boehm-gc/dyn_load.c

   1 /*
   2  * Copyright (c) 1991-1994 by Xerox Corporation.  All rights reserved.
   3  * Copyright (c) 1997 by Silicon Graphics.  All rights reserved.
   4  *
   5  * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
   6  * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
   7  *
   8  * Permission is hereby granted to use or copy this program
   9  * for any purpose,  provided the above notices are retained on all copies.
  10  * Permission to modify the code and to distribute modified code is granted,
  11  * provided the above notices are retained, and a notice that the code was
  12  * modified is included with the above copyright notice.
  13  *
  14  * Original author: Bill Janssen
  15  * Heavily modified by Hans Boehm and others
  16  */
  17
  18 /*
  19  * This is incredibly OS specific code for tracking down data sections in
  20  * dynamic libraries.  There appears to be no way of doing this quickly
  21  * without groveling through undocumented data structures.  We would argue
  22  * that this is a bug in the design of the dlopen interface.  THIS CODE
  23  * MAY BREAK IN FUTURE OS RELEASES.  If this matters to you, don't hesitate
  24  * to let your vendor know ...
  25  *
  26  * None of this is safe with dlclose and incremental collection.
  27  * But then not much of anything is safe in the presence of dlclose.
  28  */
  29 #if defined(__linux__) && !defined(_GNU_SOURCE)
  30     /* Can't test LINUX, since this must be define before other includes */
  31 #   define _GNU_SOURCE
  32 #endif
  33 #if !defined(MACOS) && !defined(_WIN32_WCE)
  34 #  include <sys/types.h>
  35 #endif
  36 #include "private/gc_priv.h"
  37
  38 /* BTL: avoid circular redefinition of dlopen if GC_SOLARIS_THREADS defined */
  39 # if (defined(GC_PTHREADS) || defined(GC_SOLARIS_THREADS)) \
  40       && defined(dlopen) && !defined(GC_USE_LD_WRAP)
  41     /* To support threads in Solaris, gc.h interposes on dlopen by       */
  42     /* defining "dlopen" to be "GC_dlopen", which is implemented below.  */
  43     /* However, both GC_FirstDLOpenedLinkMap() and GC_dlopen() use the   */
  44     /* real system dlopen() in their implementation. We first remove     */
  45     /* gc.h's dlopen definition and restore it later, after GC_dlopen(). */
  46 #   undef dlopen
  47 #   define GC_must_restore_redefined_dlopen
  48 # else
  49 #   undef GC_must_restore_redefined_dlopen
  50 # endif
  51
  52 #if (defined(DYNAMIC_LOADING) || defined(MSWIN32) || defined(MSWINCE)) \
  53     && !defined(PCR)
  54 #if !defined(SUNOS4) && !defined(SUNOS5DL) && !defined(IRIX5) && \
  55     !defined(MSWIN32) && !defined(MSWINCE) && \
  56     !(defined(ALPHA) && defined(OSF1)) && \
  57     !defined(HPUX) && !(defined(LINUX) && defined(__ELF__)) && \
  58     !defined(RS6000) && !defined(SCO_ELF) && \
  59     !(defined(FREEBSD) && defined(__ELF__)) && \
  60     !(defined(NETBSD) && defined(__ELF__)) && !defined(HURD)
  61  --> We only know how to find data segments of dynamic libraries for the
  62  --> above.  Additional SVR4 variants might not be too
  63  --> hard to add.
  64 #endif
  65
  66 #include <stdio.h>
  67 #ifdef SUNOS5DL
  68 #   include <sys/elf.h>
  69 #   include <dlfcn.h>
  70 #   include <link.h>
  71 #endif
  72 #ifdef SUNOS4
  73 #   include <dlfcn.h>
  74 #   include <link.h>
  75 #   include <a.out.h>
  76   /* struct link_map field overrides */
  77 #   define l_next       lm_next
  78 #   define l_addr       lm_addr
  79 #   define l_name       lm_name
  80 #endif
  81
  82 #if defined(LINUX) && defined(__ELF__) || defined(SCO_ELF) || \
  83     (defined(FREEBSD) && defined(__ELF__)) || \
  84     (defined(NETBSD) && defined(__ELF__)) || defined(HURD)
  85 #   include <stddef.h>
  86 #   include <elf.h>
  87 #   include <link.h>
  88 #endif
  89
  90 /* Newer versions of GNU/Linux define this macro.  We
  91  * define it similarly for any ELF systems that don't.  */
  92 #  ifndef ElfW
  93 #    if !defined(ELF_CLASS) || ELF_CLASS == ELFCLASS32
  94 #      define ElfW(type) Elf32_##type
  95 #    else
  96 #      define ElfW(type) Elf64_##type
  97 #    endif
  98 #  endif
  99
 100 #if defined(SUNOS5DL) && !defined(USE_PROC_FOR_LIBRARIES)
 101
 102 #ifdef LINT
 103     Elf32_Dyn _DYNAMIC;
 104 #endif
 105
 106 static struct link_map *
 107 GC_FirstDLOpenedLinkMap()
 108 {
 109     extern ElfW(Dyn) _DYNAMIC;
 110     ElfW(Dyn) *dp;
 111     struct r_debug *r;
 112     static struct link_map * cachedResult = 0;
 113     static ElfW(Dyn) *dynStructureAddr = 0;
 114                         /* BTL: added to avoid Solaris 5.3 ld.so _DYNAMIC bug */
 115
 116 #   ifdef SUNOS53_SHARED_LIB
 117         /* BTL: Avoid the Solaris 5.3 bug that _DYNAMIC isn't being set */
 118         /* up properly in dynamically linked .so's. This means we have  */
 119         /* to use its value in the set of original object files loaded  */
 120         /* at program startup.                                          */
 121         if( dynStructureAddr == 0 ) {
 122           void* startupSyms = dlopen(0, RTLD_LAZY);
 123           dynStructureAddr = (ElfW(Dyn)*)dlsym(startupSyms, "_DYNAMIC");
 124                 }
 125 #   else
 126         dynStructureAddr = &_DYNAMIC;
 127 #   endif
 128
 129     if( dynStructureAddr == 0) {
 130         return(0);
 131     }
 132     if( cachedResult == 0 ) {
 133         int tag;
 134         for( dp = ((ElfW(Dyn) *)(&_DYNAMIC)); (tag = dp->d_tag) != 0; dp++ ) {
 135             if( tag == DT_DEBUG ) {
 136                 struct link_map *lm
 137                         = ((struct r_debug *)(dp->d_un.d_ptr))->r_map;
 138                 if( lm != 0 ) cachedResult = lm->l_next; /* might be NIL */
 139                 break;
 140             }
 141         }
 142     }
 143     return cachedResult;
 144 }
 145
 146 #endif /* SUNOS5DL ... */
 147
 148 /* BTL: added to fix circular dlopen definition if GC_SOLARIS_THREADS defined */
 149 # if defined(GC_must_restore_redefined_dlopen)
 150 #   define dlopen GC_dlopen
 151 # endif
 152
 153 #if defined(SUNOS4) && !defined(USE_PROC_FOR_LIBRARIES)
 154
 155 #ifdef LINT
 156     struct link_dynamic _DYNAMIC;
 157 #endif
 158
 159 static struct link_map *
 160 GC_FirstDLOpenedLinkMap()
 161 {
 162     extern struct link_dynamic _DYNAMIC;
 163
 164     if( &_DYNAMIC == 0) {
 165         return(0);
 166     }
 167     return(_DYNAMIC.ld_un.ld_1->ld_loaded);
 168 }
 169
 170 /* Return the address of the ld.so allocated common symbol      */
 171 /* with the least address, or 0 if none.                        */
 172 static ptr_t GC_first_common()
 173 {
 174     ptr_t result = 0;
 175     extern struct link_dynamic _DYNAMIC;
 176     struct rtc_symb * curr_symbol;
 177
 178     if( &_DYNAMIC == 0) {
 179         return(0);
 180     }
 181     curr_symbol = _DYNAMIC.ldd -> ldd_cp;
 182     for (; curr_symbol != 0; curr_symbol = curr_symbol -> rtc_next) {
 183         if (result == 0
 184             || (ptr_t)(curr_symbol -> rtc_sp -> n_value) < result) {
 185             result = (ptr_t)(curr_symbol -> rtc_sp -> n_value);
 186         }
 187     }
 188     return(result);
 189 }
 190
 191 #endif  /* SUNOS4 ... */
 192
 193 # if defined(SUNOS4) || defined(SUNOS5DL)
 194 /* Add dynamic library data sections to the root set.           */
 195 # if !defined(PCR) && !defined(GC_SOLARIS_THREADS) && defined(THREADS)
 196 #   ifndef SRC_M3
 197         --> fix mutual exclusion with dlopen
 198 #   endif  /* We assume M3 programs don't call dlopen for now */
 199 # endif
 200
 201 # ifndef USE_PROC_FOR_LIBRARIES
 202 void GC_register_dynamic_libraries()
 203 {
 204   struct link_map *lm = GC_FirstDLOpenedLinkMap();
 205
 206
 207   for (lm = GC_FirstDLOpenedLinkMap();
 208        lm != (struct link_map *) 0;  lm = lm->l_next)
 209     {
 210 #     ifdef SUNOS4
 211         struct exec *e;
 212
 213         e = (struct exec *) lm->lm_addr;
 214         GC_add_roots_inner(
 215                     ((char *) (N_DATOFF(*e) + lm->lm_addr)),
 216                     ((char *) (N_BSSADDR(*e) + e->a_bss + lm->lm_addr)),
 217                     TRUE);
 218 #     endif
 219 #     ifdef SUNOS5DL
 220         ElfW(Ehdr) * e;
 221         ElfW(Phdr) * p;
 222         unsigned long offset;
 223         char * start;
 224         register int i;
 225
 226         e = (ElfW(Ehdr) *) lm->l_addr;
 227         p = ((ElfW(Phdr) *)(((char *)(e)) + e->e_phoff));
 228         offset = ((unsigned long)(lm->l_addr));
 229         for( i = 0; i < (int)(e->e_phnum); ((i++),(p++)) ) {
 230           switch( p->p_type ) {
 231             case PT_LOAD:
 232               {
 233                 if( !(p->p_flags & PF_W) ) break;
 234                 start = ((char *)(p->p_vaddr)) + offset;
 235                 GC_add_roots_inner(
 236                   start,
 237                   start + p->p_memsz,
 238                   TRUE
 239                 );
 240               }
 241               break;
 242             default:
 243               break;
 244           }
 245         }
 246 #     endif
 247     }
 248 #   ifdef SUNOS4
 249       {
 250         static ptr_t common_start = 0;
 251         ptr_t common_end;
 252         extern ptr_t GC_find_limit();
 253
 254         if (common_start == 0) common_start = GC_first_common();
 255         if (common_start != 0) {
 256             common_end = GC_find_limit(common_start, TRUE);
 257             GC_add_roots_inner((char *)common_start, (char *)common_end, TRUE);
 258         }
 259       }
 260 #   endif
 261 }
 262
 263 # endif /* !USE_PROC ... */
 264 # endif /* SUNOS */
 265
 266 #if defined(LINUX) && defined(__ELF__) || defined(SCO_ELF) || \
 267     (defined(FREEBSD) && defined(__ELF__)) || \
 268     (defined(NETBSD) && defined(__ELF__)) || defined(HURD)
 269
 270
 271 #ifdef USE_PROC_FOR_LIBRARIES
 272
 273 #include <string.h>
 274
 275 #include <sys/stat.h>
 276 #include <fcntl.h>
 277 #include <unistd.h>
 278
 279 #define MAPS_BUF_SIZE (32*1024)
 280
 281 extern ssize_t GC_repeat_read(int fd, char *buf, size_t count);
 282         /* Repeatedly read until buffer is filled, or EOF is encountered */
 283         /* Defined in os_dep.c.                                          */
 284
 285 static char *parse_map_entry(char *buf_ptr, word *start, word *end,
 286                              char *prot_buf, unsigned int *maj_dev);
 287
 288 void GC_register_dynamic_libraries()
 289 {
 290     int f;
 291     int result;
 292     char prot_buf[5];
 293     int maps_size;
 294     char maps_temp[32768];
 295     char *maps_buf;
 296     char *buf_ptr;
 297     int count;
 298     word start, end;
 299     unsigned int maj_dev, min_dev;
 300     word least_ha, greatest_ha;
 301     unsigned i;
 302     word datastart = (word)(DATASTART);
 303
 304     /* Read /proc/self/maps     */
 305         /* Note that we may not allocate, and thus can't use stdio.     */
 306         f = open("/proc/self/maps", O_RDONLY);
 307         if (-1 == f) ABORT("Couldn't open /proc/self/maps");
 308         /* stat() doesn't work for /proc/self/maps, so we have to
 309            read it to find out how large it is... */
 310         maps_size = 0;
 311         do {
 312             result = GC_repeat_read(f, maps_temp, sizeof(maps_temp));
 313             if (result <= 0) ABORT("Couldn't read /proc/self/maps");
 314             maps_size += result;
 315         } while (result == sizeof(maps_temp));
 316
 317         if (maps_size > sizeof(maps_temp)) {
 318             /* If larger than our buffer, close and re-read it. */
 319             close(f);
 320             f = open("/proc/self/maps", O_RDONLY);
 321             if (-1 == f) ABORT("Couldn't open /proc/self/maps");
 322             maps_buf = alloca(maps_size);
 323             if (NULL == maps_buf) ABORT("/proc/self/maps alloca failed");
 324             result = GC_repeat_read(f, maps_buf, maps_size);
 325             if (result <= 0) ABORT("Couldn't read /proc/self/maps");
 326         } else {
 327             /* Otherwise use the fixed size buffer */
 328             maps_buf = maps_temp;
 329         }
 330
 331         close(f);
 332         maps_buf[result] = '\0';
 333         buf_ptr = maps_buf;
 334     /* Compute heap bounds. Should be done by add_to_heap?      */
 335         least_ha = (word)(-1);
 336         greatest_ha = 0;
 337         for (i = 0; i < GC_n_heap_sects; ++i) {
 338             word sect_start = (word)GC_heap_sects[i].hs_start;
 339             word sect_end = sect_start + GC_heap_sects[i].hs_bytes;
 340             if (sect_start < least_ha) least_ha = sect_start;
 341             if (sect_end > greatest_ha) greatest_ha = sect_end;
 342         }
 343         if (greatest_ha < (word)GC_scratch_last_end_ptr)
 344             greatest_ha = (word)GC_scratch_last_end_ptr;
 345     for (;;) {
 346
 347         buf_ptr = parse_map_entry(buf_ptr, &start, &end, prot_buf, &maj_dev);
 348         if (buf_ptr == NULL) return;
 349
 350         if (prot_buf[1] == 'w') {
 351             /* This is a writable mapping.  Add it to           */
 352             /* the root set unless it is already otherwise      */
 353             /* accounted for.                                   */
 354             if (start <= (word)GC_stackbottom && end >= (word)GC_stackbottom) {
 355                 /* Stack mapping; discard       */
 356                 continue;
 357             }
 358             if (start <= datastart && end > datastart && maj_dev != 0) {
 359                 /* Main data segment; discard   */
 360                 continue;
 361             }
 362 #           ifdef THREADS
 363               if (GC_segment_is_thread_stack(start, end)) continue;
 364 #           endif
 365             /* The rest of this assumes that there is no mapping        */
 366             /* spanning the beginning of the data segment, or extending */
 367             /* beyond the entire heap at both ends.                     */
 368             /* Empirically these assumptions hold.                      */
 369
 370             if (start < (word)DATAEND && end > (word)DATAEND) {
 371                 /* Rld may use space at the end of the main data        */
 372                 /* segment.  Thus we add that in.                       */
 373                 start = (word)DATAEND;
 374             }
 375             if (start < least_ha && end > least_ha) {
 376                 end = least_ha;
 377             }
 378             if (start < greatest_ha && end > greatest_ha) {
 379                 start = greatest_ha;
 380             }
 381             if (start >= least_ha && end <= greatest_ha) continue;
 382             GC_add_roots_inner((char *)start, (char *)end, TRUE);
 383         }
 384      }
 385 }
 386
 387 //
 388 //  parse_map_entry parses an entry from /proc/self/maps so we can
 389 //  locate all writable data segments that belong to shared libraries.
 390 //  The format of one of these entries and the fields we care about
 391 //  is as follows:
 392 //  XXXXXXXX-XXXXXXXX r-xp 00000000 30:05 260537     name of mapping...\n
 393 //  ^^^^^^^^ ^^^^^^^^ ^^^^          ^^
 394 //  start    end      prot          maj_dev
 395 //  0        9        18            32
 396 //
 397 //  The parser is called with a pointer to the entry and the return value
 398 //  is either NULL or is advanced to the next entry(the byte after the
 399 //  trailing '\n'.)
 400 //
 401 #define OFFSET_MAP_START   0
 402 #define OFFSET_MAP_END     9
 403 #define OFFSET_MAP_PROT   18
 404 #define OFFSET_MAP_MAJDEV 32
 405
 406 static char *parse_map_entry(char *buf_ptr, word *start, word *end,
 407                              char *prot_buf, unsigned int *maj_dev)
 408 {
 409     int i;
 410     unsigned int val;
 411     char *tok;
 412
 413     if (buf_ptr == NULL || *buf_ptr == '\0') {
 414         return NULL;
 415     }
 416
 417     memcpy(prot_buf, buf_ptr+OFFSET_MAP_PROT, 4); // do the protections first
 418     prot_buf[4] = '\0';
 419
 420     if (prot_buf[1] == 'w') { // we can skip all of this if it's not writable
 421
 422         tok = buf_ptr;
 423         buf_ptr[OFFSET_MAP_START+8] = '\0';
 424         *start = strtoul(tok, NULL, 16);
 425
 426         tok = buf_ptr+OFFSET_MAP_END;
 427         buf_ptr[OFFSET_MAP_END+8] = '\0';
 428         *end = strtoul(tok, NULL, 16);
 429
 430         buf_ptr += OFFSET_MAP_MAJDEV;
 431         tok = buf_ptr;
 432         while (*buf_ptr != ':') buf_ptr++;
 433         *buf_ptr++ = '\0';
 434         *maj_dev = strtoul(tok, NULL, 16);
 435     }
 436
 437     while (*buf_ptr && *buf_ptr++ != '\n');
 438
 439     return buf_ptr;
 440 }
 441
 442 #endif /* USE_PROC_FOR_LIBRARIES */
 443
 444 #if !defined(USE_PROC_FOR_LIBRARIES)
 445 /* The following is the preferred way to walk dynamic libraries */
 446 /* For glibc 2.2.4+.  Unfortunately, it doesn't work for older  */
 447 /* versions.  Thanks to Jakub Jelinek for most of the code.     */
 448
 449 # if defined(LINUX) /* Are others OK here, too? */ \
 450      && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) \
 451          || (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && defined(DT_CONFIG)))
 452
 453 /* We have the header files for a glibc that includes dl_iterate_phdr.  */
 454 /* It may still not be available in the library on the target system.   */
 455 /* Thus we also treat it as a weak symbol.                              */
 456 #define HAVE_DL_ITERATE_PHDR
 457
 458 static int GC_register_dynlib_callback(info, size, ptr)
 459      struct dl_phdr_info * info;
 460      size_t size;
 461      void * ptr;
 462 {
 463   const ElfW(Phdr) * p;
 464   char * start;
 465   register int i;
 466
 467   /* Make sure struct dl_phdr_info is at least as big as we need.  */
 468   if (size < offsetof (struct dl_phdr_info, dlpi_phnum)
 469       + sizeof (info->dlpi_phnum))
 470     return -1;
 471
 472   /* Skip the first object - it is the main program.  */
 473   if (*(int *)ptr == 0)
 474     {
 475       *(int *)ptr = 1;
 476       return 0;
 477     }
 478
 479   p = info->dlpi_phdr;
 480   for( i = 0; i < (int)(info->dlpi_phnum); ((i++),(p++)) ) {
 481     switch( p->p_type ) {
 482       case PT_LOAD:
 483         {
 484           if( !(p->p_flags & PF_W) ) break;
 485           start = ((char *)(p->p_vaddr)) + info->dlpi_addr;
 486           GC_add_roots_inner(start, start + p->p_memsz, TRUE);
 487         }
 488       break;
 489       default:
 490         break;
 491     }
 492   }
 493
 494   return 0;
 495 }
 496
 497 /* Return TRUE if we succeed, FALSE if dl_iterate_phdr wasn't there. */
 498
 499 #pragma weak dl_iterate_phdr
 500
 501 GC_bool GC_register_dynamic_libraries_dl_iterate_phdr()
 502 {
 503   int tmp = 0;
 504
 505   if (dl_iterate_phdr) {
 506     dl_iterate_phdr(GC_register_dynlib_callback, &tmp);
 507     return TRUE;
 508   } else {
 509     return FALSE;
 510   }
 511 }
 512
 513 # else /* !LINUX || version(glibc) < 2.2.4 */
 514
 515 /* Dynamic loading code for Linux running ELF. Somewhat tested on
 516  * Linux/x86, untested but hopefully should work on Linux/Alpha.
 517  * This code was derived from the Solaris/ELF support. Thanks to
 518  * whatever kind soul wrote that.  - Patrick Bridges */
 519
 520 /* This doesn't necessarily work in all cases, e.g. with preloaded
 521  * dynamic libraries.                                           */
 522
 523 #if defined(NETBSD)
 524 #  include <sys/exec_elf.h>
 525 #else
 526 #  include <elf.h>
 527 #endif
 528 #include <link.h>
 529
 530 # endif
 531
 532 #ifdef __GNUC__
 533 # pragma weak _DYNAMIC
 534 #endif
 535 extern ElfW(Dyn) _DYNAMIC[];
 536
 537 static struct link_map *
 538 GC_FirstDLOpenedLinkMap()
 539 {
 540     ElfW(Dyn) *dp;
 541     struct r_debug *r;
 542     static struct link_map *cachedResult = 0;
 543
 544     if( _DYNAMIC == 0) {
 545         return(0);
 546     }
 547     if( cachedResult == 0 ) {
 548         int tag;
 549         for( dp = _DYNAMIC; (tag = dp->d_tag) != 0; dp++ ) {
 550             if( tag == DT_DEBUG ) {
 551                 struct link_map *lm
 552                         = ((struct r_debug *)(dp->d_un.d_ptr))->r_map;
 553                 if( lm != 0 ) cachedResult = lm->l_next; /* might be NIL */
 554                 break;
 555             }
 556         }
 557     }
 558     return cachedResult;
 559 }
 560
 561
 562 void GC_register_dynamic_libraries()
 563 {
 564   struct link_map *lm;
 565
 566
 567 # ifdef HAVE_DL_ITERATE_PHDR
 568     if (GC_register_dynamic_libraries_dl_iterate_phdr()) {
 569         return;
 570     }
 571 # endif
 572   lm = GC_FirstDLOpenedLinkMap();
 573   for (lm = GC_FirstDLOpenedLinkMap();
 574        lm != (struct link_map *) 0;  lm = lm->l_next)
 575     {
 576         ElfW(Ehdr) * e;
 577         ElfW(Phdr) * p;
 578         unsigned long offset;
 579         char * start;
 580         register int i;
 581
 582         e = (ElfW(Ehdr) *) lm->l_addr;
 583         p = ((ElfW(Phdr) *)(((char *)(e)) + e->e_phoff));
 584         offset = ((unsigned long)(lm->l_addr));
 585         for( i = 0; i < (int)(e->e_phnum); ((i++),(p++)) ) {
 586           switch( p->p_type ) {
 587             case PT_LOAD:
 588               {
 589                 if( !(p->p_flags & PF_W) ) break;
 590                 start = ((char *)(p->p_vaddr)) + offset;
 591                 GC_add_roots_inner(start, start + p->p_memsz, TRUE);
 592               }
 593               break;
 594             default:
 595               break;
 596           }
 597         }
 598     }
 599 }
 600
 601 #endif /* !USE_PROC_FOR_LIBRARIES */
 602
 603 #endif /* LINUX */
 604
 605 #if defined(IRIX5) || (defined(USE_PROC_FOR_LIBRARIES) && !defined(LINUX))
 606
 607 #include <sys/procfs.h>
 608 #include <sys/stat.h>
 609 #include <fcntl.h>
 610 #include <elf.h>
 611 #include <errno.h>
 612 #include <signal.h>  /* Only for the following test. */
 613 #ifndef _sigargs
 614 # define IRIX6
 615 #endif
 616
 617 extern void * GC_roots_present();
 618         /* The type is a lie, since the real type doesn't make sense here, */
 619         /* and we only test for NULL.                                      */
 620
 621 /* We use /proc to track down all parts of the address space that are   */
 622 /* mapped by the process, and throw out regions we know we shouldn't    */
 623 /* worry about.  This may also work under other SVR4 variants.          */
 624 void GC_register_dynamic_libraries()
 625 {
 626     static int fd = -1;
 627     char buf[30];
 628     static prmap_t * addr_map = 0;
 629     static int current_sz = 0;  /* Number of records currently in addr_map */
 630     static int needed_sz;       /* Required size of addr_map            */
 631     register int i;
 632     register long flags;
 633     register ptr_t start;
 634     register ptr_t limit;
 635     ptr_t heap_start = (ptr_t)HEAP_START;
 636     ptr_t heap_end = heap_start;
 637
 638 #   ifdef SUNOS5DL
 639 #     define MA_PHYS 0
 640 #   endif /* SUNOS5DL */
 641
 642     if (fd < 0) {
 643       sprintf(buf, "/proc/%d", getpid());
 644         /* The above generates a lint complaint, since pid_t varies.    */
 645         /* It's unclear how to improve this.                            */
 646       fd = open(buf, O_RDONLY);
 647       if (fd < 0) {
 648         ABORT("/proc open failed");
 649       }
 650     }
 651     if (ioctl(fd, PIOCNMAP, &needed_sz) < 0) {
 652         GC_err_printf2("fd = %d, errno = %d\n", fd, errno);
 653         ABORT("/proc PIOCNMAP ioctl failed");
 654     }
 655     if (needed_sz >= current_sz) {
 656         current_sz = needed_sz * 2 + 1;
 657                         /* Expansion, plus room for 0 record */
 658         addr_map = (prmap_t *)GC_scratch_alloc((word)
 659                                                 (current_sz * sizeof(prmap_t)));
 660     }
 661     if (ioctl(fd, PIOCMAP, addr_map) < 0) {
 662         GC_err_printf4("fd = %d, errno = %d, needed_sz = %d, addr_map = 0x%X\n",
 663                         fd, errno, needed_sz, addr_map);
 664         ABORT("/proc PIOCMAP ioctl failed");
 665     };
 666     if (GC_n_heap_sects > 0) {
 667         heap_end = GC_heap_sects[GC_n_heap_sects-1].hs_start
 668                         + GC_heap_sects[GC_n_heap_sects-1].hs_bytes;
 669         if (heap_end < GC_scratch_last_end_ptr) heap_end = GC_scratch_last_end_ptr;
 670     }
 671     for (i = 0; i < needed_sz; i++) {
 672         flags = addr_map[i].pr_mflags;
 673         if ((flags & (MA_BREAK | MA_STACK | MA_PHYS)) != 0) goto irrelevant;
 674         if ((flags & (MA_READ | MA_WRITE)) != (MA_READ | MA_WRITE))
 675             goto irrelevant;
 676           /* The latter test is empirically useless in very old Irix    */
 677           /* versions.  Other than the                                  */
 678           /* main data and stack segments, everything appears to be     */
 679           /* mapped readable, writable, executable, and shared(!!).     */
 680           /* This makes no sense to me. - HB                            */
 681         start = (ptr_t)(addr_map[i].pr_vaddr);
 682         if (GC_roots_present(start)) goto irrelevant;
 683         if (start < heap_end && start >= heap_start)
 684                 goto irrelevant;
 685 #       ifdef MMAP_STACKS
 686           if (GC_is_thread_stack(start)) goto irrelevant;
 687 #       endif /* MMAP_STACKS */
 688
 689         limit = start + addr_map[i].pr_size;
 690         /* The following seemed to be necessary for very old versions   */
 691         /* of Irix, but it has been reported to discard relevant        */
 692         /* segments under Irix 6.5.                                     */
 693 #       ifndef IRIX6
 694           if (addr_map[i].pr_off == 0 && strncmp(start, ELFMAG, 4) == 0) {
 695             /* Discard text segments, i.e. 0-offset mappings against    */
 696             /* executable files which appear to have ELF headers.       */
 697             caddr_t arg;
 698             int obj;
 699 #           define MAP_IRR_SZ 10
 700             static ptr_t map_irr[MAP_IRR_SZ];
 701                                         /* Known irrelevant map entries */
 702             static int n_irr = 0;
 703             struct stat buf;
 704             register int i;
 705
 706             for (i = 0; i < n_irr; i++) {
 707                 if (map_irr[i] == start) goto irrelevant;
 708             }
 709             arg = (caddr_t)start;
 710             obj = ioctl(fd, PIOCOPENM, &arg);
 711             if (obj >= 0) {
 712                 fstat(obj, &buf);
 713                 close(obj);
 714                 if ((buf.st_mode & 0111) != 0) {
 715                     if (n_irr < MAP_IRR_SZ) {
 716                         map_irr[n_irr++] = start;
 717                     }
 718                     goto irrelevant;
 719                 }
 720             }
 721           }
 722 #       endif /* !IRIX6 */
 723         GC_add_roots_inner(start, limit, TRUE);
 724       irrelevant: ;
 725     }
 726     /* Dont keep cached descriptor, for now.  Some kernels don't like us */
 727     /* to keep a /proc file descriptor around during kill -9.            */
 728         if (close(fd) < 0) ABORT("Couldnt close /proc file");
 729         fd = -1;
 730 }
 731
 732 # endif /* USE_PROC || IRIX5 */
 733
 734 # if defined(MSWIN32) || defined(MSWINCE)
 735
 736 # define WIN32_LEAN_AND_MEAN
 737 # define NOSERVICE
 738 # include <windows.h>
 739 # include <stdlib.h>
 740
 741   /* We traverse the entire address space and register all segments     */
 742   /* that could possibly have been written to.                          */
 743
 744   extern GC_bool GC_is_heap_base (ptr_t p);
 745
 746 # ifdef GC_WIN32_THREADS
 747     extern void GC_get_next_stack(char *start, char **lo, char **hi);
 748     void GC_cond_add_roots(char *base, char * limit)
 749     {
 750       char * curr_base = base;
 751       char * next_stack_lo;
 752       char * next_stack_hi;
 753
 754       if (base == limit) return;
 755       for(;;) {
 756           GC_get_next_stack(curr_base, &next_stack_lo, &next_stack_hi);
 757           if (next_stack_lo >= limit) break;
 758           GC_add_roots_inner(curr_base, next_stack_lo, TRUE);
 759           curr_base = next_stack_hi;
 760       }
 761       if (curr_base < limit) GC_add_roots_inner(curr_base, limit, TRUE);
 762     }
 763 # else
 764     void GC_cond_add_roots(char *base, char * limit)
 765     {
 766       char dummy;
 767       char * stack_top
 768          = (char *) ((word)(&dummy) & ~(GC_sysinfo.dwAllocationGranularity-1));
 769       if (base == limit) return;
 770       if (limit > stack_top && base < GC_stackbottom) {
 771           /* Part of the stack; ignore it. */
 772           return;
 773       }
 774       GC_add_roots_inner(base, limit, TRUE);
 775     }
 776 # endif
 777
 778 # ifndef MSWINCE
 779   extern GC_bool GC_no_win32_dlls;
 780 # endif
 781
 782   void GC_register_dynamic_libraries()
 783   {
 784     MEMORY_BASIC_INFORMATION buf;
 785     DWORD result;
 786     DWORD protect;
 787     LPVOID p;
 788     char * base;
 789     char * limit, * new_limit;
 790
 791 #   ifdef MSWIN32
 792       if (GC_no_win32_dlls) return;
 793 #   endif
 794     base = limit = p = GC_sysinfo.lpMinimumApplicationAddress;
 795 #   if defined(MSWINCE) && !defined(_WIN32_WCE_EMULATION)
 796     /* Only the first 32 MB of address space belongs to the current process */
 797     while (p < (LPVOID)0x02000000) {
 798         result = VirtualQuery(p, &buf, sizeof(buf));
 799         if (result == 0) {
 800             /* Page is free; advance to the next possible allocation base */
 801             new_limit = (char *)
 802                 (((DWORD) p + GC_sysinfo.dwAllocationGranularity)
 803                  & ~(GC_sysinfo.dwAllocationGranularity-1));
 804         } else
 805 #   else
 806     while (p < GC_sysinfo.lpMaximumApplicationAddress) {
 807         result = VirtualQuery(p, &buf, sizeof(buf));
 808 #   endif
 809         {
 810             if (result != sizeof(buf)) {
 811                 ABORT("Weird VirtualQuery result");
 812             }
 813             new_limit = (char *)p + buf.RegionSize;
 814             protect = buf.Protect;
 815             if (buf.State == MEM_COMMIT
 816                 && (protect == PAGE_EXECUTE_READWRITE
 817                     || protect == PAGE_READWRITE)
 818                 && !GC_is_heap_base(buf.AllocationBase)) {
 819                 if ((char *)p != limit) {
 820                     GC_cond_add_roots(base, limit);
 821                     base = p;
 822                 }
 823                 limit = new_limit;
 824             }
 825         }
 826         if (p > (LPVOID)new_limit /* overflow */) break;
 827         p = (LPVOID)new_limit;
 828     }
 829     GC_cond_add_roots(base, limit);
 830   }
 831
 832 #endif /* MSWIN32 || MSWINCE */
 833
 834 #if defined(ALPHA) && defined(OSF1)
 835
 836 #include <loader.h>
 837
 838 void GC_register_dynamic_libraries()
 839 {
 840   int status;
 841   ldr_process_t mypid;
 842
 843   /* module */
 844     ldr_module_t moduleid = LDR_NULL_MODULE;
 845     ldr_module_info_t moduleinfo;
 846     size_t moduleinfosize = sizeof(moduleinfo);
 847     size_t modulereturnsize;
 848
 849   /* region */
 850     ldr_region_t region;
 851     ldr_region_info_t regioninfo;
 852     size_t regioninfosize = sizeof(regioninfo);
 853     size_t regionreturnsize;
 854
 855   /* Obtain id of this process */
 856     mypid = ldr_my_process();
 857
 858   /* For each module */
 859     while (TRUE) {
 860
 861       /* Get the next (first) module */
 862         status = ldr_next_module(mypid, &moduleid);
 863
 864       /* Any more modules? */
 865         if (moduleid == LDR_NULL_MODULE)
 866             break;    /* No more modules */
 867
 868       /* Check status AFTER checking moduleid because */
 869       /* of a bug in the non-shared ldr_next_module stub */
 870         if (status != 0 ) {
 871             GC_printf1("dynamic_load: status = %ld\n", (long)status);
 872             {
 873                 extern char *sys_errlist[];
 874                 extern int sys_nerr;
 875                 extern int errno;
 876                 if (errno <= sys_nerr) {
 877                     GC_printf1("dynamic_load: %s\n", (long)sys_errlist[errno]);
 878                } else {
 879                     GC_printf1("dynamic_load: %d\n", (long)errno);
 880                 }
 881         }
 882             ABORT("ldr_next_module failed");
 883          }
 884
 885       /* Get the module information */
 886         status = ldr_inq_module(mypid, moduleid, &moduleinfo,
 887                                 moduleinfosize, &modulereturnsize);
 888         if (status != 0 )
 889             ABORT("ldr_inq_module failed");
 890
 891       /* is module for the main program (i.e. nonshared portion)? */
 892           if (moduleinfo.lmi_flags & LDR_MAIN)
 893               continue;    /* skip the main module */
 894
 895 #     ifdef VERBOSE
 896           GC_printf("---Module---\n");
 897           GC_printf("Module ID            = %16ld\n", moduleinfo.lmi_modid);
 898           GC_printf("Count of regions     = %16d\n", moduleinfo.lmi_nregion);
 899           GC_printf("flags for module     = %16lx\n", moduleinfo.lmi_flags);
 900           GC_printf("pathname of module   = \"%s\"\n", moduleinfo.lmi_name);
 901 #     endif
 902
 903       /* For each region in this module */
 904         for (region = 0; region < moduleinfo.lmi_nregion; region++) {
 905
 906           /* Get the region information */
 907             status = ldr_inq_region(mypid, moduleid, region, &regioninfo,
 908                                     regioninfosize, &regionreturnsize);
 909             if (status != 0 )
 910                 ABORT("ldr_inq_region failed");
 911
 912           /* only process writable (data) regions */
 913             if (! (regioninfo.lri_prot & LDR_W))
 914                 continue;
 915
 916 #         ifdef VERBOSE
 917               GC_printf("--- Region ---\n");
 918               GC_printf("Region number    = %16ld\n",
 919                         regioninfo.lri_region_no);
 920               GC_printf("Protection flags = %016x\n",  regioninfo.lri_prot);
 921               GC_printf("Virtual address  = %16p\n",   regioninfo.lri_vaddr);
 922               GC_printf("Mapped address   = %16p\n",   regioninfo.lri_mapaddr);
 923               GC_printf("Region size      = %16ld\n",  regioninfo.lri_size);
 924               GC_printf("Region name      = \"%s\"\n", regioninfo.lri_name);
 925 #         endif
 926
 927           /* register region as a garbage collection root */
 928             GC_add_roots_inner (
 929                 (char *)regioninfo.lri_mapaddr,
 930                 (char *)regioninfo.lri_mapaddr + regioninfo.lri_size,
 931                 TRUE);
 932
 933         }
 934     }
 935 }
 936 #endif
 937
 938 #if defined(HPUX)
 939
 940 #include <errno.h>
 941 #include <dl.h>
 942
 943 extern int errno;
 944 extern char *sys_errlist[];
 945 extern int sys_nerr;
 946
 947 void GC_register_dynamic_libraries()
 948 {
 949   int status;
 950   int index = 1; /* Ordinal position in shared library search list */
 951   struct shl_descriptor *shl_desc; /* Shared library info, see dl.h */
 952
 953   /* For each dynamic library loaded */
 954     while (TRUE) {
 955
 956       /* Get info about next shared library */
 957         status = shl_get(index, &shl_desc);
 958
 959       /* Check if this is the end of the list or if some error occured */
 960         if (status != 0) {
 961 #        ifdef GC_HPUX_THREADS
 962            /* I've seen errno values of 0.  The man page is not clear   */
 963            /* as to whether errno should get set on a -1 return.        */
 964            break;
 965 #        else
 966           if (errno == EINVAL) {
 967               break; /* Moved past end of shared library list --> finished */
 968           } else {
 969               if (errno <= sys_nerr) {
 970                     GC_printf1("dynamic_load: %s\n", (long) sys_errlist[errno]);
 971               } else {
 972                     GC_printf1("dynamic_load: %d\n", (long) errno);
 973               }
 974               ABORT("shl_get failed");
 975           }
 976 #        endif
 977         }
 978
 979 #     ifdef VERBOSE
 980           GC_printf0("---Shared library---\n");
 981           GC_printf1("\tfilename        = \"%s\"\n", shl_desc->filename);
 982           GC_printf1("\tindex           = %d\n", index);
 983           GC_printf1("\thandle          = %08x\n",
 984                                         (unsigned long) shl_desc->handle);
 985           GC_printf1("\ttext seg. start = %08x\n", shl_desc->tstart);
 986           GC_printf1("\ttext seg. end   = %08x\n", shl_desc->tend);
 987           GC_printf1("\tdata seg. start = %08x\n", shl_desc->dstart);
 988           GC_printf1("\tdata seg. end   = %08x\n", shl_desc->dend);
 989           GC_printf1("\tref. count      = %lu\n", shl_desc->ref_count);
 990 #     endif
 991
 992       /* register shared library's data segment as a garbage collection root */
 993         GC_add_roots_inner((char *) shl_desc->dstart,
 994                            (char *) shl_desc->dend, TRUE);
 995
 996         index++;
 997     }
 998 }
 999 #endif /* HPUX */
1000
1001 #ifdef RS6000
1002 #pragma alloca
1003 #include <sys/ldr.h>
1004 #include <sys/errno.h>
1005 void GC_register_dynamic_libraries()
1006 {
1007         int len;
1008         char *ldibuf;
1009         int ldibuflen;
1010         struct ld_info *ldi;
1011
1012         ldibuf = alloca(ldibuflen = 8192);
1013
1014         while ( (len = loadquery(L_GETINFO,ldibuf,ldibuflen)) < 0) {
1015                 if (errno != ENOMEM) {
1016                         ABORT("loadquery failed");
1017                 }
1018                 ldibuf = alloca(ldibuflen *= 2);
1019         }
1020
1021         ldi = (struct ld_info *)ldibuf;
1022         while (ldi) {
1023                 len = ldi->ldinfo_next;
1024                 GC_add_roots_inner(
1025                                 ldi->ldinfo_dataorg,
1026                                 (unsigned long)ldi->ldinfo_dataorg
1027                                 + ldi->ldinfo_datasize,
1028                                 TRUE);
1029                 ldi = len ? (struct ld_info *)((char *)ldi + len) : 0;
1030         }
1031 }
1032 #endif /* RS6000 */
1033
1034
1035
1036 #else /* !DYNAMIC_LOADING */
1037
1038 #ifdef PCR
1039
1040 #   include "il/PCR_IL.h"
1041 #   include "th/PCR_ThCtl.h"
1042 #   include "mm/PCR_MM.h"
1043
1044 void GC_register_dynamic_libraries()
1045 {
1046     /* Add new static data areas of dynamically loaded modules. */
1047         {
1048           PCR_IL_LoadedFile * p = PCR_IL_GetLastLoadedFile();
1049           PCR_IL_LoadedSegment * q;
1050
1051           /* Skip uncommited files */
1052           while (p != NIL && !(p -> lf_commitPoint)) {
1053               /* The loading of this file has not yet been committed    */
1054               /* Hence its description could be inconsistent.           */
1055               /* Furthermore, it hasn't yet been run.  Hence its data   */
1056               /* segments can't possibly reference heap allocated       */
1057               /* objects.                                               */
1058               p = p -> lf_prev;
1059           }
1060           for (; p != NIL; p = p -> lf_prev) {
1061             for (q = p -> lf_ls; q != NIL; q = q -> ls_next) {
1062               if ((q -> ls_flags & PCR_IL_SegFlags_Traced_MASK)
1063                   == PCR_IL_SegFlags_Traced_on) {
1064                 GC_add_roots_inner
1065                         ((char *)(q -> ls_addr),
1066                          (char *)(q -> ls_addr) + q -> ls_bytes,
1067                          TRUE);
1068               }
1069             }
1070           }
1071         }
1072 }
1073
1074
1075 #else /* !PCR */
1076
1077 void GC_register_dynamic_libraries(){}
1078
1079 int GC_no_dynamic_loading;
1080
1081 #endif /* !PCR */
1082 #endif /* !DYNAMIC_LOADING */