1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995,96,97,98,99,2000,2001 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
29 #include <sys/param.h>
31 #include <sys/types.h>
32 #include "dynamic-link.h"
34 #include <dl-osinfo.h>
38 /* On some systems, no flag bits are given to specify file mapping. */
43 /* The right way to map in the shared library files is MAP_COPY, which
44 makes a virtual copy of the data at the time of the mmap call; this
45 guarantees the mapped pages will be consistent even if the file is
46 overwritten. Some losing VM systems like Linux's lack MAP_COPY. All we
47 get is MAP_PRIVATE, which copies each page when it is modified; this
48 means if the file is overwritten, we may at some point get some pages
49 from the new version after starting with pages from the old version. */
51 # define MAP_COPY MAP_PRIVATE
54 /* Some systems link their relocatable objects for another base address
55 than 0. We want to know the base address for these such that we can
56 subtract this address from the segment addresses during mapping.
57 This results in a more efficient address space usage. Defaults to
58 zero for almost all systems. */
60 # define MAP_BASE_ADDR(l) 0
65 #if BYTE_ORDER == BIG_ENDIAN
66 # define byteorder ELFDATA2MSB
67 #elif BYTE_ORDER == LITTLE_ENDIAN
68 # define byteorder ELFDATA2LSB
70 # error "Unknown BYTE_ORDER " BYTE_ORDER
71 # define byteorder ELFDATANONE
74 #define STRING(x) __STRING (x)
77 /* The fd is not examined when using MAP_ANON. */
81 # define ANONFD _dl_zerofd
84 /* Handle situations where we have a preferred location in memory for
85 the shared objects. */
86 #ifdef ELF_PREFERRED_ADDRESS_DATA
87 ELF_PREFERRED_ADDRESS_DATA;
89 #ifndef ELF_PREFERRED_ADDRESS
90 # define ELF_PREFERRED_ADDRESS(loader, maplength, mapstartpref) (mapstartpref)
92 #ifndef ELF_FIXED_ADDRESS
93 # define ELF_FIXED_ADDRESS(loader, mapstart) ((void) 0)
96 /* Type for the buffer we put the ELF header and hopefully the program
97 header. This buffer does not really have to be too large. In most
98 cases the program header follows the ELF header directly. If this
99 is not the case all bets are off and we can make the header arbitrarily
100 large and still won't get it read. This means the only question is
101 how large are the ELF and program header combined. The ELF header
102 in 64-bit files is 56 bytes long. Each program header entry is again
103 56 bytes long. I.e., even with a file which has 17 program header
104 entries we only have to read 1kB. And 17 program header entries is
105 plenty, normal files have < 10. If this heuristic should really fail
106 for some file the code in `_dl_map_object_from_fd' knows how to
116 unsigned int _dl_osversion;
120 extern const char *_dl_platform;
121 extern size_t _dl_platformlen;
123 /* The object to be initialized first. */
124 struct link_map *_dl_initfirst;
126 /* This is the decomposed LD_LIBRARY_PATH search path. */
127 static struct r_search_path_struct env_path_list;
129 /* List of the hardware capabilities we might end up using. */
130 static const struct r_strlenpair *capstr;
131 static size_t ncapstr;
132 static size_t max_capstrlen;
134 const unsigned char _dl_pf_to_prot[8] =
139 [PF_R | PF_W] = PROT_READ | PROT_WRITE,
141 [PF_R | PF_X] = PROT_READ | PROT_EXEC,
142 [PF_W | PF_X] = PROT_WRITE | PROT_EXEC,
143 [PF_R | PF_W | PF_X] = PROT_READ | PROT_WRITE | PROT_EXEC
147 /* Get the generated information about the trusted directories. */
148 #include "trusted-dirs.h"
150 static const char system_dirs[] = SYSTEM_DIRS;
151 static const size_t system_dirs_len[] =
155 #define nsystem_dirs_len \
156 (sizeof (system_dirs_len) / sizeof (system_dirs_len[0]))
159 /* Local version of `strdup' function. */
161 local_strdup (const char *s)
163 size_t len = strlen (s) + 1;
164 void *new = malloc (len);
169 return (char *) memcpy (new, s, len);
174 _dl_dst_count (const char *name, int is_path)
176 const char *const start = name;
183 /* $ORIGIN is not expanded for SUID/GUID programs (except if it
184 is $ORIGIN alone) and it must always appear first in path.
186 Note that it is no bug that the string in the second and
187 fourth `strncmp' call is longer than the sequence which is
189 if (((strncmp (&name[1], "{ORIGIN}", 8) == 0 && (len = 9) != 0)
190 || (strncmp (&name[1], "{ORIGIN}" + 1, 6) == 0
191 && (name[7] == '\0' || name[7] == '/'
192 || (is_path && name[7] == ':'))
195 if ((__builtin_expect (!__libc_enable_secure, 1)
196 || name[len] == '\0' || (is_path && name[len] == ':'))
197 && (name == start || (is_path && name[-1] == ':')))
200 else if ((strncmp (&name[1], "{PLATFORM}", 10) == 0
202 || (strncmp (&name[1], "{PLATFORM}" + 1, 8) == 0
203 && (name[9] == '\0' || name[9] == '/'
204 || (is_path && name[9] == ':'))
208 name = strchr (name + len, '$');
210 while (name != NULL);
217 _dl_dst_substitute (struct link_map *l, const char *name, char *result,
220 const char *const start = name;
221 char *last_elem, *wp;
223 /* Now fill the result path. While copying over the string we keep
224 track of the start of the last path element. When we come accross
225 a DST we copy over the value or (if the value is not available)
226 leave the entire path element out. */
227 last_elem = wp = result;
231 if (__builtin_expect (*name, 'a') == '$')
233 const char *repl = NULL;
236 /* Note that it is no bug that the string in the second and
237 fourth `strncmp' call is longer than the sequence which
238 is actually tested. */
239 if (((strncmp (&name[1], "{ORIGIN}", 8) == 0 && (len = 9) != 0)
240 || (strncmp (&name[1], "{ORIGIN}" + 1, 6) == 0
241 && (name[7] == '\0' || name[7] == '/'
242 || (is_path && name[7] == ':'))
245 if ((__builtin_expect (!__libc_enable_secure, 1)
246 || name[len] == '\0' || (is_path && name[len] == ':'))
247 && (name == start || (is_path && name[-1] == ':')))
250 else if ((strncmp (&name[1], "{PLATFORM}", 10) == 0
252 || (strncmp (&name[1], "{PLATFORM}" + 1, 8) == 0
253 && (name[9] == '\0' || name[9] == '/' || name[9] == ':')
258 if (repl != NULL && repl != (const char *) -1)
260 wp = __stpcpy (wp, repl);
265 /* We cannot use this path element, the value of the
266 replacement is unknown. */
269 while (*name != '\0' && (!is_path || *name != ':'))
273 /* No DST we recognize. */
279 if (is_path && *name == ':')
283 while (*name != '\0');
291 /* Return copy of argument with all recognized dynamic string tokens
292 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
293 might not be possible to determine the path from which the object
294 belonging to the map is loaded. In this case the path element
295 containing $ORIGIN is left out. */
297 expand_dynamic_string_token (struct link_map *l, const char *s)
299 /* We make two runs over the string. First we determine how large the
300 resulting string is and then we copy it over. Since this is now
301 frequently executed operation we are looking here not for performance
302 but rather for code size. */
307 /* Determine the number of DST elements. */
308 cnt = DL_DST_COUNT (s, 1);
310 /* If we do not have to replace anything simply copy the string. */
311 if (__builtin_expect (cnt, 0) == 0)
312 return local_strdup (s);
314 /* Determine the length of the substituted string. */
315 total = DL_DST_REQUIRED (l, s, strlen (s), cnt);
317 /* Allocate the necessary memory. */
318 result = (char *) malloc (total + 1);
322 return DL_DST_SUBSTITUTE (l, s, result, 1);
326 /* Add `name' to the list of names for a particular shared object.
327 `name' is expected to have been allocated with malloc and will
328 be freed if the shared object already has this name.
329 Returns false if the object already had this name. */
332 add_name_to_object (struct link_map *l, const char *name)
334 struct libname_list *lnp, *lastp;
335 struct libname_list *newname;
339 for (lnp = l->l_libname; lnp != NULL; lastp = lnp, lnp = lnp->next)
340 if (strcmp (name, lnp->name) == 0)
343 name_len = strlen (name) + 1;
344 newname = (struct libname_list *) malloc (sizeof *newname + name_len);
347 /* No more memory. */
348 _dl_signal_error (ENOMEM, name, NULL, N_("cannot allocate name record"));
351 /* The object should have a libname set from _dl_new_object. */
352 assert (lastp != NULL);
354 newname->name = memcpy (newname + 1, name, name_len);
355 newname->next = NULL;
356 newname->dont_free = 0;
357 lastp->next = newname;
360 /* All known directories in sorted order. */
361 struct r_search_path_elem *_dl_all_dirs;
363 /* All directories after startup. */
364 struct r_search_path_elem *_dl_init_all_dirs;
366 /* Standard search directories. */
367 static struct r_search_path_struct rtld_search_dirs;
369 static size_t max_dirnamelen;
371 static inline struct r_search_path_elem **
372 fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
373 int check_trusted, const char *what, const char *where)
378 while ((cp = __strsep (&rpath, sep)) != NULL)
380 struct r_search_path_elem *dirp;
381 size_t len = strlen (cp);
383 /* `strsep' can pass an empty string. This has to be
384 interpreted as `use the current directory'. */
387 static const char curwd[] = "./";
391 /* Remove trailing slashes (except for "/"). */
392 while (len > 1 && cp[len - 1] == '/')
395 /* Now add one if there is none so far. */
396 if (len > 0 && cp[len - 1] != '/')
399 /* Make sure we don't use untrusted directories if we run SUID. */
400 if (__builtin_expect (check_trusted, 0))
402 const char *trun = system_dirs;
406 /* All trusted directories must be complete names. */
409 for (idx = 0; idx < nsystem_dirs_len; ++idx)
411 if (len == system_dirs_len[idx]
412 && memcmp (trun, cp, len) == 0)
419 trun += system_dirs_len[idx] + 1;
424 /* Simply drop this directory. */
428 /* See if this directory is already known. */
429 for (dirp = _dl_all_dirs; dirp != NULL; dirp = dirp->next)
430 if (dirp->dirnamelen == len && memcmp (cp, dirp->dirname, len) == 0)
435 /* It is available, see whether it's on our own list. */
437 for (cnt = 0; cnt < nelems; ++cnt)
438 if (result[cnt] == dirp)
442 result[nelems++] = dirp;
447 enum r_dir_status init_val;
448 size_t where_len = where ? strlen (where) + 1 : 0;
450 /* It's a new directory. Create an entry and add it. */
451 dirp = (struct r_search_path_elem *)
452 malloc (sizeof (*dirp) + ncapstr * sizeof (enum r_dir_status)
453 + where_len + len + 1);
455 _dl_signal_error (ENOMEM, NULL, NULL,
456 N_("cannot create cache for search path"));
458 dirp->dirname = ((char *) dirp + sizeof (*dirp)
459 + ncapstr * sizeof (enum r_dir_status));
460 *((char *) __mempcpy ((char *) dirp->dirname, cp, len)) = '\0';
461 dirp->dirnamelen = len;
463 if (len > max_dirnamelen)
464 max_dirnamelen = len;
466 /* We have to make sure all the relative directories are
467 never ignored. The current directory might change and
468 all our saved information would be void. */
469 init_val = cp[0] != '/' ? existing : unknown;
470 for (cnt = 0; cnt < ncapstr; ++cnt)
471 dirp->status[cnt] = init_val;
474 if (__builtin_expect (where != NULL, 1))
475 dirp->where = memcpy ((char *) dirp + sizeof (*dirp) + len + 1
476 + ncapstr * sizeof (enum r_dir_status),
481 dirp->next = _dl_all_dirs;
484 /* Put it in the result array. */
485 result[nelems++] = dirp;
489 /* Terminate the array. */
490 result[nelems] = NULL;
498 decompose_rpath (struct r_search_path_struct *sps,
499 const char *rpath, struct link_map *l, const char *what)
501 /* Make a copy we can work with. */
502 const char *where = l->l_name;
505 struct r_search_path_elem **result;
508 /* First see whether we must forget the RUNPATH and RPATH from this
510 if (__builtin_expect (_dl_inhibit_rpath != NULL, 0) && !__libc_enable_secure)
512 const char *found = strstr (_dl_inhibit_rpath, where);
515 size_t len = strlen (where);
516 if ((found == _dl_inhibit_rpath || found[-1] == ':')
517 && (found[len] == '\0' || found[len] == ':'))
519 /* This object is on the list of objects for which the
520 RUNPATH and RPATH must not be used. */
521 result = (struct r_search_path_elem **)
522 malloc (sizeof (*result));
524 _dl_signal_error (ENOMEM, NULL, NULL,
525 N_("cannot create cache for search path"));
536 /* Make a writable copy. At the same time expand possible dynamic
538 copy = expand_dynamic_string_token (l, rpath);
540 _dl_signal_error (ENOMEM, NULL, NULL,
541 N_("cannot create RUNPATH/RPATH copy"));
543 /* Count the number of necessary elements in the result array. */
545 for (cp = copy; *cp != '\0'; ++cp)
549 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
550 number of necessary entries. */
551 result = (struct r_search_path_elem **) malloc ((nelems + 1 + 1)
554 _dl_signal_error (ENOMEM, NULL, NULL,
555 N_("cannot create cache for search path"));
557 fillin_rpath (copy, result, ":", 0, what, where);
559 /* Free the copied RPATH string. `fillin_rpath' make own copies if
564 /* The caller will change this value if we haven't used a real malloc. */
571 _dl_init_paths (const char *llp)
575 struct r_search_path_elem *pelem, **aelem;
581 /* Fill in the information about the application's RPATH and the
582 directories addressed by the LD_LIBRARY_PATH environment variable. */
584 /* Get the capabilities. */
585 capstr = _dl_important_hwcaps (_dl_platform, _dl_platformlen,
586 &ncapstr, &max_capstrlen);
588 /* First set up the rest of the default search directory entries. */
589 aelem = rtld_search_dirs.dirs = (struct r_search_path_elem **)
590 malloc ((nsystem_dirs_len + 1) * sizeof (struct r_search_path_elem *));
591 if (rtld_search_dirs.dirs == NULL)
592 _dl_signal_error (ENOMEM, NULL, NULL,
593 N_("cannot create search path array"));
595 round_size = ((2 * sizeof (struct r_search_path_elem) - 1
596 + ncapstr * sizeof (enum r_dir_status))
597 / sizeof (struct r_search_path_elem));
599 rtld_search_dirs.dirs[0] = (struct r_search_path_elem *)
600 malloc ((sizeof (system_dirs) / sizeof (system_dirs[0]))
601 * round_size * sizeof (struct r_search_path_elem));
602 if (rtld_search_dirs.dirs[0] == NULL)
603 _dl_signal_error (ENOMEM, NULL, NULL,
604 N_("cannot create cache for search path"));
606 rtld_search_dirs.malloced = 0;
607 pelem = _dl_all_dirs = rtld_search_dirs.dirs[0];
617 pelem->what = "system search path";
620 pelem->dirname = strp;
621 pelem->dirnamelen = system_dirs_len[idx];
622 strp += system_dirs_len[idx] + 1;
624 /* System paths must be absolute. */
625 assert (pelem->dirname[0] == '/');
626 for (cnt = 0; cnt < ncapstr; ++cnt)
627 pelem->status[cnt] = unknown;
629 pelem->next = (++idx == nsystem_dirs_len ? NULL : (pelem + round_size));
633 while (idx < nsystem_dirs_len);
635 max_dirnamelen = SYSTEM_DIRS_MAX_LEN;
639 /* This points to the map of the main object. */
643 assert (l->l_type != lt_loaded);
645 if (l->l_info[DT_RUNPATH])
647 /* Allocate room for the search path and fill in information
649 decompose_rpath (&l->l_runpath_dirs,
650 (const void *) (D_PTR (l, l_info[DT_STRTAB])
651 + l->l_info[DT_RUNPATH]->d_un.d_val),
654 /* The RPATH is ignored. */
655 l->l_rpath_dirs.dirs = (void *) -1;
659 l->l_runpath_dirs.dirs = (void *) -1;
661 if (l->l_info[DT_RPATH])
663 /* Allocate room for the search path and fill in information
665 decompose_rpath (&l->l_rpath_dirs,
666 (const void *) (D_PTR (l, l_info[DT_STRTAB])
667 + l->l_info[DT_RPATH]->d_un.d_val),
669 l->l_rpath_dirs.malloced = 0;
672 l->l_rpath_dirs.dirs = (void *) -1;
677 if (llp != NULL && *llp != '\0')
680 const char *cp = llp;
681 char *llp_tmp = strdupa (llp);
683 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
688 if (*cp == ':' || *cp == ';')
693 env_path_list.dirs = (struct r_search_path_elem **)
694 malloc ((nllp + 1) * sizeof (struct r_search_path_elem *));
695 if (env_path_list.dirs == NULL)
696 _dl_signal_error (ENOMEM, NULL, NULL,
697 N_("cannot create cache for search path"));
699 (void) fillin_rpath (llp_tmp, env_path_list.dirs, ":;",
700 __libc_enable_secure, "LD_LIBRARY_PATH", NULL);
702 if (env_path_list.dirs[0] == NULL)
704 free (env_path_list.dirs);
705 env_path_list.dirs = (void *) -1;
708 env_path_list.malloced = 0;
711 env_path_list.dirs = (void *) -1;
713 /* Remember the last search directory added at startup. */
714 _dl_init_all_dirs = _dl_all_dirs;
718 /* Think twice before changing anything in this function. It is placed
719 here and prepared using the `alloca' magic to prevent it from being
720 inlined. The function is only called in case of an error. But then
721 performance does not count. The function used to be "inlinable" and
722 the compiled did so all the time. This increased the code size for
723 absolutely no good reason. */
724 #define LOSE(code, s) lose (code, fd, name, realname, l, s)
726 __attribute__ ((noreturn))
727 lose (int code, int fd, const char *name, char *realname, struct link_map *l,
730 /* The use of `alloca' here looks ridiculous but it helps. The goal
731 is to avoid the function from being inlined. There is no official
732 way to do this so we use this trick. gcc never inlines functions
733 which use `alloca'. */
734 int *a = alloca (sizeof (int));
736 (void) __close (a[0]);
739 /* Remove the stillborn object from the list and free it. */
741 l->l_prev->l_next = l->l_next;
743 l->l_next->l_prev = l->l_prev;
748 _dl_signal_error (code, name, NULL, msg);
752 /* Map in the shared object NAME, actually located in REALNAME, and already
755 #ifndef EXTERNAL_MAP_FROM_FD
759 _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp,
760 char *realname, struct link_map *loader, int l_type,
763 struct link_map *l = NULL;
765 auto inline caddr_t map_segment (ElfW(Addr) mapstart, size_t len,
766 int prot, int fixed, off_t offset);
768 inline caddr_t map_segment (ElfW(Addr) mapstart, size_t len,
769 int prot, int fixed, off_t offset)
771 caddr_t mapat = __mmap ((caddr_t) mapstart, len, prot,
772 fixed|MAP_COPY|MAP_FILE,
774 if (mapat == MAP_FAILED)
775 LOSE (errno, N_("failed to map segment from shared object"));
779 const ElfW(Ehdr) *header;
780 const ElfW(Phdr) *phdr;
781 const ElfW(Phdr) *ph;
786 /* Get file information. */
787 if (__fxstat64 (_STAT_VER, fd, &st) < 0)
788 LOSE (errno, N_("cannot stat shared object"));
790 /* Look again to see if the real name matched another already loaded. */
791 for (l = _dl_loaded; l; l = l->l_next)
792 if (l->l_ino == st.st_ino && l->l_dev == st.st_dev)
794 /* The object is already loaded.
795 Just bump its reference count and return it. */
798 /* If the name is not in the list of names for this object add
801 add_name_to_object (l, name);
806 if (mode & RTLD_NOLOAD)
807 /* We are not supposed to load the object unless it is already
808 loaded. So return now. */
811 /* Print debugging message. */
812 if (__builtin_expect (_dl_debug_mask & DL_DEBUG_FILES, 0))
813 _dl_debug_printf ("file=%s; generating link map\n", name);
815 /* This is the ELF header. We read it in `open_verify'. */
816 header = (void *) fbp->buf;
820 if (_dl_zerofd == -1)
822 _dl_zerofd = _dl_sysdep_open_zero_fill ();
823 if (_dl_zerofd == -1)
826 _dl_signal_error (errno, NULL, NULL,
827 N_("cannot open zero fill device"));
832 /* Enter the new object in the list of loaded objects. */
833 l = _dl_new_object (realname, name, l_type, loader);
834 if (__builtin_expect (! l, 0))
835 LOSE (ENOMEM, N_("cannot create shared object descriptor"));
837 /* Extract the remaining details we need from the ELF header
838 and then read in the program header table. */
839 l->l_entry = header->e_entry;
840 type = header->e_type;
841 l->l_phnum = header->e_phnum;
843 maplength = header->e_phnum * sizeof (ElfW(Phdr));
844 if (header->e_phoff + maplength <= fbp->len)
845 phdr = (void *) (fbp->buf + header->e_phoff);
848 phdr = alloca (maplength);
849 __lseek (fd, SEEK_SET, header->e_phoff);
850 if (__libc_read (fd, (void *) phdr, maplength) != maplength)
851 LOSE (errno, N_("cannot read file data"));
855 /* Scan the program header table, collecting its load commands. */
858 ElfW(Addr) mapstart, mapend, dataend, allocend;
861 } loadcmds[l->l_phnum], *c;
862 size_t nloadcmds = 0;
864 /* The struct is initialized to zero so this is not necessary:
868 for (ph = phdr; ph < &phdr[l->l_phnum]; ++ph)
871 /* These entries tell us where to find things once the file's
872 segments are mapped in. We record the addresses it says
873 verbatim, and later correct for the run-time load address. */
875 l->l_ld = (void *) ph->p_vaddr;
876 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
879 l->l_phdr = (void *) ph->p_vaddr;
883 /* A load command tells us to map in part of the file.
884 We record the load commands and process them all later. */
885 if (ph->p_align % _dl_pagesize != 0)
886 LOSE (0, N_("ELF load command alignment not page-aligned"));
887 if ((ph->p_vaddr - ph->p_offset) % ph->p_align)
889 N_("ELF load command address/offset not properly aligned"));
891 struct loadcmd *c = &loadcmds[nloadcmds++];
892 c->mapstart = ph->p_vaddr & ~(ph->p_align - 1);
893 c->mapend = ((ph->p_vaddr + ph->p_filesz + _dl_pagesize - 1)
894 & ~(_dl_pagesize - 1));
895 c->dataend = ph->p_vaddr + ph->p_filesz;
896 c->allocend = ph->p_vaddr + ph->p_memsz;
897 c->mapoff = ph->p_offset & ~(ph->p_align - 1);
899 /* Optimize a common case. */
900 if ((PF_R | PF_W | PF_X) == 7
901 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7)
902 c->prot = _dl_pf_to_prot[ph->p_flags & (PF_R | PF_W | PF_X)];
906 if (ph->p_flags & PF_R)
907 c->prot |= PROT_READ;
908 if (ph->p_flags & PF_W)
909 c->prot |= PROT_WRITE;
910 if (ph->p_flags & PF_X)
911 c->prot |= PROT_EXEC;
917 /* Now process the load commands and map segments into memory. */
920 /* Length of the sections to be loaded. */
921 maplength = loadcmds[nloadcmds - 1].allocend - c->mapstart;
923 if (__builtin_expect (type, ET_DYN) == ET_DYN)
925 /* This is a position-independent shared object. We can let the
926 kernel map it anywhere it likes, but we must have space for all
927 the segments in their specified positions relative to the first.
928 So we map the first segment without MAP_FIXED, but with its
929 extent increased to cover all the segments. Then we remove
930 access from excess portion, and there is known sufficient space
931 there to remap from the later segments.
933 As a refinement, sometimes we have an address that we would
934 prefer to map such objects at; but this is only a preference,
935 the OS can do whatever it likes. */
937 mappref = (ELF_PREFERRED_ADDRESS (loader, maplength, c->mapstart)
938 - MAP_BASE_ADDR (l));
940 /* Remember which part of the address space this object uses. */
941 l->l_map_start = (ElfW(Addr)) map_segment (mappref, maplength, c->prot,
943 l->l_map_end = l->l_map_start + maplength;
944 l->l_addr = l->l_map_start - c->mapstart;
946 /* Change protection on the excess portion to disallow all access;
947 the portions we do not remap later will be inaccessible as if
948 unallocated. Then jump into the normal segment-mapping loop to
949 handle the portion of the segment past the end of the file
951 __mprotect ((caddr_t) (l->l_addr + c->mapend),
952 loadcmds[nloadcmds - 1].allocend - c->mapend,
959 /* This object is loaded at a fixed address. This must never
960 happen for objects loaded with dlopen(). */
961 if (__builtin_expect (mode & __RTLD_DLOPEN, 0))
963 LOSE (0, N_("cannot dynamically load executable"));
966 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
968 ELF_FIXED_ADDRESS (loader, c->mapstart);
971 /* Remember which part of the address space this object uses. */
972 l->l_map_start = c->mapstart + l->l_addr;
973 l->l_map_end = l->l_map_start + maplength;
975 while (c < &loadcmds[nloadcmds])
977 if (c->mapend > c->mapstart)
978 /* Map the segment contents from the file. */
979 map_segment (l->l_addr + c->mapstart, c->mapend - c->mapstart,
980 c->prot, MAP_FIXED, c->mapoff);
984 && c->mapoff <= header->e_phoff
985 && (c->mapend - c->mapstart + c->mapoff
986 >= header->e_phoff + header->e_phnum * sizeof (ElfW(Phdr))))
987 /* Found the program header in this segment. */
988 l->l_phdr = (void *) (c->mapstart + header->e_phoff - c->mapoff);
990 if (c->allocend > c->dataend)
992 /* Extra zero pages should appear at the end of this segment,
993 after the data mapped from the file. */
994 ElfW(Addr) zero, zeroend, zeropage;
996 zero = l->l_addr + c->dataend;
997 zeroend = l->l_addr + c->allocend;
998 zeropage = (zero + _dl_pagesize - 1) & ~(_dl_pagesize - 1);
1000 if (zeroend < zeropage)
1001 /* All the extra data is in the last page of the segment.
1002 We can just zero it. */
1005 if (zeropage > zero)
1007 /* Zero the final part of the last page of the segment. */
1008 if ((c->prot & PROT_WRITE) == 0)
1011 if (__mprotect ((caddr_t) (zero & ~(_dl_pagesize - 1)),
1012 _dl_pagesize, c->prot|PROT_WRITE) < 0)
1013 LOSE (errno, N_("cannot change memory protections"));
1015 memset ((void *) zero, '\0', zeropage - zero);
1016 if ((c->prot & PROT_WRITE) == 0)
1017 __mprotect ((caddr_t) (zero & ~(_dl_pagesize - 1)),
1018 _dl_pagesize, c->prot);
1021 if (zeroend > zeropage)
1023 /* Map the remaining zero pages in from the zero fill FD. */
1025 mapat = __mmap ((caddr_t) zeropage, zeroend - zeropage,
1026 c->prot, MAP_ANON|MAP_PRIVATE|MAP_FIXED,
1028 if (mapat == MAP_FAILED)
1029 LOSE (errno, N_("cannot map zero-fill pages"));
1036 if (l->l_phdr == NULL)
1038 /* The program header is not contained in any of the segments.
1039 We have to allocate memory ourself and copy it over from
1040 out temporary place. */
1041 ElfW(Phdr) *newp = (ElfW(Phdr) *) malloc (header->e_phnum
1042 * sizeof (ElfW(Phdr)));
1044 LOSE (ENOMEM, N_("cannot allocate memory for program header"));
1046 l->l_phdr = memcpy (newp, phdr,
1047 (header->e_phnum * sizeof (ElfW(Phdr))));
1048 l->l_phdr_allocated = 1;
1051 /* Adjust the PT_PHDR value by the runtime load address. */
1052 (ElfW(Addr)) l->l_phdr += l->l_addr;
1055 /* We are done mapping in the file. We no longer need the descriptor. */
1058 if (l->l_type == lt_library && type == ET_EXEC)
1059 l->l_type = lt_executable;
1064 LOSE (0, N_("object file has no dynamic section"));
1067 (ElfW(Addr)) l->l_ld += l->l_addr;
1069 l->l_entry += l->l_addr;
1071 if (__builtin_expect (_dl_debug_mask & DL_DEBUG_FILES, 0))
1072 _dl_debug_printf (" dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n"
1073 " entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1074 (int) sizeof (void *) * 2, (unsigned long int) l->l_ld,
1075 (int) sizeof (void *) * 2, (unsigned long int) l->l_addr,
1076 (int) sizeof (void *) * 2, maplength,
1077 (int) sizeof (void *) * 2, (unsigned long int) l->l_entry,
1078 (int) sizeof (void *) * 2, (unsigned long int) l->l_phdr,
1079 (int) sizeof (void *) * 2, l->l_phnum);
1081 elf_get_dynamic_info (l);
1083 /* Make sure we are dlopen()ing an object which has the DF_1_NOOPEN
1085 if (__builtin_expect (l->l_flags_1 & DF_1_NOOPEN, 0)
1086 && (mode & __RTLD_DLOPEN))
1088 /* Remove from the module list. */
1089 assert (l->l_next == NULL);
1091 if (l->l_prev == NULL)
1092 /* No other module loaded. */
1096 l->l_prev->l_next = NULL;
1099 /* We are not supposed to load this object. Free all resources. */
1100 __munmap ((void *) l->l_map_start, l->l_map_end - l->l_map_start);
1102 if (!l->l_libname->dont_free)
1103 free (l->l_libname);
1105 if (l->l_phdr_allocated)
1106 free ((void *) l->l_phdr);
1110 _dl_signal_error (0, name, NULL,
1111 N_("shared object cannot be dlopen()ed"));
1114 if (l->l_info[DT_HASH])
1117 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1118 have to do this for the main map. */
1119 if (__builtin_expect (l->l_info[DT_SYMBOLIC] != NULL, 0)
1120 && &l->l_searchlist != l->l_scope[0])
1122 /* Create an appropriate searchlist. It contains only this map.
1124 XXX This is the definition of DT_SYMBOLIC in SysVr4. The old
1125 GNU ld.so implementation had a different interpretation which
1126 is more reasonable. We are prepared to add this possibility
1127 back as part of a GNU extension of the ELF format. */
1128 l->l_symbolic_searchlist.r_list =
1129 (struct link_map **) malloc (sizeof (struct link_map *));
1131 if (l->l_symbolic_searchlist.r_list == NULL)
1132 LOSE (ENOMEM, N_("cannot create searchlist"));
1134 l->l_symbolic_searchlist.r_list[0] = l;
1135 l->l_symbolic_searchlist.r_nlist = 1;
1137 /* Now move the existing entries one back. */
1138 memmove (&l->l_scope[1], &l->l_scope[0],
1139 (l->l_scope_max - 1) * sizeof (l->l_scope[0]));
1141 /* Now add the new entry. */
1142 l->l_scope[0] = &l->l_symbolic_searchlist;
1145 /* Remember whether this object must be initialized first. */
1146 if (__builtin_expect (l->l_flags_1 & DF_1_INITFIRST, 0))
1149 /* Finally the file information. */
1150 l->l_dev = st.st_dev;
1151 l->l_ino = st.st_ino;
1156 /* Print search path. */
1158 print_search_path (struct r_search_path_elem **list,
1159 const char *what, const char *name)
1161 char buf[max_dirnamelen + max_capstrlen];
1164 _dl_debug_printf (" search path=");
1166 while (*list != NULL && (*list)->what == what) /* Yes, ==. */
1168 char *endp = __mempcpy (buf, (*list)->dirname, (*list)->dirnamelen);
1171 for (cnt = 0; cnt < ncapstr; ++cnt)
1172 if ((*list)->status[cnt] != nonexisting)
1174 char *cp = __mempcpy (endp, capstr[cnt].str, capstr[cnt].len);
1175 if (cp == buf || (cp == buf + 1 && buf[0] == '/'))
1181 _dl_debug_printf_c ("%s", buf);
1185 _dl_debug_printf_c (":%s", buf);
1192 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what,
1193 name[0] ? name : _dl_argv[0]);
1195 _dl_debug_printf_c ("\t\t(%s)\n", what);
1198 /* Open a file and verify it is an ELF file for this architecture. We
1199 ignore only ELF files for other architectures. Non-ELF files and
1200 ELF files with different header information cause fatal errors since
1201 this could mean there is something wrong in the installation and the
1202 user might want to know about this. */
1204 open_verify (const char *name, struct filebuf *fbp)
1206 /* This is the expected ELF header. */
1207 #define ELF32_CLASS ELFCLASS32
1208 #define ELF64_CLASS ELFCLASS64
1209 #ifndef VALID_ELF_HEADER
1210 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1211 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1212 # define VALID_ELF_ABIVERSION(ver) (ver == 0)
1214 static const unsigned char expected[EI_PAD] =
1216 [EI_MAG0] = ELFMAG0,
1217 [EI_MAG1] = ELFMAG1,
1218 [EI_MAG2] = ELFMAG2,
1219 [EI_MAG3] = ELFMAG3,
1220 [EI_CLASS] = ELFW(CLASS),
1221 [EI_DATA] = byteorder,
1222 [EI_VERSION] = EV_CURRENT,
1223 [EI_OSABI] = ELFOSABI_SYSV,
1226 static const struct {
1227 ElfW(Word) vendorlen, datalen, type;
1229 } expected_note = { 4, 16, 1, "GNU" };
1232 /* Open the file. We always open files read-only. */
1233 fd = __open (name, O_RDONLY);
1237 ElfW(Phdr) *phdr, *ph;
1238 ElfW(Word) *abi_note, abi_note_buf[8];
1239 unsigned int osversion;
1242 /* We successfully openened the file. Now verify it is a file
1245 fbp->len = __libc_read (fd, fbp->buf, sizeof (fbp->buf));
1247 /* This is where the ELF header is loaded. */
1248 assert (sizeof (fbp->buf) > sizeof (ElfW(Ehdr)));
1249 ehdr = (ElfW(Ehdr) *) fbp->buf;
1251 /* Now run the tests. */
1252 if (__builtin_expect (fbp->len < (ssize_t) sizeof (ElfW(Ehdr)), 0))
1253 lose (errno, fd, name, NULL, NULL,
1254 errno == 0 ? N_("file too short") : N_("cannot read file data"));
1256 /* See whether the ELF header is what we expect. */
1257 if (__builtin_expect (! VALID_ELF_HEADER (ehdr->e_ident, expected,
1260 /* Something is wrong. */
1261 if (*(Elf32_Word *) &ehdr->e_ident !=
1262 #if BYTE_ORDER == LITTLE_ENDIAN
1263 ((ELFMAG0 << (EI_MAG0 * 8)) |
1264 (ELFMAG1 << (EI_MAG1 * 8)) |
1265 (ELFMAG2 << (EI_MAG2 * 8)) |
1266 (ELFMAG3 << (EI_MAG3 * 8)))
1268 ((ELFMAG0 << (EI_MAG3 * 8)) |
1269 (ELFMAG1 << (EI_MAG2 * 8)) |
1270 (ELFMAG2 << (EI_MAG1 * 8)) |
1271 (ELFMAG3 << (EI_MAG0 * 8)))
1274 lose (0, fd, name, NULL, NULL, N_("invalid ELF header"));
1276 if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS))
1277 /* This is not a fatal error. On architectures where
1278 32-bit and 64-bit binaries can be run this might
1282 if (ehdr->e_ident[EI_DATA] != byteorder)
1284 if (BYTE_ORDER == BIG_ENDIAN)
1285 lose (0, fd, name, NULL, NULL,
1286 "ELF file data encoding not big-endian");
1288 lose (0, fd, name, NULL, NULL,
1289 "ELF file data encoding not little-endian");
1291 if (ehdr->e_ident[EI_VERSION] != EV_CURRENT)
1292 lose (0, fd, name, NULL, NULL,
1293 N_("ELF file version ident does not match current one"));
1294 /* XXX We should be able so set system specific versions which are
1296 if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI]))
1297 lose (0, fd, name, NULL, NULL, N_("ELF file OS ABI invalid"));
1298 if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_ABIVERSION]))
1299 lose (0, fd, name, NULL, NULL,
1300 N_("ELF file ABI version invalid"));
1301 lose (0, fd, name, NULL, NULL, N_("internal error"));
1304 if (__builtin_expect (ehdr->e_version, EV_CURRENT) != EV_CURRENT)
1305 lose (0, fd, name, NULL, NULL,
1306 N_("ELF file version does not match current one"));
1307 if (! __builtin_expect (elf_machine_matches_host (ehdr), 1))
1309 else if (__builtin_expect (ehdr->e_phentsize, sizeof (ElfW(Phdr)))
1310 != sizeof (ElfW(Phdr)))
1311 lose (0, fd, name, NULL, NULL,
1312 N_("ELF file's phentsize not the expected size"));
1313 else if (__builtin_expect (ehdr->e_type, ET_DYN) != ET_DYN
1314 && __builtin_expect (ehdr->e_type, ET_EXEC) != ET_EXEC)
1315 lose (0, fd, name, NULL, NULL,
1316 N_("only ET_DYN and ET_EXEC can be loaded"));
1318 maplength = ehdr->e_phnum * sizeof (ElfW(Phdr));
1319 if (ehdr->e_phoff + maplength <= fbp->len)
1320 phdr = (void *) (fbp->buf + ehdr->e_phoff);
1323 phdr = alloca (maplength);
1324 __lseek (fd, SEEK_SET, ehdr->e_phoff);
1325 if (__libc_read (fd, (void *) phdr, maplength) != maplength)
1326 lose (errno, fd, name, NULL, NULL, N_("cannot read file data"));
1329 /* Check .note.ABI-tag if present. */
1330 for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
1331 if (ph->p_type == PT_NOTE && ph->p_filesz == 32 && ph->p_align >= 4)
1333 if (ph->p_offset + 32 <= fbp->len)
1334 abi_note = (void *) (fbp->buf + ph->p_offset);
1337 __lseek (fd, SEEK_SET, ph->p_offset);
1338 if (__libc_read (fd, (void *) abi_note_buf, 32) != 32)
1339 lose (errno, fd, name, NULL, NULL,
1340 N_("cannot read file data"));
1341 abi_note = abi_note_buf;
1344 if (memcmp (abi_note, &expected_note, sizeof (expected_note)))
1347 osversion = (abi_note[5] & 0xff) * 65536
1348 + (abi_note[6] & 0xff) * 256
1349 + (abi_note[7] & 0xff);
1350 if (abi_note[4] != __ABI_TAG_OS
1351 || (_dl_osversion && _dl_osversion < osversion))
1355 __set_errno (ENOENT);
1366 /* Try to open NAME in one of the directories in *DIRSP.
1367 Return the fd, or -1. If successful, fill in *REALNAME
1368 with the malloc'd full directory name. If it turns out
1369 that none of the directories in *DIRSP exists, *DIRSP is
1370 replaced with (void *) -1, and the old value is free()d
1371 if MAY_FREE_DIRS is true. */
1374 open_path (const char *name, size_t namelen, int preloaded,
1375 struct r_search_path_struct *sps, char **realname,
1376 struct filebuf *fbp)
1378 struct r_search_path_elem **dirs = sps->dirs;
1381 const char *current_what = NULL;
1384 buf = alloca (max_dirnamelen + max_capstrlen + namelen);
1387 struct r_search_path_elem *this_dir = *dirs;
1394 /* If we are debugging the search for libraries print the path
1395 now if it hasn't happened now. */
1396 if (__builtin_expect (_dl_debug_mask & DL_DEBUG_LIBS, 0)
1397 && current_what != this_dir->what)
1399 current_what = this_dir->what;
1400 print_search_path (dirs, current_what, this_dir->where);
1403 edp = (char *) __mempcpy (buf, this_dir->dirname, this_dir->dirnamelen);
1404 for (cnt = 0; fd == -1 && cnt < ncapstr; ++cnt)
1406 /* Skip this directory if we know it does not exist. */
1407 if (this_dir->status[cnt] == nonexisting)
1411 ((char *) __mempcpy (__mempcpy (edp,
1412 capstr[cnt].str, capstr[cnt].len),
1416 /* Print name we try if this is wanted. */
1417 if (__builtin_expect (_dl_debug_mask & DL_DEBUG_LIBS, 0))
1418 _dl_debug_printf (" trying file=%s\n", buf);
1420 fd = open_verify (buf, fbp);
1421 if (this_dir->status[cnt] == unknown)
1424 this_dir->status[cnt] = existing;
1427 /* We failed to open machine dependent library. Let's
1428 test whether there is any directory at all. */
1431 buf[buflen - namelen - 1] = '\0';
1433 if (__xstat64 (_STAT_VER, buf, &st) != 0
1434 || ! S_ISDIR (st.st_mode))
1435 /* The directory does not exist or it is no directory. */
1436 this_dir->status[cnt] = nonexisting;
1438 this_dir->status[cnt] = existing;
1442 /* Remember whether we found any existing directory. */
1443 here_any |= this_dir->status[cnt] == existing;
1445 if (fd != -1 && __builtin_expect (preloaded, 0)
1446 && __libc_enable_secure)
1448 /* This is an extra security effort to make sure nobody can
1449 preload broken shared objects which are in the trusted
1450 directories and so exploit the bugs. */
1453 if (__fxstat64 (_STAT_VER, fd, &st) != 0
1454 || (st.st_mode & S_ISUID) == 0)
1456 /* The shared object cannot be tested for being SUID
1457 or this bit is not set. In this case we must not
1461 /* We simply ignore the file, signal this by setting
1462 the error value which would have been set by `open'. */
1470 *realname = (char *) malloc (buflen);
1471 if (*realname != NULL)
1473 memcpy (*realname, buf, buflen);
1478 /* No memory for the name, we certainly won't be able
1479 to load and link it. */
1484 if (here_any && (err = errno) != ENOENT && err != EACCES)
1485 /* The file exists and is readable, but something went wrong. */
1488 /* Remember whether we found anything. */
1491 while (*++dirs != NULL);
1493 /* Remove the whole path if none of the directories exists. */
1494 if (__builtin_expect (! any, 0))
1496 /* Paths which were allocated using the minimal malloc() in ld.so
1497 must not be freed using the general free() in libc. */
1500 sps->dirs = (void *) -1;
1506 /* Map in the shared object file NAME. */
1510 _dl_map_object (struct link_map *loader, const char *name, int preloaded,
1511 int type, int trace_mode, int mode)
1519 /* Look for this name among those already loaded. */
1520 for (l = _dl_loaded; l; l = l->l_next)
1522 /* If the requested name matches the soname of a loaded object,
1523 use that object. Elide this check for names that have not
1525 if (__builtin_expect (l->l_faked, 0) != 0)
1527 if (!_dl_name_match_p (name, l))
1531 if (__builtin_expect (l->l_soname_added, 1)
1532 || l->l_info[DT_SONAME] == NULL)
1535 soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
1536 + l->l_info[DT_SONAME]->d_un.d_val);
1537 if (strcmp (name, soname) != 0)
1540 /* We have a match on a new name -- cache it. */
1541 add_name_to_object (l, soname);
1542 l->l_soname_added = 1;
1545 /* We have a match. */
1549 /* Display information if we are debugging. */
1550 if (__builtin_expect (_dl_debug_mask & DL_DEBUG_FILES, 0) && loader != NULL)
1551 _dl_debug_printf ("\nfile=%s; needed by %s\n", name,
1552 loader->l_name[0] ? loader->l_name : _dl_argv[0]);
1554 if (strchr (name, '/') == NULL)
1556 /* Search for NAME in several places. */
1558 size_t namelen = strlen (name) + 1;
1560 if (__builtin_expect (_dl_debug_mask & DL_DEBUG_LIBS, 0))
1561 _dl_debug_printf ("find library=%s; searching\n", name);
1565 /* When the object has the RUNPATH information we don't use any
1567 if (loader == NULL || loader->l_info[DT_RUNPATH] == NULL)
1569 /* First try the DT_RPATH of the dependent object that caused NAME
1570 to be loaded. Then that object's dependent, and on up. */
1571 for (l = loader; fd == -1 && l; l = l->l_loader)
1573 if (l->l_rpath_dirs.dirs == NULL)
1575 if (l->l_info[DT_RPATH] == NULL)
1577 /* There is no path. */
1578 l->l_rpath_dirs.dirs = (void *) -1;
1583 /* Make sure the cache information is available. */
1584 size_t ptrval = (D_PTR (l, l_info[DT_STRTAB])
1585 + l->l_info[DT_RPATH]->d_un.d_val);
1586 decompose_rpath (&l->l_rpath_dirs,
1587 (const char *) ptrval, l, "RPATH");
1591 if (l->l_rpath_dirs.dirs != (void *) -1)
1592 fd = open_path (name, namelen, preloaded, &l->l_rpath_dirs,
1596 /* If dynamically linked, try the DT_RPATH of the executable
1599 if (fd == -1 && l && l->l_type != lt_loaded && l != loader
1600 && l->l_rpath_dirs.dirs != (void *) -1)
1601 fd = open_path (name, namelen, preloaded, &l->l_rpath_dirs,
1605 /* Try the LD_LIBRARY_PATH environment variable. */
1606 if (fd == -1 && env_path_list.dirs != (void *) -1)
1607 fd = open_path (name, namelen, preloaded, &env_path_list,
1610 /* Look at the RUNPATH information for this binary.
1612 Note that this is no real loop. 'while' is used only to enable
1613 us to use 'break' instead of a 'goto' to jump to the end. The
1614 loop is always left after the first round. */
1615 while (fd == -1 && loader != NULL
1616 && loader->l_runpath_dirs.dirs != (void *) -1)
1618 if (loader->l_runpath_dirs.dirs == NULL)
1620 if (loader->l_info[DT_RUNPATH] == NULL)
1623 loader->l_runpath_dirs.dirs = (void *) -1;
1628 /* Make sure the cache information is available. */
1629 size_t ptrval = (D_PTR (loader, l_info[DT_STRTAB])
1630 + loader->l_info[DT_RUNPATH]->d_un.d_val);
1631 decompose_rpath (&loader->l_runpath_dirs,
1632 (const char *) ptrval, loader, "RUNPATH");
1636 if (loader->l_runpath_dirs.dirs != (void *) -1)
1637 fd = open_path (name, namelen, preloaded,
1638 &loader->l_runpath_dirs, &realname, &fb);
1643 && (__builtin_expect (! preloaded, 1) || ! __libc_enable_secure))
1645 /* Check the list of libraries in the file /etc/ld.so.cache,
1646 for compatibility with Linux's ldconfig program. */
1647 const char *cached = _dl_load_cache_lookup (name);
1652 l = loader ?: _dl_loaded;
1657 /* If the loader has the DF_1_NODEFLIB flag set we must not
1658 use a cache entry from any of these directories. */
1661 /* 'l' is always != NULL for dynamically linked objects. */
1664 __builtin_expect (l->l_flags_1 & DF_1_NODEFLIB, 0))
1666 const char *dirp = system_dirs;
1667 unsigned int cnt = 0;
1671 if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0)
1673 /* The prefix matches. Don't use the entry. */
1678 dirp += system_dirs_len[cnt] + 1;
1681 while (cnt < nsystem_dirs_len);
1686 fd = open_verify (cached, &fb);
1687 if (__builtin_expect (fd != -1, 1))
1689 realname = local_strdup (cached);
1690 if (realname == NULL)
1700 /* Finally, try the default path. */
1702 && ((l = loader ?: _dl_loaded)
1703 /* 'l' is always != NULL for dynamically linked objects. */
1709 __builtin_expect (!(l->l_flags_1 & DF_1_NODEFLIB), 1))
1710 && rtld_search_dirs.dirs != (void *) -1)
1711 fd = open_path (name, namelen, preloaded, &rtld_search_dirs,
1714 /* Add another newline when we a tracing the library loading. */
1715 if (__builtin_expect (_dl_debug_mask & DL_DEBUG_LIBS, 0))
1716 _dl_debug_printf ("\n");
1720 /* The path may contain dynamic string tokens. */
1722 ? expand_dynamic_string_token (loader, name)
1723 : local_strdup (name));
1724 if (realname == NULL)
1728 fd = open_verify (realname, &fb);
1729 if (__builtin_expect (fd, 0) == -1)
1734 if (__builtin_expect (fd, 0) == -1)
1738 /* We haven't found an appropriate library. But since we
1739 are only interested in the list of libraries this isn't
1740 so severe. Fake an entry with all the information we
1742 static const Elf_Symndx dummy_bucket = STN_UNDEF;
1744 /* Enter the new object in the list of loaded objects. */
1745 if ((name_copy = local_strdup (name)) == NULL
1746 || (l = _dl_new_object (name_copy, name, type, loader)) == NULL)
1747 _dl_signal_error (ENOMEM, name, NULL,
1748 N_("cannot create shared object descriptor"));
1749 /* Signal that this is a faked entry. */
1751 /* Since the descriptor is initialized with zero we do not
1753 l->l_reserved = 0; */
1754 l->l_buckets = &dummy_bucket;
1761 _dl_signal_error (errno, name, NULL,
1762 N_("cannot open shared object file"));
1765 return _dl_map_object_from_fd (name, fd, &fb, realname, loader, type, mode);