC_heap_sects[i].hs_bytes;
2513 if (protect_all) {
2514 PROTECT(start, len);
2515 } else {
2516 GC_ASSERT(PAGE_ALIGNED(len))
2517 GC_ASSERT(PAGE_ALIGNED(start))
2518 current_start = current = (struct hblk *)start;
2519 limit = (struct hblk *)(start + len);
2520 while (current < limit) {
2521 hdr * hhdr;
2522 word nhblks;
2523 GC_bool is_ptrfree;
2524
2525 GC_ASSERT(PAGE_ALIGNED(current));
2526 GET_HDR(current, hhdr);
2527 if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
2528 /* This can happen only if we're at the beginning of a */
2529 /* heap segment, and a block spans heap segments. */
2530 /* We will handle that block as part of the preceding */
2531 /* segment. */
2532 GC_ASSERT(current_start == current);
2533 current_start = ++current;
2534 continue;
2535 }
2536 if (HBLK_IS_FREE(hhdr)) {
2537 GC_ASSERT(PAGE_ALIGNED(hhdr -> hb_sz));
2538 nhblks = divHBLKSZ(hhdr -> hb_sz);
2539 is_ptrfree = TRUE; /* dirty on alloc */
2540 } else {
2541 nhblks = OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz);
2542 is_ptrfree = IS_PTRFREE(hhdr);
2543 }
2544 if (is_ptrfree) {
2545 if (current_start < current) {
2546 PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
2547 }
2548 current_start = (current += nhblks);
2549 } else {
2550 current += nhblks;
2551 }
2552 }
2553 if (current_start < current) {
2554 PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
2555 }
2556 }
2557 }
2558 }
2559
2560 /* We assume that either the world is stopped or its OK to lose dirty */
2561 /* bits while this is happenning (as in GC_enable_incremental). */
2562 void GC_read_dirty()
2563 {
2564 BCOPY((word *)GC_dirty_pages, GC_grungy_pages,
2565 (sizeof GC_dirty_pages));
2566 BZERO((word *)GC_dirty_pages, (sizeof GC_dirty_pages));
2567 GC_protect_heap();
2568 }
2569
2570 GC_bool GC_page_was_dirty(h)
2571 struct hblk * h;
2572 {
2573 register word index = PHT_HASH(h);
2574
2575 return(HDR(h) == 0 || get_pht_entry_from_index(GC_grungy_pages, index));
2576 }
2577
2578 /*
2579 * Acquiring the allocation lock here is dangerous, since this
2580 * can be called from within GC_call_with_alloc_lock, and the cord
2581 * package does so. On systems that allow nested lock acquisition, this
2582 * happens to work.
2583 * On other systems, SET_LOCK_HOLDER and friends must be suitably defined.
2584 */
2585
2586 static GC_bool syscall_acquired_lock = FALSE; /* Protected by GC lock. */
2587
2588 void GC_begin_syscall()
2589 {
2590 if (!I_HOLD_LOCK()) {
2591 LOCK();
2592 syscall_acquired_lock = TRUE;
2593 }
2594 }
2595
2596 void GC_end_syscall()
2597 {
2598 if (syscall_acquired_lock) {
2599 syscall_acquired_lock = FALSE;
2600 UNLOCK();
2601 }
2602 }
2603
2604 void GC_unprotect_range(addr, len)
2605 ptr_t addr;
2606 word len;
2607 {
2608 struct hblk * start_block;
2609 struct hblk * end_block;
2610 register struct hblk *h;
2611 ptr_t obj_start;
2612
2613 if (!GC_dirty_maintained) return;
2614 obj_start = GC_base(addr);
2615 if (obj_start == 0) return;
2616 if (GC_base(addr + len - 1) != obj_start) {
2617 ABORT("GC_unprotect_range(range bigger than object)");
2618 }
2619 start_block = (struct hblk *)((word)addr & ~(GC_page_size - 1));
2620 end_block = (struct hblk *)((word)(addr + len - 1) & ~(GC_page_size - 1));
2621 end_block += GC_page_size/HBLKSIZE - 1;
2622 for (h = start_block; h <= end_block; h++) {
2623 register word index = PHT_HASH(h);
2624
2625 async_set_pht_entry_from_index(GC_dirty_pages, index);
2626 }
2627 UNPROTECT(start_block,
2628 ((ptr_t)end_block - (ptr_t)start_block) + HBLKSIZE);
2629 }
2630
2631 #if !defined(MSWIN32) && !defined(MSWINCE) && !defined(THREADS) \
2632 && !defined(GC_USE_LD_WRAP)
2633 /* Replacement for UNIX system call. */
2634 /* Other calls that write to the heap should be handled similarly. */
2635 /* Note that this doesn't work well for blocking reads: It will hold */
2636 /* tha allocation lock for the entur duration of the call. Multithreaded */
2637 /* clients should really ensure that it won't block, either by setting */
2638 /* the descriptor nonblocking, or by calling select or poll first, to */
2639 /* make sure that input is available. */
2640 # if defined(__STDC__) && !defined(SUNOS4)
2641 # include <unistd.h>
2642 # include <sys/uio.h>
2643 ssize_t read(int fd, void *buf, size_t nbyte)
2644 # else
2645 # ifndef LINT
2646 int read(fd, buf, nbyte)
2647 # else
2648 int GC_read(fd, buf, nbyte)
2649 # endif
2650 int fd;
2651 char *buf;
2652 int nbyte;
2653 # endif
2654 {
2655 int result;
2656
2657 GC_begin_syscall();
2658 GC_unprotect_range(buf, (word)nbyte);
2659 # if defined(IRIX5) || defined(GC_LINUX_THREADS)
2660 /* Indirect system call may not always be easily available. */
2661 /* We could call _read, but that would interfere with the */
2662 /* libpthread interception of read. */
2663 /* On Linux, we have to be careful with the linuxthreads */
2664 /* read interception. */
2665 {
2666 struct iovec iov;
2667
2668 iov.iov_base = buf;
2669 iov.iov_len = nbyte;
2670 result = readv(fd, &iov, 1);
2671 }
2672 # else
2673 # if defined(HURD)
2674 result = __read(fd, buf, nbyte);
2675 # else
2676 /* The two zero args at the end of this list are because one
2677 IA-64 syscall() implementation actually requires six args
2678 to be passed, even though they aren't always used. */
2679 result = syscall(SYS_read, fd, buf, nbyte, 0, 0);
2680 # endif /* !HURD */
2681 # endif
2682 GC_end_syscall();
2683 return(result);
2684 }
2685 #endif /* !MSWIN32 && !MSWINCE && !GC_LINUX_THREADS */
2686
2687 #if defined(GC_USE_LD_WRAP) && !defined(THREADS)
2688 /* We use the GNU ld call wrapping facility. */
2689 /* This requires that the linker be invoked with "--wrap read". */
2690 /* This can be done by passing -Wl,"--wrap read" to gcc. */
2691 /* I'm not sure that this actually wraps whatever version of read */
2692 /* is called by stdio. That code also mentions __read. */
2693 # include <unistd.h>
2694 ssize_t __wrap_read(int fd, void *buf, size_t nbyte)
2695 {
2696 int result;
2697
2698 GC_begin_syscall();
2699 GC_unprotect_range(buf, (word)nbyte);
2700 result = __real_read(fd, buf, nbyte);
2701 GC_end_syscall();
2702 return(result);
2703 }
2704
2705 /* We should probably also do this for __read, or whatever stdio */
2706 /* actually calls. */
2707 #endif
2708
2709 /*ARGSUSED*/
2710 GC_bool GC_page_was_ever_dirty(h)
2711 struct hblk *h;
2712 {
2713 return(TRUE);
2714 }
2715
2716 /* Reset the n pages starting at h to "was never dirty" status. */
2717 /*ARGSUSED*/
2718 void GC_is_fresh(h, n)
2719 struct hblk *h;
2720 word n;
2721 {
2722 }
2723
2724 # else /* !MPROTECT_VDB */
2725
2726 # ifdef GC_USE_LD_WRAP
2727 ssize_t __wrap_read(int fd, void *buf, size_t nbyte)
2728 { return __real_read(fd, buf, nbyte); }
2729 # endif
2730
2731 # endif /* MPROTECT_VDB */
2732
2733 # ifdef PROC_VDB
2734
2735 /*
2736 * See DEFAULT_VDB for interface descriptions.
2737 */
2738
2739 /*
2740 * This implementaion assumes a Solaris 2.X like /proc pseudo-file-system
2741 * from which we can read page modified bits. This facility is far from
2742 * optimal (e.g. we would like to get the info for only some of the
2743 * address space), but it avoids intercepting system calls.
2744 */
2745
2746 #include <errno.h>
2747 #include <sys/types.h>
2748 #include <sys/signal.h>
2749 #include <sys/fault.h>
2750 #include <sys/syscall.h>
2751 #include <sys/procfs.h>
2752 #include <sys/stat.h>
2753
2754 #define INITIAL_BUF_SZ 4096
2755 word GC_proc_buf_size = INITIAL_BUF_SZ;
2756 char *GC_proc_buf;
2757
2758 #ifdef GC_SOLARIS_THREADS
2759 /* We don't have exact sp values for threads. So we count on */
2760 /* occasionally declaring stack pages to be fresh. Thus we */
2761 /* need a real implementation of GC_is_fresh. We can't clear */
2762 /* entries in GC_written_pages, since that would declare all */
2763 /* pages with the given hash address to be fresh. */
2764 # define MAX_FRESH_PAGES 8*1024 /* Must be power of 2 */
2765 struct hblk ** GC_fresh_pages; /* A direct mapped cache. */
2766 /* Collisions are dropped. */
2767
2768 # define FRESH_PAGE_SLOT(h) (divHBLKSZ((word)(h)) & (MAX_FRESH_PAGES-1))
2769 # define ADD_FRESH_PAGE(h) \
2770 GC_fresh_pages[FRESH_PAGE_SLOT(h)] = (h)
2771 # define PAGE_IS_FRESH(h) \
2772 (GC_fresh_pages[FRESH_PAGE_SLOT(h)] == (h) && (h) != 0)
2773 #endif
2774
2775 /* Add all pages in pht2 to pht1 */
2776 void GC_or_pages(pht1, pht2)
2777 page_hash_table pht1, pht2;
2778 {
2779 register int i;
2780
2781 for (i = 0; i < PHT_SIZE; i++) pht1[i] |= pht2[i];
2782 }
2783
2784 int GC_proc_fd;
2785
2786 void GC_dirty_init()
2787 {
2788 int fd;
2789 char buf[30];
2790
2791 GC_dirty_maintained = TRUE;
2792 if (GC_words_allocd != 0 || GC_words_allocd_before_gc != 0) {
2793 register int i;
2794
2795 for (i = 0; i < PHT_SIZE; i++) GC_written_pages[i] = (word)(-1);
2796 # ifdef PRINTSTATS
2797 GC_printf1("Allocated words:%lu:all pages may have been written\n",
2798 (unsigned long)
2799 (GC_words_allocd + GC_words_allocd_before_gc));
2800 # endif
2801 }
2802 sprintf(buf, "/proc/%d", getpid());
2803 fd = open(buf, O_RDONLY);
2804 if (fd < 0) {
2805 ABORT("/proc open failed");
2806 }
2807 GC_proc_fd = syscall(SYS_ioctl, fd, PIOCOPENPD, 0);
2808 close(fd);
2809 if (GC_proc_fd < 0) {
2810 ABORT("/proc ioctl failed");
2811 }
2812 GC_proc_buf = GC_scratch_alloc(GC_proc_buf_size);
2813 # ifdef GC_SOLARIS_THREADS
2814 GC_fresh_pages = (struct hblk **)
2815 GC_scratch_alloc(MAX_FRESH_PAGES * sizeof (struct hblk *));
2816 if (GC_fresh_pages == 0) {
2817 GC_err_printf0("No space for fresh pages\n");
2818 EXIT();
2819 }
2820 BZERO(GC_fresh_pages, MAX_FRESH_PAGES * sizeof (struct hblk *));
2821 # endif
2822 }
2823
2824 /* Ignore write hints. They don't help us here. */
2825 /*ARGSUSED*/
2826 void GC_remove_protection(h, nblocks, is_ptrfree)
2827 struct hblk *h;
2828 word nblocks;
2829 GC_bool is_ptrfree;
2830 {
2831 }
2832
2833 #ifdef GC_SOLARIS_THREADS
2834 # define READ(fd,buf,nbytes) syscall(SYS_read, fd, buf, nbytes)
2835 #else
2836 # define READ(fd,buf,nbytes) read(fd, buf, nbytes)
2837 #endif
2838
2839 void GC_read_dirty()
2840 {
2841 unsigned long ps, np;
2842 int nmaps;
2843 ptr_t vaddr;
2844 struct prasmap * map;
2845 char * bufp;
2846 ptr_t current_addr, limit;
2847 int i;
2848 int dummy;
2849
2850 BZERO(GC_grungy_pages, (sizeof GC_grungy_pages));
2851
2852 bufp = GC_proc_buf;
2853 if (READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
2854 # ifdef PRINTSTATS
2855 GC_printf1("/proc read failed: GC_proc_buf_size = %lu\n",
2856 GC_proc_buf_size);
2857 # endif
2858 {
2859 /* Retry with larger buffer. */
2860 word new_size = 2 * GC_proc_buf_size;
2861 char * new_buf = GC_scratch_alloc(new_size);
2862
2863 if (new_buf != 0) {
2864 GC_proc_buf = bufp = new_buf;
2865 GC_proc_buf_size = new_size;
2866 }
2867 if (syscall(SYS_read, GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
2868 WARN("Insufficient space for /proc read\n", 0);
2869 /* Punt: */
2870 memset(GC_grungy_pages, 0xff, sizeof (page_hash_table));
2871 memset(GC_written_pages, 0xff, sizeof(page_hash_table));
2872 # ifdef GC_SOLARIS_THREADS
2873 BZERO(GC_fresh_pages,
2874 MAX_FRESH_PAGES * sizeof (struct hblk *));
2875 # endif
2876 return;
2877 }
2878 }
2879 }
2880 /* Copy dirty bits into GC_grungy_pages */
2881 nmaps = ((struct prpageheader *)bufp) -> pr_nmap;
2882 /* printf( "nmaps = %d, PG_REFERENCED = %d, PG_MODIFIED = %d\n",
2883 nmaps, PG_REFERENCED, PG_MODIFIED); */
2884 bufp = bufp + sizeof(struct prpageheader);
2885 for (i = 0; i < nmaps; i++) {
2886 map = (struct prasmap *)bufp;
2887 vaddr = (ptr_t)(map -> pr_vaddr);
2888 ps = map -> pr_pagesize;
2889 np = map -> pr_npage;
2890 /* printf("vaddr = 0x%X, ps = 0x%X, np = 0x%X\n", vaddr, ps, np); */
2891 limit = vaddr + ps * np;
2892 bufp += sizeof (struct prasmap);
2893 for (current_addr = vaddr;
2894 current_addr < limit; current_addr += ps){
2895 if ((*bufp++) & PG_MODIFIED) {
2896 register struct hblk * h = (struct hblk *) current_addr;
2897
2898 while ((ptr_t)h < current_addr + ps) {
2899 register word index = PHT_HASH(h);
2900
2901 set_pht_entry_from_index(GC_grungy_pages, index);
2902 # ifdef GC_SOLARIS_THREADS
2903 {
2904 register int slot = FRESH_PAGE_SLOT(h);
2905
2906 if (GC_fresh_pages[slot] == h) {
2907 GC_fresh_pages[slot] = 0;
2908 }
2909 }
2910 # endif
2911 h++;
2912 }
2913 }
2914 }
2915 bufp += sizeof(long) - 1;
2916 bufp = (char *)((unsigned long)bufp & ~(sizeof(long)-1));
2917 }
2918 /* Update GC_written_pages. */
2919 GC_or_pages(GC_written_pages, GC_grungy_pages);
2920 # ifdef GC_SOLARIS_THREADS
2921 /* Make sure that old stacks are considered completely clean */
2922 /* unless written again. */
2923 GC_old_stacks_are_fresh();
2924 # endif
2925 }
2926
2927 #undef READ
2928
2929 GC_bool GC_page_was_dirty(h)
2930 struct hblk *h;
2931 {
2932 register word index = PHT_HASH(h);
2933 register GC_bool result;
2934
2935 result = get_pht_entry_from_index(GC_grungy_pages, index);
2936 # ifdef GC_SOLARIS_THREADS
2937 if (result && PAGE_IS_FRESH(h)) result = FALSE;
2938 /* This happens only if page was declared fresh since */
2939 /* the read_dirty call, e.g. because it's in an unused */
2940 /* thread stack. It's OK to treat it as clean, in */
2941 /* that case. And it's consistent with */
2942 /* GC_page_was_ever_dirty. */
2943 # endif
2944 return(result);
2945 }
2946
2947 GC_bool GC_page_was_ever_dirty(h)
2948 struct hblk *h;
2949 {
2950 register word index = PHT_HASH(h);
2951 register GC_bool result;
2952
2953 result = get_pht_entry_from_index(GC_written_pages, index);
2954 # ifdef GC_SOLARIS_THREADS
2955 if (result && PAGE_IS_FRESH(h)) result = FALSE;
2956 # endif
2957 return(result);
2958 }
2959
2960 /* Caller holds allocation lock. */
2961 void GC_is_fresh(h, n)
2962 struct hblk *h;
2963 word n;
2964 {
2965
2966 register word index;
2967
2968 # ifdef GC_SOLARIS_THREADS
2969 register word i;
2970
2971 if (GC_fresh_pages != 0) {
2972 for (i = 0; i < n; i++) {
2973 ADD_FRESH_PAGE(h + i);
2974 }
2975 }
2976 # endif
2977 }
2978
2979 # endif /* PROC_VDB */
2980
2981
2982 # ifdef PCR_VDB
2983
2984 # include "vd/PCR_VD.h"
2985
2986 # define NPAGES (32*1024) /* 128 MB */
2987
2988 PCR_VD_DB GC_grungy_bits[NPAGES];
2989
2990 ptr_t GC_vd_base; /* Address corresponding to GC_grungy_bits[0] */
2991 /* HBLKSIZE aligned. */
2992
2993 void GC_dirty_init()
2994 {
2995 GC_dirty_maintained = TRUE;
2996 /* For the time being, we assume the heap generally grows up */
2997 GC_vd_base = GC_heap_sects[0].hs_start;
2998 if (GC_vd_base == 0) {
2999 ABORT("Bad initial heap segment");
3000 }
3001 if (PCR_VD_Start(HBLKSIZE, GC_vd_base, NPAGES*HBLKSIZE)
3002 != PCR_ERes_okay) {
3003 ABORT("dirty bit initialization failed");
3004 }
3005 }
3006
3007 void GC_read_dirty()
3008 {
3009 /* lazily enable dirty bits on newly added heap sects */
3010 {
3011 static int onhs = 0;
3012 int nhs = GC_n_heap_sects;
3013 for( ; onhs < nhs; onhs++ ) {
3014 PCR_VD_WriteProtectEnable(
3015 GC_heap_sects[onhs].hs_start,
3016 GC_heap_sects[onhs].hs_bytes );
3017 }
3018 }
3019
3020
3021 if (PCR_VD_Clear(GC_vd_base, NPAGES*HBLKSIZE, GC_grungy_bits)
3022 != PCR_ERes_okay) {
3023 ABORT("dirty bit read failed");
3024 }
3025 }
3026
3027 GC_bool GC_page_was_dirty(h)
3028 struct hblk *h;
3029 {
3030 if((ptr_t)h < GC_vd_base || (ptr_t)h >= GC_vd_base + NPAGES*HBLKSIZE) {
3031 return(TRUE);
3032 }
3033 return(GC_grungy_bits[h - (struct hblk *)GC_vd_base] & PCR_VD_DB_dirtyBit);
3034 }
3035
3036 /*ARGSUSED*/
3037 void GC_remove_protection(h, nblocks, is_ptrfree)
3038 struct hblk *h;
3039 word nblocks;
3040 GC_bool is_ptrfree;
3041 {
3042 PCR_VD_WriteProtectDisable(h, nblocks*HBLKSIZE);
3043 PCR_VD_WriteProtectEnable(h, nblocks*HBLKSIZE);
3044 }
3045
3046 # endif /* PCR_VDB */
3047
3048 # ifndef HAVE_INCREMENTAL_PROTECTION_NEEDS
3049 int GC_incremental_protection_needs()
3050 {
3051 return GC_PROTECTS_NONE;
3052 }
3053 # endif /* !HAVE_INCREMENTAL_PROTECTION_NEEDS */
3054
3055 /*
3056 * Call stack save code for debugging.
3057 * Should probably be in mach_dep.c, but that requires reorganization.
3058 */
3059
3060 /* I suspect the following works for most X86 *nix variants, so */
3061 /* long as the frame pointer is explicitly stored. In the case of gcc, */
3062 /* compiler flags (e.g. -fomit-frame-pointer) determine whether it is. */
3063 #if defined(I386) && defined(LINUX) && defined(SAVE_CALL_CHAIN)
3064 # include <features.h>
3065
3066 struct frame {
3067 struct frame *fr_savfp;
3068 long fr_savpc;
3069 long fr_arg[NARGS]; /* All the arguments go here. */
3070 };
3071 #endif
3072
3073 #if defined(SPARC)
3074 # if defined(LINUX)
3075 # include <features.h>
3076
3077 struct frame {
3078 long fr_local[8];
3079 long fr_arg[6];
3080 struct frame *fr_savfp;
3081 long fr_savpc;
3082 # ifndef __arch64__
3083 char *fr_stret;
3084 # endif
3085 long fr_argd[6];
3086 long fr_argx[0];
3087 };
3088 # else
3089 # if defined(SUNOS4)
3090 # include <machine/frame.h>
3091 # else
3092 # if defined (DRSNX)
3093 # include <sys/sparc/frame.h>
3094 # else
3095 # if defined(OPENBSD) || defined(NETBSD)
3096 # include <frame.h>
3097 # else
3098 # include <sys/frame.h>
3099 # endif
3100 # endif
3101 # endif
3102 # endif
3103 # if NARGS > 6
3104 --> We only know how to to get the first 6 arguments
3105 # endif
3106 #endif /* SPARC */
3107
3108 #ifdef SAVE_CALL_CHAIN
3109 /* Fill in the pc and argument information for up to NFRAMES of my */
3110 /* callers. Ignore my frame and my callers frame. */
3111
3112 #ifdef LINUX
3113 # include <features.h>
3114 # if __GLIBC__ == 2 && __GLIBC_MINOR__ >= 1 || __GLIBC__ > 2
3115 # define HAVE_BUILTIN_BACKTRACE
3116 # endif
3117 #endif
3118
3119 #if NARGS == 0 && NFRAMES % 2 == 0 /* No padding */ \
3120 && defined(HAVE_BUILTIN_BACKTRACE)
3121
3122 #include <execinfo.h>
3123
3124 void GC_save_callers (info)
3125 struct callinfo info[NFRAMES];
3126 {
3127 void * tmp_info[NFRAMES + 1];
3128 int npcs, i;
3129 # define IGNORE_FRAMES 1
3130
3131 /* We retrieve NFRAMES+1 pc values, but discard the first, since it */
3132 /* points to our own frame. */
3133 GC_ASSERT(sizeof(struct callinfo) == sizeof(void *));
3134 npcs = backtrace((void **)tmp_info, NFRAMES + IGNORE_FRAMES);
3135 BCOPY(tmp_info+IGNORE_FRAMES, info, (npcs - IGNORE_FRAMES) * sizeof(void *));
3136 for (i = npcs - IGNORE_FRAMES; i < NFRAMES; ++i) info[i].ci_pc = 0;
3137 }
3138
3139 #else /* No builtin backtrace; do it ourselves */
3140
3141 #if (defined(OPENBSD) || defined(NETBSD)) && defined(SPARC)
3142 # define FR_SAVFP fr_fp
3143 # define FR_SAVPC fr_pc
3144 #else
3145 # define FR_SAVFP fr_savfp
3146 # define FR_SAVPC fr_savpc
3147 #endif
3148
3149 #if defined(SPARC) && (defined(__arch64__) || defined(__sparcv9))
3150 # define BIAS 2047
3151 #else
3152 # define BIAS 0
3153 #endif
3154
3155 void GC_save_callers (info)
3156 struct callinfo info[NFRAMES];
3157 {
3158 struct frame *frame;
3159 struct frame *fp;
3160 int nframes = 0;
3161 # ifdef I386
3162 /* We assume this is turned on only with gcc as the compiler. */
3163 asm("movl %%ebp,%0" : "=r"(frame));
3164 fp = frame;
3165 # else
3166 word GC_save_regs_in_stack();
3167
3168 frame = (struct frame *) GC_save_regs_in_stack ();
3169 fp = (struct frame *)((long) frame -> FR_SAVFP + BIAS);
3170 #endif
3171
3172 for (; (!(fp HOTTER_THAN frame) && !(GC_stackbottom HOTTER_THAN (ptr_t)fp)
3173 && (nframes < NFRAMES));
3174 fp = (struct frame *)((long) fp -> FR_SAVFP + BIAS), nframes++) {
3175 register int i;
3176
3177 info[nframes].ci_pc = fp->FR_SAVPC;
3178 # if NARGS > 0
3179 for (i = 0; i < NARGS; i++) {
3180 info[nframes].ci_arg[i] = ~(fp->fr_arg[i]);
3181 }
3182 # endif /* NARGS > 0 */
3183 }
3184 if (nframes < NFRAMES) info[nframes].ci_pc = 0;
3185 }
3186
3187 #endif /* No builtin backtrace */
3188
3189 #endif /* SAVE_CALL_CHAIN */
3190
3191 #if defined(LINUX) && defined(__ELF__) && \
3192 (!defined(SMALL_CONFIG) || defined(USE_PROC_FOR_LIBRARIES))
3193 #ifdef GC_USE_LD_WRAP
3194 # define READ __real_read
3195 #else
3196 # define READ read
3197 #endif
3198
3199
3200 /* Repeatedly perform a read call until the buffer is filled or */
3201 /* we encounter EOF. */
3202 ssize_t GC_repeat_read(int fd, char *buf, size_t count)
3203 {
3204 ssize_t num_read = 0;
3205 ssize_t result;
3206
3207 while (num_read < count) {
3208 result = READ(fd, buf + num_read, count - num_read);
3209 if (result < 0) return result;
3210 if (result == 0) break;
3211 num_read += result;
3212 }
3213 return num_read;
3214 }
3215 #endif /* LINUX && ... */
3216
3217
3218 #if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG)
3219
3220 /* Dump /proc/self/maps to GC_stderr, to enable looking up names for
3221 addresses in FIND_LEAK output. */
3222
3223 void GC_print_address_map()
3224 {
3225 int f;
3226 int result;
3227 char maps_temp[32768];
3228 GC_err_printf0("---------- Begin address map ----------\n");
3229 f = open("/proc/self/maps", O_RDONLY);
3230 if (-1 == f) ABORT("Couldn't open /proc/self/maps");
3231 do {
3232 result = GC_repeat_read(f, maps_temp, sizeof(maps_temp));
3233 if (result <= 0) ABORT("Couldn't read /proc/self/maps");
3234 GC_err_write(maps_temp, result);
3235 } while (result == sizeof(maps_temp));
3236
3237 GC_err_printf0("---------- End address map ----------\n");
3238 }
3239
3240 #endif
3241
3242
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