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(MACOS) && !defined(_WIN32_WCE)
  30 #  include <sys/types.h>
  31 #endif
  32 #include "private/gc_priv.h"
  33
  34 /* BTL: avoid circular redefinition of dlopen if SOLARIS_THREADS defined */
  35 # if (defined(LINUX_THREADS) || defined(SOLARIS_THREADS) \
  36       || defined(HPUX_THREADS) || defined(IRIX_THREADS)) && defined(dlopen) \
  37      && !defined(GC_USE_LD_WRAP)
  38     /* To support threads in Solaris, gc.h interposes on dlopen by       */
  39     /* defining "dlopen" to be "GC_dlopen", which is implemented below.  */
  40     /* However, both GC_FirstDLOpenedLinkMap() and GC_dlopen() use the   */
  41     /* real system dlopen() in their implementation. We first remove     */
  42     /* gc.h's dlopen definition and restore it later, after GC_dlopen(). */
  43 #   undef dlopen
  44 #   define GC_must_restore_redefined_dlopen
  45 # else
  46 #   undef GC_must_restore_redefined_dlopen
  47 # endif
  48
  49 #if (defined(DYNAMIC_LOADING) || defined(MSWIN32) || defined(MSWINCE)) \
  50     && !defined(PCR)
  51 #if !defined(SUNOS4) && !defined(SUNOS5DL) && !defined(IRIX5) && \
  52     !defined(MSWIN32) && !defined(MSWINCE) && \
  53     !(defined(ALPHA) && defined(OSF1)) && \
  54     !defined(HPUX) && !(defined(LINUX) && defined(__ELF__)) && \
  55     !defined(RS6000) && !defined(SCO_ELF) && \
  56     !(defined(NETBSD) && defined(__ELF__))
  57  --> We only know how to find data segments of dynamic libraries for the
  58  --> above.  Additional SVR4 variants might not be too
  59  --> hard to add.
  60 #endif
  61
  62 #include <stdio.h>
  63 #ifdef SUNOS5DL
  64 #   include <sys/elf.h>
  65 #   include <dlfcn.h>
  66 #   include <link.h>
  67 #endif
  68 #ifdef SUNOS4
  69 #   include <dlfcn.h>
  70 #   include <link.h>
  71 #   include <a.out.h>
  72   /* struct link_map field overrides */
  73 #   define l_next       lm_next
  74 #   define l_addr       lm_addr
  75 #   define l_name       lm_name
  76 #endif
  77
  78
  79 #if defined(SUNOS5DL) && !defined(USE_PROC_FOR_LIBRARIES)
  80
  81 #ifdef LINT
  82     Elf32_Dyn _DYNAMIC;
  83 #endif
  84
  85 static struct link_map *
  86 GC_FirstDLOpenedLinkMap()
  87 {
  88     extern Elf32_Dyn _DYNAMIC;
  89     Elf32_Dyn *dp;
  90     struct r_debug *r;
  91     static struct link_map * cachedResult = 0;
  92     static Elf32_Dyn *dynStructureAddr = 0;
  93                         /* BTL: added to avoid Solaris 5.3 ld.so _DYNAMIC bug */
  94
  95 #   ifdef SUNOS53_SHARED_LIB
  96         /* BTL: Avoid the Solaris 5.3 bug that _DYNAMIC isn't being set */
  97         /* up properly in dynamically linked .so's. This means we have  */
  98         /* to use its value in the set of original object files loaded  */
  99         /* at program startup.                                          */
 100         if( dynStructureAddr == 0 ) {
 101           void* startupSyms = dlopen(0, RTLD_LAZY);
 102           dynStructureAddr = (Elf32_Dyn*)dlsym(startupSyms, "_DYNAMIC");
 103                 }
 104 #   else
 105         dynStructureAddr = &_DYNAMIC;
 106 #   endif
 107
 108     if( dynStructureAddr == 0) {
 109         return(0);
 110     }
 111     if( cachedResult == 0 ) {
 112         int tag;
 113         for( dp = ((Elf32_Dyn *)(&_DYNAMIC)); (tag = dp->d_tag) != 0; dp++ ) {
 114             if( tag == DT_DEBUG ) {
 115                 struct link_map *lm
 116                         = ((struct r_debug *)(dp->d_un.d_ptr))->r_map;
 117                 if( lm != 0 ) cachedResult = lm->l_next; /* might be NIL */
 118                 break;
 119             }
 120         }
 121     }
 122     return cachedResult;
 123 }
 124
 125 #endif /* SUNOS5DL ... */
 126
 127 /* BTL: added to fix circular dlopen definition if SOLARIS_THREADS defined */
 128 # if defined(GC_must_restore_redefined_dlopen)
 129 #   define dlopen GC_dlopen
 130 # endif
 131
 132 #if defined(SUNOS4) && !defined(USE_PROC_FOR_LIBRARIES)
 133
 134 #ifdef LINT
 135     struct link_dynamic _DYNAMIC;
 136 #endif
 137
 138 static struct link_map *
 139 GC_FirstDLOpenedLinkMap()
 140 {
 141     extern struct link_dynamic _DYNAMIC;
 142
 143     if( &_DYNAMIC == 0) {
 144         return(0);
 145     }
 146     return(_DYNAMIC.ld_un.ld_1->ld_loaded);
 147 }
 148
 149 /* Return the address of the ld.so allocated common symbol      */
 150 /* with the least address, or 0 if none.                        */
 151 static ptr_t GC_first_common()
 152 {
 153     ptr_t result = 0;
 154     extern struct link_dynamic _DYNAMIC;
 155     struct rtc_symb * curr_symbol;
 156
 157     if( &_DYNAMIC == 0) {
 158         return(0);
 159     }
 160     curr_symbol = _DYNAMIC.ldd -> ldd_cp;
 161     for (; curr_symbol != 0; curr_symbol = curr_symbol -> rtc_next) {
 162         if (result == 0
 163             || (ptr_t)(curr_symbol -> rtc_sp -> n_value) < result) {
 164             result = (ptr_t)(curr_symbol -> rtc_sp -> n_value);
 165         }
 166     }
 167     return(result);
 168 }
 169
 170 #endif  /* SUNOS4 ... */
 171
 172 # if defined(SUNOS4) || defined(SUNOS5DL)
 173 /* Add dynamic library data sections to the root set.           */
 174 # if !defined(PCR) && !defined(SOLARIS_THREADS) && defined(THREADS)
 175 #   ifndef SRC_M3
 176         --> fix mutual exclusion with dlopen
 177 #   endif  /* We assume M3 programs don't call dlopen for now */
 178 # endif
 179
 180 # ifndef USE_PROC_FOR_LIBRARIES
 181 void GC_register_dynamic_libraries()
 182 {
 183   struct link_map *lm = GC_FirstDLOpenedLinkMap();
 184
 185
 186   for (lm = GC_FirstDLOpenedLinkMap();
 187        lm != (struct link_map *) 0;  lm = lm->l_next)
 188     {
 189 #     ifdef SUNOS4
 190         struct exec *e;
 191
 192         e = (struct exec *) lm->lm_addr;
 193         GC_add_roots_inner(
 194                     ((char *) (N_DATOFF(*e) + lm->lm_addr)),
 195                     ((char *) (N_BSSADDR(*e) + e->a_bss + lm->lm_addr)),
 196                     TRUE);
 197 #     endif
 198 #     ifdef SUNOS5DL
 199         Elf32_Ehdr * e;
 200         Elf32_Phdr * p;
 201         unsigned long offset;
 202         char * start;
 203         register int i;
 204
 205         e = (Elf32_Ehdr *) lm->l_addr;
 206         p = ((Elf32_Phdr *)(((char *)(e)) + e->e_phoff));
 207         offset = ((unsigned long)(lm->l_addr));
 208         for( i = 0; i < (int)(e->e_phnum); ((i++),(p++)) ) {
 209           switch( p->p_type ) {
 210             case PT_LOAD:
 211               {
 212                 if( !(p->p_flags & PF_W) ) break;
 213                 start = ((char *)(p->p_vaddr)) + offset;
 214                 GC_add_roots_inner(
 215                   start,
 216                   start + p->p_memsz,
 217                   TRUE
 218                 );
 219               }
 220               break;
 221             default:
 222               break;
 223           }
 224         }
 225 #     endif
 226     }
 227 #   ifdef SUNOS4
 228       {
 229         static ptr_t common_start = 0;
 230         ptr_t common_end;
 231         extern ptr_t GC_find_limit();
 232
 233         if (common_start == 0) common_start = GC_first_common();
 234         if (common_start != 0) {
 235             common_end = GC_find_limit(common_start, TRUE);
 236             GC_add_roots_inner((char *)common_start, (char *)common_end, TRUE);
 237         }
 238       }
 239 #   endif
 240 }
 241
 242 # endif /* !USE_PROC ... */
 243 # endif /* SUNOS */
 244
 245 #if defined(LINUX) && defined(__ELF__) || defined(SCO_ELF) || \
 246     (defined(NETBSD) && defined(__ELF__))
 247
 248
 249 #ifdef USE_PROC_FOR_LIBRARIES
 250
 251 #include <string.h>
 252
 253 #include <sys/stat.h>
 254 #include <fcntl.h>
 255 #include <unistd.h>
 256
 257 #define MAPS_BUF_SIZE (32*1024)
 258
 259 extern ssize_t GC_repeat_read(int fd, char *buf, size_t count);
 260         /* Repeatedly read until buffer is filled, or EOF is encountered */
 261         /* Defined in os_dep.c.                                          */
 262
 263 static char *parse_map_entry(char *buf_ptr, word *start, word *end,
 264                              char *prot_buf, unsigned int *maj_dev);
 265
 266 void GC_register_dynamic_libraries()
 267 {
 268     int f;
 269     int result;
 270     char prot_buf[5];
 271     int maps_size;
 272     char maps_temp[32768];
 273     char *maps_buf;
 274     char *buf_ptr;
 275     int count;
 276     word start, end;
 277     unsigned int maj_dev, min_dev;
 278     word least_ha, greatest_ha;
 279     unsigned i;
 280     word datastart = (word)(DATASTART);
 281
 282     /* Read /proc/self/maps     */
 283         /* Note that we may not allocate, and thus can't use stdio.     */
 284         f = open("/proc/self/maps", O_RDONLY);
 285         if (-1 == f) ABORT("Couldn't open /proc/self/maps");
 286         /* stat() doesn't work for /proc/self/maps, so we have to
 287            read it to find out how large it is... */
 288         maps_size = 0;
 289         do {
 290             result = GC_repeat_read(f, maps_temp, sizeof(maps_temp));
 291             if (result <= 0) ABORT("Couldn't read /proc/self/maps");
 292             maps_size += result;
 293         } while (result == sizeof(maps_temp));
 294
 295         if (maps_size > sizeof(maps_temp)) {
 296             /* If larger than our buffer, close and re-read it. */
 297             close(f);
 298             f = open("/proc/self/maps", O_RDONLY);
 299             if (-1 == f) ABORT("Couldn't open /proc/self/maps");
 300             maps_buf = alloca(maps_size);
 301             if (NULL == maps_buf) ABORT("/proc/self/maps alloca failed");
 302             result = GC_repeat_read(f, maps_buf, maps_size);
 303             if (result <= 0) ABORT("Couldn't read /proc/self/maps");
 304         } else {
 305             /* Otherwise use the fixed size buffer */
 306             maps_buf = maps_temp;
 307         }
 308
 309         close(f);
 310         maps_buf[result] = '\0';
 311         buf_ptr = maps_buf;
 312     /* Compute heap bounds. Should be done by add_to_heap?      */
 313         least_ha = (word)(-1);
 314         greatest_ha = 0;
 315         for (i = 0; i < GC_n_heap_sects; ++i) {
 316             word sect_start = (word)GC_heap_sects[i].hs_start;
 317             word sect_end = sect_start + GC_heap_sects[i].hs_bytes;
 318             if (sect_start < least_ha) least_ha = sect_start;
 319             if (sect_end > greatest_ha) greatest_ha = sect_end;
 320         }
 321         if (greatest_ha < (word)GC_scratch_last_end_ptr)
 322             greatest_ha = (word)GC_scratch_last_end_ptr;
 323     for (;;) {
 324
 325         buf_ptr = parse_map_entry(buf_ptr, &start, &end, prot_buf, &maj_dev);
 326         if (buf_ptr == NULL) return;
 327
 328         if (prot_buf[1] == 'w') {
 329             /* This is a writable mapping.  Add it to           */
 330             /* the root set unless it is already otherwise      */
 331             /* accounted for.                                   */
 332             if (start <= (word)GC_stackbottom && end >= (word)GC_stackbottom) {
 333                 /* Stack mapping; discard       */
 334                 continue;
 335             }
 336             if (start <= datastart && end > datastart && maj_dev != 0) {
 337                 /* Main data segment; discard   */
 338                 continue;
 339             }
 340 #           ifdef THREADS
 341               if (GC_segment_is_thread_stack(start, end)) continue;
 342 #           endif
 343             /* The rest of this assumes that there is no mapping        */
 344             /* spanning the beginning of the data segment, or extending */
 345             /* beyond the entire heap at both ends.                     */
 346             /* Empirically these assumptions hold.                      */
 347
 348             if (start < (word)DATAEND && end > (word)DATAEND) {
 349                 /* Rld may use space at the end of the main data        */
 350                 /* segment.  Thus we add that in.                       */
 351                 start = (word)DATAEND;
 352             }
 353             if (start < least_ha && end > least_ha) {
 354                 end = least_ha;
 355             }
 356             if (start < greatest_ha && end > greatest_ha) {
 357                 start = greatest_ha;
 358             }
 359             if (start >= least_ha && end <= greatest_ha) continue;
 360             GC_add_roots_inner((char *)start, (char *)end, TRUE);
 361         }
 362      }
 363 }
 364
 365 //
 366 //  parse_map_entry parses an entry from /proc/self/maps so we can
 367 //  locate all writable data segments that belong to shared libraries.
 368 //  The format of one of these entries and the fields we care about
 369 //  is as follows:
 370 //  XXXXXXXX-XXXXXXXX r-xp 00000000 30:05 260537     name of mapping...\n
 371 //  ^^^^^^^^ ^^^^^^^^ ^^^^          ^^
 372 //  start    end      prot          maj_dev
 373 //  0        9        18            32
 374 //
 375 //  The parser is called with a pointer to the entry and the return value
 376 //  is either NULL or is advanced to the next entry(the byte after the
 377 //  trailing '\n'.)
 378 //
 379 #define OFFSET_MAP_START   0
 380 #define OFFSET_MAP_END     9
 381 #define OFFSET_MAP_PROT   18
 382 #define OFFSET_MAP_MAJDEV 32
 383
 384 static char *parse_map_entry(char *buf_ptr, word *start, word *end,
 385                              char *prot_buf, unsigned int *maj_dev)
 386 {
 387     int i;
 388     unsigned int val;
 389     char *tok;
 390
 391     if (buf_ptr == NULL || *buf_ptr == '\0') {
 392         return NULL;
 393     }
 394
 395     memcpy(prot_buf, buf_ptr+OFFSET_MAP_PROT, 4); // do the protections first
 396     prot_buf[4] = '\0';
 397
 398     if (prot_buf[1] == 'w') { // we can skip all of this if it's not writable
 399
 400         tok = buf_ptr;
 401         buf_ptr[OFFSET_MAP_START+8] = '\0';
 402         *start = strtoul(tok, NULL, 16);
 403
 404         tok = buf_ptr+OFFSET_MAP_END;
 405         buf_ptr[OFFSET_MAP_END+8] = '\0';
 406         *end = strtoul(tok, NULL, 16);
 407
 408         buf_ptr += OFFSET_MAP_MAJDEV;
 409         tok = buf_ptr;
 410         while (*buf_ptr != ':') buf_ptr++;
 411         *buf_ptr++ = '\0';
 412         *maj_dev = strtoul(tok, NULL, 16);
 413     }
 414
 415     while (*buf_ptr && *buf_ptr++ != '\n');
 416
 417     return buf_ptr;
 418 }
 419
 420 #else /* !USE_PROC_FOR_LIBRARIES */
 421
 422 /* Dynamic loading code for Linux running ELF. Somewhat tested on
 423  * Linux/x86, untested but hopefully should work on Linux/Alpha.
 424  * This code was derived from the Solaris/ELF support. Thanks to
 425  * whatever kind soul wrote that.  - Patrick Bridges */
 426
 427 #if defined(NETBSD)
 428 #  include <sys/exec_elf.h>
 429 #else
 430 #  include <elf.h>
 431 #endif
 432 #include <link.h>
 433
 434 /* Newer versions of Linux/Alpha and Linux/x86 define this macro.  We
 435  * define it for those older versions that don't.  */
 436 #  ifndef ElfW
 437 #    if !defined(ELF_CLASS) || ELF_CLASS == ELFCLASS32
 438 #      define ElfW(type) Elf32_##type
 439 #    else
 440 #      define ElfW(type) Elf64_##type
 441 #    endif
 442 #  endif
 443
 444 static struct link_map *
 445 GC_FirstDLOpenedLinkMap()
 446 {
 447 #   ifdef __GNUC__
 448 #     pragma weak _DYNAMIC
 449 #   endif
 450     extern ElfW(Dyn) _DYNAMIC[];
 451     ElfW(Dyn) *dp;
 452     struct r_debug *r;
 453     static struct link_map *cachedResult = 0;
 454
 455     if( _DYNAMIC == 0) {
 456         return(0);
 457     }
 458     if( cachedResult == 0 ) {
 459         int tag;
 460         for( dp = _DYNAMIC; (tag = dp->d_tag) != 0; dp++ ) {
 461             if( tag == DT_DEBUG ) {
 462                 struct link_map *lm
 463                         = ((struct r_debug *)(dp->d_un.d_ptr))->r_map;
 464                 if( lm != 0 ) cachedResult = lm->l_next; /* might be NIL */
 465                 break;
 466             }
 467         }
 468     }
 469     return cachedResult;
 470 }
 471
 472
 473 void GC_register_dynamic_libraries()
 474 {
 475   struct link_map *lm = GC_FirstDLOpenedLinkMap();
 476
 477
 478   for (lm = GC_FirstDLOpenedLinkMap();
 479        lm != (struct link_map *) 0;  lm = lm->l_next)
 480     {
 481         ElfW(Ehdr) * e;
 482         ElfW(Phdr) * p;
 483         unsigned long offset;
 484         char * start;
 485         register int i;
 486
 487         e = (ElfW(Ehdr) *) lm->l_addr;
 488         p = ((ElfW(Phdr) *)(((char *)(e)) + e->e_phoff));
 489         offset = ((unsigned long)(lm->l_addr));
 490         for( i = 0; i < (int)(e->e_phnum); ((i++),(p++)) ) {
 491           switch( p->p_type ) {
 492             case PT_LOAD:
 493               {
 494                 if( !(p->p_flags & PF_W) ) break;
 495                 start = ((char *)(p->p_vaddr)) + offset;
 496                 GC_add_roots_inner(start, start + p->p_memsz, TRUE);
 497               }
 498               break;
 499             default:
 500               break;
 501           }
 502         }
 503     }
 504 }
 505
 506 #endif /* !USE_PROC_FOR_LIBRARIES */
 507
 508 #endif /* LINUX */
 509
 510 #if defined(IRIX5) || (defined(USE_PROC_FOR_LIBRARIES) && !defined(LINUX))
 511
 512 #include <sys/procfs.h>
 513 #include <sys/stat.h>
 514 #include <fcntl.h>
 515 #include <elf.h>
 516 #include <errno.h>
 517
 518 extern void * GC_roots_present();
 519         /* The type is a lie, since the real type doesn't make sense here, */
 520         /* and we only test for NULL.                                      */
 521
 522 /* We use /proc to track down all parts of the address space that are   */
 523 /* mapped by the process, and throw out regions we know we shouldn't    */
 524 /* worry about.  This may also work under other SVR4 variants.          */
 525 void GC_register_dynamic_libraries()
 526 {
 527     static int fd = -1;
 528     char buf[30];
 529     static prmap_t * addr_map = 0;
 530     static int current_sz = 0;  /* Number of records currently in addr_map */
 531     static int needed_sz;       /* Required size of addr_map            */
 532     register int i;
 533     register long flags;
 534     register ptr_t start;
 535     register ptr_t limit;
 536     ptr_t heap_start = (ptr_t)HEAP_START;
 537     ptr_t heap_end = heap_start;
 538
 539 #   ifdef SUNOS5DL
 540 #     define MA_PHYS 0
 541 #   endif /* SUNOS5DL */
 542
 543     if (fd < 0) {
 544       sprintf(buf, "/proc/%d", getpid());
 545         /* The above generates a lint complaint, since pid_t varies.    */
 546         /* It's unclear how to improve this.                            */
 547       fd = open(buf, O_RDONLY);
 548       if (fd < 0) {
 549         ABORT("/proc open failed");
 550       }
 551     }
 552     if (ioctl(fd, PIOCNMAP, &needed_sz) < 0) {
 553         GC_err_printf2("fd = %d, errno = %d\n", fd, errno);
 554         ABORT("/proc PIOCNMAP ioctl failed");
 555     }
 556     if (needed_sz >= current_sz) {
 557         current_sz = needed_sz * 2 + 1;
 558                         /* Expansion, plus room for 0 record */
 559         addr_map = (prmap_t *)GC_scratch_alloc((word)
 560                                                 (current_sz * sizeof(prmap_t)));
 561     }
 562     if (ioctl(fd, PIOCMAP, addr_map) < 0) {
 563         GC_err_printf4("fd = %d, errno = %d, needed_sz = %d, addr_map = 0x%X\n",
 564                         fd, errno, needed_sz, addr_map);
 565         ABORT("/proc PIOCMAP ioctl failed");
 566     };
 567     if (GC_n_heap_sects > 0) {
 568         heap_end = GC_heap_sects[GC_n_heap_sects-1].hs_start
 569                         + GC_heap_sects[GC_n_heap_sects-1].hs_bytes;
 570         if (heap_end < GC_scratch_last_end_ptr) heap_end = GC_scratch_last_end_ptr;
 571     }
 572     for (i = 0; i < needed_sz; i++) {
 573         flags = addr_map[i].pr_mflags;
 574         if ((flags & (MA_BREAK | MA_STACK | MA_PHYS)) != 0) goto irrelevant;
 575         if ((flags & (MA_READ | MA_WRITE)) != (MA_READ | MA_WRITE))
 576             goto irrelevant;
 577           /* The latter test is empirically useless.  Other than the    */
 578           /* main data and stack segments, everything appears to be     */
 579           /* mapped readable, writable, executable, and shared(!!).     */
 580           /* This makes no sense to me. - HB                            */
 581         start = (ptr_t)(addr_map[i].pr_vaddr);
 582         if (GC_roots_present(start)) goto irrelevant;
 583         if (start < heap_end && start >= heap_start)
 584                 goto irrelevant;
 585 #       ifdef MMAP_STACKS
 586           if (GC_is_thread_stack(start)) goto irrelevant;
 587 #       endif /* MMAP_STACKS */
 588
 589         limit = start + addr_map[i].pr_size;
 590         if (addr_map[i].pr_off == 0 && strncmp(start, ELFMAG, 4) == 0) {
 591             /* Discard text segments, i.e. 0-offset mappings against    */
 592             /* executable files which appear to have ELF headers.       */
 593             caddr_t arg;
 594             int obj;
 595 #           define MAP_IRR_SZ 10
 596             static ptr_t map_irr[MAP_IRR_SZ];
 597                                         /* Known irrelevant map entries */
 598             static int n_irr = 0;
 599             struct stat buf;
 600             register int i;
 601
 602             for (i = 0; i < n_irr; i++) {
 603                 if (map_irr[i] == start) goto irrelevant;
 604             }
 605             arg = (caddr_t)start;
 606             obj = ioctl(fd, PIOCOPENM, &arg);
 607             if (obj >= 0) {
 608                 fstat(obj, &buf);
 609                 close(obj);
 610                 if ((buf.st_mode & 0111) != 0) {
 611                     if (n_irr < MAP_IRR_SZ) {
 612                         map_irr[n_irr++] = start;
 613                     }
 614                     goto irrelevant;
 615                 }
 616             }
 617         }
 618         GC_add_roots_inner(start, limit, TRUE);
 619       irrelevant: ;
 620     }
 621     /* Dont keep cached descriptor, for now.  Some kernels don't like us */
 622     /* to keep a /proc file descriptor around during kill -9.            */
 623         if (close(fd) < 0) ABORT("Couldnt close /proc file");
 624         fd = -1;
 625 }
 626
 627 # endif /* USE_PROC || IRIX5 */
 628
 629 # if defined(MSWIN32) || defined(MSWINCE)
 630
 631 # define WIN32_LEAN_AND_MEAN
 632 # define NOSERVICE
 633 # include <windows.h>
 634 # include <stdlib.h>
 635
 636   /* We traverse the entire address space and register all segments     */
 637   /* that could possibly have been written to.                          */
 638
 639   extern GC_bool GC_is_heap_base (ptr_t p);
 640
 641 # ifdef WIN32_THREADS
 642     extern void GC_get_next_stack(char *start, char **lo, char **hi);
 643     void GC_cond_add_roots(char *base, char * limit)
 644     {
 645       char * curr_base = base;
 646       char * next_stack_lo;
 647       char * next_stack_hi;
 648
 649       if (base == limit) return;
 650       for(;;) {
 651           GC_get_next_stack(curr_base, &next_stack_lo, &next_stack_hi);
 652           if (next_stack_lo >= limit) break;
 653           GC_add_roots_inner(curr_base, next_stack_lo, TRUE);
 654           curr_base = next_stack_hi;
 655       }
 656       if (curr_base < limit) GC_add_roots_inner(curr_base, limit, TRUE);
 657     }
 658 # else
 659     void GC_cond_add_roots(char *base, char * limit)
 660     {
 661       char dummy;
 662       char * stack_top
 663          = (char *) ((word)(&dummy) & ~(GC_sysinfo.dwAllocationGranularity-1));
 664       if (base == limit) return;
 665       if (limit > stack_top && base < GC_stackbottom) {
 666           /* Part of the stack; ignore it. */
 667           return;
 668       }
 669       GC_add_roots_inner(base, limit, TRUE);
 670     }
 671 # endif
 672
 673 # ifndef MSWINCE
 674   extern GC_bool GC_win32s;
 675 # endif
 676
 677   void GC_register_dynamic_libraries()
 678   {
 679     MEMORY_BASIC_INFORMATION buf;
 680     DWORD result;
 681     DWORD protect;
 682     LPVOID p;
 683     char * base;
 684     char * limit, * new_limit;
 685
 686 #   ifdef MSWIN32
 687       if (GC_win32s) return;
 688 #   endif
 689     base = limit = p = GC_sysinfo.lpMinimumApplicationAddress;
 690 #   if defined(MSWINCE) && !defined(_WIN32_WCE_EMULATION)
 691     /* Only the first 32 MB of address space belongs to the current process */
 692     while (p < (LPVOID)0x02000000) {
 693         result = VirtualQuery(p, &buf, sizeof(buf));
 694         if (result == 0) {
 695             /* Page is free; advance to the next possible allocation base */
 696             new_limit = (char *)
 697                 (((DWORD) p + GC_sysinfo.dwAllocationGranularity)
 698                  & ~(GC_sysinfo.dwAllocationGranularity-1));
 699         } else
 700 #   else
 701     while (p < GC_sysinfo.lpMaximumApplicationAddress) {
 702         result = VirtualQuery(p, &buf, sizeof(buf));
 703 #   endif
 704         {
 705             if (result != sizeof(buf)) {
 706                 ABORT("Weird VirtualQuery result");
 707             }
 708             new_limit = (char *)p + buf.RegionSize;
 709             protect = buf.Protect;
 710             if (buf.State == MEM_COMMIT
 711                 && (protect == PAGE_EXECUTE_READWRITE
 712                     || protect == PAGE_READWRITE)
 713                 && !GC_is_heap_base(buf.AllocationBase)) {
 714                 if ((char *)p != limit) {
 715                     GC_cond_add_roots(base, limit);
 716                     base = p;
 717                 }
 718                 limit = new_limit;
 719             }
 720         }
 721         if (p > (LPVOID)new_limit /* overflow */) break;
 722         p = (LPVOID)new_limit;
 723     }
 724     GC_cond_add_roots(base, limit);
 725   }
 726
 727 #endif /* MSWIN32 || MSWINCE */
 728
 729 #if defined(ALPHA) && defined(OSF1)
 730
 731 #include <loader.h>
 732
 733 void GC_register_dynamic_libraries()
 734 {
 735   int status;
 736   ldr_process_t mypid;
 737
 738   /* module */
 739     ldr_module_t moduleid = LDR_NULL_MODULE;
 740     ldr_module_info_t moduleinfo;
 741     size_t moduleinfosize = sizeof(moduleinfo);
 742     size_t modulereturnsize;
 743
 744   /* region */
 745     ldr_region_t region;
 746     ldr_region_info_t regioninfo;
 747     size_t regioninfosize = sizeof(regioninfo);
 748     size_t regionreturnsize;
 749
 750   /* Obtain id of this process */
 751     mypid = ldr_my_process();
 752
 753   /* For each module */
 754     while (TRUE) {
 755
 756       /* Get the next (first) module */
 757         status = ldr_next_module(mypid, &moduleid);
 758
 759       /* Any more modules? */
 760         if (moduleid == LDR_NULL_MODULE)
 761             break;    /* No more modules */
 762
 763       /* Check status AFTER checking moduleid because */
 764       /* of a bug in the non-shared ldr_next_module stub */
 765         if (status != 0 ) {
 766             GC_printf1("dynamic_load: status = %ld\n", (long)status);
 767             {
 768                 extern char *sys_errlist[];
 769                 extern int sys_nerr;
 770                 extern int errno;
 771                 if (errno <= sys_nerr) {
 772                     GC_printf1("dynamic_load: %s\n", (long)sys_errlist[errno]);
 773                } else {
 774                     GC_printf1("dynamic_load: %d\n", (long)errno);
 775                 }
 776         }
 777             ABORT("ldr_next_module failed");
 778          }
 779
 780       /* Get the module information */
 781         status = ldr_inq_module(mypid, moduleid, &moduleinfo,
 782                                 moduleinfosize, &modulereturnsize);
 783         if (status != 0 )
 784             ABORT("ldr_inq_module failed");
 785
 786       /* is module for the main program (i.e. nonshared portion)? */
 787           if (moduleinfo.lmi_flags & LDR_MAIN)
 788               continue;    /* skip the main module */
 789
 790 #     ifdef VERBOSE
 791           GC_printf("---Module---\n");
 792           GC_printf("Module ID            = %16ld\n", moduleinfo.lmi_modid);
 793           GC_printf("Count of regions     = %16d\n", moduleinfo.lmi_nregion);
 794           GC_printf("flags for module     = %16lx\n", moduleinfo.lmi_flags);
 795           GC_printf("pathname of module   = \"%s\"\n", moduleinfo.lmi_name);
 796 #     endif
 797
 798       /* For each region in this module */
 799         for (region = 0; region < moduleinfo.lmi_nregion; region++) {
 800
 801           /* Get the region information */
 802             status = ldr_inq_region(mypid, moduleid, region, &regioninfo,
 803                                     regioninfosize, &regionreturnsize);
 804             if (status != 0 )
 805                 ABORT("ldr_inq_region failed");
 806
 807           /* only process writable (data) regions */
 808             if (! (regioninfo.lri_prot & LDR_W))
 809                 continue;
 810
 811 #         ifdef VERBOSE
 812               GC_printf("--- Region ---\n");
 813               GC_printf("Region number    = %16ld\n",
 814                         regioninfo.lri_region_no);
 815               GC_printf("Protection flags = %016x\n",  regioninfo.lri_prot);
 816               GC_printf("Virtual address  = %16p\n",   regioninfo.lri_vaddr);
 817               GC_printf("Mapped address   = %16p\n",   regioninfo.lri_mapaddr);
 818               GC_printf("Region size      = %16ld\n",  regioninfo.lri_size);
 819               GC_printf("Region name      = \"%s\"\n", regioninfo.lri_name);
 820 #         endif
 821
 822           /* register region as a garbage collection root */
 823             GC_add_roots_inner (
 824                 (char *)regioninfo.lri_mapaddr,
 825                 (char *)regioninfo.lri_mapaddr + regioninfo.lri_size,
 826                 TRUE);
 827
 828         }
 829     }
 830 }
 831 #endif
 832
 833 #if defined(HPUX)
 834
 835 #include <errno.h>
 836 #include <dl.h>
 837
 838 extern int errno;
 839 extern char *sys_errlist[];
 840 extern int sys_nerr;
 841
 842 void GC_register_dynamic_libraries()
 843 {
 844   int status;
 845   int index = 1; /* Ordinal position in shared library search list */
 846   struct shl_descriptor *shl_desc; /* Shared library info, see dl.h */
 847
 848   /* For each dynamic library loaded */
 849     while (TRUE) {
 850
 851       /* Get info about next shared library */
 852         status = shl_get(index, &shl_desc);
 853
 854       /* Check if this is the end of the list or if some error occured */
 855         if (status != 0) {
 856 #        ifdef HPUX_THREADS
 857            /* I've seen errno values of 0.  The man page is not clear   */
 858            /* as to whether errno should get set on a -1 return.        */
 859            break;
 860 #        else
 861           if (errno == EINVAL) {
 862               break; /* Moved past end of shared library list --> finished */
 863           } else {
 864               if (errno <= sys_nerr) {
 865                     GC_printf1("dynamic_load: %s\n", (long) sys_errlist[errno]);
 866               } else {
 867                     GC_printf1("dynamic_load: %d\n", (long) errno);
 868               }
 869               ABORT("shl_get failed");
 870           }
 871 #        endif
 872         }
 873
 874 #     ifdef VERBOSE
 875           GC_printf0("---Shared library---\n");
 876           GC_printf1("\tfilename        = \"%s\"\n", shl_desc->filename);
 877           GC_printf1("\tindex           = %d\n", index);
 878           GC_printf1("\thandle          = %08x\n",
 879                                         (unsigned long) shl_desc->handle);
 880           GC_printf1("\ttext seg. start = %08x\n", shl_desc->tstart);
 881           GC_printf1("\ttext seg. end   = %08x\n", shl_desc->tend);
 882           GC_printf1("\tdata seg. start = %08x\n", shl_desc->dstart);
 883           GC_printf1("\tdata seg. end   = %08x\n", shl_desc->dend);
 884           GC_printf1("\tref. count      = %lu\n", shl_desc->ref_count);
 885 #     endif
 886
 887       /* register shared library's data segment as a garbage collection root */
 888         GC_add_roots_inner((char *) shl_desc->dstart,
 889                            (char *) shl_desc->dend, TRUE);
 890
 891         index++;
 892     }
 893 }
 894 #endif /* HPUX */
 895
 896 #ifdef RS6000
 897 #pragma alloca
 898 #include <sys/ldr.h>
 899 #include <sys/errno.h>
 900 void GC_register_dynamic_libraries()
 901 {
 902         int len;
 903         char *ldibuf;
 904         int ldibuflen;
 905         struct ld_info *ldi;
 906
 907         ldibuf = alloca(ldibuflen = 8192);
 908
 909         while ( (len = loadquery(L_GETINFO,ldibuf,ldibuflen)) < 0) {
 910                 if (errno != ENOMEM) {
 911                         ABORT("loadquery failed");
 912                 }
 913                 ldibuf = alloca(ldibuflen *= 2);
 914         }
 915
 916         ldi = (struct ld_info *)ldibuf;
 917         while (ldi) {
 918                 len = ldi->ldinfo_next;
 919                 GC_add_roots_inner(
 920                                 ldi->ldinfo_dataorg,
 921                                 (unsigned long)ldi->ldinfo_dataorg
 922                                 + ldi->ldinfo_datasize,
 923                                 TRUE);
 924                 ldi = len ? (struct ld_info *)((char *)ldi + len) : 0;
 925         }
 926 }
 927 #endif /* RS6000 */
 928
 929
 930
 931 #else /* !DYNAMIC_LOADING */
 932
 933 #ifdef PCR
 934
 935 #   include "il/PCR_IL.h"
 936 #   include "th/PCR_ThCtl.h"
 937 #   include "mm/PCR_MM.h"
 938
 939 void GC_register_dynamic_libraries()
 940 {
 941     /* Add new static data areas of dynamically loaded modules. */
 942         {
 943           PCR_IL_LoadedFile * p = PCR_IL_GetLastLoadedFile();
 944           PCR_IL_LoadedSegment * q;
 945
 946           /* Skip uncommited files */
 947           while (p != NIL && !(p -> lf_commitPoint)) {
 948               /* The loading of this file has not yet been committed    */
 949               /* Hence its description could be inconsistent.           */
 950               /* Furthermore, it hasn't yet been run.  Hence its data   */
 951               /* segments can't possibly reference heap allocated       */
 952               /* objects.                                               */
 953               p = p -> lf_prev;
 954           }
 955           for (; p != NIL; p = p -> lf_prev) {
 956             for (q = p -> lf_ls; q != NIL; q = q -> ls_next) {
 957               if ((q -> ls_flags & PCR_IL_SegFlags_Traced_MASK)
 958                   == PCR_IL_SegFlags_Traced_on) {
 959                 GC_add_roots_inner
 960                         ((char *)(q -> ls_addr),
 961                          (char *)(q -> ls_addr) + q -> ls_bytes,
 962                          TRUE);
 963               }
 964             }
 965           }
 966         }
 967 }
 968
 969
 970 #else /* !PCR */
 971
 972 void GC_register_dynamic_libraries(){}
 973
 974 int GC_no_dynamic_loading;
 975
 976 #endif /* !PCR */
 977 #endif /* !DYNAMIC_LOADING */