* sysdeps/unix/sysv/linux/m68k/sysdep.h: Support inline syscall
[glibc.git] / elf / dl-load.c
blob3452c0b1b4c8744dc40a8f4802ea19cbbfac825a
1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995,96,97,98,99,2000,2001,2002 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <elf.h>
21 #include <errno.h>
22 #include <fcntl.h>
23 #include <libintl.h>
24 #include <stdbool.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <unistd.h>
28 #include <ldsodefs.h>
29 #include <sys/mman.h>
30 #include <sys/param.h>
31 #include <sys/stat.h>
32 #include <sys/types.h>
33 #include "dynamic-link.h"
34 #include <abi-tag.h>
35 #include <dl-osinfo.h>
37 #include <dl-dst.h>
39 /* On some systems, no flag bits are given to specify file mapping. */
40 #ifndef MAP_FILE
41 # define MAP_FILE 0
42 #endif
44 /* The right way to map in the shared library files is MAP_COPY, which
45 makes a virtual copy of the data at the time of the mmap call; this
46 guarantees the mapped pages will be consistent even if the file is
47 overwritten. Some losing VM systems like Linux's lack MAP_COPY. All we
48 get is MAP_PRIVATE, which copies each page when it is modified; this
49 means if the file is overwritten, we may at some point get some pages
50 from the new version after starting with pages from the old version. */
51 #ifndef MAP_COPY
52 # define MAP_COPY MAP_PRIVATE
53 #endif
55 /* Some systems link their relocatable objects for another base address
56 than 0. We want to know the base address for these such that we can
57 subtract this address from the segment addresses during mapping.
58 This results in a more efficient address space usage. Defaults to
59 zero for almost all systems. */
60 #ifndef MAP_BASE_ADDR
61 # define MAP_BASE_ADDR(l) 0
62 #endif
65 #include <endian.h>
66 #if BYTE_ORDER == BIG_ENDIAN
67 # define byteorder ELFDATA2MSB
68 #elif BYTE_ORDER == LITTLE_ENDIAN
69 # define byteorder ELFDATA2LSB
70 #else
71 # error "Unknown BYTE_ORDER " BYTE_ORDER
72 # define byteorder ELFDATANONE
73 #endif
75 #define STRING(x) __STRING (x)
77 #ifdef MAP_ANON
78 /* The fd is not examined when using MAP_ANON. */
79 # define ANONFD -1
80 #else
81 int _dl_zerofd = -1;
82 # define ANONFD _dl_zerofd
83 #endif
85 /* Handle situations where we have a preferred location in memory for
86 the shared objects. */
87 #ifdef ELF_PREFERRED_ADDRESS_DATA
88 ELF_PREFERRED_ADDRESS_DATA;
89 #endif
90 #ifndef ELF_PREFERRED_ADDRESS
91 # define ELF_PREFERRED_ADDRESS(loader, maplength, mapstartpref) (mapstartpref)
92 #endif
93 #ifndef ELF_FIXED_ADDRESS
94 # define ELF_FIXED_ADDRESS(loader, mapstart) ((void) 0)
95 #endif
97 /* Type for the buffer we put the ELF header and hopefully the program
98 header. This buffer does not really have to be too large. In most
99 cases the program header follows the ELF header directly. If this
100 is not the case all bets are off and we can make the header arbitrarily
101 large and still won't get it read. This means the only question is
102 how large are the ELF and program header combined. The ELF header
103 in 64-bit files is 56 bytes long. Each program header entry is again
104 56 bytes long. I.e., even with a file which has 17 program header
105 entries we only have to read 1kB. And 17 program header entries is
106 plenty, normal files have < 10. If this heuristic should really fail
107 for some file the code in `_dl_map_object_from_fd' knows how to
108 recover. */
109 struct filebuf
111 ssize_t len;
112 char buf[1024] __attribute__ ((aligned (__alignof (ElfW(Ehdr)))));
115 /* This is the decomposed LD_LIBRARY_PATH search path. */
116 static struct r_search_path_struct env_path_list;
118 /* List of the hardware capabilities we might end up using. */
119 static const struct r_strlenpair *capstr;
120 static size_t ncapstr;
121 static size_t max_capstrlen;
124 /* Get the generated information about the trusted directories. */
125 #include "trusted-dirs.h"
127 static const char system_dirs[] = SYSTEM_DIRS;
128 static const size_t system_dirs_len[] =
130 SYSTEM_DIRS_LEN
132 #define nsystem_dirs_len \
133 (sizeof (system_dirs_len) / sizeof (system_dirs_len[0]))
136 /* Local version of `strdup' function. */
137 static inline char *
138 local_strdup (const char *s)
140 size_t len = strlen (s) + 1;
141 void *new = malloc (len);
143 if (new == NULL)
144 return NULL;
146 return (char *) memcpy (new, s, len);
150 static size_t
151 is_dst (const char *start, const char *name, const char *str,
152 int is_path, int secure)
154 size_t len;
155 bool is_curly = false;
157 if (name[0] == '{')
159 is_curly = true;
160 ++name;
163 len = 0;
164 while (name[len] == str[len] && name[len] != '\0')
165 ++len;
167 if (is_curly)
169 if (name[len] != '}')
170 return 0;
172 /* Point again at the beginning of the name. */
173 --name;
174 /* Skip over closing curly brace and adjust for the --name. */
175 len += 2;
177 else if (name[len] != '\0' && name[len] != '/'
178 && (!is_path || name[len] != ':'))
179 return 0;
181 if (__builtin_expect (secure, 0)
182 && ((name[len] != '\0' && (!is_path || name[len] != ':'))
183 || (name != start + 1 && (!is_path || name[-2] != ':'))))
184 return 0;
186 return len;
190 size_t
191 _dl_dst_count (const char *name, int is_path)
193 const char *const start = name;
194 size_t cnt = 0;
198 size_t len;
200 /* $ORIGIN is not expanded for SUID/GUID programs (except if it
201 is $ORIGIN alone) and it must always appear first in path. */
202 ++name;
203 if ((len = is_dst (start, name, "ORIGIN", is_path,
204 INTUSE(__libc_enable_secure))) != 0
205 || (len = is_dst (start, name, "PLATFORM", is_path, 0)) != 0
206 || (len = is_dst (start, name, "LIB", is_path, 0)) != 0)
207 ++cnt;
209 name = strchr (name + len, '$');
211 while (name != NULL);
213 return cnt;
215 INTDEF (_dl_dst_count)
218 char *
219 _dl_dst_substitute (struct link_map *l, const char *name, char *result,
220 int is_path)
222 const char *const start = name;
223 char *last_elem, *wp;
225 /* Now fill the result path. While copying over the string we keep
226 track of the start of the last path element. When we come accross
227 a DST we copy over the value or (if the value is not available)
228 leave the entire path element out. */
229 last_elem = wp = result;
233 if (__builtin_expect (*name == '$', 0))
235 const char *repl = NULL;
236 size_t len;
238 ++name;
239 if ((len = is_dst (start, name, "ORIGIN", is_path,
240 INTUSE(__libc_enable_secure))) != 0)
241 repl = l->l_origin;
242 else if ((len = is_dst (start, name, "PLATFORM", is_path, 0)) != 0)
243 repl = GL(dl_platform);
244 else if ((len = is_dst (start, name, "LIB", is_path, 0)) != 0)
245 repl = DL_DST_LIB;
247 if (repl != NULL && repl != (const char *) -1)
249 wp = __stpcpy (wp, repl);
250 name += len;
252 else if (len > 1)
254 /* We cannot use this path element, the value of the
255 replacement is unknown. */
256 wp = last_elem;
257 name += len;
258 while (*name != '\0' && (!is_path || *name != ':'))
259 ++name;
261 else
262 /* No DST we recognize. */
263 *wp++ = '$';
265 else
267 *wp++ = *name++;
268 if (is_path && *name == ':')
269 last_elem = wp;
272 while (*name != '\0');
274 *wp = '\0';
276 return result;
278 INTDEF (_dl_dst_substitute)
281 /* Return copy of argument with all recognized dynamic string tokens
282 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
283 might not be possible to determine the path from which the object
284 belonging to the map is loaded. In this case the path element
285 containing $ORIGIN is left out. */
286 static char *
287 expand_dynamic_string_token (struct link_map *l, const char *s)
289 /* We make two runs over the string. First we determine how large the
290 resulting string is and then we copy it over. Since this is now
291 frequently executed operation we are looking here not for performance
292 but rather for code size. */
293 size_t cnt;
294 size_t total;
295 char *result;
297 /* Determine the number of DST elements. */
298 cnt = DL_DST_COUNT (s, 1);
300 /* If we do not have to replace anything simply copy the string. */
301 if (__builtin_expect (cnt, 0) == 0)
302 return local_strdup (s);
304 /* Determine the length of the substituted string. */
305 total = DL_DST_REQUIRED (l, s, strlen (s), cnt);
307 /* Allocate the necessary memory. */
308 result = (char *) malloc (total + 1);
309 if (result == NULL)
310 return NULL;
312 return INTUSE(_dl_dst_substitute) (l, s, result, 1);
316 /* Add `name' to the list of names for a particular shared object.
317 `name' is expected to have been allocated with malloc and will
318 be freed if the shared object already has this name.
319 Returns false if the object already had this name. */
320 static void
321 internal_function
322 add_name_to_object (struct link_map *l, const char *name)
324 struct libname_list *lnp, *lastp;
325 struct libname_list *newname;
326 size_t name_len;
328 lastp = NULL;
329 for (lnp = l->l_libname; lnp != NULL; lastp = lnp, lnp = lnp->next)
330 if (strcmp (name, lnp->name) == 0)
331 return;
333 name_len = strlen (name) + 1;
334 newname = (struct libname_list *) malloc (sizeof *newname + name_len);
335 if (newname == NULL)
337 /* No more memory. */
338 INTUSE(_dl_signal_error) (ENOMEM, name, NULL,
339 N_("cannot allocate name record"));
340 return;
342 /* The object should have a libname set from _dl_new_object. */
343 assert (lastp != NULL);
345 newname->name = memcpy (newname + 1, name, name_len);
346 newname->next = NULL;
347 newname->dont_free = 0;
348 lastp->next = newname;
351 /* Standard search directories. */
352 static struct r_search_path_struct rtld_search_dirs;
354 static size_t max_dirnamelen;
356 static inline struct r_search_path_elem **
357 fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
358 int check_trusted, const char *what, const char *where)
360 char *cp;
361 size_t nelems = 0;
363 while ((cp = __strsep (&rpath, sep)) != NULL)
365 struct r_search_path_elem *dirp;
366 size_t len = strlen (cp);
368 /* `strsep' can pass an empty string. This has to be
369 interpreted as `use the current directory'. */
370 if (len == 0)
372 static const char curwd[] = "./";
373 cp = (char *) curwd;
376 /* Remove trailing slashes (except for "/"). */
377 while (len > 1 && cp[len - 1] == '/')
378 --len;
380 /* Now add one if there is none so far. */
381 if (len > 0 && cp[len - 1] != '/')
382 cp[len++] = '/';
384 /* Make sure we don't use untrusted directories if we run SUID. */
385 if (__builtin_expect (check_trusted, 0))
387 const char *trun = system_dirs;
388 size_t idx;
389 int unsecure = 1;
391 /* All trusted directories must be complete names. */
392 if (cp[0] == '/')
394 for (idx = 0; idx < nsystem_dirs_len; ++idx)
396 if (len == system_dirs_len[idx]
397 && memcmp (trun, cp, len) == 0)
399 /* Found it. */
400 unsecure = 0;
401 break;
404 trun += system_dirs_len[idx] + 1;
408 if (unsecure)
409 /* Simply drop this directory. */
410 continue;
413 /* See if this directory is already known. */
414 for (dirp = GL(dl_all_dirs); dirp != NULL; dirp = dirp->next)
415 if (dirp->dirnamelen == len && memcmp (cp, dirp->dirname, len) == 0)
416 break;
418 if (dirp != NULL)
420 /* It is available, see whether it's on our own list. */
421 size_t cnt;
422 for (cnt = 0; cnt < nelems; ++cnt)
423 if (result[cnt] == dirp)
424 break;
426 if (cnt == nelems)
427 result[nelems++] = dirp;
429 else
431 size_t cnt;
432 enum r_dir_status init_val;
433 size_t where_len = where ? strlen (where) + 1 : 0;
435 /* It's a new directory. Create an entry and add it. */
436 dirp = (struct r_search_path_elem *)
437 malloc (sizeof (*dirp) + ncapstr * sizeof (enum r_dir_status)
438 + where_len + len + 1);
439 if (dirp == NULL)
440 INTUSE(_dl_signal_error) (ENOMEM, NULL, NULL,
441 N_("cannot create cache for search path"));
443 dirp->dirname = ((char *) dirp + sizeof (*dirp)
444 + ncapstr * sizeof (enum r_dir_status));
445 *((char *) __mempcpy ((char *) dirp->dirname, cp, len)) = '\0';
446 dirp->dirnamelen = len;
448 if (len > max_dirnamelen)
449 max_dirnamelen = len;
451 /* We have to make sure all the relative directories are
452 never ignored. The current directory might change and
453 all our saved information would be void. */
454 init_val = cp[0] != '/' ? existing : unknown;
455 for (cnt = 0; cnt < ncapstr; ++cnt)
456 dirp->status[cnt] = init_val;
458 dirp->what = what;
459 if (__builtin_expect (where != NULL, 1))
460 dirp->where = memcpy ((char *) dirp + sizeof (*dirp) + len + 1
461 + (ncapstr * sizeof (enum r_dir_status)),
462 where, where_len);
463 else
464 dirp->where = NULL;
466 dirp->next = GL(dl_all_dirs);
467 GL(dl_all_dirs) = dirp;
469 /* Put it in the result array. */
470 result[nelems++] = dirp;
474 /* Terminate the array. */
475 result[nelems] = NULL;
477 return result;
481 static void
482 internal_function
483 decompose_rpath (struct r_search_path_struct *sps,
484 const char *rpath, struct link_map *l, const char *what)
486 /* Make a copy we can work with. */
487 const char *where = l->l_name;
488 char *copy;
489 char *cp;
490 struct r_search_path_elem **result;
491 size_t nelems;
492 /* Initialize to please the compiler. */
493 const char *errstring = NULL;
495 /* First see whether we must forget the RUNPATH and RPATH from this
496 object. */
497 if (__builtin_expect (GL(dl_inhibit_rpath) != NULL, 0)
498 && !INTUSE(__libc_enable_secure))
500 const char *inhp = GL(dl_inhibit_rpath);
504 const char *wp = where;
506 while (*inhp == *wp && *wp != '\0')
508 ++inhp;
509 ++wp;
512 if (*wp == '\0' && (*inhp == '\0' || *inhp == ':'))
514 /* This object is on the list of objects for which the
515 RUNPATH and RPATH must not be used. */
516 result = (struct r_search_path_elem **)
517 malloc (sizeof (*result));
518 if (result == NULL)
520 signal_error_cache:
521 errstring = N_("cannot create cache for search path");
522 signal_error:
523 INTUSE(_dl_signal_error) (ENOMEM, NULL, NULL, errstring);
526 result[0] = NULL;
528 sps->dirs = result;
529 sps->malloced = 1;
531 return;
534 while (*inhp != '\0')
535 if (*inhp++ == ':')
536 break;
538 while (*inhp != '\0');
541 /* Make a writable copy. At the same time expand possible dynamic
542 string tokens. */
543 copy = expand_dynamic_string_token (l, rpath);
544 if (copy == NULL)
546 errstring = N_("cannot create RUNPATH/RPATH copy");
547 goto signal_error;
550 /* Count the number of necessary elements in the result array. */
551 nelems = 0;
552 for (cp = copy; *cp != '\0'; ++cp)
553 if (*cp == ':')
554 ++nelems;
556 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
557 number of necessary entries. */
558 result = (struct r_search_path_elem **) malloc ((nelems + 1 + 1)
559 * sizeof (*result));
560 if (result == NULL)
561 goto signal_error_cache;
563 fillin_rpath (copy, result, ":", 0, what, where);
565 /* Free the copied RPATH string. `fillin_rpath' make own copies if
566 necessary. */
567 free (copy);
569 sps->dirs = result;
570 /* The caller will change this value if we haven't used a real malloc. */
571 sps->malloced = 1;
575 void
576 internal_function
577 _dl_init_paths (const char *llp)
579 size_t idx;
580 const char *strp;
581 struct r_search_path_elem *pelem, **aelem;
582 size_t round_size;
583 #ifdef SHARED
584 struct link_map *l;
585 #endif
586 /* Initialize to please the compiler. */
587 const char *errstring = NULL;
589 /* Fill in the information about the application's RPATH and the
590 directories addressed by the LD_LIBRARY_PATH environment variable. */
592 /* Get the capabilities. */
593 capstr = _dl_important_hwcaps (GL(dl_platform), GL(dl_platformlen),
594 &ncapstr, &max_capstrlen);
596 /* First set up the rest of the default search directory entries. */
597 aelem = rtld_search_dirs.dirs = (struct r_search_path_elem **)
598 malloc ((nsystem_dirs_len + 1) * sizeof (struct r_search_path_elem *));
599 if (rtld_search_dirs.dirs == NULL)
601 errstring = N_("cannot create search path array");
602 signal_error:
603 INTUSE(_dl_signal_error) (ENOMEM, NULL, NULL, errstring);
606 round_size = ((2 * sizeof (struct r_search_path_elem) - 1
607 + ncapstr * sizeof (enum r_dir_status))
608 / sizeof (struct r_search_path_elem));
610 rtld_search_dirs.dirs[0] = (struct r_search_path_elem *)
611 malloc ((sizeof (system_dirs) / sizeof (system_dirs[0]))
612 * round_size * sizeof (struct r_search_path_elem));
613 if (rtld_search_dirs.dirs[0] == NULL)
615 errstring = N_("cannot create cache for search path");
616 goto signal_error;
619 rtld_search_dirs.malloced = 0;
620 pelem = GL(dl_all_dirs) = rtld_search_dirs.dirs[0];
621 strp = system_dirs;
622 idx = 0;
626 size_t cnt;
628 *aelem++ = pelem;
630 pelem->what = "system search path";
631 pelem->where = NULL;
633 pelem->dirname = strp;
634 pelem->dirnamelen = system_dirs_len[idx];
635 strp += system_dirs_len[idx] + 1;
637 /* System paths must be absolute. */
638 assert (pelem->dirname[0] == '/');
639 for (cnt = 0; cnt < ncapstr; ++cnt)
640 pelem->status[cnt] = unknown;
642 pelem->next = (++idx == nsystem_dirs_len ? NULL : (pelem + round_size));
644 pelem += round_size;
646 while (idx < nsystem_dirs_len);
648 max_dirnamelen = SYSTEM_DIRS_MAX_LEN;
649 *aelem = NULL;
651 #ifdef SHARED
652 /* This points to the map of the main object. */
653 l = GL(dl_loaded);
654 if (l != NULL)
656 assert (l->l_type != lt_loaded);
658 if (l->l_info[DT_RUNPATH])
660 /* Allocate room for the search path and fill in information
661 from RUNPATH. */
662 decompose_rpath (&l->l_runpath_dirs,
663 (const void *) (D_PTR (l, l_info[DT_STRTAB])
664 + l->l_info[DT_RUNPATH]->d_un.d_val),
665 l, "RUNPATH");
667 /* The RPATH is ignored. */
668 l->l_rpath_dirs.dirs = (void *) -1;
670 else
672 l->l_runpath_dirs.dirs = (void *) -1;
674 if (l->l_info[DT_RPATH])
676 /* Allocate room for the search path and fill in information
677 from RPATH. */
678 decompose_rpath (&l->l_rpath_dirs,
679 (const void *) (D_PTR (l, l_info[DT_STRTAB])
680 + l->l_info[DT_RPATH]->d_un.d_val),
681 l, "RPATH");
682 l->l_rpath_dirs.malloced = 0;
684 else
685 l->l_rpath_dirs.dirs = (void *) -1;
688 #endif /* SHARED */
690 if (llp != NULL && *llp != '\0')
692 size_t nllp;
693 const char *cp = llp;
694 char *llp_tmp = strdupa (llp);
696 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
697 elements it has. */
698 nllp = 1;
699 while (*cp)
701 if (*cp == ':' || *cp == ';')
702 ++nllp;
703 ++cp;
706 env_path_list.dirs = (struct r_search_path_elem **)
707 malloc ((nllp + 1) * sizeof (struct r_search_path_elem *));
708 if (env_path_list.dirs == NULL)
710 errstring = N_("cannot create cache for search path");
711 goto signal_error;
714 (void) fillin_rpath (llp_tmp, env_path_list.dirs, ":;",
715 INTUSE(__libc_enable_secure), "LD_LIBRARY_PATH",
716 NULL);
718 if (env_path_list.dirs[0] == NULL)
720 free (env_path_list.dirs);
721 env_path_list.dirs = (void *) -1;
724 env_path_list.malloced = 0;
726 else
727 env_path_list.dirs = (void *) -1;
729 /* Remember the last search directory added at startup. */
730 GL(dl_init_all_dirs) = GL(dl_all_dirs);
734 /* Think twice before changing anything in this function. It is placed
735 here and prepared using the `alloca' magic to prevent it from being
736 inlined. The function is only called in case of an error. But then
737 performance does not count. The function used to be "inlinable" and
738 the compiled did so all the time. This increased the code size for
739 absolutely no good reason. */
740 static void
741 __attribute__ ((noreturn))
742 lose (int code, int fd, const char *name, char *realname, struct link_map *l,
743 const char *msg)
745 /* The use of `alloca' here looks ridiculous but it helps. The goal
746 is to avoid the function from being inlined. There is no official
747 way to do this so we use this trick. gcc never inlines functions
748 which use `alloca'. */
749 int *a = (int *) alloca (sizeof (int));
750 a[0] = fd;
751 /* The file might already be closed. */
752 if (a[0] != -1)
753 (void) __close (a[0]);
754 if (l != NULL)
756 /* Remove the stillborn object from the list and free it. */
757 assert (l->l_next == NULL);
758 if (l->l_prev == NULL)
759 /* No other module loaded. This happens only in the static library,
760 or in rtld under --verify. */
761 GL(dl_loaded) = NULL;
762 else
763 l->l_prev->l_next = NULL;
764 --GL(dl_nloaded);
765 free (l);
767 free (realname);
768 INTUSE(_dl_signal_error) (code, name, NULL, msg);
772 /* Map in the shared object NAME, actually located in REALNAME, and already
773 opened on FD. */
775 #ifndef EXTERNAL_MAP_FROM_FD
776 static
777 #endif
778 struct link_map *
779 _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp,
780 char *realname, struct link_map *loader, int l_type,
781 int mode)
783 struct link_map *l = NULL;
784 const ElfW(Ehdr) *header;
785 const ElfW(Phdr) *phdr;
786 const ElfW(Phdr) *ph;
787 size_t maplength;
788 int type;
789 struct stat64 st;
790 /* Initialize to keep the compiler happy. */
791 const char *errstring = NULL;
792 int errval = 0;
794 /* Get file information. */
795 if (__builtin_expect (__fxstat64 (_STAT_VER, fd, &st) < 0, 0))
797 errstring = N_("cannot stat shared object");
798 call_lose_errno:
799 errval = errno;
800 call_lose:
801 lose (errval, fd, name, realname, l, errstring);
804 /* Look again to see if the real name matched another already loaded. */
805 for (l = GL(dl_loaded); l; l = l->l_next)
806 if (l->l_ino == st.st_ino && l->l_dev == st.st_dev)
808 /* The object is already loaded.
809 Just bump its reference count and return it. */
810 __close (fd);
812 /* If the name is not in the list of names for this object add
813 it. */
814 free (realname);
815 add_name_to_object (l, name);
817 return l;
820 if (mode & RTLD_NOLOAD)
821 /* We are not supposed to load the object unless it is already
822 loaded. So return now. */
823 return NULL;
825 /* Print debugging message. */
826 if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_FILES, 0))
827 INTUSE(_dl_debug_printf) ("file=%s; generating link map\n", name);
829 /* This is the ELF header. We read it in `open_verify'. */
830 header = (void *) fbp->buf;
832 #ifndef MAP_ANON
833 # define MAP_ANON 0
834 if (_dl_zerofd == -1)
836 _dl_zerofd = _dl_sysdep_open_zero_fill ();
837 if (_dl_zerofd == -1)
839 __close (fd);
840 INTUSE(_dl_signal_error) (errno, NULL, NULL,
841 N_("cannot open zero fill device"));
844 #endif
846 /* Enter the new object in the list of loaded objects. */
847 l = _dl_new_object (realname, name, l_type, loader);
848 if (__builtin_expect (! l, 0))
850 errstring = N_("cannot create shared object descriptor");
851 goto call_lose_errno;
854 /* Extract the remaining details we need from the ELF header
855 and then read in the program header table. */
856 l->l_entry = header->e_entry;
857 type = header->e_type;
858 l->l_phnum = header->e_phnum;
860 maplength = header->e_phnum * sizeof (ElfW(Phdr));
861 if (header->e_phoff + maplength <= (size_t) fbp->len)
862 phdr = (void *) (fbp->buf + header->e_phoff);
863 else
865 phdr = alloca (maplength);
866 __lseek (fd, header->e_phoff, SEEK_SET);
867 if ((size_t) __libc_read (fd, (void *) phdr, maplength) != maplength)
869 errstring = N_("cannot read file data");
870 goto call_lose_errno;
875 /* Scan the program header table, collecting its load commands. */
876 struct loadcmd
878 ElfW(Addr) mapstart, mapend, dataend, allocend;
879 off_t mapoff;
880 int prot;
881 } loadcmds[l->l_phnum], *c;
882 size_t nloadcmds = 0;
884 /* The struct is initialized to zero so this is not necessary:
885 l->l_ld = 0;
886 l->l_phdr = 0;
887 l->l_addr = 0; */
888 for (ph = phdr; ph < &phdr[l->l_phnum]; ++ph)
889 switch (ph->p_type)
891 /* These entries tell us where to find things once the file's
892 segments are mapped in. We record the addresses it says
893 verbatim, and later correct for the run-time load address. */
894 case PT_DYNAMIC:
895 l->l_ld = (void *) ph->p_vaddr;
896 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
897 break;
899 case PT_PHDR:
900 l->l_phdr = (void *) ph->p_vaddr;
901 break;
903 case PT_LOAD:
904 /* A load command tells us to map in part of the file.
905 We record the load commands and process them all later. */
906 if (__builtin_expect ((ph->p_align & (GL(dl_pagesize) - 1)) != 0,
909 errstring = N_("ELF load command alignment not page-aligned");
910 goto call_lose;
912 if (__builtin_expect (((ph->p_vaddr - ph->p_offset)
913 & (ph->p_align - 1)) != 0, 0))
915 errstring
916 = N_("ELF load command address/offset not properly aligned");
917 goto call_lose;
920 c = &loadcmds[nloadcmds++];
921 c->mapstart = ph->p_vaddr & ~(ph->p_align - 1);
922 c->mapend = ((ph->p_vaddr + ph->p_filesz + GL(dl_pagesize) - 1)
923 & ~(GL(dl_pagesize) - 1));
924 c->dataend = ph->p_vaddr + ph->p_filesz;
925 c->allocend = ph->p_vaddr + ph->p_memsz;
926 c->mapoff = ph->p_offset & ~(ph->p_align - 1);
928 /* Optimize a common case. */
929 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
930 c->prot = (PF_TO_PROT
931 >> ((ph->p_flags & (PF_R | PF_W | PF_X)) * 4)) & 0xf;
932 #else
933 c->prot = 0;
934 if (ph->p_flags & PF_R)
935 c->prot |= PROT_READ;
936 if (ph->p_flags & PF_W)
937 c->prot |= PROT_WRITE;
938 if (ph->p_flags & PF_X)
939 c->prot |= PROT_EXEC;
940 #endif
941 break;
943 case PT_TLS:
944 #ifdef USE_TLS
945 if (ph->p_memsz > 0)
947 l->l_tls_blocksize = ph->p_memsz;
948 l->l_tls_align = ph->p_align;
949 l->l_tls_initimage_size = ph->p_filesz;
950 /* Since we don't know the load address yet only store the
951 offset. We will adjust it later. */
952 l->l_tls_initimage = (void *) ph->p_vaddr;
954 /* Assign the next available module ID. */
955 l->l_tls_modid = _dl_next_tls_modid ();
957 #else
958 /* Uh-oh, the binary expects TLS support but we cannot
959 provide it. */
960 errval = 0;
961 errstring = N_("cannot handle TLS data");
962 goto call_lose;
963 #endif
964 break;
967 /* Now process the load commands and map segments into memory. */
968 c = loadcmds;
970 /* Length of the sections to be loaded. */
971 maplength = loadcmds[nloadcmds - 1].allocend - c->mapstart;
973 if (__builtin_expect (type, ET_DYN) == ET_DYN)
975 /* This is a position-independent shared object. We can let the
976 kernel map it anywhere it likes, but we must have space for all
977 the segments in their specified positions relative to the first.
978 So we map the first segment without MAP_FIXED, but with its
979 extent increased to cover all the segments. Then we remove
980 access from excess portion, and there is known sufficient space
981 there to remap from the later segments.
983 As a refinement, sometimes we have an address that we would
984 prefer to map such objects at; but this is only a preference,
985 the OS can do whatever it likes. */
986 ElfW(Addr) mappref;
987 mappref = (ELF_PREFERRED_ADDRESS (loader, maplength, c->mapstart)
988 - MAP_BASE_ADDR (l));
990 /* Remember which part of the address space this object uses. */
991 l->l_map_start = (ElfW(Addr)) __mmap ((void *) mappref, maplength,
992 c->prot, MAP_COPY | MAP_FILE,
993 fd, c->mapoff);
994 if (__builtin_expect ((void *) l->l_map_start == MAP_FAILED, 0))
996 map_error:
997 errstring = N_("failed to map segment from shared object");
998 goto call_lose_errno;
1001 l->l_map_end = l->l_map_start + maplength;
1002 l->l_addr = l->l_map_start - c->mapstart;
1004 /* Change protection on the excess portion to disallow all access;
1005 the portions we do not remap later will be inaccessible as if
1006 unallocated. Then jump into the normal segment-mapping loop to
1007 handle the portion of the segment past the end of the file
1008 mapping. */
1009 __mprotect ((caddr_t) (l->l_addr + c->mapend),
1010 loadcmds[nloadcmds - 1].allocend - c->mapend,
1011 PROT_NONE);
1013 goto postmap;
1015 else
1017 /* This object is loaded at a fixed address. This must never
1018 happen for objects loaded with dlopen(). */
1019 if (__builtin_expect (mode & __RTLD_DLOPEN, 0))
1021 errstring = N_("cannot dynamically load executable");
1022 goto call_lose;
1025 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1026 fixed. */
1027 ELF_FIXED_ADDRESS (loader, c->mapstart);
1030 /* Remember which part of the address space this object uses. */
1031 l->l_map_start = c->mapstart + l->l_addr;
1032 l->l_map_end = l->l_map_start + maplength;
1034 while (c < &loadcmds[nloadcmds])
1036 if (c->mapend > c->mapstart
1037 /* Map the segment contents from the file. */
1038 && (__mmap ((void *) (l->l_addr + c->mapstart),
1039 c->mapend - c->mapstart, c->prot,
1040 MAP_FIXED | MAP_COPY | MAP_FILE, fd, c->mapoff)
1041 == MAP_FAILED))
1042 goto map_error;
1044 postmap:
1045 if (l->l_phdr == 0
1046 && (ElfW(Off)) c->mapoff <= header->e_phoff
1047 && ((size_t) (c->mapend - c->mapstart + c->mapoff)
1048 >= header->e_phoff + header->e_phnum * sizeof (ElfW(Phdr))))
1049 /* Found the program header in this segment. */
1050 l->l_phdr = (void *) (c->mapstart + header->e_phoff - c->mapoff);
1052 if (c->allocend > c->dataend)
1054 /* Extra zero pages should appear at the end of this segment,
1055 after the data mapped from the file. */
1056 ElfW(Addr) zero, zeroend, zeropage;
1058 zero = l->l_addr + c->dataend;
1059 zeroend = l->l_addr + c->allocend;
1060 zeropage = ((zero + GL(dl_pagesize) - 1)
1061 & ~(GL(dl_pagesize) - 1));
1063 if (zeroend < zeropage)
1064 /* All the extra data is in the last page of the segment.
1065 We can just zero it. */
1066 zeropage = zeroend;
1068 if (zeropage > zero)
1070 /* Zero the final part of the last page of the segment. */
1071 if ((c->prot & PROT_WRITE) == 0)
1073 /* Dag nab it. */
1074 if (__builtin_expect (__mprotect ((caddr_t)
1075 (zero
1076 & ~(GL(dl_pagesize)
1077 - 1)),
1078 GL(dl_pagesize),
1079 c->prot|PROT_WRITE) < 0,
1082 errstring = N_("cannot change memory protections");
1083 goto call_lose_errno;
1086 memset ((void *) zero, '\0', zeropage - zero);
1087 if ((c->prot & PROT_WRITE) == 0)
1088 __mprotect ((caddr_t) (zero & ~(GL(dl_pagesize) - 1)),
1089 GL(dl_pagesize), c->prot);
1092 if (zeroend > zeropage)
1094 /* Map the remaining zero pages in from the zero fill FD. */
1095 caddr_t mapat;
1096 mapat = __mmap ((caddr_t) zeropage, zeroend - zeropage,
1097 c->prot, MAP_ANON|MAP_PRIVATE|MAP_FIXED,
1098 ANONFD, 0);
1099 if (__builtin_expect (mapat == MAP_FAILED, 0))
1101 errstring = N_("cannot map zero-fill pages");
1102 goto call_lose_errno;
1107 ++c;
1110 if (l->l_phdr == NULL)
1112 /* The program header is not contained in any of the segments.
1113 We have to allocate memory ourself and copy it over from
1114 out temporary place. */
1115 ElfW(Phdr) *newp = (ElfW(Phdr) *) malloc (header->e_phnum
1116 * sizeof (ElfW(Phdr)));
1117 if (newp == NULL)
1119 errstring = N_("cannot allocate memory for program header");
1120 goto call_lose_errno;
1123 l->l_phdr = memcpy (newp, phdr,
1124 (header->e_phnum * sizeof (ElfW(Phdr))));
1125 l->l_phdr_allocated = 1;
1127 else
1128 /* Adjust the PT_PHDR value by the runtime load address. */
1129 (ElfW(Addr)) l->l_phdr += l->l_addr;
1132 #ifdef USE_TLS
1133 /* Adjust the address of the TLS initialization image. */
1134 if (l->l_tls_initimage != NULL)
1135 l->l_tls_initimage = (char *) l->l_tls_initimage + l->l_addr;
1136 #endif
1138 /* We are done mapping in the file. We no longer need the descriptor. */
1139 __close (fd);
1140 /* Signal that we closed the file. */
1141 fd = -1;
1143 if (l->l_type == lt_library && type == ET_EXEC)
1144 l->l_type = lt_executable;
1146 if (l->l_ld == 0)
1148 if (__builtin_expect (type == ET_DYN, 0))
1150 errstring = N_("object file has no dynamic section");
1151 goto call_lose;
1154 else
1155 (ElfW(Addr)) l->l_ld += l->l_addr;
1157 l->l_entry += l->l_addr;
1159 if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_FILES, 0))
1160 INTUSE(_dl_debug_printf) ("\
1161 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1162 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1163 (int) sizeof (void *) * 2,
1164 (unsigned long int) l->l_ld,
1165 (int) sizeof (void *) * 2,
1166 (unsigned long int) l->l_addr,
1167 (int) sizeof (void *) * 2, maplength,
1168 (int) sizeof (void *) * 2,
1169 (unsigned long int) l->l_entry,
1170 (int) sizeof (void *) * 2,
1171 (unsigned long int) l->l_phdr,
1172 (int) sizeof (void *) * 2, l->l_phnum);
1174 elf_get_dynamic_info (l);
1176 /* Make sure we are not dlopen'ing an object
1177 that has the DF_1_NOOPEN flag set. */
1178 if (__builtin_expect (l->l_flags_1 & DF_1_NOOPEN, 0)
1179 && (mode & __RTLD_DLOPEN))
1181 /* We are not supposed to load this object. Free all resources. */
1182 __munmap ((void *) l->l_map_start, l->l_map_end - l->l_map_start);
1184 if (!l->l_libname->dont_free)
1185 free (l->l_libname);
1187 if (l->l_phdr_allocated)
1188 free ((void *) l->l_phdr);
1190 errstring = N_("shared object cannot be dlopen()ed");
1191 goto call_lose;
1194 if (l->l_info[DT_HASH])
1195 _dl_setup_hash (l);
1197 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1198 have to do this for the main map. */
1199 if (__builtin_expect (l->l_info[DT_SYMBOLIC] != NULL, 0)
1200 && &l->l_searchlist != l->l_scope[0])
1202 /* Create an appropriate searchlist. It contains only this map.
1204 XXX This is the definition of DT_SYMBOLIC in SysVr4. The old
1205 GNU ld.so implementation had a different interpretation which
1206 is more reasonable. We are prepared to add this possibility
1207 back as part of a GNU extension of the ELF format. */
1208 l->l_symbolic_searchlist.r_list =
1209 (struct link_map **) malloc (sizeof (struct link_map *));
1211 if (l->l_symbolic_searchlist.r_list == NULL)
1213 errstring = N_("cannot create searchlist");
1214 goto call_lose_errno;
1217 l->l_symbolic_searchlist.r_list[0] = l;
1218 l->l_symbolic_searchlist.r_nlist = 1;
1220 /* Now move the existing entries one back. */
1221 memmove (&l->l_scope[1], &l->l_scope[0],
1222 (l->l_scope_max - 1) * sizeof (l->l_scope[0]));
1224 /* Now add the new entry. */
1225 l->l_scope[0] = &l->l_symbolic_searchlist;
1228 /* Remember whether this object must be initialized first. */
1229 if (l->l_flags_1 & DF_1_INITFIRST)
1230 GL(dl_initfirst) = l;
1232 /* Finally the file information. */
1233 l->l_dev = st.st_dev;
1234 l->l_ino = st.st_ino;
1236 /* When we profile the SONAME might be needed for something else but
1237 loading. Add it right away. */
1238 if (__builtin_expect (GL(dl_profile) != NULL, 0)
1239 && l->l_info[DT_SONAME] != NULL)
1240 add_name_to_object (l, ((const char *) D_PTR (l, l_info[DT_STRTAB])
1241 + l->l_info[DT_SONAME]->d_un.d_val));
1243 return l;
1246 /* Print search path. */
1247 static void
1248 print_search_path (struct r_search_path_elem **list,
1249 const char *what, const char *name)
1251 char buf[max_dirnamelen + max_capstrlen];
1252 int first = 1;
1254 INTUSE(_dl_debug_printf) (" search path=");
1256 while (*list != NULL && (*list)->what == what) /* Yes, ==. */
1258 char *endp = __mempcpy (buf, (*list)->dirname, (*list)->dirnamelen);
1259 size_t cnt;
1261 for (cnt = 0; cnt < ncapstr; ++cnt)
1262 if ((*list)->status[cnt] != nonexisting)
1264 char *cp = __mempcpy (endp, capstr[cnt].str, capstr[cnt].len);
1265 if (cp == buf || (cp == buf + 1 && buf[0] == '/'))
1266 cp[0] = '\0';
1267 else
1268 cp[-1] = '\0';
1270 _dl_debug_printf_c (first ? "%s" : ":%s", buf);
1271 first = 0;
1274 ++list;
1277 if (name != NULL)
1278 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what,
1279 name[0] ? name : rtld_progname);
1280 else
1281 _dl_debug_printf_c ("\t\t(%s)\n", what);
1284 /* Open a file and verify it is an ELF file for this architecture. We
1285 ignore only ELF files for other architectures. Non-ELF files and
1286 ELF files with different header information cause fatal errors since
1287 this could mean there is something wrong in the installation and the
1288 user might want to know about this. */
1289 static int
1290 open_verify (const char *name, struct filebuf *fbp)
1292 /* This is the expected ELF header. */
1293 #define ELF32_CLASS ELFCLASS32
1294 #define ELF64_CLASS ELFCLASS64
1295 #ifndef VALID_ELF_HEADER
1296 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1297 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1298 # define VALID_ELF_ABIVERSION(ver) (ver == 0)
1299 #endif
1300 static const unsigned char expected[EI_PAD] =
1302 [EI_MAG0] = ELFMAG0,
1303 [EI_MAG1] = ELFMAG1,
1304 [EI_MAG2] = ELFMAG2,
1305 [EI_MAG3] = ELFMAG3,
1306 [EI_CLASS] = ELFW(CLASS),
1307 [EI_DATA] = byteorder,
1308 [EI_VERSION] = EV_CURRENT,
1309 [EI_OSABI] = ELFOSABI_SYSV,
1310 [EI_ABIVERSION] = 0
1312 static const struct
1314 ElfW(Word) vendorlen;
1315 ElfW(Word) datalen;
1316 ElfW(Word) type;
1317 char vendor[4];
1318 } expected_note = { 4, 16, 1, "GNU" };
1319 int fd;
1320 /* Initialize it to make the compiler happy. */
1321 const char *errstring = NULL;
1322 int errval = 0;
1324 /* Open the file. We always open files read-only. */
1325 fd = __open (name, O_RDONLY);
1326 if (fd != -1)
1328 ElfW(Ehdr) *ehdr;
1329 ElfW(Phdr) *phdr, *ph;
1330 ElfW(Word) *abi_note, abi_note_buf[8];
1331 unsigned int osversion;
1332 size_t maplength;
1334 /* We successfully openened the file. Now verify it is a file
1335 we can use. */
1336 __set_errno (0);
1337 fbp->len = __libc_read (fd, fbp->buf, sizeof (fbp->buf));
1339 /* This is where the ELF header is loaded. */
1340 assert (sizeof (fbp->buf) > sizeof (ElfW(Ehdr)));
1341 ehdr = (ElfW(Ehdr) *) fbp->buf;
1343 /* Now run the tests. */
1344 if (__builtin_expect (fbp->len < (ssize_t) sizeof (ElfW(Ehdr)), 0))
1346 errval = errno;
1347 errstring = (errval == 0
1348 ? N_("file too short") : N_("cannot read file data"));
1349 call_lose:
1350 lose (errval, fd, name, NULL, NULL, errstring);
1353 /* See whether the ELF header is what we expect. */
1354 if (__builtin_expect (! VALID_ELF_HEADER (ehdr->e_ident, expected,
1355 EI_PAD), 0))
1357 /* Something is wrong. */
1358 if (*(Elf32_Word *) &ehdr->e_ident !=
1359 #if BYTE_ORDER == LITTLE_ENDIAN
1360 ((ELFMAG0 << (EI_MAG0 * 8)) |
1361 (ELFMAG1 << (EI_MAG1 * 8)) |
1362 (ELFMAG2 << (EI_MAG2 * 8)) |
1363 (ELFMAG3 << (EI_MAG3 * 8)))
1364 #else
1365 ((ELFMAG0 << (EI_MAG3 * 8)) |
1366 (ELFMAG1 << (EI_MAG2 * 8)) |
1367 (ELFMAG2 << (EI_MAG1 * 8)) |
1368 (ELFMAG3 << (EI_MAG0 * 8)))
1369 #endif
1371 errstring = N_("invalid ELF header");
1372 else if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS))
1373 /* This is not a fatal error. On architectures where
1374 32-bit and 64-bit binaries can be run this might
1375 happen. */
1376 goto close_and_out;
1377 else if (ehdr->e_ident[EI_DATA] != byteorder)
1379 if (BYTE_ORDER == BIG_ENDIAN)
1380 errstring = N_("ELF file data encoding not big-endian");
1381 else
1382 errstring = N_("ELF file data encoding not little-endian");
1384 else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT)
1385 errstring
1386 = N_("ELF file version ident does not match current one");
1387 /* XXX We should be able so set system specific versions which are
1388 allowed here. */
1389 else if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI]))
1390 errstring = N_("ELF file OS ABI invalid");
1391 else if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_ABIVERSION]))
1392 errstring = N_("ELF file ABI version invalid");
1393 else
1394 /* Otherwise we don't know what went wrong. */
1395 errstring = N_("internal error");
1397 goto call_lose;
1400 if (__builtin_expect (ehdr->e_version, EV_CURRENT) != EV_CURRENT)
1402 errstring = N_("ELF file version does not match current one");
1403 goto call_lose;
1405 if (! __builtin_expect (elf_machine_matches_host (ehdr), 1))
1406 goto close_and_out;
1407 else if (__builtin_expect (ehdr->e_phentsize, sizeof (ElfW(Phdr)))
1408 != sizeof (ElfW(Phdr)))
1410 errstring = N_("ELF file's phentsize not the expected size");
1411 goto call_lose;
1413 else if (__builtin_expect (ehdr->e_type, ET_DYN) != ET_DYN
1414 && __builtin_expect (ehdr->e_type, ET_EXEC) != ET_EXEC)
1416 errstring = N_("only ET_DYN and ET_EXEC can be loaded");
1417 goto call_lose;
1420 maplength = ehdr->e_phnum * sizeof (ElfW(Phdr));
1421 if (ehdr->e_phoff + maplength <= (size_t) fbp->len)
1422 phdr = (void *) (fbp->buf + ehdr->e_phoff);
1423 else
1425 phdr = alloca (maplength);
1426 __lseek (fd, ehdr->e_phoff, SEEK_SET);
1427 if ((size_t) __libc_read (fd, (void *) phdr, maplength) != maplength)
1429 read_error:
1430 errval = errno;
1431 errstring = N_("cannot read file data");
1432 goto call_lose;
1436 /* Check .note.ABI-tag if present. */
1437 for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
1438 if (ph->p_type == PT_NOTE && ph->p_filesz == 32 && ph->p_align >= 4)
1440 if (ph->p_offset + 32 <= (size_t) fbp->len)
1441 abi_note = (void *) (fbp->buf + ph->p_offset);
1442 else
1444 __lseek (fd, ph->p_offset, SEEK_SET);
1445 if (__libc_read (fd, (void *) abi_note_buf, 32) != 32)
1446 goto read_error;
1448 abi_note = abi_note_buf;
1451 if (memcmp (abi_note, &expected_note, sizeof (expected_note)))
1452 continue;
1454 osversion = (abi_note[5] & 0xff) * 65536
1455 + (abi_note[6] & 0xff) * 256
1456 + (abi_note[7] & 0xff);
1457 if (abi_note[4] != __ABI_TAG_OS
1458 || (GL(dl_osversion) && GL(dl_osversion) < osversion))
1460 close_and_out:
1461 __close (fd);
1462 __set_errno (ENOENT);
1463 fd = -1;
1466 break;
1470 return fd;
1473 /* Try to open NAME in one of the directories in *DIRSP.
1474 Return the fd, or -1. If successful, fill in *REALNAME
1475 with the malloc'd full directory name. If it turns out
1476 that none of the directories in *DIRSP exists, *DIRSP is
1477 replaced with (void *) -1, and the old value is free()d
1478 if MAY_FREE_DIRS is true. */
1480 static int
1481 open_path (const char *name, size_t namelen, int preloaded,
1482 struct r_search_path_struct *sps, char **realname,
1483 struct filebuf *fbp)
1485 struct r_search_path_elem **dirs = sps->dirs;
1486 char *buf;
1487 int fd = -1;
1488 const char *current_what = NULL;
1489 int any = 0;
1491 buf = alloca (max_dirnamelen + max_capstrlen + namelen);
1494 struct r_search_path_elem *this_dir = *dirs;
1495 size_t buflen = 0;
1496 size_t cnt;
1497 char *edp;
1498 int here_any = 0;
1499 int err;
1501 /* If we are debugging the search for libraries print the path
1502 now if it hasn't happened now. */
1503 if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_LIBS, 0)
1504 && current_what != this_dir->what)
1506 current_what = this_dir->what;
1507 print_search_path (dirs, current_what, this_dir->where);
1510 edp = (char *) __mempcpy (buf, this_dir->dirname, this_dir->dirnamelen);
1511 for (cnt = 0; fd == -1 && cnt < ncapstr; ++cnt)
1513 /* Skip this directory if we know it does not exist. */
1514 if (this_dir->status[cnt] == nonexisting)
1515 continue;
1517 buflen =
1518 ((char *) __mempcpy (__mempcpy (edp, capstr[cnt].str,
1519 capstr[cnt].len),
1520 name, namelen)
1521 - buf);
1523 /* Print name we try if this is wanted. */
1524 if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_LIBS, 0))
1525 INTUSE(_dl_debug_printf) (" trying file=%s\n", buf);
1527 fd = open_verify (buf, fbp);
1528 if (this_dir->status[cnt] == unknown)
1530 if (fd != -1)
1531 this_dir->status[cnt] = existing;
1532 else
1534 /* We failed to open machine dependent library. Let's
1535 test whether there is any directory at all. */
1536 struct stat64 st;
1538 buf[buflen - namelen - 1] = '\0';
1540 if (__xstat64 (_STAT_VER, buf, &st) != 0
1541 || ! S_ISDIR (st.st_mode))
1542 /* The directory does not exist or it is no directory. */
1543 this_dir->status[cnt] = nonexisting;
1544 else
1545 this_dir->status[cnt] = existing;
1549 /* Remember whether we found any existing directory. */
1550 here_any |= this_dir->status[cnt] == existing;
1552 if (fd != -1 && __builtin_expect (preloaded, 0)
1553 && INTUSE(__libc_enable_secure))
1555 /* This is an extra security effort to make sure nobody can
1556 preload broken shared objects which are in the trusted
1557 directories and so exploit the bugs. */
1558 struct stat64 st;
1560 if (__fxstat64 (_STAT_VER, fd, &st) != 0
1561 || (st.st_mode & S_ISUID) == 0)
1563 /* The shared object cannot be tested for being SUID
1564 or this bit is not set. In this case we must not
1565 use this object. */
1566 __close (fd);
1567 fd = -1;
1568 /* We simply ignore the file, signal this by setting
1569 the error value which would have been set by `open'. */
1570 errno = ENOENT;
1575 if (fd != -1)
1577 *realname = (char *) malloc (buflen);
1578 if (*realname != NULL)
1580 memcpy (*realname, buf, buflen);
1581 return fd;
1583 else
1585 /* No memory for the name, we certainly won't be able
1586 to load and link it. */
1587 __close (fd);
1588 return -1;
1591 if (here_any && (err = errno) != ENOENT && err != EACCES)
1592 /* The file exists and is readable, but something went wrong. */
1593 return -1;
1595 /* Remember whether we found anything. */
1596 any |= here_any;
1598 while (*++dirs != NULL);
1600 /* Remove the whole path if none of the directories exists. */
1601 if (__builtin_expect (! any, 0))
1603 /* Paths which were allocated using the minimal malloc() in ld.so
1604 must not be freed using the general free() in libc. */
1605 if (sps->malloced)
1606 free (sps->dirs);
1607 sps->dirs = (void *) -1;
1610 return -1;
1613 /* Map in the shared object file NAME. */
1615 struct link_map *
1616 internal_function
1617 _dl_map_object (struct link_map *loader, const char *name, int preloaded,
1618 int type, int trace_mode, int mode)
1620 int fd;
1621 char *realname;
1622 char *name_copy;
1623 struct link_map *l;
1624 struct filebuf fb;
1626 /* Look for this name among those already loaded. */
1627 for (l = GL(dl_loaded); l; l = l->l_next)
1629 /* If the requested name matches the soname of a loaded object,
1630 use that object. Elide this check for names that have not
1631 yet been opened. */
1632 if (__builtin_expect (l->l_faked, 0) != 0)
1633 continue;
1634 if (!_dl_name_match_p (name, l))
1636 const char *soname;
1638 if (__builtin_expect (l->l_soname_added, 1)
1639 || l->l_info[DT_SONAME] == NULL)
1640 continue;
1642 soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
1643 + l->l_info[DT_SONAME]->d_un.d_val);
1644 if (strcmp (name, soname) != 0)
1645 continue;
1647 /* We have a match on a new name -- cache it. */
1648 add_name_to_object (l, soname);
1649 l->l_soname_added = 1;
1652 /* We have a match. */
1653 return l;
1656 /* Display information if we are debugging. */
1657 if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_FILES, 0)
1658 && loader != NULL)
1659 INTUSE(_dl_debug_printf) ("\nfile=%s; needed by %s\n", name,
1660 loader->l_name[0]
1661 ? loader->l_name : rtld_progname);
1663 if (strchr (name, '/') == NULL)
1665 /* Search for NAME in several places. */
1667 size_t namelen = strlen (name) + 1;
1669 if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_LIBS, 0))
1670 INTUSE(_dl_debug_printf) ("find library=%s; searching\n", name);
1672 fd = -1;
1674 /* When the object has the RUNPATH information we don't use any
1675 RPATHs. */
1676 if (loader == NULL || loader->l_info[DT_RUNPATH] == NULL)
1678 /* First try the DT_RPATH of the dependent object that caused NAME
1679 to be loaded. Then that object's dependent, and on up. */
1680 for (l = loader; fd == -1 && l; l = l->l_loader)
1682 if (l->l_rpath_dirs.dirs == NULL)
1684 if (l->l_info[DT_RPATH] == NULL)
1686 /* There is no path. */
1687 l->l_rpath_dirs.dirs = (void *) -1;
1688 continue;
1690 else
1692 /* Make sure the cache information is available. */
1693 size_t ptrval = (D_PTR (l, l_info[DT_STRTAB])
1694 + l->l_info[DT_RPATH]->d_un.d_val);
1695 decompose_rpath (&l->l_rpath_dirs,
1696 (const char *) ptrval, l, "RPATH");
1700 if (l->l_rpath_dirs.dirs != (void *) -1)
1701 fd = open_path (name, namelen, preloaded, &l->l_rpath_dirs,
1702 &realname, &fb);
1705 /* If dynamically linked, try the DT_RPATH of the executable
1706 itself. */
1707 l = GL(dl_loaded);
1708 if (fd == -1 && l && l->l_type != lt_loaded && l != loader
1709 && l->l_rpath_dirs.dirs != (void *) -1)
1710 fd = open_path (name, namelen, preloaded, &l->l_rpath_dirs,
1711 &realname, &fb);
1714 /* Try the LD_LIBRARY_PATH environment variable. */
1715 if (fd == -1 && env_path_list.dirs != (void *) -1)
1716 fd = open_path (name, namelen, preloaded, &env_path_list,
1717 &realname, &fb);
1719 /* Look at the RUNPATH information for this binary.
1721 Note that this is no real loop. 'while' is used only to enable
1722 us to use 'break' instead of a 'goto' to jump to the end. The
1723 loop is always left after the first round. */
1724 while (fd == -1 && loader != NULL
1725 && loader->l_runpath_dirs.dirs != (void *) -1)
1727 if (loader->l_runpath_dirs.dirs == NULL)
1729 if (loader->l_info[DT_RUNPATH] == NULL)
1731 /* No RUNPATH. */
1732 loader->l_runpath_dirs.dirs = (void *) -1;
1733 break;
1735 else
1737 /* Make sure the cache information is available. */
1738 size_t ptrval = (D_PTR (loader, l_info[DT_STRTAB])
1739 + loader->l_info[DT_RUNPATH]->d_un.d_val);
1740 decompose_rpath (&loader->l_runpath_dirs,
1741 (const char *) ptrval, loader, "RUNPATH");
1745 if (loader->l_runpath_dirs.dirs != (void *) -1)
1746 fd = open_path (name, namelen, preloaded,
1747 &loader->l_runpath_dirs, &realname, &fb);
1748 break;
1751 if (fd == -1
1752 && (__builtin_expect (! preloaded, 1)
1753 || ! INTUSE(__libc_enable_secure)))
1755 /* Check the list of libraries in the file /etc/ld.so.cache,
1756 for compatibility with Linux's ldconfig program. */
1757 const char *cached = _dl_load_cache_lookup (name);
1759 if (cached != NULL)
1761 #ifdef SHARED
1762 l = loader ?: GL(dl_loaded);
1763 #else
1764 l = loader;
1765 #endif
1767 /* If the loader has the DF_1_NODEFLIB flag set we must not
1768 use a cache entry from any of these directories. */
1769 if (
1770 #ifndef SHARED
1771 /* 'l' is always != NULL for dynamically linked objects. */
1772 l != NULL &&
1773 #endif
1774 __builtin_expect (l->l_flags_1 & DF_1_NODEFLIB, 0))
1776 const char *dirp = system_dirs;
1777 unsigned int cnt = 0;
1781 if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0)
1783 /* The prefix matches. Don't use the entry. */
1784 cached = NULL;
1785 break;
1788 dirp += system_dirs_len[cnt] + 1;
1789 ++cnt;
1791 while (cnt < nsystem_dirs_len);
1794 if (cached != NULL)
1796 fd = open_verify (cached, &fb);
1797 if (__builtin_expect (fd != -1, 1))
1799 realname = local_strdup (cached);
1800 if (realname == NULL)
1802 __close (fd);
1803 fd = -1;
1810 /* Finally, try the default path. */
1811 if (fd == -1
1812 && ((l = loader ?: GL(dl_loaded)) == NULL
1813 || __builtin_expect (!(l->l_flags_1 & DF_1_NODEFLIB), 1))
1814 && rtld_search_dirs.dirs != (void *) -1)
1815 fd = open_path (name, namelen, preloaded, &rtld_search_dirs,
1816 &realname, &fb);
1818 /* Add another newline when we are tracing the library loading. */
1819 if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_LIBS, 0))
1820 INTUSE(_dl_debug_printf) ("\n");
1822 else
1824 /* The path may contain dynamic string tokens. */
1825 realname = (loader
1826 ? expand_dynamic_string_token (loader, name)
1827 : local_strdup (name));
1828 if (realname == NULL)
1829 fd = -1;
1830 else
1832 fd = open_verify (realname, &fb);
1833 if (__builtin_expect (fd, 0) == -1)
1834 free (realname);
1838 if (__builtin_expect (fd, 0) == -1)
1840 if (trace_mode
1841 && __builtin_expect (GL(dl_debug_mask) & DL_DEBUG_PRELINK, 0) == 0)
1843 /* We haven't found an appropriate library. But since we
1844 are only interested in the list of libraries this isn't
1845 so severe. Fake an entry with all the information we
1846 have. */
1847 static const Elf_Symndx dummy_bucket = STN_UNDEF;
1849 /* Enter the new object in the list of loaded objects. */
1850 if ((name_copy = local_strdup (name)) == NULL
1851 || (l = _dl_new_object (name_copy, name, type, loader)) == NULL)
1852 INTUSE(_dl_signal_error) (ENOMEM, name, NULL, N_("\
1853 cannot create shared object descriptor"));
1854 /* Signal that this is a faked entry. */
1855 l->l_faked = 1;
1856 /* Since the descriptor is initialized with zero we do not
1857 have do this here.
1858 l->l_reserved = 0; */
1859 l->l_buckets = &dummy_bucket;
1860 l->l_nbuckets = 1;
1861 l->l_relocated = 1;
1863 return l;
1865 else
1866 INTUSE(_dl_signal_error) (errno, name, NULL,
1867 N_("cannot open shared object file"));
1870 return _dl_map_object_from_fd (name, fd, &fb, realname, loader, type, mode);
1872 INTDEF (_dl_map_object)