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[glibc.git] / elf / rtld.c
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1 /* Run time dynamic linker.
2 Copyright (C) 1995-1999, 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
18 02111-1307 USA. */
20 #include <fcntl.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <unistd.h>
24 #include <sys/mman.h> /* Check if MAP_ANON is defined. */
25 #include <sys/stat.h>
26 #include <ldsodefs.h>
27 #include <stdio-common/_itoa.h>
28 #include <entry.h>
29 #include <fpu_control.h>
30 #include <hp-timing.h>
31 #include <bits/libc-lock.h>
32 #include "dynamic-link.h"
33 #include "dl-librecon.h"
34 #include <unsecvars.h>
36 #include <assert.h>
38 /* Helper function to handle errors while resolving symbols. */
39 static void print_unresolved (int errcode, const char *objname,
40 const char *errsting);
42 /* Helper function to handle errors when a version is missing. */
43 static void print_missing_version (int errcode, const char *objname,
44 const char *errsting);
46 /* Print the various times we collected. */
47 static void print_statistics (void);
49 /* This is a list of all the modes the dynamic loader can be in. */
50 enum mode { normal, list, verify, trace };
52 /* Process all environments variables the dynamic linker must recognize.
53 Since all of them start with `LD_' we are a bit smarter while finding
54 all the entries. */
55 static void process_envvars (enum mode *modep);
57 int _dl_argc;
58 char **_dl_argv;
59 unsigned int _dl_skip_args; /* Nonzero if we were run directly. */
60 int _dl_verbose;
61 const char *_dl_platform;
62 size_t _dl_platformlen;
63 unsigned long _dl_hwcap;
64 fpu_control_t _dl_fpu_control = _FPU_DEFAULT;
65 struct r_search_path *_dl_search_paths;
66 const char *_dl_profile;
67 const char *_dl_profile_output;
68 struct link_map *_dl_profile_map;
69 int _dl_lazy = 1;
70 /* XXX I know about at least one case where we depend on the old weak
71 behavior (it has to do with librt). Until we get DSO groups implemented
72 we have to make this the default. Bummer. --drepper */
73 #if 0
74 int _dl_dynamic_weak;
75 #else
76 int _dl_dynamic_weak = 1;
77 #endif
78 int _dl_debug_mask;
79 const char *_dl_inhibit_rpath; /* RPATH values which should be
80 ignored. */
81 const char *_dl_origin_path;
82 int _dl_bind_not;
84 /* This is a pointer to the map for the main object and through it to
85 all loaded objects. */
86 struct link_map *_dl_loaded;
87 /* Number of object in the _dl_loaded list. */
88 unsigned int _dl_nloaded;
89 /* Pointer to the l_searchlist element of the link map of the main object. */
90 struct r_scope_elem *_dl_main_searchlist;
91 /* Copy of the content of `_dl_main_searchlist'. */
92 struct r_scope_elem _dl_initial_searchlist;
93 /* Array which is used when looking up in the global scope. */
94 struct r_scope_elem *_dl_global_scope[2];
96 /* During the program run we must not modify the global data of
97 loaded shared object simultanously in two threads. Therefore we
98 protect `_dl_open' and `_dl_close' in dl-close.c.
100 This must be a recursive lock since the initializer function of
101 the loaded object might as well require a call to this function.
102 At this time it is not anymore a problem to modify the tables. */
103 __libc_lock_define_initialized_recursive (, _dl_load_lock)
105 /* Set nonzero during loading and initialization of executable and
106 libraries, cleared before the executable's entry point runs. This
107 must not be initialized to nonzero, because the unused dynamic
108 linker loaded in for libc.so's "ld.so.1" dep will provide the
109 definition seen by libc.so's initializer; that value must be zero,
110 and will be since that dynamic linker's _dl_start and dl_main will
111 never be called. */
112 int _dl_starting_up;
115 static void dl_main (const ElfW(Phdr) *phdr,
116 ElfW(Word) phnum,
117 ElfW(Addr) *user_entry);
119 struct link_map _dl_rtld_map;
120 struct libname_list _dl_rtld_libname;
121 struct libname_list _dl_rtld_libname2;
123 /* Variable for statistics. */
124 #ifndef HP_TIMING_NONAVAIL
125 static hp_timing_t rtld_total_time;
126 static hp_timing_t relocate_time;
127 static hp_timing_t load_time;
128 #endif
129 extern unsigned long int _dl_num_relocations; /* in dl-lookup.c */
131 static ElfW(Addr) _dl_start_final (void *arg, struct link_map *bootstrap_map_p,
132 hp_timing_t start_time);
134 #ifdef RTLD_START
135 RTLD_START
136 #else
137 #error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
138 #endif
140 static ElfW(Addr)
141 _dl_start (void *arg)
143 struct link_map bootstrap_map;
144 hp_timing_t start_time;
145 size_t cnt;
147 /* This #define produces dynamic linking inline functions for
148 bootstrap relocation instead of general-purpose relocation. */
149 #define RTLD_BOOTSTRAP
150 #define RESOLVE_MAP(sym, version, flags) \
151 ((*(sym))->st_shndx == SHN_UNDEF ? 0 : &bootstrap_map)
152 #define RESOLVE(sym, version, flags) \
153 ((*(sym))->st_shndx == SHN_UNDEF ? 0 : bootstrap_map.l_addr)
154 #include "dynamic-link.h"
156 if (HP_TIMING_INLINE && HP_TIMING_AVAIL)
157 HP_TIMING_NOW (start_time);
159 /* Partly clean the `bootstrap_map' structure up. Don't use `memset'
160 since it might nor be built in or inlined and we cannot make function
161 calls at this point. */
162 for (cnt = 0;
163 cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]);
164 ++cnt)
165 bootstrap_map.l_info[cnt] = 0;
167 /* Figure out the run-time load address of the dynamic linker itself. */
168 bootstrap_map.l_addr = elf_machine_load_address ();
170 /* Read our own dynamic section and fill in the info array. */
171 bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
172 elf_get_dynamic_info (&bootstrap_map);
174 #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
175 ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info);
176 #endif
178 /* Relocate ourselves so we can do normal function calls and
179 data access using the global offset table. */
181 ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0);
182 /* Please note that we don't allow profiling of this object and
183 therefore need not test whether we have to allocate the array
184 for the relocation results (as done in dl-reloc.c). */
186 /* Now life is sane; we can call functions and access global data.
187 Set up to use the operating system facilities, and find out from
188 the operating system's program loader where to find the program
189 header table in core. Put the rest of _dl_start into a separate
190 function, that way the compiler cannot put accesses to the GOT
191 before ELF_DYNAMIC_RELOCATE. */
193 ElfW(Addr) entry = _dl_start_final (arg, &bootstrap_map, start_time);
195 #ifndef ELF_MACHINE_START_ADDRESS
196 # define ELF_MACHINE_START_ADDRESS(map, start) (start)
197 #endif
199 return ELF_MACHINE_START_ADDRESS (_dl_loaded, entry);
204 static ElfW(Addr)
205 _dl_start_final (void *arg, struct link_map *bootstrap_map_p,
206 hp_timing_t start_time)
208 /* The use of `alloca' here looks ridiculous but it helps. The goal
209 is to avoid the function from being inlined. There is no official
210 way to do this so we use this trick. gcc never inlines functions
211 which use `alloca'. */
212 ElfW(Addr) *start_addr = alloca (sizeof (ElfW(Addr)));
214 if (HP_TIMING_AVAIL)
216 /* If it hasn't happen yet record the startup time. */
217 if (! HP_TIMING_INLINE)
218 HP_TIMING_NOW (start_time);
220 /* Initialize the timing functions. */
221 HP_TIMING_DIFF_INIT ();
224 /* Transfer data about ourselves to the permanent link_map structure. */
225 _dl_rtld_map.l_addr = bootstrap_map_p->l_addr;
226 _dl_rtld_map.l_ld = bootstrap_map_p->l_ld;
227 _dl_rtld_map.l_opencount = 1;
228 memcpy (_dl_rtld_map.l_info, bootstrap_map_p->l_info,
229 sizeof _dl_rtld_map.l_info);
230 _dl_setup_hash (&_dl_rtld_map);
232 /* Don't bother trying to work out how ld.so is mapped in memory. */
233 _dl_rtld_map.l_map_start = ~0;
234 _dl_rtld_map.l_map_end = ~0;
236 /* Call the OS-dependent function to set up life so we can do things like
237 file access. It will call `dl_main' (below) to do all the real work
238 of the dynamic linker, and then unwind our frame and run the user
239 entry point on the same stack we entered on. */
240 *start_addr = _dl_sysdep_start (arg, &dl_main);
241 #ifndef HP_TIMING_NONAVAIL
242 if (HP_TIMING_AVAIL)
244 hp_timing_t end_time;
246 /* Get the current time. */
247 HP_TIMING_NOW (end_time);
249 /* Compute the difference. */
250 HP_TIMING_DIFF (rtld_total_time, start_time, end_time);
252 #endif
254 if (__builtin_expect (_dl_debug_mask & DL_DEBUG_STATISTICS, 0))
255 print_statistics ();
257 return *start_addr;
260 /* Now life is peachy; we can do all normal operations.
261 On to the real work. */
263 /* Some helper functions. */
265 /* Arguments to relocate_doit. */
266 struct relocate_args
268 struct link_map *l;
269 int lazy;
272 struct map_args
274 /* Argument to map_doit. */
275 char *str;
276 /* Return value of map_doit. */
277 struct link_map *main_map;
280 /* Arguments to version_check_doit. */
281 struct version_check_args
283 int doexit;
284 int dotrace;
287 static void
288 relocate_doit (void *a)
290 struct relocate_args *args = (struct relocate_args *) a;
292 _dl_relocate_object (args->l, args->l->l_scope,
293 args->lazy, 0);
296 static void
297 map_doit (void *a)
299 struct map_args *args = (struct map_args *) a;
300 args->main_map = _dl_map_object (NULL, args->str, 0, lt_library, 0, 0);
303 static void
304 version_check_doit (void *a)
306 struct version_check_args *args = (struct version_check_args *) a;
307 if (_dl_check_all_versions (_dl_loaded, 1, args->dotrace) && args->doexit)
308 /* We cannot start the application. Abort now. */
309 _exit (1);
313 static inline struct link_map *
314 find_needed (const char *name)
316 unsigned int n = _dl_loaded->l_searchlist.r_nlist;
318 while (n-- > 0)
319 if (_dl_name_match_p (name, _dl_loaded->l_searchlist.r_list[n]))
320 return _dl_loaded->l_searchlist.r_list[n];
322 /* Should never happen. */
323 return NULL;
326 static int
327 match_version (const char *string, struct link_map *map)
329 const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
330 ElfW(Verdef) *def;
332 #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
333 if (map->l_info[VERDEFTAG] == NULL)
334 /* The file has no symbol versioning. */
335 return 0;
337 def = (ElfW(Verdef) *) ((char *) map->l_addr
338 + map->l_info[VERDEFTAG]->d_un.d_ptr);
339 while (1)
341 ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux);
343 /* Compare the version strings. */
344 if (strcmp (string, strtab + aux->vda_name) == 0)
345 /* Bingo! */
346 return 1;
348 /* If no more definitions we failed to find what we want. */
349 if (def->vd_next == 0)
350 break;
352 /* Next definition. */
353 def = (ElfW(Verdef) *) ((char *) def + def->vd_next);
356 return 0;
359 static const char *library_path; /* The library search path. */
360 static const char *preloadlist; /* The list preloaded objects. */
361 static int version_info; /* Nonzero if information about
362 versions has to be printed. */
364 static void
365 dl_main (const ElfW(Phdr) *phdr,
366 ElfW(Word) phnum,
367 ElfW(Addr) *user_entry)
369 const ElfW(Phdr) *ph;
370 enum mode mode;
371 struct link_map **preloads;
372 unsigned int npreloads;
373 size_t file_size;
374 char *file;
375 int has_interp = 0;
376 unsigned int i;
377 int rtld_is_main = 0;
378 #ifndef HP_TIMING_NONAVAIL
379 hp_timing_t start;
380 hp_timing_t stop;
381 hp_timing_t diff;
382 #endif
384 /* Process the environment variable which control the behaviour. */
385 process_envvars (&mode);
387 /* Set up a flag which tells we are just starting. */
388 _dl_starting_up = 1;
390 if (*user_entry == (ElfW(Addr)) ENTRY_POINT)
392 /* Ho ho. We are not the program interpreter! We are the program
393 itself! This means someone ran ld.so as a command. Well, that
394 might be convenient to do sometimes. We support it by
395 interpreting the args like this:
397 ld.so PROGRAM ARGS...
399 The first argument is the name of a file containing an ELF
400 executable we will load and run with the following arguments.
401 To simplify life here, PROGRAM is searched for using the
402 normal rules for shared objects, rather than $PATH or anything
403 like that. We just load it and use its entry point; we don't
404 pay attention to its PT_INTERP command (we are the interpreter
405 ourselves). This is an easy way to test a new ld.so before
406 installing it. */
407 rtld_is_main = 1;
409 /* Note the place where the dynamic linker actually came from. */
410 _dl_rtld_map.l_name = _dl_argv[0];
412 while (_dl_argc > 1)
413 if (! strcmp (_dl_argv[1], "--list"))
415 mode = list;
416 _dl_lazy = -1; /* This means do no dependency analysis. */
418 ++_dl_skip_args;
419 --_dl_argc;
420 ++_dl_argv;
422 else if (! strcmp (_dl_argv[1], "--verify"))
424 mode = verify;
426 ++_dl_skip_args;
427 --_dl_argc;
428 ++_dl_argv;
430 else if (! strcmp (_dl_argv[1], "--library-path") && _dl_argc > 2)
432 library_path = _dl_argv[2];
434 _dl_skip_args += 2;
435 _dl_argc -= 2;
436 _dl_argv += 2;
438 else if (! strcmp (_dl_argv[1], "--inhibit-rpath") && _dl_argc > 2)
440 _dl_inhibit_rpath = _dl_argv[2];
442 _dl_skip_args += 2;
443 _dl_argc -= 2;
444 _dl_argv += 2;
446 else
447 break;
449 /* If we have no further argument the program was called incorrectly.
450 Grant the user some education. */
451 if (_dl_argc < 2)
452 _dl_fatal_printf ("\
453 Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\
454 You have invoked `ld.so', the helper program for shared library executables.\n\
455 This program usually lives in the file `/lib/ld.so', and special directives\n\
456 in executable files using ELF shared libraries tell the system's program\n\
457 loader to load the helper program from this file. This helper program loads\n\
458 the shared libraries needed by the program executable, prepares the program\n\
459 to run, and runs it. You may invoke this helper program directly from the\n\
460 command line to load and run an ELF executable file; this is like executing\n\
461 that file itself, but always uses this helper program from the file you\n\
462 specified, instead of the helper program file specified in the executable\n\
463 file you run. This is mostly of use for maintainers to test new versions\n\
464 of this helper program; chances are you did not intend to run this program.\n\
466 --list list all dependencies and how they are resolved\n\
467 --verify verify that given object really is a dynamically linked\n\
468 object we can handle\n\
469 --library-path PATH use given PATH instead of content of the environment\n\
470 variable LD_LIBRARY_PATH\n\
471 --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\
472 in LIST\n");
474 ++_dl_skip_args;
475 --_dl_argc;
476 ++_dl_argv;
478 /* Initialize the data structures for the search paths for shared
479 objects. */
480 _dl_init_paths (library_path);
482 if (__builtin_expect (mode, normal) == verify)
484 const char *objname;
485 const char *err_str = NULL;
486 struct map_args args;
488 args.str = _dl_argv[0];
489 (void) _dl_catch_error (&objname, &err_str, map_doit, &args);
490 if (__builtin_expect (err_str != NULL, 0))
492 if (err_str != _dl_out_of_memory)
493 free ((char *) err_str);
494 _exit (EXIT_FAILURE);
497 else
499 HP_TIMING_NOW (start);
500 _dl_map_object (NULL, _dl_argv[0], 0, lt_library, 0, 0);
501 HP_TIMING_NOW (stop);
503 HP_TIMING_DIFF (load_time, start, stop);
506 phdr = _dl_loaded->l_phdr;
507 phnum = _dl_loaded->l_phnum;
508 /* We overwrite here a pointer to a malloc()ed string. But since
509 the malloc() implementation used at this point is the dummy
510 implementations which has no real free() function it does not
511 makes sense to free the old string first. */
512 _dl_loaded->l_name = (char *) "";
513 *user_entry = _dl_loaded->l_entry;
515 else
517 /* Create a link_map for the executable itself.
518 This will be what dlopen on "" returns. */
519 _dl_new_object ((char *) "", "", lt_executable, NULL);
520 if (_dl_loaded == NULL)
521 _dl_fatal_printf ("cannot allocate memory for link map\n");
522 _dl_loaded->l_phdr = phdr;
523 _dl_loaded->l_phnum = phnum;
524 _dl_loaded->l_entry = *user_entry;
526 /* At this point we are in a bit of trouble. We would have to
527 fill in the values for l_dev and l_ino. But in general we
528 do not know where the file is. We also do not handle AT_EXECFD
529 even if it would be passed up.
531 We leave the values here defined to 0. This is normally no
532 problem as the program code itself is normally no shared
533 object and therefore cannot be loaded dynamically. Nothing
534 prevent the use of dynamic binaries and in these situations
535 we might get problems. We might not be able to find out
536 whether the object is already loaded. But since there is no
537 easy way out and because the dynamic binary must also not
538 have an SONAME we ignore this program for now. If it becomes
539 a problem we can force people using SONAMEs. */
541 /* We delay initializing the path structure until we got the dynamic
542 information for the program. */
545 _dl_loaded->l_map_end = 0;
546 /* Perhaps the executable has no PT_LOAD header entries at all. */
547 _dl_loaded->l_map_start = ~0;
549 /* Scan the program header table for the dynamic section. */
550 for (ph = phdr; ph < &phdr[phnum]; ++ph)
551 switch (ph->p_type)
553 case PT_PHDR:
554 /* Find out the load address. */
555 _dl_loaded->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr;
556 break;
557 case PT_DYNAMIC:
558 /* This tells us where to find the dynamic section,
559 which tells us everything we need to do. */
560 _dl_loaded->l_ld = (void *) _dl_loaded->l_addr + ph->p_vaddr;
561 break;
562 case PT_INTERP:
563 /* This "interpreter segment" was used by the program loader to
564 find the program interpreter, which is this program itself, the
565 dynamic linker. We note what name finds us, so that a future
566 dlopen call or DT_NEEDED entry, for something that wants to link
567 against the dynamic linker as a shared library, will know that
568 the shared object is already loaded. */
569 _dl_rtld_libname.name = ((const char *) _dl_loaded->l_addr
570 + ph->p_vaddr);
571 /* _dl_rtld_libname.next = NULL; Already zero. */
572 _dl_rtld_map.l_libname = &_dl_rtld_libname;
574 /* Ordinarilly, we would get additional names for the loader from
575 our DT_SONAME. This can't happen if we were actually linked as
576 a static executable (detect this case when we have no DYNAMIC).
577 If so, assume the filename component of the interpreter path to
578 be our SONAME, and add it to our name list. */
579 if (_dl_rtld_map.l_ld == NULL)
581 char *p = strrchr (_dl_rtld_libname.name, '/');
582 if (p)
584 _dl_rtld_libname2.name = p+1;
585 /* _dl_rtld_libname2.next = NULL; Already zero. */
586 _dl_rtld_libname.next = &_dl_rtld_libname2;
590 has_interp = 1;
591 break;
592 case PT_LOAD:
594 ElfW(Addr) mapstart;
595 ElfW(Addr) allocend;
597 /* Remember where the main program starts in memory. */
598 mapstart = _dl_loaded->l_addr + (ph->p_vaddr & ~(ph->p_align - 1));
599 if (_dl_loaded->l_map_start > mapstart)
600 _dl_loaded->l_map_start = mapstart;
602 /* Also where it ends. */
603 allocend = _dl_loaded->l_addr + ph->p_vaddr + ph->p_memsz;
604 if (_dl_loaded->l_map_end < allocend)
605 _dl_loaded->l_map_end = allocend;
607 break;
609 if (! _dl_loaded->l_map_end)
610 _dl_loaded->l_map_end = ~0;
611 if (! _dl_rtld_map.l_libname && _dl_rtld_map.l_name)
613 /* We were invoked directly, so the program might not have a
614 PT_INTERP. */
615 _dl_rtld_libname.name = _dl_rtld_map.l_name;
616 /* _dl_rtld_libname.next = NULL; Alread zero. */
617 _dl_rtld_map.l_libname = &_dl_rtld_libname;
619 else
620 assert (_dl_rtld_map.l_libname); /* How else did we get here? */
622 if (! rtld_is_main)
624 /* Extract the contents of the dynamic section for easy access. */
625 elf_get_dynamic_info (_dl_loaded);
626 if (_dl_loaded->l_info[DT_HASH])
627 /* Set up our cache of pointers into the hash table. */
628 _dl_setup_hash (_dl_loaded);
631 if (__builtin_expect (mode, normal) == verify)
633 /* We were called just to verify that this is a dynamic
634 executable using us as the program interpreter. Exit with an
635 error if we were not able to load the binary or no interpreter
636 is specified (i.e., this is no dynamically linked binary. */
637 if (_dl_loaded->l_ld == NULL)
638 _exit (1);
640 /* We allow here some platform specific code. */
641 #ifdef DISTINGUISH_LIB_VERSIONS
642 DISTINGUISH_LIB_VERSIONS;
643 #endif
644 _exit (has_interp ? 0 : 2);
647 if (! rtld_is_main)
648 /* Initialize the data structures for the search paths for shared
649 objects. */
650 _dl_init_paths (library_path);
652 /* Put the link_map for ourselves on the chain so it can be found by
653 name. Note that at this point the global chain of link maps contains
654 exactly one element, which is pointed to by _dl_loaded. */
655 if (! _dl_rtld_map.l_name)
656 /* If not invoked directly, the dynamic linker shared object file was
657 found by the PT_INTERP name. */
658 _dl_rtld_map.l_name = (char *) _dl_rtld_map.l_libname->name;
659 _dl_rtld_map.l_type = lt_library;
660 _dl_loaded->l_next = &_dl_rtld_map;
661 _dl_rtld_map.l_prev = _dl_loaded;
662 ++_dl_nloaded;
664 /* We have two ways to specify objects to preload: via environment
665 variable and via the file /etc/ld.so.preload. The latter can also
666 be used when security is enabled. */
667 preloads = NULL;
668 npreloads = 0;
670 if (__builtin_expect (preloadlist != NULL, 0))
672 /* The LD_PRELOAD environment variable gives list of libraries
673 separated by white space or colons that are loaded before the
674 executable's dependencies and prepended to the global scope
675 list. If the binary is running setuid all elements
676 containing a '/' are ignored since it is insecure. */
677 char *list = strdupa (preloadlist);
678 char *p;
680 HP_TIMING_NOW (start);
682 while ((p = strsep (&list, " :")) != NULL)
683 if (p[0] != '\0'
684 && (__builtin_expect (! __libc_enable_secure, 1)
685 || strchr (p, '/') == NULL))
687 struct link_map *new_map = _dl_map_object (_dl_loaded, p, 1,
688 lt_library, 0, 0);
689 if (++new_map->l_opencount == 1)
690 /* It is no duplicate. */
691 ++npreloads;
694 HP_TIMING_NOW (stop);
695 HP_TIMING_DIFF (diff, start, stop);
696 HP_TIMING_ACCUM_NT (load_time, diff);
699 /* Read the contents of the file. */
700 file = _dl_sysdep_read_whole_file ("/etc/ld.so.preload", &file_size,
701 PROT_READ | PROT_WRITE);
702 if (__builtin_expect (file != NULL, 0))
704 /* Parse the file. It contains names of libraries to be loaded,
705 separated by white spaces or `:'. It may also contain
706 comments introduced by `#'. */
707 char *problem;
708 char *runp;
709 size_t rest;
711 /* Eliminate comments. */
712 runp = file;
713 rest = file_size;
714 while (rest > 0)
716 char *comment = memchr (runp, '#', rest);
717 if (comment == NULL)
718 break;
720 rest -= comment - runp;
722 *comment = ' ';
723 while (--rest > 0 && *++comment != '\n');
726 /* We have one problematic case: if we have a name at the end of
727 the file without a trailing terminating characters, we cannot
728 place the \0. Handle the case separately. */
729 if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t'
730 && file[file_size - 1] != '\n' && file[file_size - 1] != ':')
732 problem = &file[file_size];
733 while (problem > file && problem[-1] != ' ' && problem[-1] != '\t'
734 && problem[-1] != '\n' && problem[-1] != ':')
735 --problem;
737 if (problem > file)
738 problem[-1] = '\0';
740 else
742 problem = NULL;
743 file[file_size - 1] = '\0';
746 HP_TIMING_NOW (start);
748 if (file != problem)
750 char *p;
751 runp = file;
752 while ((p = strsep (&runp, ": \t\n")) != NULL)
753 if (p[0] != '\0')
755 struct link_map *new_map = _dl_map_object (_dl_loaded, p, 1,
756 lt_library, 0, 0);
757 if (++new_map->l_opencount == 1)
758 /* It is no duplicate. */
759 ++npreloads;
763 if (problem != NULL)
765 char *p = strndupa (problem, file_size - (problem - file));
766 struct link_map *new_map = _dl_map_object (_dl_loaded, p, 1,
767 lt_library, 0, 0);
768 if (++new_map->l_opencount == 1)
769 /* It is no duplicate. */
770 ++npreloads;
773 HP_TIMING_NOW (stop);
774 HP_TIMING_DIFF (diff, start, stop);
775 HP_TIMING_ACCUM_NT (load_time, diff);
777 /* We don't need the file anymore. */
778 __munmap (file, file_size);
781 if (__builtin_expect (npreloads, 0) != 0)
783 /* Set up PRELOADS with a vector of the preloaded libraries. */
784 struct link_map *l;
785 preloads = __alloca (npreloads * sizeof preloads[0]);
786 l = _dl_rtld_map.l_next; /* End of the chain before preloads. */
787 i = 0;
790 preloads[i++] = l;
791 l = l->l_next;
792 } while (l);
793 assert (i == npreloads);
796 /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD
797 specified some libraries to load, these are inserted before the actual
798 dependencies in the executable's searchlist for symbol resolution. */
799 HP_TIMING_NOW (start);
800 _dl_map_object_deps (_dl_loaded, preloads, npreloads, mode == trace);
801 HP_TIMING_NOW (stop);
802 HP_TIMING_DIFF (diff, start, stop);
803 HP_TIMING_ACCUM_NT (load_time, diff);
805 /* Mark all objects as being in the global scope and set the open
806 counter. */
807 for (i = _dl_loaded->l_searchlist.r_nlist; i > 0; )
809 --i;
810 _dl_loaded->l_searchlist.r_list[i]->l_global = 1;
811 ++_dl_loaded->l_searchlist.r_list[i]->l_opencount;
814 #ifndef MAP_ANON
815 /* We are done mapping things, so close the zero-fill descriptor. */
816 __close (_dl_zerofd);
817 _dl_zerofd = -1;
818 #endif
820 /* Remove _dl_rtld_map from the chain. */
821 _dl_rtld_map.l_prev->l_next = _dl_rtld_map.l_next;
822 if (_dl_rtld_map.l_next)
823 _dl_rtld_map.l_next->l_prev = _dl_rtld_map.l_prev;
825 if (__builtin_expect (_dl_rtld_map.l_opencount, 2) > 1)
827 /* Some DT_NEEDED entry referred to the interpreter object itself, so
828 put it back in the list of visible objects. We insert it into the
829 chain in symbol search order because gdb uses the chain's order as
830 its symbol search order. */
831 i = 1;
832 while (_dl_loaded->l_searchlist.r_list[i] != &_dl_rtld_map)
833 ++i;
834 _dl_rtld_map.l_prev = _dl_loaded->l_searchlist.r_list[i - 1];
835 if (__builtin_expect (mode, normal) == normal)
836 _dl_rtld_map.l_next = (i + 1 < _dl_loaded->l_searchlist.r_nlist
837 ? _dl_loaded->l_searchlist.r_list[i + 1]
838 : NULL);
839 else
840 /* In trace mode there might be an invisible object (which we
841 could not find) after the previous one in the search list.
842 In this case it doesn't matter much where we put the
843 interpreter object, so we just initialize the list pointer so
844 that the assertion below holds. */
845 _dl_rtld_map.l_next = _dl_rtld_map.l_prev->l_next;
847 assert (_dl_rtld_map.l_prev->l_next == _dl_rtld_map.l_next);
848 _dl_rtld_map.l_prev->l_next = &_dl_rtld_map;
849 if (_dl_rtld_map.l_next)
851 assert (_dl_rtld_map.l_next->l_prev == _dl_rtld_map.l_prev);
852 _dl_rtld_map.l_next->l_prev = &_dl_rtld_map;
856 /* Now let us see whether all libraries are available in the
857 versions we need. */
859 struct version_check_args args;
860 args.doexit = mode == normal;
861 args.dotrace = mode == trace;
862 _dl_receive_error (print_missing_version, version_check_doit, &args);
865 if (__builtin_expect (mode, normal) != normal)
867 /* We were run just to list the shared libraries. It is
868 important that we do this before real relocation, because the
869 functions we call below for output may no longer work properly
870 after relocation. */
871 if (! _dl_loaded->l_info[DT_NEEDED])
872 _dl_printf ("\tstatically linked\n");
873 else
875 struct link_map *l;
877 for (l = _dl_loaded->l_next; l; l = l->l_next)
878 if (l->l_faked)
879 /* The library was not found. */
880 _dl_printf ("\t%s => not found\n", l->l_libname->name);
881 else
882 _dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name,
883 l->l_name, (int) sizeof l->l_addr * 2, l->l_addr);
886 if (__builtin_expect (mode, trace) != trace)
887 for (i = 1; i < _dl_argc; ++i)
889 const ElfW(Sym) *ref = NULL;
890 ElfW(Addr) loadbase;
891 lookup_t result;
893 result = _dl_lookup_symbol (_dl_argv[i], _dl_loaded,
894 &ref, _dl_loaded->l_scope,
895 ELF_MACHINE_JMP_SLOT, 1);
897 loadbase = LOOKUP_VALUE_ADDRESS (result);
899 _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n",
900 _dl_argv[i],
901 (int) sizeof ref->st_value * 2, ref->st_value,
902 (int) sizeof loadbase * 2, loadbase);
904 else
906 /* If LD_WARN is set warn about undefined symbols. */
907 if (_dl_lazy >= 0 && _dl_verbose)
909 /* We have to do symbol dependency testing. */
910 struct relocate_args args;
911 struct link_map *l;
913 args.lazy = _dl_lazy;
915 l = _dl_loaded;
916 while (l->l_next)
917 l = l->l_next;
920 if (l != &_dl_rtld_map && ! l->l_faked)
922 args.l = l;
923 _dl_receive_error (print_unresolved, relocate_doit,
924 &args);
926 l = l->l_prev;
927 } while (l);
930 #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
931 if (version_info)
933 /* Print more information. This means here, print information
934 about the versions needed. */
935 int first = 1;
936 struct link_map *map = _dl_loaded;
938 for (map = _dl_loaded; map != NULL; map = map->l_next)
940 const char *strtab;
941 ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG];
942 ElfW(Verneed) *ent;
944 if (dyn == NULL)
945 continue;
947 strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
948 ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
950 if (first)
952 _dl_printf ("\n\tVersion information:\n");
953 first = 0;
956 _dl_printf ("\t%s:\n",
957 map->l_name[0] ? map->l_name : _dl_argv[0]);
959 while (1)
961 ElfW(Vernaux) *aux;
962 struct link_map *needed;
964 needed = find_needed (strtab + ent->vn_file);
965 aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
967 while (1)
969 const char *fname = NULL;
971 if (needed != NULL
972 && match_version (strtab + aux->vna_name,
973 needed))
974 fname = needed->l_name;
976 _dl_printf ("\t\t%s (%s) %s=> %s\n",
977 strtab + ent->vn_file,
978 strtab + aux->vna_name,
979 aux->vna_flags & VER_FLG_WEAK
980 ? "[WEAK] " : "",
981 fname ?: "not found");
983 if (aux->vna_next == 0)
984 /* No more symbols. */
985 break;
987 /* Next symbol. */
988 aux = (ElfW(Vernaux) *) ((char *) aux
989 + aux->vna_next);
992 if (ent->vn_next == 0)
993 /* No more dependencies. */
994 break;
996 /* Next dependency. */
997 ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
1003 _exit (0);
1007 /* Now we have all the objects loaded. Relocate them all except for
1008 the dynamic linker itself. We do this in reverse order so that copy
1009 relocs of earlier objects overwrite the data written by later
1010 objects. We do not re-relocate the dynamic linker itself in this
1011 loop because that could result in the GOT entries for functions we
1012 call being changed, and that would break us. It is safe to relocate
1013 the dynamic linker out of order because it has no copy relocs (we
1014 know that because it is self-contained). */
1016 struct link_map *l;
1017 int consider_profiling = _dl_profile != NULL;
1018 #ifndef HP_TIMING_NONAVAIL
1019 hp_timing_t start;
1020 hp_timing_t stop;
1021 hp_timing_t add;
1022 #endif
1024 /* If we are profiling we also must do lazy reloaction. */
1025 _dl_lazy |= consider_profiling;
1027 l = _dl_loaded;
1028 while (l->l_next)
1029 l = l->l_next;
1031 HP_TIMING_NOW (start);
1034 /* While we are at it, help the memory handling a bit. We have to
1035 mark some data structures as allocated with the fake malloc()
1036 implementation in ld.so. */
1037 struct libname_list *lnp = l->l_libname->next;
1039 while (__builtin_expect (lnp != NULL, 0))
1041 lnp->dont_free = 1;
1042 lnp = lnp->next;
1045 if (l != &_dl_rtld_map)
1046 _dl_relocate_object (l, l->l_scope, _dl_lazy, consider_profiling);
1048 l = l->l_prev;
1050 while (l);
1051 HP_TIMING_NOW (stop);
1053 HP_TIMING_DIFF (relocate_time, start, stop);
1055 /* Do any necessary cleanups for the startup OS interface code.
1056 We do these now so that no calls are made after rtld re-relocation
1057 which might be resolved to different functions than we expect.
1058 We cannot do this before relocating the other objects because
1059 _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
1060 _dl_sysdep_start_cleanup ();
1062 /* Now enable profiling if needed. Like the previous call,
1063 this has to go here because the calls it makes should use the
1064 rtld versions of the functions (particularly calloc()), but it
1065 needs to have _dl_profile_map set up by the relocator. */
1066 if (__builtin_expect (_dl_profile_map != NULL, 0))
1067 /* We must prepare the profiling. */
1068 _dl_start_profile (_dl_profile_map, _dl_profile_output);
1070 if (_dl_rtld_map.l_opencount > 1)
1072 /* There was an explicit ref to the dynamic linker as a shared lib.
1073 Re-relocate ourselves with user-controlled symbol definitions. */
1074 HP_TIMING_NOW (start);
1075 _dl_relocate_object (&_dl_rtld_map, _dl_loaded->l_scope, 0, 0);
1076 HP_TIMING_NOW (stop);
1077 HP_TIMING_DIFF (add, start, stop);
1078 HP_TIMING_ACCUM_NT (relocate_time, add);
1082 /* Now set up the variable which helps the assembler startup code. */
1083 _dl_main_searchlist = &_dl_loaded->l_searchlist;
1084 _dl_global_scope[0] = &_dl_loaded->l_searchlist;
1086 /* Safe the information about the original global scope list since
1087 we need it in the memory handling later. */
1088 _dl_initial_searchlist = *_dl_main_searchlist;
1091 /* Initialize _r_debug. */
1092 struct r_debug *r = _dl_debug_initialize (_dl_rtld_map.l_addr);
1093 struct link_map *l;
1095 l = _dl_loaded;
1097 #ifdef ELF_MACHINE_DEBUG_SETUP
1099 /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
1101 ELF_MACHINE_DEBUG_SETUP (l, r);
1102 ELF_MACHINE_DEBUG_SETUP (&_dl_rtld_map, r);
1104 #else
1106 if (l->l_info[DT_DEBUG])
1107 /* There is a DT_DEBUG entry in the dynamic section. Fill it in
1108 with the run-time address of the r_debug structure */
1109 l->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1111 /* Fill in the pointer in the dynamic linker's own dynamic section, in
1112 case you run gdb on the dynamic linker directly. */
1113 if (_dl_rtld_map.l_info[DT_DEBUG])
1114 _dl_rtld_map.l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1116 #endif
1118 /* Notify the debugger that all objects are now mapped in. */
1119 r->r_state = RT_ADD;
1120 _dl_debug_state ();
1123 #ifndef MAP_COPY
1124 /* We must munmap() the cache file. */
1125 _dl_unload_cache ();
1126 #endif
1128 /* Once we return, _dl_sysdep_start will invoke
1129 the DT_INIT functions and then *USER_ENTRY. */
1132 /* This is a little helper function for resolving symbols while
1133 tracing the binary. */
1134 static void
1135 print_unresolved (int errcode __attribute__ ((unused)), const char *objname,
1136 const char *errstring)
1138 if (objname[0] == '\0')
1139 objname = _dl_argv[0] ?: "<main program>";
1140 _dl_error_printf ("%s (%s)\n", errstring, objname);
1143 /* This is a little helper function for resolving symbols while
1144 tracing the binary. */
1145 static void
1146 print_missing_version (int errcode __attribute__ ((unused)),
1147 const char *objname, const char *errstring)
1149 _dl_error_printf ("%s: %s: %s\n", _dl_argv[0] ?: "<program name unknown>",
1150 objname, errstring);
1153 /* Nonzero if any of the debugging options is enabled. */
1154 static int any_debug;
1156 /* Process the string given as the parameter which explains which debugging
1157 options are enabled. */
1158 static void
1159 process_dl_debug (const char *dl_debug)
1161 size_t len;
1162 #define separators " ,:"
1165 len = 0;
1166 /* Skip separating white spaces and commas. */
1167 dl_debug += strspn (dl_debug, separators);
1168 if (*dl_debug != '\0')
1170 len = strcspn (dl_debug, separators);
1172 switch (len)
1174 case 3:
1175 /* This option is not documented since it is not generally
1176 useful. */
1177 if (memcmp (dl_debug, "all", 3) == 0)
1179 _dl_debug_mask = (DL_DEBUG_LIBS | DL_DEBUG_IMPCALLS
1180 | DL_DEBUG_RELOC | DL_DEBUG_FILES
1181 | DL_DEBUG_SYMBOLS | DL_DEBUG_BINDINGS
1182 | DL_DEBUG_VERSIONS);
1183 any_debug = 1;
1184 continue;
1186 break;
1188 case 4:
1189 if (memcmp (dl_debug, "help", 4) == 0)
1191 _dl_printf ("\
1192 Valid options for the LD_DEBUG environment variable are:\n\
1194 bindings display information about symbol binding\n\
1195 files display processing of files and libraries\n\
1196 help display this help message and exit\n\
1197 libs display library search paths\n\
1198 reloc display relocation processing\n\
1199 statistics display relocation statistics\n\
1200 symbols display symbol table processing\n\
1201 versions display version dependencies\n\
1203 To direct the debugging output into a file instead of standard output\n\
1204 a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
1205 _exit (0);
1208 if (memcmp (dl_debug, "libs", 4) == 0)
1210 _dl_debug_mask |= DL_DEBUG_LIBS | DL_DEBUG_IMPCALLS;
1211 any_debug = 1;
1212 continue;
1214 break;
1216 case 5:
1217 if (memcmp (dl_debug, "reloc", 5) == 0)
1219 _dl_debug_mask |= DL_DEBUG_RELOC | DL_DEBUG_IMPCALLS;
1220 any_debug = 1;
1221 continue;
1224 if (memcmp (dl_debug, "files", 5) == 0)
1226 _dl_debug_mask |= DL_DEBUG_FILES | DL_DEBUG_IMPCALLS;
1227 any_debug = 1;
1228 continue;
1230 break;
1232 case 7:
1233 if (memcmp (dl_debug, "symbols", 7) == 0)
1235 _dl_debug_mask |= DL_DEBUG_SYMBOLS | DL_DEBUG_IMPCALLS;
1236 any_debug = 1;
1237 continue;
1239 break;
1241 case 8:
1242 if (memcmp (dl_debug, "bindings", 8) == 0)
1244 _dl_debug_mask |= DL_DEBUG_BINDINGS | DL_DEBUG_IMPCALLS;
1245 any_debug = 1;
1246 continue;
1249 if (memcmp (dl_debug, "versions", 8) == 0)
1251 _dl_debug_mask |= DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS;
1252 any_debug = 1;
1253 continue;
1255 break;
1257 case 10:
1258 if (memcmp (dl_debug, "statistics", 10) == 0)
1260 _dl_debug_mask |= DL_DEBUG_STATISTICS;
1261 continue;
1263 break;
1265 default:
1266 break;
1270 /* Display a warning and skip everything until next separator. */
1271 char *startp = strndupa (dl_debug, len);
1272 _dl_error_printf ("\
1273 warning: debug option `%s' unknown; try LD_DEBUG=help\n", startp);
1274 break;
1278 while (*(dl_debug += len) != '\0');
1281 /* Process all environments variables the dynamic linker must recognize.
1282 Since all of them start with `LD_' we are a bit smarter while finding
1283 all the entries. */
1284 static void
1285 process_envvars (enum mode *modep)
1287 char **runp = NULL;
1288 char *envline;
1289 enum mode mode = normal;
1290 char *debug_output = NULL;
1292 /* This is the default place for profiling data file. */
1293 _dl_profile_output = __libc_enable_secure ? "/var/profile" : "/var/tmp";
1295 while ((envline = _dl_next_ld_env_entry (&runp)) != NULL)
1297 size_t len = strcspn (envline, "=");
1299 if (envline[len] != '=')
1300 /* This is a "LD_" variable at the end of the string without
1301 a '=' character. Ignore it since otherwise we will access
1302 invalid memory below. */
1303 break;
1305 switch (len - 3)
1307 case 4:
1308 /* Warning level, verbose or not. */
1309 if (memcmp (&envline[3], "WARN", 4) == 0)
1310 _dl_verbose = envline[8] != '\0';
1311 break;
1313 case 5:
1314 /* Debugging of the dynamic linker? */
1315 if (memcmp (&envline[3], "DEBUG", 5) == 0)
1316 process_dl_debug (&envline[9]);
1317 break;
1319 case 7:
1320 /* Print information about versions. */
1321 if (memcmp (&envline[3], "VERBOSE", 7) == 0)
1323 version_info = envline[11] != '\0';
1324 break;
1327 /* List of objects to be preloaded. */
1328 if (memcmp (&envline[3], "PRELOAD", 7) == 0)
1330 preloadlist = &envline[11];
1331 break;
1334 /* Which shared object shall be profiled. */
1335 if (memcmp (&envline[3], "PROFILE", 7) == 0)
1336 _dl_profile = &envline[11];
1337 break;
1339 case 8:
1340 /* Do we bind early? */
1341 if (memcmp (&envline[3], "BIND_NOW", 8) == 0)
1343 _dl_lazy = envline[12] == '\0';
1344 break;
1346 if (memcmp (&envline[3], "BIND_NOT", 8) == 0)
1347 _dl_bind_not = envline[12] != '\0';
1348 break;
1350 case 9:
1351 /* Test whether we want to see the content of the auxiliary
1352 array passed up from the kernel. */
1353 if (memcmp (&envline[3], "SHOW_AUXV", 9) == 0)
1354 _dl_show_auxv ();
1355 break;
1357 case 10:
1358 /* Mask for the important hardware capabilities. */
1359 if (memcmp (&envline[3], "HWCAP_MASK", 10) == 0)
1360 _dl_hwcap_mask = __strtoul_internal (&envline[14], NULL, 0, 0);
1361 break;
1363 case 11:
1364 /* Path where the binary is found. */
1365 if (!__libc_enable_secure
1366 && memcmp (&envline[3], "ORIGIN_PATH", 11) == 0)
1367 _dl_origin_path = &envline[15];
1368 break;
1370 case 12:
1371 /* The library search path. */
1372 if (memcmp (&envline[3], "LIBRARY_PATH", 12) == 0)
1374 library_path = &envline[16];
1375 break;
1378 /* Where to place the profiling data file. */
1379 if (memcmp (&envline[3], "DEBUG_OUTPUT", 12) == 0)
1381 debug_output = &envline[16];
1382 break;
1385 if (memcmp (&envline[3], "DYNAMIC_WEAK", 12) == 0)
1386 _dl_dynamic_weak = 1;
1387 break;
1389 case 14:
1390 /* Where to place the profiling data file. */
1391 if (!__libc_enable_secure
1392 && memcmp (&envline[3], "PROFILE_OUTPUT", 14) == 0)
1394 _dl_profile_output = &envline[18];
1395 if (*_dl_profile_output == '\0')
1396 _dl_profile_output = "/var/tmp";
1398 break;
1400 case 20:
1401 /* The mode of the dynamic linker can be set. */
1402 if (memcmp (&envline[3], "TRACE_LOADED_OBJECTS", 20) == 0)
1403 mode = trace;
1404 break;
1406 /* We might have some extra environment variable to handle. This
1407 is tricky due to the pre-processing of the length of the name
1408 in the switch statement here. The code here assumes that added
1409 environment variables have a different length. */
1410 #ifdef EXTRA_LD_ENVVARS
1411 EXTRA_LD_ENVVARS
1412 #endif
1416 /* Extra security for SUID binaries. Remove all dangerous environment
1417 variables. */
1418 if (__builtin_expect (__libc_enable_secure, 0))
1420 static const char *unsecure_envvars[] =
1422 UNSECURE_ENVVARS,
1423 #ifdef EXTRA_UNSECURE_ENVVARS
1424 EXTRA_UNSECURE_ENVVARS
1425 #endif
1427 size_t cnt;
1429 if (preloadlist != NULL)
1430 unsetenv ("LD_PRELOAD");
1431 if (library_path != NULL)
1432 unsetenv ("LD_LIBRARY_PATH");
1433 if (_dl_origin_path != NULL)
1434 unsetenv ("LD_ORIGIN_PATH");
1435 if (debug_output != NULL)
1436 unsetenv ("LD_DEBUG_OUTPUT");
1437 if (_dl_profile != NULL)
1438 unsetenv ("LD_PROFILE");
1440 for (cnt = 0;
1441 cnt < sizeof (unsecure_envvars) / sizeof (unsecure_envvars[0]);
1442 ++cnt)
1443 unsetenv (unsecure_envvars[cnt]);
1445 if (__access ("/etc/suid-debug", F_OK) != 0)
1446 unsetenv ("MALLOC_CHECK_");
1449 /* The name of the object to profile cannot be empty. */
1450 if (_dl_profile != NULL && *_dl_profile == '\0')
1451 _dl_profile = NULL;
1453 /* If we have to run the dynamic linker in debugging mode and the
1454 LD_DEBUG_OUTPUT environment variable is given, we write the debug
1455 messages to this file. */
1456 if (any_debug && debug_output != NULL && !__libc_enable_secure)
1458 #ifdef O_NOFOLLOW
1459 const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW;
1460 #else
1461 const int flags = O_WRONLY | O_APPEND | O_CREAT;
1462 #endif
1463 size_t name_len = strlen (debug_output);
1464 char buf[name_len + 12];
1465 char *startp;
1467 buf[name_len + 11] = '\0';
1468 startp = _itoa_word (__getpid (), &buf[name_len + 11], 10, 0);
1469 *--startp = '.';
1470 startp = memcpy (startp - name_len, debug_output, name_len);
1472 _dl_debug_fd = __open (startp, flags, DEFFILEMODE);
1473 if (_dl_debug_fd == -1)
1474 /* We use standard output if opening the file failed. */
1475 _dl_debug_fd = STDOUT_FILENO;
1478 *modep = mode;
1482 /* Print the various times we collected. */
1483 static void
1484 print_statistics (void)
1486 #ifndef HP_TIMING_NONAVAIL
1487 char buf[200];
1488 char *cp;
1489 char *wp;
1491 /* Total time rtld used. */
1492 if (HP_TIMING_AVAIL)
1494 HP_TIMING_PRINT (buf, sizeof (buf), rtld_total_time);
1495 _dl_debug_printf ("\nruntime linker statistics:\n"
1496 " total startup time in dynamic loader: %s\n", buf);
1499 /* Print relocation statistics. */
1500 if (HP_TIMING_AVAIL)
1502 char pbuf[30];
1503 HP_TIMING_PRINT (buf, sizeof (buf), relocate_time);
1504 cp = _itoa_word ((1000 * relocate_time) / rtld_total_time,
1505 pbuf + sizeof (pbuf), 10, 0);
1506 wp = pbuf;
1507 switch (pbuf + sizeof (pbuf) - cp)
1509 case 3:
1510 *wp++ = *cp++;
1511 case 2:
1512 *wp++ = *cp++;
1513 case 1:
1514 *wp++ = '.';
1515 *wp++ = *cp++;
1517 *wp = '\0';
1518 _dl_debug_printf (" time needed for relocation: %s (%s)\n",
1519 buf, pbuf);
1521 #endif
1522 _dl_debug_printf (" number of relocations: %lu\n",
1523 _dl_num_relocations);
1525 #ifndef HP_TIMING_NONAVAIL
1526 /* Time spend while loading the object and the dependencies. */
1527 if (HP_TIMING_AVAIL)
1529 char pbuf[30];
1530 HP_TIMING_PRINT (buf, sizeof (buf), load_time);
1531 cp = _itoa_word ((1000 * load_time) / rtld_total_time,
1532 pbuf + sizeof (pbuf), 10, 0);
1533 wp = pbuf;
1534 switch (pbuf + sizeof (pbuf) - cp)
1536 case 3:
1537 *wp++ = *cp++;
1538 case 2:
1539 *wp++ = *cp++;
1540 case 1:
1541 *wp++ = '.';
1542 *wp++ = *cp++;
1544 *wp = '\0';
1545 _dl_debug_printf (" time needed to load objects: %s (%s)\n",
1546 buf, pbuf);
1548 #endif