Update.
[glibc.git] / elf / dl-load.c
blobcb0642a6d2f698d5a446fc255afaa0d073a535f6
1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2002, 2003, 2004 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 <bits/wordsize.h>
30 #include <sys/mman.h>
31 #include <sys/param.h>
32 #include <sys/stat.h>
33 #include <sys/types.h>
34 #include "dynamic-link.h"
35 #include <abi-tag.h>
36 #include <dl-osinfo.h>
38 #include <dl-dst.h>
40 /* On some systems, no flag bits are given to specify file mapping. */
41 #ifndef MAP_FILE
42 # define MAP_FILE 0
43 #endif
45 /* The right way to map in the shared library files is MAP_COPY, which
46 makes a virtual copy of the data at the time of the mmap call; this
47 guarantees the mapped pages will be consistent even if the file is
48 overwritten. Some losing VM systems like Linux's lack MAP_COPY. All we
49 get is MAP_PRIVATE, which copies each page when it is modified; this
50 means if the file is overwritten, we may at some point get some pages
51 from the new version after starting with pages from the old version. */
52 #ifndef MAP_COPY
53 # define MAP_COPY MAP_PRIVATE
54 #endif
56 /* We want to prevent people from modifying DSOs which are currently in
57 use. This is what MAP_DENYWRITE is for. */
58 #ifndef MAP_DENYWRITE
59 # define MAP_DENYWRITE 0
60 #endif
62 /* Some systems link their relocatable objects for another base address
63 than 0. We want to know the base address for these such that we can
64 subtract this address from the segment addresses during mapping.
65 This results in a more efficient address space usage. Defaults to
66 zero for almost all systems. */
67 #ifndef MAP_BASE_ADDR
68 # define MAP_BASE_ADDR(l) 0
69 #endif
72 #include <endian.h>
73 #if BYTE_ORDER == BIG_ENDIAN
74 # define byteorder ELFDATA2MSB
75 #elif BYTE_ORDER == LITTLE_ENDIAN
76 # define byteorder ELFDATA2LSB
77 #else
78 # error "Unknown BYTE_ORDER " BYTE_ORDER
79 # define byteorder ELFDATANONE
80 #endif
82 #define STRING(x) __STRING (x)
84 #ifdef MAP_ANON
85 /* The fd is not examined when using MAP_ANON. */
86 # define ANONFD -1
87 #else
88 int _dl_zerofd = -1;
89 # define ANONFD _dl_zerofd
90 #endif
92 /* Handle situations where we have a preferred location in memory for
93 the shared objects. */
94 #ifdef ELF_PREFERRED_ADDRESS_DATA
95 ELF_PREFERRED_ADDRESS_DATA;
96 #endif
97 #ifndef ELF_PREFERRED_ADDRESS
98 # define ELF_PREFERRED_ADDRESS(loader, maplength, mapstartpref) (mapstartpref)
99 #endif
100 #ifndef ELF_FIXED_ADDRESS
101 # define ELF_FIXED_ADDRESS(loader, mapstart) ((void) 0)
102 #endif
104 /* Type for the buffer we put the ELF header and hopefully the program
105 header. This buffer does not really have to be too large. In most
106 cases the program header follows the ELF header directly. If this
107 is not the case all bets are off and we can make the header
108 arbitrarily large and still won't get it read. This means the only
109 question is how large are the ELF and program header combined. The
110 ELF header 32-bit files is 52 bytes long and in 64-bit files is 64
111 bytes long. Each program header entry is again 32 and 56 bytes
112 long respectively. I.e., even with a file which has 7 program
113 header entries we only have to read 512B. Add to this a bit of
114 margin for program notes and reading 512B and 640B for 32-bit and
115 64-bit files respecitvely is enough. If this heuristic should
116 really fail for some file the code in `_dl_map_object_from_fd'
117 knows how to recover. */
118 struct filebuf
120 ssize_t len;
121 #if __WORDSIZE == 32
122 # define FILEBUF_SIZE 512
123 #else
124 # define FILEBUF_SIZE 640
125 #endif
126 char buf[FILEBUF_SIZE] __attribute__ ((aligned (__alignof (ElfW(Ehdr)))));
129 /* This is the decomposed LD_LIBRARY_PATH search path. */
130 static struct r_search_path_struct env_path_list attribute_relro;
132 /* List of the hardware capabilities we might end up using. */
133 static const struct r_strlenpair *capstr attribute_relro;
134 static size_t ncapstr attribute_relro;
135 static size_t max_capstrlen attribute_relro;
138 /* Get the generated information about the trusted directories. */
139 #include "trusted-dirs.h"
141 static const char system_dirs[] = SYSTEM_DIRS;
142 static const size_t system_dirs_len[] =
144 SYSTEM_DIRS_LEN
146 #define nsystem_dirs_len \
147 (sizeof (system_dirs_len) / sizeof (system_dirs_len[0]))
150 /* Local version of `strdup' function. */
151 static inline char *
152 local_strdup (const char *s)
154 size_t len = strlen (s) + 1;
155 void *new = malloc (len);
157 if (new == NULL)
158 return NULL;
160 return (char *) memcpy (new, s, len);
164 static size_t
165 is_dst (const char *start, const char *name, const char *str,
166 int is_path, int secure)
168 size_t len;
169 bool is_curly = false;
171 if (name[0] == '{')
173 is_curly = true;
174 ++name;
177 len = 0;
178 while (name[len] == str[len] && name[len] != '\0')
179 ++len;
181 if (is_curly)
183 if (name[len] != '}')
184 return 0;
186 /* Point again at the beginning of the name. */
187 --name;
188 /* Skip over closing curly brace and adjust for the --name. */
189 len += 2;
191 else if (name[len] != '\0' && name[len] != '/'
192 && (!is_path || name[len] != ':'))
193 return 0;
195 if (__builtin_expect (secure, 0)
196 && ((name[len] != '\0' && (!is_path || name[len] != ':'))
197 || (name != start + 1 && (!is_path || name[-2] != ':'))))
198 return 0;
200 return len;
204 size_t
205 _dl_dst_count (const char *name, int is_path)
207 const char *const start = name;
208 size_t cnt = 0;
212 size_t len;
214 /* $ORIGIN is not expanded for SUID/GUID programs (except if it
215 is $ORIGIN alone) and it must always appear first in path. */
216 ++name;
217 if ((len = is_dst (start, name, "ORIGIN", is_path,
218 INTUSE(__libc_enable_secure))) != 0
219 || (len = is_dst (start, name, "PLATFORM", is_path, 0)) != 0
220 || (len = is_dst (start, name, "LIB", is_path, 0)) != 0)
221 ++cnt;
223 name = strchr (name + len, '$');
225 while (name != NULL);
227 return cnt;
231 char *
232 _dl_dst_substitute (struct link_map *l, const char *name, char *result,
233 int is_path)
235 const char *const start = name;
236 char *last_elem, *wp;
238 /* Now fill the result path. While copying over the string we keep
239 track of the start of the last path element. When we come accross
240 a DST we copy over the value or (if the value is not available)
241 leave the entire path element out. */
242 last_elem = wp = result;
246 if (__builtin_expect (*name == '$', 0))
248 const char *repl = NULL;
249 size_t len;
251 ++name;
252 if ((len = is_dst (start, name, "ORIGIN", is_path,
253 INTUSE(__libc_enable_secure))) != 0)
254 repl = l->l_origin;
255 else if ((len = is_dst (start, name, "PLATFORM", is_path, 0)) != 0)
256 repl = GLRO(dl_platform);
257 else if ((len = is_dst (start, name, "LIB", is_path, 0)) != 0)
258 repl = DL_DST_LIB;
260 if (repl != NULL && repl != (const char *) -1)
262 wp = __stpcpy (wp, repl);
263 name += len;
265 else if (len > 1)
267 /* We cannot use this path element, the value of the
268 replacement is unknown. */
269 wp = last_elem;
270 name += len;
271 while (*name != '\0' && (!is_path || *name != ':'))
272 ++name;
274 else
275 /* No DST we recognize. */
276 *wp++ = '$';
278 else
280 *wp++ = *name++;
281 if (is_path && *name == ':')
282 last_elem = wp;
285 while (*name != '\0');
287 *wp = '\0';
289 return result;
293 /* Return copy of argument with all recognized dynamic string tokens
294 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
295 might not be possible to determine the path from which the object
296 belonging to the map is loaded. In this case the path element
297 containing $ORIGIN is left out. */
298 static char *
299 expand_dynamic_string_token (struct link_map *l, const char *s)
301 /* We make two runs over the string. First we determine how large the
302 resulting string is and then we copy it over. Since this is now
303 frequently executed operation we are looking here not for performance
304 but rather for code size. */
305 size_t cnt;
306 size_t total;
307 char *result;
309 /* Determine the number of DST elements. */
310 cnt = DL_DST_COUNT (s, 1);
312 /* If we do not have to replace anything simply copy the string. */
313 if (__builtin_expect (cnt, 0) == 0)
314 return local_strdup (s);
316 /* Determine the length of the substituted string. */
317 total = DL_DST_REQUIRED (l, s, strlen (s), cnt);
319 /* Allocate the necessary memory. */
320 result = (char *) malloc (total + 1);
321 if (result == NULL)
322 return NULL;
324 return _dl_dst_substitute (l, s, result, 1);
328 /* Add `name' to the list of names for a particular shared object.
329 `name' is expected to have been allocated with malloc and will
330 be freed if the shared object already has this name.
331 Returns false if the object already had this name. */
332 static void
333 internal_function
334 add_name_to_object (struct link_map *l, const char *name)
336 struct libname_list *lnp, *lastp;
337 struct libname_list *newname;
338 size_t name_len;
340 lastp = NULL;
341 for (lnp = l->l_libname; lnp != NULL; lastp = lnp, lnp = lnp->next)
342 if (strcmp (name, lnp->name) == 0)
343 return;
345 name_len = strlen (name) + 1;
346 newname = (struct libname_list *) malloc (sizeof *newname + name_len);
347 if (newname == NULL)
349 /* No more memory. */
350 _dl_signal_error (ENOMEM, name, NULL, N_("cannot allocate name record"));
351 return;
353 /* The object should have a libname set from _dl_new_object. */
354 assert (lastp != NULL);
356 newname->name = memcpy (newname + 1, name, name_len);
357 newname->next = NULL;
358 newname->dont_free = 0;
359 lastp->next = newname;
362 /* Standard search directories. */
363 static struct r_search_path_struct rtld_search_dirs attribute_relro;
365 static size_t max_dirnamelen;
367 static struct r_search_path_elem **
368 fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
369 int check_trusted, const char *what, const char *where)
371 char *cp;
372 size_t nelems = 0;
374 while ((cp = __strsep (&rpath, sep)) != NULL)
376 struct r_search_path_elem *dirp;
377 size_t len = strlen (cp);
379 /* `strsep' can pass an empty string. This has to be
380 interpreted as `use the current directory'. */
381 if (len == 0)
383 static const char curwd[] = "./";
384 cp = (char *) curwd;
387 /* Remove trailing slashes (except for "/"). */
388 while (len > 1 && cp[len - 1] == '/')
389 --len;
391 /* Now add one if there is none so far. */
392 if (len > 0 && cp[len - 1] != '/')
393 cp[len++] = '/';
395 /* Make sure we don't use untrusted directories if we run SUID. */
396 if (__builtin_expect (check_trusted, 0))
398 const char *trun = system_dirs;
399 size_t idx;
400 int unsecure = 1;
402 /* All trusted directories must be complete names. */
403 if (cp[0] == '/')
405 for (idx = 0; idx < nsystem_dirs_len; ++idx)
407 if (len == system_dirs_len[idx]
408 && memcmp (trun, cp, len) == 0)
410 /* Found it. */
411 unsecure = 0;
412 break;
415 trun += system_dirs_len[idx] + 1;
419 if (unsecure)
420 /* Simply drop this directory. */
421 continue;
424 /* See if this directory is already known. */
425 for (dirp = GL(dl_all_dirs); dirp != NULL; dirp = dirp->next)
426 if (dirp->dirnamelen == len && memcmp (cp, dirp->dirname, len) == 0)
427 break;
429 if (dirp != NULL)
431 /* It is available, see whether it's on our own list. */
432 size_t cnt;
433 for (cnt = 0; cnt < nelems; ++cnt)
434 if (result[cnt] == dirp)
435 break;
437 if (cnt == nelems)
438 result[nelems++] = dirp;
440 else
442 size_t cnt;
443 enum r_dir_status init_val;
444 size_t where_len = where ? strlen (where) + 1 : 0;
446 /* It's a new directory. Create an entry and add it. */
447 dirp = (struct r_search_path_elem *)
448 malloc (sizeof (*dirp) + ncapstr * sizeof (enum r_dir_status)
449 + where_len + len + 1);
450 if (dirp == NULL)
451 _dl_signal_error (ENOMEM, NULL, NULL,
452 N_("cannot create cache for search path"));
454 dirp->dirname = ((char *) dirp + sizeof (*dirp)
455 + ncapstr * sizeof (enum r_dir_status));
456 *((char *) __mempcpy ((char *) dirp->dirname, cp, len)) = '\0';
457 dirp->dirnamelen = len;
459 if (len > max_dirnamelen)
460 max_dirnamelen = len;
462 /* We have to make sure all the relative directories are
463 never ignored. The current directory might change and
464 all our saved information would be void. */
465 init_val = cp[0] != '/' ? existing : unknown;
466 for (cnt = 0; cnt < ncapstr; ++cnt)
467 dirp->status[cnt] = init_val;
469 dirp->what = what;
470 if (__builtin_expect (where != NULL, 1))
471 dirp->where = memcpy ((char *) dirp + sizeof (*dirp) + len + 1
472 + (ncapstr * sizeof (enum r_dir_status)),
473 where, where_len);
474 else
475 dirp->where = NULL;
477 dirp->next = GL(dl_all_dirs);
478 GL(dl_all_dirs) = dirp;
480 /* Put it in the result array. */
481 result[nelems++] = dirp;
485 /* Terminate the array. */
486 result[nelems] = NULL;
488 return result;
492 static void
493 internal_function
494 decompose_rpath (struct r_search_path_struct *sps,
495 const char *rpath, struct link_map *l, const char *what)
497 /* Make a copy we can work with. */
498 const char *where = l->l_name;
499 char *copy;
500 char *cp;
501 struct r_search_path_elem **result;
502 size_t nelems;
503 /* Initialize to please the compiler. */
504 const char *errstring = NULL;
506 /* First see whether we must forget the RUNPATH and RPATH from this
507 object. */
508 if (__builtin_expect (GLRO(dl_inhibit_rpath) != NULL, 0)
509 && !INTUSE(__libc_enable_secure))
511 const char *inhp = GLRO(dl_inhibit_rpath);
515 const char *wp = where;
517 while (*inhp == *wp && *wp != '\0')
519 ++inhp;
520 ++wp;
523 if (*wp == '\0' && (*inhp == '\0' || *inhp == ':'))
525 /* This object is on the list of objects for which the
526 RUNPATH and RPATH must not be used. */
527 result = calloc (1, sizeof *result);
528 if (result == NULL)
530 signal_error_cache:
531 errstring = N_("cannot create cache for search path");
532 signal_error:
533 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
536 sps->dirs = result;
537 sps->malloced = 1;
539 return;
542 while (*inhp != '\0')
543 if (*inhp++ == ':')
544 break;
546 while (*inhp != '\0');
549 /* Make a writable copy. At the same time expand possible dynamic
550 string tokens. */
551 copy = expand_dynamic_string_token (l, rpath);
552 if (copy == NULL)
554 errstring = N_("cannot create RUNPATH/RPATH copy");
555 goto signal_error;
558 /* Count the number of necessary elements in the result array. */
559 nelems = 0;
560 for (cp = copy; *cp != '\0'; ++cp)
561 if (*cp == ':')
562 ++nelems;
564 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
565 number of necessary entries. */
566 result = (struct r_search_path_elem **) malloc ((nelems + 1 + 1)
567 * sizeof (*result));
568 if (result == NULL)
569 goto signal_error_cache;
571 fillin_rpath (copy, result, ":", 0, what, where);
573 /* Free the copied RPATH string. `fillin_rpath' make own copies if
574 necessary. */
575 free (copy);
577 sps->dirs = result;
578 /* The caller will change this value if we haven't used a real malloc. */
579 sps->malloced = 1;
582 /* Make sure cached path information is stored in *SP
583 and return true if there are any paths to search there. */
584 static bool
585 cache_rpath (struct link_map *l,
586 struct r_search_path_struct *sp,
587 int tag,
588 const char *what)
590 if (sp->dirs == (void *) -1)
591 return false;
593 if (sp->dirs != NULL)
594 return true;
596 if (l->l_info[tag] == NULL)
598 /* There is no path. */
599 sp->dirs = (void *) -1;
600 return false;
603 /* Make sure the cache information is available. */
604 decompose_rpath (sp, (const char *) (D_PTR (l, l_info[DT_STRTAB])
605 + l->l_info[tag]->d_un.d_val),
606 l, what);
607 return true;
611 void
612 internal_function
613 _dl_init_paths (const char *llp)
615 size_t idx;
616 const char *strp;
617 struct r_search_path_elem *pelem, **aelem;
618 size_t round_size;
619 #ifdef SHARED
620 struct link_map *l;
621 #endif
622 /* Initialize to please the compiler. */
623 const char *errstring = NULL;
625 /* Fill in the information about the application's RPATH and the
626 directories addressed by the LD_LIBRARY_PATH environment variable. */
628 /* Get the capabilities. */
629 capstr = _dl_important_hwcaps (GLRO(dl_platform), GLRO(dl_platformlen),
630 &ncapstr, &max_capstrlen);
632 /* First set up the rest of the default search directory entries. */
633 aelem = rtld_search_dirs.dirs = (struct r_search_path_elem **)
634 malloc ((nsystem_dirs_len + 1) * sizeof (struct r_search_path_elem *));
635 if (rtld_search_dirs.dirs == NULL)
637 errstring = N_("cannot create search path array");
638 signal_error:
639 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
642 round_size = ((2 * sizeof (struct r_search_path_elem) - 1
643 + ncapstr * sizeof (enum r_dir_status))
644 / sizeof (struct r_search_path_elem));
646 rtld_search_dirs.dirs[0] = (struct r_search_path_elem *)
647 malloc ((sizeof (system_dirs) / sizeof (system_dirs[0]))
648 * round_size * sizeof (struct r_search_path_elem));
649 if (rtld_search_dirs.dirs[0] == NULL)
651 errstring = N_("cannot create cache for search path");
652 goto signal_error;
655 rtld_search_dirs.malloced = 0;
656 pelem = GL(dl_all_dirs) = rtld_search_dirs.dirs[0];
657 strp = system_dirs;
658 idx = 0;
662 size_t cnt;
664 *aelem++ = pelem;
666 pelem->what = "system search path";
667 pelem->where = NULL;
669 pelem->dirname = strp;
670 pelem->dirnamelen = system_dirs_len[idx];
671 strp += system_dirs_len[idx] + 1;
673 /* System paths must be absolute. */
674 assert (pelem->dirname[0] == '/');
675 for (cnt = 0; cnt < ncapstr; ++cnt)
676 pelem->status[cnt] = unknown;
678 pelem->next = (++idx == nsystem_dirs_len ? NULL : (pelem + round_size));
680 pelem += round_size;
682 while (idx < nsystem_dirs_len);
684 max_dirnamelen = SYSTEM_DIRS_MAX_LEN;
685 *aelem = NULL;
687 #ifdef SHARED
688 /* This points to the map of the main object. */
689 l = GL(dl_loaded);
690 if (l != NULL)
692 assert (l->l_type != lt_loaded);
694 if (l->l_info[DT_RUNPATH])
696 /* Allocate room for the search path and fill in information
697 from RUNPATH. */
698 decompose_rpath (&l->l_runpath_dirs,
699 (const void *) (D_PTR (l, l_info[DT_STRTAB])
700 + l->l_info[DT_RUNPATH]->d_un.d_val),
701 l, "RUNPATH");
703 /* The RPATH is ignored. */
704 l->l_rpath_dirs.dirs = (void *) -1;
706 else
708 l->l_runpath_dirs.dirs = (void *) -1;
710 if (l->l_info[DT_RPATH])
712 /* Allocate room for the search path and fill in information
713 from RPATH. */
714 decompose_rpath (&l->l_rpath_dirs,
715 (const void *) (D_PTR (l, l_info[DT_STRTAB])
716 + l->l_info[DT_RPATH]->d_un.d_val),
717 l, "RPATH");
718 l->l_rpath_dirs.malloced = 0;
720 else
721 l->l_rpath_dirs.dirs = (void *) -1;
724 #endif /* SHARED */
726 if (llp != NULL && *llp != '\0')
728 size_t nllp;
729 const char *cp = llp;
730 char *llp_tmp = strdupa (llp);
732 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
733 elements it has. */
734 nllp = 1;
735 while (*cp)
737 if (*cp == ':' || *cp == ';')
738 ++nllp;
739 ++cp;
742 env_path_list.dirs = (struct r_search_path_elem **)
743 malloc ((nllp + 1) * sizeof (struct r_search_path_elem *));
744 if (env_path_list.dirs == NULL)
746 errstring = N_("cannot create cache for search path");
747 goto signal_error;
750 (void) fillin_rpath (llp_tmp, env_path_list.dirs, ":;",
751 INTUSE(__libc_enable_secure), "LD_LIBRARY_PATH",
752 NULL);
754 if (env_path_list.dirs[0] == NULL)
756 free (env_path_list.dirs);
757 env_path_list.dirs = (void *) -1;
760 env_path_list.malloced = 0;
762 else
763 env_path_list.dirs = (void *) -1;
765 /* Remember the last search directory added at startup. */
766 GLRO(dl_init_all_dirs) = GL(dl_all_dirs);
770 static void
771 __attribute__ ((noreturn, noinline))
772 lose (int code, int fd, const char *name, char *realname, struct link_map *l,
773 const char *msg)
775 /* The file might already be closed. */
776 if (fd != -1)
777 (void) __close (fd);
778 if (l != NULL)
780 /* Remove the stillborn object from the list and free it. */
781 assert (l->l_next == NULL);
782 if (l->l_prev == NULL)
783 /* No other module loaded. This happens only in the static library,
784 or in rtld under --verify. */
785 GL(dl_loaded) = NULL;
786 else
787 l->l_prev->l_next = NULL;
788 --GL(dl_nloaded);
789 free (l);
791 free (realname);
792 _dl_signal_error (code, name, NULL, msg);
796 /* Map in the shared object NAME, actually located in REALNAME, and already
797 opened on FD. */
799 #ifndef EXTERNAL_MAP_FROM_FD
800 static
801 #endif
802 struct link_map *
803 _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp,
804 char *realname, struct link_map *loader, int l_type,
805 int mode, void **stack_endp)
807 struct link_map *l = NULL;
808 const ElfW(Ehdr) *header;
809 const ElfW(Phdr) *phdr;
810 const ElfW(Phdr) *ph;
811 size_t maplength;
812 int type;
813 struct stat64 st;
814 /* Initialize to keep the compiler happy. */
815 const char *errstring = NULL;
816 int errval = 0;
818 /* Get file information. */
819 if (__builtin_expect (__fxstat64 (_STAT_VER, fd, &st) < 0, 0))
821 errstring = N_("cannot stat shared object");
822 call_lose_errno:
823 errval = errno;
824 call_lose:
825 lose (errval, fd, name, realname, l, errstring);
828 /* Look again to see if the real name matched another already loaded. */
829 for (l = GL(dl_loaded); l; l = l->l_next)
830 if (l->l_ino == st.st_ino && l->l_dev == st.st_dev)
832 /* The object is already loaded.
833 Just bump its reference count and return it. */
834 __close (fd);
836 /* If the name is not in the list of names for this object add
837 it. */
838 free (realname);
839 add_name_to_object (l, name);
841 return l;
844 if (mode & RTLD_NOLOAD)
845 /* We are not supposed to load the object unless it is already
846 loaded. So return now. */
847 return NULL;
849 /* Print debugging message. */
850 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0))
851 _dl_debug_printf ("file=%s; generating link map\n", name);
853 /* This is the ELF header. We read it in `open_verify'. */
854 header = (void *) fbp->buf;
856 #ifndef MAP_ANON
857 # define MAP_ANON 0
858 if (_dl_zerofd == -1)
860 _dl_zerofd = _dl_sysdep_open_zero_fill ();
861 if (_dl_zerofd == -1)
863 __close (fd);
864 _dl_signal_error (errno, NULL, NULL,
865 N_("cannot open zero fill device"));
868 #endif
870 /* Enter the new object in the list of loaded objects. */
871 l = _dl_new_object (realname, name, l_type, loader);
872 if (__builtin_expect (! l, 0))
874 errstring = N_("cannot create shared object descriptor");
875 goto call_lose_errno;
878 /* Extract the remaining details we need from the ELF header
879 and then read in the program header table. */
880 l->l_entry = header->e_entry;
881 type = header->e_type;
882 l->l_phnum = header->e_phnum;
884 maplength = header->e_phnum * sizeof (ElfW(Phdr));
885 if (header->e_phoff + maplength <= (size_t) fbp->len)
886 phdr = (void *) (fbp->buf + header->e_phoff);
887 else
889 phdr = alloca (maplength);
890 __lseek (fd, header->e_phoff, SEEK_SET);
891 if ((size_t) __libc_read (fd, (void *) phdr, maplength) != maplength)
893 errstring = N_("cannot read file data");
894 goto call_lose_errno;
898 /* Presumed absent PT_GNU_STACK. */
899 uint_fast16_t stack_flags = PF_R|PF_W|PF_X;
902 /* Scan the program header table, collecting its load commands. */
903 struct loadcmd
905 ElfW(Addr) mapstart, mapend, dataend, allocend;
906 off_t mapoff;
907 int prot;
908 } loadcmds[l->l_phnum], *c;
909 size_t nloadcmds = 0;
910 bool has_holes = false;
912 /* The struct is initialized to zero so this is not necessary:
913 l->l_ld = 0;
914 l->l_phdr = 0;
915 l->l_addr = 0; */
916 for (ph = phdr; ph < &phdr[l->l_phnum]; ++ph)
917 switch (ph->p_type)
919 /* These entries tell us where to find things once the file's
920 segments are mapped in. We record the addresses it says
921 verbatim, and later correct for the run-time load address. */
922 case PT_DYNAMIC:
923 l->l_ld = (void *) ph->p_vaddr;
924 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
925 break;
927 case PT_PHDR:
928 l->l_phdr = (void *) ph->p_vaddr;
929 break;
931 case PT_LOAD:
932 /* A load command tells us to map in part of the file.
933 We record the load commands and process them all later. */
934 if (__builtin_expect ((ph->p_align & (GLRO(dl_pagesize) - 1)) != 0,
937 errstring = N_("ELF load command alignment not page-aligned");
938 goto call_lose;
940 if (__builtin_expect (((ph->p_vaddr - ph->p_offset)
941 & (ph->p_align - 1)) != 0, 0))
943 errstring
944 = N_("ELF load command address/offset not properly aligned");
945 goto call_lose;
948 c = &loadcmds[nloadcmds++];
949 c->mapstart = ph->p_vaddr & ~(ph->p_align - 1);
950 c->mapend = ((ph->p_vaddr + ph->p_filesz + GLRO(dl_pagesize) - 1)
951 & ~(GLRO(dl_pagesize) - 1));
952 c->dataend = ph->p_vaddr + ph->p_filesz;
953 c->allocend = ph->p_vaddr + ph->p_memsz;
954 c->mapoff = ph->p_offset & ~(ph->p_align - 1);
956 /* Determine whether there is a gap between the last segment
957 and this one. */
958 if (nloadcmds > 1 && c[-1].mapend != c->mapstart)
959 has_holes = true;
961 /* Optimize a common case. */
962 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
963 c->prot = (PF_TO_PROT
964 >> ((ph->p_flags & (PF_R | PF_W | PF_X)) * 4)) & 0xf;
965 #else
966 c->prot = 0;
967 if (ph->p_flags & PF_R)
968 c->prot |= PROT_READ;
969 if (ph->p_flags & PF_W)
970 c->prot |= PROT_WRITE;
971 if (ph->p_flags & PF_X)
972 c->prot |= PROT_EXEC;
973 #endif
974 break;
976 case PT_TLS:
977 #ifdef USE_TLS
978 if (ph->p_memsz == 0)
979 /* Nothing to do for an empty segment. */
980 break;
982 l->l_tls_blocksize = ph->p_memsz;
983 l->l_tls_align = ph->p_align;
984 if (ph->p_align == 0)
985 l->l_tls_firstbyte_offset = 0;
986 else
987 l->l_tls_firstbyte_offset = ph->p_vaddr & (ph->p_align - 1);
988 l->l_tls_initimage_size = ph->p_filesz;
989 /* Since we don't know the load address yet only store the
990 offset. We will adjust it later. */
991 l->l_tls_initimage = (void *) ph->p_vaddr;
993 /* If not loading the initial set of shared libraries,
994 check whether we should permit loading a TLS segment. */
995 if (__builtin_expect (l->l_type == lt_library, 1)
996 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
997 not set up TLS data structures, so don't use them now. */
998 || __builtin_expect (GL(dl_tls_dtv_slotinfo_list) != NULL, 1))
1000 /* Assign the next available module ID. */
1001 l->l_tls_modid = _dl_next_tls_modid ();
1002 break;
1005 # ifdef SHARED
1006 if (l->l_prev == NULL)
1007 /* We are loading the executable itself when the dynamic linker
1008 was executed directly. The setup will happen later. */
1009 break;
1011 /* In a static binary there is no way to tell if we dynamically
1012 loaded libpthread. */
1013 if (GL(dl_error_catch_tsd) == &_dl_initial_error_catch_tsd)
1014 # endif
1016 /* We have not yet loaded libpthread.
1017 We can do the TLS setup right now! */
1019 void *tcb;
1021 /* The first call allocates TLS bookkeeping data structures.
1022 Then we allocate the TCB for the initial thread. */
1023 if (__builtin_expect (_dl_tls_setup (), 0)
1024 || __builtin_expect ((tcb = _dl_allocate_tls (NULL)) == NULL,
1027 errval = ENOMEM;
1028 errstring = N_("\
1029 cannot allocate TLS data structures for initial thread");
1030 goto call_lose;
1033 /* Now we install the TCB in the thread register. */
1034 errstring = TLS_INIT_TP (tcb, 0);
1035 if (__builtin_expect (errstring == NULL, 1))
1037 /* Now we are all good. */
1038 l->l_tls_modid = ++GL(dl_tls_max_dtv_idx);
1039 break;
1042 /* The kernel is too old or somesuch. */
1043 errval = 0;
1044 _dl_deallocate_tls (tcb, 1);
1045 goto call_lose;
1047 #endif
1049 /* Uh-oh, the binary expects TLS support but we cannot
1050 provide it. */
1051 errval = 0;
1052 errstring = N_("cannot handle TLS data");
1053 goto call_lose;
1054 break;
1056 case PT_GNU_STACK:
1057 stack_flags = ph->p_flags;
1058 break;
1060 case PT_GNU_RELRO:
1061 l->l_relro_addr = ph->p_vaddr;
1062 l->l_relro_size = ph->p_memsz;
1063 break;
1066 if (__builtin_expect (nloadcmds == 0, 0))
1068 /* This only happens for a bogus object that will be caught with
1069 another error below. But we don't want to go through the
1070 calculations below using NLOADCMDS - 1. */
1071 errstring = N_("object file has no loadable segments");
1072 goto call_lose;
1075 /* Now process the load commands and map segments into memory. */
1076 c = loadcmds;
1078 /* Length of the sections to be loaded. */
1079 maplength = loadcmds[nloadcmds - 1].allocend - c->mapstart;
1081 if (__builtin_expect (type, ET_DYN) == ET_DYN)
1083 /* This is a position-independent shared object. We can let the
1084 kernel map it anywhere it likes, but we must have space for all
1085 the segments in their specified positions relative to the first.
1086 So we map the first segment without MAP_FIXED, but with its
1087 extent increased to cover all the segments. Then we remove
1088 access from excess portion, and there is known sufficient space
1089 there to remap from the later segments.
1091 As a refinement, sometimes we have an address that we would
1092 prefer to map such objects at; but this is only a preference,
1093 the OS can do whatever it likes. */
1094 ElfW(Addr) mappref;
1095 mappref = (ELF_PREFERRED_ADDRESS (loader, maplength,
1096 c->mapstart & GLRO(dl_use_load_bias))
1097 - MAP_BASE_ADDR (l));
1099 /* Remember which part of the address space this object uses. */
1100 l->l_map_start = (ElfW(Addr)) __mmap ((void *) mappref, maplength,
1101 c->prot,
1102 MAP_COPY|MAP_FILE|MAP_DENYWRITE,
1103 fd, c->mapoff);
1104 if (__builtin_expect ((void *) l->l_map_start == MAP_FAILED, 0))
1106 map_error:
1107 errstring = N_("failed to map segment from shared object");
1108 goto call_lose_errno;
1111 l->l_map_end = l->l_map_start + maplength;
1112 l->l_addr = l->l_map_start - c->mapstart;
1114 if (has_holes)
1115 /* Change protection on the excess portion to disallow all access;
1116 the portions we do not remap later will be inaccessible as if
1117 unallocated. Then jump into the normal segment-mapping loop to
1118 handle the portion of the segment past the end of the file
1119 mapping. */
1120 __mprotect ((caddr_t) (l->l_addr + c->mapend),
1121 loadcmds[nloadcmds - 1].allocend - c->mapend,
1122 PROT_NONE);
1124 goto postmap;
1126 else
1128 /* This object is loaded at a fixed address. This must never
1129 happen for objects loaded with dlopen(). */
1130 if (__builtin_expect ((mode & __RTLD_OPENEXEC) == 0, 0))
1132 errstring = N_("cannot dynamically load executable");
1133 goto call_lose;
1136 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1137 fixed. */
1138 ELF_FIXED_ADDRESS (loader, c->mapstart);
1141 /* Remember which part of the address space this object uses. */
1142 l->l_map_start = c->mapstart + l->l_addr;
1143 l->l_map_end = l->l_map_start + maplength;
1145 while (c < &loadcmds[nloadcmds])
1147 if (c->mapend > c->mapstart
1148 /* Map the segment contents from the file. */
1149 && (__mmap ((void *) (l->l_addr + c->mapstart),
1150 c->mapend - c->mapstart, c->prot,
1151 MAP_FIXED|MAP_COPY|MAP_FILE|MAP_DENYWRITE,
1152 fd, c->mapoff)
1153 == MAP_FAILED))
1154 goto map_error;
1156 postmap:
1157 if (c->prot & PROT_EXEC)
1158 l->l_text_end = l->l_addr + c->mapend;
1160 if (l->l_phdr == 0
1161 && (ElfW(Off)) c->mapoff <= header->e_phoff
1162 && ((size_t) (c->mapend - c->mapstart + c->mapoff)
1163 >= header->e_phoff + header->e_phnum * sizeof (ElfW(Phdr))))
1164 /* Found the program header in this segment. */
1165 l->l_phdr = (void *) (c->mapstart + header->e_phoff - c->mapoff);
1167 if (c->allocend > c->dataend)
1169 /* Extra zero pages should appear at the end of this segment,
1170 after the data mapped from the file. */
1171 ElfW(Addr) zero, zeroend, zeropage;
1173 zero = l->l_addr + c->dataend;
1174 zeroend = l->l_addr + c->allocend;
1175 zeropage = ((zero + GLRO(dl_pagesize) - 1)
1176 & ~(GLRO(dl_pagesize) - 1));
1178 if (zeroend < zeropage)
1179 /* All the extra data is in the last page of the segment.
1180 We can just zero it. */
1181 zeropage = zeroend;
1183 if (zeropage > zero)
1185 /* Zero the final part of the last page of the segment. */
1186 if (__builtin_expect ((c->prot & PROT_WRITE) == 0, 0))
1188 /* Dag nab it. */
1189 if (__mprotect ((caddr_t) (zero
1190 & ~(GLRO(dl_pagesize) - 1)),
1191 GLRO(dl_pagesize), c->prot|PROT_WRITE) < 0)
1193 errstring = N_("cannot change memory protections");
1194 goto call_lose_errno;
1197 memset ((void *) zero, '\0', zeropage - zero);
1198 if (__builtin_expect ((c->prot & PROT_WRITE) == 0, 0))
1199 __mprotect ((caddr_t) (zero & ~(GLRO(dl_pagesize) - 1)),
1200 GLRO(dl_pagesize), c->prot);
1203 if (zeroend > zeropage)
1205 /* Map the remaining zero pages in from the zero fill FD. */
1206 caddr_t mapat;
1207 mapat = __mmap ((caddr_t) zeropage, zeroend - zeropage,
1208 c->prot, MAP_ANON|MAP_PRIVATE|MAP_FIXED,
1209 ANONFD, 0);
1210 if (__builtin_expect (mapat == MAP_FAILED, 0))
1212 errstring = N_("cannot map zero-fill pages");
1213 goto call_lose_errno;
1218 ++c;
1221 if (l->l_phdr == NULL)
1223 /* The program header is not contained in any of the segments.
1224 We have to allocate memory ourself and copy it over from
1225 out temporary place. */
1226 ElfW(Phdr) *newp = (ElfW(Phdr) *) malloc (header->e_phnum
1227 * sizeof (ElfW(Phdr)));
1228 if (newp == NULL)
1230 errstring = N_("cannot allocate memory for program header");
1231 goto call_lose_errno;
1234 l->l_phdr = memcpy (newp, phdr,
1235 (header->e_phnum * sizeof (ElfW(Phdr))));
1236 l->l_phdr_allocated = 1;
1238 else
1239 /* Adjust the PT_PHDR value by the runtime load address. */
1240 l->l_phdr = (ElfW(Phdr) *) ((ElfW(Addr)) l->l_phdr + l->l_addr);
1243 #ifdef USE_TLS
1244 /* Adjust the address of the TLS initialization image. */
1245 if (l->l_tls_initimage != NULL)
1246 l->l_tls_initimage = (char *) l->l_tls_initimage + l->l_addr;
1247 #endif
1249 /* We are done mapping in the file. We no longer need the descriptor. */
1250 __close (fd);
1251 /* Signal that we closed the file. */
1252 fd = -1;
1254 if (l->l_type == lt_library && type == ET_EXEC)
1255 l->l_type = lt_executable;
1257 if (l->l_ld == 0)
1259 if (__builtin_expect (type == ET_DYN, 0))
1261 errstring = N_("object file has no dynamic section");
1262 goto call_lose;
1265 else
1266 l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1268 l->l_entry += l->l_addr;
1270 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0))
1271 _dl_debug_printf ("\
1272 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1273 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1274 (int) sizeof (void *) * 2,
1275 (unsigned long int) l->l_ld,
1276 (int) sizeof (void *) * 2,
1277 (unsigned long int) l->l_addr,
1278 (int) sizeof (void *) * 2, maplength,
1279 (int) sizeof (void *) * 2,
1280 (unsigned long int) l->l_entry,
1281 (int) sizeof (void *) * 2,
1282 (unsigned long int) l->l_phdr,
1283 (int) sizeof (void *) * 2, l->l_phnum);
1285 elf_get_dynamic_info (l, NULL);
1287 /* Make sure we are not dlopen'ing an object
1288 that has the DF_1_NOOPEN flag set. */
1289 if (__builtin_expect (l->l_flags_1 & DF_1_NOOPEN, 0)
1290 && (mode & __RTLD_DLOPEN))
1292 /* We are not supposed to load this object. Free all resources. */
1293 __munmap ((void *) l->l_map_start, l->l_map_end - l->l_map_start);
1295 if (!l->l_libname->dont_free)
1296 free (l->l_libname);
1298 if (l->l_phdr_allocated)
1299 free ((void *) l->l_phdr);
1301 errstring = N_("shared object cannot be dlopen()ed");
1302 goto call_lose;
1305 if (l->l_info[DT_HASH])
1306 _dl_setup_hash (l);
1308 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1309 have to do this for the main map. */
1310 if (__builtin_expect (l->l_info[DT_SYMBOLIC] != NULL, 0)
1311 && &l->l_searchlist != l->l_scope[0])
1313 /* Create an appropriate searchlist. It contains only this map.
1315 XXX This is the definition of DT_SYMBOLIC in SysVr4. The old
1316 GNU ld.so implementation had a different interpretation which
1317 is more reasonable. We are prepared to add this possibility
1318 back as part of a GNU extension of the ELF format. */
1319 l->l_symbolic_searchlist.r_list =
1320 (struct link_map **) malloc (sizeof (struct link_map *));
1322 if (l->l_symbolic_searchlist.r_list == NULL)
1324 errstring = N_("cannot create searchlist");
1325 goto call_lose_errno;
1328 l->l_symbolic_searchlist.r_list[0] = l;
1329 l->l_symbolic_searchlist.r_nlist = 1;
1331 /* Now move the existing entries one back. */
1332 memmove (&l->l_scope[1], &l->l_scope[0],
1333 (l->l_scope_max - 1) * sizeof (l->l_scope[0]));
1335 /* Now add the new entry. */
1336 l->l_scope[0] = &l->l_symbolic_searchlist;
1339 /* Remember whether this object must be initialized first. */
1340 if (l->l_flags_1 & DF_1_INITFIRST)
1341 GL(dl_initfirst) = l;
1343 /* Finally the file information. */
1344 l->l_dev = st.st_dev;
1345 l->l_ino = st.st_ino;
1347 if (__builtin_expect ((stack_flags &~ GL(dl_stack_flags)) & PF_X, 0))
1349 /* The stack is presently not executable, but this module
1350 requires that it be executable. */
1351 errval = (*GL(dl_make_stack_executable_hook)) (stack_endp);
1352 if (errval)
1354 errstring = N_("\
1355 cannot enable executable stack as shared object requires");
1356 goto call_lose;
1360 /* When we profile the SONAME might be needed for something else but
1361 loading. Add it right away. */
1362 if (__builtin_expect (GLRO(dl_profile) != NULL, 0)
1363 && l->l_info[DT_SONAME] != NULL)
1364 add_name_to_object (l, ((const char *) D_PTR (l, l_info[DT_STRTAB])
1365 + l->l_info[DT_SONAME]->d_un.d_val));
1367 return l;
1370 /* Print search path. */
1371 static void
1372 print_search_path (struct r_search_path_elem **list,
1373 const char *what, const char *name)
1375 char buf[max_dirnamelen + max_capstrlen];
1376 int first = 1;
1378 _dl_debug_printf (" search path=");
1380 while (*list != NULL && (*list)->what == what) /* Yes, ==. */
1382 char *endp = __mempcpy (buf, (*list)->dirname, (*list)->dirnamelen);
1383 size_t cnt;
1385 for (cnt = 0; cnt < ncapstr; ++cnt)
1386 if ((*list)->status[cnt] != nonexisting)
1388 char *cp = __mempcpy (endp, capstr[cnt].str, capstr[cnt].len);
1389 if (cp == buf || (cp == buf + 1 && buf[0] == '/'))
1390 cp[0] = '\0';
1391 else
1392 cp[-1] = '\0';
1394 _dl_debug_printf_c (first ? "%s" : ":%s", buf);
1395 first = 0;
1398 ++list;
1401 if (name != NULL)
1402 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what,
1403 name[0] ? name : rtld_progname);
1404 else
1405 _dl_debug_printf_c ("\t\t(%s)\n", what);
1408 /* Open a file and verify it is an ELF file for this architecture. We
1409 ignore only ELF files for other architectures. Non-ELF files and
1410 ELF files with different header information cause fatal errors since
1411 this could mean there is something wrong in the installation and the
1412 user might want to know about this. */
1413 static int
1414 open_verify (const char *name, struct filebuf *fbp)
1416 /* This is the expected ELF header. */
1417 #define ELF32_CLASS ELFCLASS32
1418 #define ELF64_CLASS ELFCLASS64
1419 #ifndef VALID_ELF_HEADER
1420 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1421 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1422 # define VALID_ELF_ABIVERSION(ver) (ver == 0)
1423 #endif
1424 static const unsigned char expected[EI_PAD] =
1426 [EI_MAG0] = ELFMAG0,
1427 [EI_MAG1] = ELFMAG1,
1428 [EI_MAG2] = ELFMAG2,
1429 [EI_MAG3] = ELFMAG3,
1430 [EI_CLASS] = ELFW(CLASS),
1431 [EI_DATA] = byteorder,
1432 [EI_VERSION] = EV_CURRENT,
1433 [EI_OSABI] = ELFOSABI_SYSV,
1434 [EI_ABIVERSION] = 0
1436 static const struct
1438 ElfW(Word) vendorlen;
1439 ElfW(Word) datalen;
1440 ElfW(Word) type;
1441 char vendor[4];
1442 } expected_note = { 4, 16, 1, "GNU" };
1443 int fd;
1444 /* Initialize it to make the compiler happy. */
1445 const char *errstring = NULL;
1446 int errval = 0;
1448 /* Open the file. We always open files read-only. */
1449 fd = __open (name, O_RDONLY);
1450 if (fd != -1)
1452 ElfW(Ehdr) *ehdr;
1453 ElfW(Phdr) *phdr, *ph;
1454 ElfW(Word) *abi_note, abi_note_buf[8];
1455 unsigned int osversion;
1456 size_t maplength;
1458 /* We successfully openened the file. Now verify it is a file
1459 we can use. */
1460 __set_errno (0);
1461 fbp->len = __libc_read (fd, fbp->buf, sizeof (fbp->buf));
1463 /* This is where the ELF header is loaded. */
1464 assert (sizeof (fbp->buf) > sizeof (ElfW(Ehdr)));
1465 ehdr = (ElfW(Ehdr) *) fbp->buf;
1467 /* Now run the tests. */
1468 if (__builtin_expect (fbp->len < (ssize_t) sizeof (ElfW(Ehdr)), 0))
1470 errval = errno;
1471 errstring = (errval == 0
1472 ? N_("file too short") : N_("cannot read file data"));
1473 call_lose:
1474 lose (errval, fd, name, NULL, NULL, errstring);
1477 /* See whether the ELF header is what we expect. */
1478 if (__builtin_expect (! VALID_ELF_HEADER (ehdr->e_ident, expected,
1479 EI_PAD), 0))
1481 /* Something is wrong. */
1482 if (*(Elf32_Word *) &ehdr->e_ident !=
1483 #if BYTE_ORDER == LITTLE_ENDIAN
1484 ((ELFMAG0 << (EI_MAG0 * 8)) |
1485 (ELFMAG1 << (EI_MAG1 * 8)) |
1486 (ELFMAG2 << (EI_MAG2 * 8)) |
1487 (ELFMAG3 << (EI_MAG3 * 8)))
1488 #else
1489 ((ELFMAG0 << (EI_MAG3 * 8)) |
1490 (ELFMAG1 << (EI_MAG2 * 8)) |
1491 (ELFMAG2 << (EI_MAG1 * 8)) |
1492 (ELFMAG3 << (EI_MAG0 * 8)))
1493 #endif
1495 errstring = N_("invalid ELF header");
1496 else if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS))
1497 /* This is not a fatal error. On architectures where
1498 32-bit and 64-bit binaries can be run this might
1499 happen. */
1500 goto close_and_out;
1501 else if (ehdr->e_ident[EI_DATA] != byteorder)
1503 if (BYTE_ORDER == BIG_ENDIAN)
1504 errstring = N_("ELF file data encoding not big-endian");
1505 else
1506 errstring = N_("ELF file data encoding not little-endian");
1508 else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT)
1509 errstring
1510 = N_("ELF file version ident does not match current one");
1511 /* XXX We should be able so set system specific versions which are
1512 allowed here. */
1513 else if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI]))
1514 errstring = N_("ELF file OS ABI invalid");
1515 else if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_ABIVERSION]))
1516 errstring = N_("ELF file ABI version invalid");
1517 else
1518 /* Otherwise we don't know what went wrong. */
1519 errstring = N_("internal error");
1521 goto call_lose;
1524 if (__builtin_expect (ehdr->e_version, EV_CURRENT) != EV_CURRENT)
1526 errstring = N_("ELF file version does not match current one");
1527 goto call_lose;
1529 if (! __builtin_expect (elf_machine_matches_host (ehdr), 1))
1530 goto close_and_out;
1531 else if (__builtin_expect (ehdr->e_type, ET_DYN) != ET_DYN
1532 && __builtin_expect (ehdr->e_type, ET_EXEC) != ET_EXEC)
1534 errstring = N_("only ET_DYN and ET_EXEC can be loaded");
1535 goto call_lose;
1537 else if (__builtin_expect (ehdr->e_phentsize, sizeof (ElfW(Phdr)))
1538 != sizeof (ElfW(Phdr)))
1540 errstring = N_("ELF file's phentsize not the expected size");
1541 goto call_lose;
1544 maplength = ehdr->e_phnum * sizeof (ElfW(Phdr));
1545 if (ehdr->e_phoff + maplength <= (size_t) fbp->len)
1546 phdr = (void *) (fbp->buf + ehdr->e_phoff);
1547 else
1549 phdr = alloca (maplength);
1550 __lseek (fd, ehdr->e_phoff, SEEK_SET);
1551 if ((size_t) __libc_read (fd, (void *) phdr, maplength) != maplength)
1553 read_error:
1554 errval = errno;
1555 errstring = N_("cannot read file data");
1556 goto call_lose;
1560 /* Check .note.ABI-tag if present. */
1561 for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
1562 if (ph->p_type == PT_NOTE && ph->p_filesz == 32 && ph->p_align >= 4)
1564 if (ph->p_offset + 32 <= (size_t) fbp->len)
1565 abi_note = (void *) (fbp->buf + ph->p_offset);
1566 else
1568 __lseek (fd, ph->p_offset, SEEK_SET);
1569 if (__libc_read (fd, (void *) abi_note_buf, 32) != 32)
1570 goto read_error;
1572 abi_note = abi_note_buf;
1575 if (memcmp (abi_note, &expected_note, sizeof (expected_note)))
1576 continue;
1578 osversion = (abi_note[5] & 0xff) * 65536
1579 + (abi_note[6] & 0xff) * 256
1580 + (abi_note[7] & 0xff);
1581 if (abi_note[4] != __ABI_TAG_OS
1582 || (GLRO(dl_osversion) && GLRO(dl_osversion) < osversion))
1584 close_and_out:
1585 __close (fd);
1586 __set_errno (ENOENT);
1587 fd = -1;
1590 break;
1594 return fd;
1597 /* Try to open NAME in one of the directories in *DIRSP.
1598 Return the fd, or -1. If successful, fill in *REALNAME
1599 with the malloc'd full directory name. If it turns out
1600 that none of the directories in *DIRSP exists, *DIRSP is
1601 replaced with (void *) -1, and the old value is free()d
1602 if MAY_FREE_DIRS is true. */
1604 static int
1605 open_path (const char *name, size_t namelen, int preloaded,
1606 struct r_search_path_struct *sps, char **realname,
1607 struct filebuf *fbp)
1609 struct r_search_path_elem **dirs = sps->dirs;
1610 char *buf;
1611 int fd = -1;
1612 const char *current_what = NULL;
1613 int any = 0;
1615 buf = alloca (max_dirnamelen + max_capstrlen + namelen);
1618 struct r_search_path_elem *this_dir = *dirs;
1619 size_t buflen = 0;
1620 size_t cnt;
1621 char *edp;
1622 int here_any = 0;
1623 int err;
1625 /* If we are debugging the search for libraries print the path
1626 now if it hasn't happened now. */
1627 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0)
1628 && current_what != this_dir->what)
1630 current_what = this_dir->what;
1631 print_search_path (dirs, current_what, this_dir->where);
1634 edp = (char *) __mempcpy (buf, this_dir->dirname, this_dir->dirnamelen);
1635 for (cnt = 0; fd == -1 && cnt < ncapstr; ++cnt)
1637 /* Skip this directory if we know it does not exist. */
1638 if (this_dir->status[cnt] == nonexisting)
1639 continue;
1641 buflen =
1642 ((char *) __mempcpy (__mempcpy (edp, capstr[cnt].str,
1643 capstr[cnt].len),
1644 name, namelen)
1645 - buf);
1647 /* Print name we try if this is wanted. */
1648 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
1649 _dl_debug_printf (" trying file=%s\n", buf);
1651 fd = open_verify (buf, fbp);
1652 if (this_dir->status[cnt] == unknown)
1654 if (fd != -1)
1655 this_dir->status[cnt] = existing;
1656 else
1658 /* We failed to open machine dependent library. Let's
1659 test whether there is any directory at all. */
1660 struct stat64 st;
1662 buf[buflen - namelen - 1] = '\0';
1664 if (__xstat64 (_STAT_VER, buf, &st) != 0
1665 || ! S_ISDIR (st.st_mode))
1666 /* The directory does not exist or it is no directory. */
1667 this_dir->status[cnt] = nonexisting;
1668 else
1669 this_dir->status[cnt] = existing;
1673 /* Remember whether we found any existing directory. */
1674 here_any |= this_dir->status[cnt] == existing;
1676 if (fd != -1 && __builtin_expect (preloaded, 0)
1677 && INTUSE(__libc_enable_secure))
1679 /* This is an extra security effort to make sure nobody can
1680 preload broken shared objects which are in the trusted
1681 directories and so exploit the bugs. */
1682 struct stat64 st;
1684 if (__fxstat64 (_STAT_VER, fd, &st) != 0
1685 || (st.st_mode & S_ISUID) == 0)
1687 /* The shared object cannot be tested for being SUID
1688 or this bit is not set. In this case we must not
1689 use this object. */
1690 __close (fd);
1691 fd = -1;
1692 /* We simply ignore the file, signal this by setting
1693 the error value which would have been set by `open'. */
1694 errno = ENOENT;
1699 if (fd != -1)
1701 *realname = (char *) malloc (buflen);
1702 if (*realname != NULL)
1704 memcpy (*realname, buf, buflen);
1705 return fd;
1707 else
1709 /* No memory for the name, we certainly won't be able
1710 to load and link it. */
1711 __close (fd);
1712 return -1;
1715 if (here_any && (err = errno) != ENOENT && err != EACCES)
1716 /* The file exists and is readable, but something went wrong. */
1717 return -1;
1719 /* Remember whether we found anything. */
1720 any |= here_any;
1722 while (*++dirs != NULL);
1724 /* Remove the whole path if none of the directories exists. */
1725 if (__builtin_expect (! any, 0))
1727 /* Paths which were allocated using the minimal malloc() in ld.so
1728 must not be freed using the general free() in libc. */
1729 if (sps->malloced)
1730 free (sps->dirs);
1731 sps->dirs = (void *) -1;
1734 return -1;
1737 /* Map in the shared object file NAME. */
1739 struct link_map *
1740 internal_function
1741 _dl_map_object (struct link_map *loader, const char *name, int preloaded,
1742 int type, int trace_mode, int mode)
1744 int fd;
1745 char *realname;
1746 char *name_copy;
1747 struct link_map *l;
1748 struct filebuf fb;
1750 /* Look for this name among those already loaded. */
1751 for (l = GL(dl_loaded); l; l = l->l_next)
1753 /* If the requested name matches the soname of a loaded object,
1754 use that object. Elide this check for names that have not
1755 yet been opened. */
1756 if (__builtin_expect (l->l_faked, 0) != 0)
1757 continue;
1758 if (!_dl_name_match_p (name, l))
1760 const char *soname;
1762 if (__builtin_expect (l->l_soname_added, 1)
1763 || l->l_info[DT_SONAME] == NULL)
1764 continue;
1766 soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
1767 + l->l_info[DT_SONAME]->d_un.d_val);
1768 if (strcmp (name, soname) != 0)
1769 continue;
1771 /* We have a match on a new name -- cache it. */
1772 add_name_to_object (l, soname);
1773 l->l_soname_added = 1;
1776 /* We have a match. */
1777 return l;
1780 /* Display information if we are debugging. */
1781 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0)
1782 && loader != NULL)
1783 _dl_debug_printf ("\nfile=%s; needed by %s\n", name,
1784 loader->l_name[0]
1785 ? loader->l_name : rtld_progname);
1787 if (strchr (name, '/') == NULL)
1789 /* Search for NAME in several places. */
1791 size_t namelen = strlen (name) + 1;
1793 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
1794 _dl_debug_printf ("find library=%s; searching\n", name);
1796 fd = -1;
1798 /* When the object has the RUNPATH information we don't use any
1799 RPATHs. */
1800 if (loader == NULL || loader->l_info[DT_RUNPATH] == NULL)
1802 /* First try the DT_RPATH of the dependent object that caused NAME
1803 to be loaded. Then that object's dependent, and on up. */
1804 for (l = loader; fd == -1 && l; l = l->l_loader)
1805 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
1806 fd = open_path (name, namelen, preloaded, &l->l_rpath_dirs,
1807 &realname, &fb);
1809 /* If dynamically linked, try the DT_RPATH of the executable
1810 itself. */
1811 l = GL(dl_loaded);
1812 if (fd == -1 && l && l->l_type != lt_loaded && l != loader
1813 && l->l_rpath_dirs.dirs != (void *) -1)
1814 fd = open_path (name, namelen, preloaded, &l->l_rpath_dirs,
1815 &realname, &fb);
1818 /* Try the LD_LIBRARY_PATH environment variable. */
1819 if (fd == -1 && env_path_list.dirs != (void *) -1)
1820 fd = open_path (name, namelen, preloaded, &env_path_list,
1821 &realname, &fb);
1823 /* Look at the RUNPATH information for this binary. */
1824 if (fd == -1 && loader != NULL
1825 && cache_rpath (loader, &loader->l_runpath_dirs,
1826 DT_RUNPATH, "RUNPATH"))
1827 fd = open_path (name, namelen, preloaded,
1828 &loader->l_runpath_dirs, &realname, &fb);
1830 if (fd == -1
1831 && (__builtin_expect (! preloaded, 1)
1832 || ! INTUSE(__libc_enable_secure)))
1834 /* Check the list of libraries in the file /etc/ld.so.cache,
1835 for compatibility with Linux's ldconfig program. */
1836 const char *cached = _dl_load_cache_lookup (name);
1838 if (cached != NULL)
1840 #ifdef SHARED
1841 l = loader ?: GL(dl_loaded);
1842 #else
1843 l = loader;
1844 #endif
1846 /* If the loader has the DF_1_NODEFLIB flag set we must not
1847 use a cache entry from any of these directories. */
1848 if (
1849 #ifndef SHARED
1850 /* 'l' is always != NULL for dynamically linked objects. */
1851 l != NULL &&
1852 #endif
1853 __builtin_expect (l->l_flags_1 & DF_1_NODEFLIB, 0))
1855 const char *dirp = system_dirs;
1856 unsigned int cnt = 0;
1860 if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0)
1862 /* The prefix matches. Don't use the entry. */
1863 cached = NULL;
1864 break;
1867 dirp += system_dirs_len[cnt] + 1;
1868 ++cnt;
1870 while (cnt < nsystem_dirs_len);
1873 if (cached != NULL)
1875 fd = open_verify (cached, &fb);
1876 if (__builtin_expect (fd != -1, 1))
1878 realname = local_strdup (cached);
1879 if (realname == NULL)
1881 __close (fd);
1882 fd = -1;
1889 /* Finally, try the default path. */
1890 if (fd == -1
1891 && ((l = loader ?: GL(dl_loaded)) == NULL
1892 || __builtin_expect (!(l->l_flags_1 & DF_1_NODEFLIB), 1))
1893 && rtld_search_dirs.dirs != (void *) -1)
1894 fd = open_path (name, namelen, preloaded, &rtld_search_dirs,
1895 &realname, &fb);
1897 /* Add another newline when we are tracing the library loading. */
1898 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
1899 _dl_debug_printf ("\n");
1901 else
1903 /* The path may contain dynamic string tokens. */
1904 realname = (loader
1905 ? expand_dynamic_string_token (loader, name)
1906 : local_strdup (name));
1907 if (realname == NULL)
1908 fd = -1;
1909 else
1911 fd = open_verify (realname, &fb);
1912 if (__builtin_expect (fd, 0) == -1)
1913 free (realname);
1917 /* In case the LOADER information has only been provided to get to
1918 the appropriate RUNPATH/RPATH information we do not need it
1919 anymore. */
1920 if (mode & __RTLD_CALLMAP)
1921 loader = NULL;
1923 if (__builtin_expect (fd, 0) == -1)
1925 if (trace_mode
1926 && __builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK, 0) == 0)
1928 /* We haven't found an appropriate library. But since we
1929 are only interested in the list of libraries this isn't
1930 so severe. Fake an entry with all the information we
1931 have. */
1932 static const Elf_Symndx dummy_bucket = STN_UNDEF;
1934 /* Enter the new object in the list of loaded objects. */
1935 if ((name_copy = local_strdup (name)) == NULL
1936 || (l = _dl_new_object (name_copy, name, type, loader)) == NULL)
1937 _dl_signal_error (ENOMEM, name, NULL,
1938 N_("cannot create shared object descriptor"));
1939 /* Signal that this is a faked entry. */
1940 l->l_faked = 1;
1941 /* Since the descriptor is initialized with zero we do not
1942 have do this here.
1943 l->l_reserved = 0; */
1944 l->l_buckets = &dummy_bucket;
1945 l->l_nbuckets = 1;
1946 l->l_relocated = 1;
1948 return l;
1950 else
1951 _dl_signal_error (errno, name, NULL,
1952 N_("cannot open shared object file"));
1955 void *stack_end = __libc_stack_end;
1956 return _dl_map_object_from_fd (name, fd, &fb, realname, loader, type, mode,
1957 &stack_end);
1961 void
1962 internal_function
1963 _dl_rtld_di_serinfo (struct link_map *loader, Dl_serinfo *si, bool counting)
1965 if (counting)
1967 si->dls_cnt = 0;
1968 si->dls_size = 0;
1971 unsigned int idx = 0;
1972 char *allocptr = (char *) &si->dls_serpath[si->dls_cnt];
1973 void add_path (const struct r_search_path_struct *sps, unsigned int flags)
1974 # define add_path(sps, flags) add_path(sps, 0) /* XXX */
1976 if (sps->dirs != (void *) -1)
1978 struct r_search_path_elem **dirs = sps->dirs;
1981 const struct r_search_path_elem *const r = *dirs++;
1982 if (counting)
1984 si->dls_cnt++;
1985 si->dls_size += r->dirnamelen;
1987 else
1989 Dl_serpath *const sp = &si->dls_serpath[idx++];
1990 sp->dls_name = allocptr;
1991 allocptr = __mempcpy (allocptr,
1992 r->dirname, r->dirnamelen - 1);
1993 *allocptr++ = '\0';
1994 sp->dls_flags = flags;
1997 while (*dirs != NULL);
2001 /* When the object has the RUNPATH information we don't use any RPATHs. */
2002 if (loader->l_info[DT_RUNPATH] == NULL)
2004 /* First try the DT_RPATH of the dependent object that caused NAME
2005 to be loaded. Then that object's dependent, and on up. */
2007 struct link_map *l = loader;
2010 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2011 add_path (&l->l_rpath_dirs, XXX_RPATH);
2012 l = l->l_loader;
2014 while (l != NULL);
2016 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2017 l = GL(dl_loaded);
2018 if (l != NULL && l->l_type != lt_loaded && l != loader)
2019 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2020 add_path (&l->l_rpath_dirs, XXX_RPATH);
2023 /* Try the LD_LIBRARY_PATH environment variable. */
2024 add_path (&env_path_list, XXX_ENV);
2026 /* Look at the RUNPATH information for this binary. */
2027 if (cache_rpath (loader, &loader->l_runpath_dirs, DT_RUNPATH, "RUNPATH"))
2028 add_path (&loader->l_runpath_dirs, XXX_RUNPATH);
2030 /* XXX
2031 Here is where ld.so.cache gets checked, but we don't have
2032 a way to indicate that in the results for Dl_serinfo. */
2034 /* Finally, try the default path. */
2035 if (!(loader->l_flags_1 & DF_1_NODEFLIB))
2036 add_path (&rtld_search_dirs, XXX_default);
2038 if (counting)
2039 /* Count the struct size before the string area, which we didn't
2040 know before we completed dls_cnt. */
2041 si->dls_size += (char *) &si->dls_serpath[si->dls_cnt] - (char *) si;