1 /* vi: set sw=4 ts=4: */
3 * Program to load an ELF binary on a linux system, and run it
4 * after resolving ELF shared library symbols
6 * Copyright (C) 2005 by Joakim Tjernlund
7 * Copyright (C) 2000-2006 by Erik Andersen <andersen@codepoet.org>
8 * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
9 * David Engel, Hongjiu Lu and Mitch D'Souza
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. The name of the above contributors may not be
17 * used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 #include "unsecvars.h"
36 /* Pull in common debug code */
39 #define ALLOW_ZERO_PLTGOT
45 /* Pull in the value of _dl_progname */
46 #include LDSO_ELFINTERP
48 /* Global variables used within the shared library loader */
49 char *_dl_library_path = NULL; /* Where we look for libraries */
50 char *_dl_preload = NULL; /* Things to be loaded before the libs */
51 char *_dl_ldsopath = NULL; /* Location of the shared lib loader */
52 int _dl_errno = 0; /* We can't use the real errno in ldso */
53 size_t _dl_pagesize = 0; /* Store the page size for use later */
54 struct r_debug *_dl_debug_addr = NULL; /* Used to communicate with the gdb debugger */
55 void *(*_dl_malloc_function) (size_t size) = NULL;
56 void (*_dl_free_function) (void *p) = NULL;
58 static int _dl_secure = 1; /* Are we dealing with setuid stuff? */
60 #ifdef __SUPPORT_LD_DEBUG__
61 char *_dl_debug = NULL;
62 char *_dl_debug_symbols = NULL;
63 char *_dl_debug_move = NULL;
64 char *_dl_debug_reloc = NULL;
65 char *_dl_debug_detail = NULL;
66 char *_dl_debug_nofixups = NULL;
67 char *_dl_debug_bindings = NULL;
68 int _dl_debug_file = 2;
71 /* Needed for standalone execution. */
72 unsigned long attribute_hidden _dl_skip_args = 0;
73 const char *_dl_progname = UCLIBC_LDSO; /* The name of the executable being run */
74 #include "dl-startup.c"
75 #include "dl-symbols.c"
79 * This stub function is used by some debuggers. The idea is that they
80 * can set an internal breakpoint on it, so that we are notified when the
81 * address mapping is changed in some way.
83 void _dl_debug_state(void);
84 rtld_hidden_proto(_dl_debug_state, noinline);
85 void _dl_debug_state(void)
87 /* Make sure GCC doesn't recognize this function as pure, to avoid
88 * having the calls optimized away.
92 rtld_hidden_def(_dl_debug_state);
94 static unsigned char *_dl_malloc_addr = NULL; /* Lets _dl_malloc use the already allocated memory page */
95 static unsigned char *_dl_mmap_zero = NULL; /* Also used by _dl_malloc */
97 static struct elf_resolve **init_fini_list;
98 static unsigned int nlist; /* # items in init_fini_list */
99 extern void _start(void);
101 #ifdef __UCLIBC_HAS_SSP__
102 # include <dl-osinfo.h>
103 uintptr_t stack_chk_guard;
104 # ifndef THREAD_SET_STACK_GUARD
105 /* Only exported for architectures that don't store the stack guard canary
106 * in local thread area. */
107 uintptr_t __stack_chk_guard attribute_relro;
108 # ifdef __UCLIBC_HAS_SSP_COMPAT__
109 strong_alias(__stack_chk_guard,__guard)
111 # elif __UCLIBC_HAS_SSP_COMPAT__
112 uintptr_t __guard attribute_relro;
116 char *_dl_getenv(const char *symbol, char **envp)
121 while ((pnt = *envp++)) {
123 while (*pnt && *pnt == *pnt1)
125 if (!*pnt || *pnt != '=' || *pnt1)
132 void _dl_unsetenv(const char *symbol, char **envp)
136 char **newenvp = envp;
138 for (pnt = *envp; pnt; pnt = *++envp) {
140 while (*pnt && *pnt == *pnt1)
142 if (!*pnt || *pnt != '=' || *pnt1)
149 static int _dl_suid_ok(void)
151 __kernel_uid_t uid, euid;
152 __kernel_gid_t gid, egid;
155 euid = _dl_geteuid();
157 egid = _dl_getegid();
159 if (uid == euid && gid == egid) {
165 void *_dl_malloc(size_t size)
170 _dl_debug_early("request for %d bytes\n", size);
173 if (_dl_malloc_function)
174 return (*_dl_malloc_function) (size);
176 if (_dl_malloc_addr - _dl_mmap_zero + size > _dl_pagesize) {
179 /* Since the above assumes we get a full page even if
180 we request less than that, make sure we request a
181 full page, since uClinux may give us less than than
182 a full page. We might round even
183 larger-than-a-page sizes, but we end up never
184 reusing _dl_mmap_zero/_dl_malloc_addr in that case,
187 The actual page size doesn't really matter; as long
188 as we're self-consistent here, we're safe. */
189 if (size < _dl_pagesize)
190 rounded_size = (size + ADDR_ALIGN) & _dl_pagesize;
194 _dl_debug_early("mmapping more memory\n");
195 _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, rounded_size,
196 PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
197 if (_dl_mmap_check_error(_dl_mmap_zero)) {
198 _dl_dprintf(_dl_debug_file, "%s: mmap of a spare page failed!\n", _dl_progname);
202 retval = _dl_malloc_addr;
203 _dl_malloc_addr += size;
206 * Align memory to DL_MALLOC_ALIGN byte boundary. Some
207 * platforms require this, others simply get better
210 _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + DL_MALLOC_ALIGN - 1) & ~(DL_MALLOC_ALIGN - 1));
214 static void *_dl_zalloc(size_t size)
216 void *p = _dl_malloc(size);
218 _dl_memset(p, 0, size);
222 void _dl_free(void *p)
224 if (_dl_free_function)
225 (*_dl_free_function) (p);
229 void *_dl_memalign(size_t __boundary, size_t __size)
236 if (_dl_memalign_function)
237 return (*_dl_memalign_function) (__boundary, __size);
239 while (rounded < __boundary) {
240 rounded = (1 << i++);
243 delta = (((size_t) _dl_malloc_addr + __size) & (rounded - 1));
245 if ((result = _dl_malloc(rounded - delta)) == NULL)
248 result = _dl_malloc(__size);
254 static void __attribute__ ((destructor)) __attribute_used__ _dl_fini(void)
257 struct elf_resolve * tpnt;
259 for (i = 0; i < nlist; ++i) {
260 tpnt = init_fini_list[i];
261 if (tpnt->init_flag & FINI_FUNCS_CALLED)
263 tpnt->init_flag |= FINI_FUNCS_CALLED;
264 _dl_run_fini_array(tpnt);
265 if (tpnt->dynamic_info[DT_FINI]) {
266 void (*dl_elf_func) (void);
268 dl_elf_func = (void (*)(void)) (intptr_t) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_FINI]);
269 _dl_if_debug_dprint("\ncalling FINI: %s\n\n", tpnt->libname);
270 DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
275 void _dl_get_ready_to_run(struct elf_resolve *tpnt, DL_LOADADDR_TYPE load_addr,
276 ElfW(auxv_t) auxvt[AT_EGID + 1], char **envp,
278 DL_GET_READY_TO_RUN_EXTRA_PARMS)
280 ElfW(Addr) app_mapaddr = 0;
285 int unlazy = 0, trace_loaded_objects = 0;
286 struct dyn_elf *rpnt;
287 struct elf_resolve *tcurr;
288 struct elf_resolve *tpnt1;
289 struct elf_resolve app_tpnt_tmp;
290 struct elf_resolve *app_tpnt = &app_tpnt_tmp;
291 struct r_debug *debug_addr;
293 unsigned long *_dl_envp; /* The environment address */
294 ElfW(Addr) relro_addr = 0;
295 size_t relro_size = 0;
301 /* Wahoo!!! We managed to make a function call! Get malloc
302 * setup so we can use _dl_dprintf() to print debug noise
303 * instead of the SEND_STDERR macros used in dl-startup.c */
305 _dl_memset(app_tpnt, 0, sizeof(*app_tpnt));
307 /* Store the page size for later use */
308 _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
309 /* Make it so _dl_malloc can use the page of memory we have already
310 * allocated. We shouldn't need to grab any more memory. This must
311 * be first since things like _dl_dprintf() use _dl_malloc()...
313 _dl_malloc_addr = (unsigned char *)_dl_pagesize;
317 _dl_debug_early("Cool, ldso survived making function calls\n");
319 /* Now we have done the mandatory linking of some things. We are now
320 * free to start using global variables, since these things have all
321 * been fixed up by now. Still no function calls outside of this
322 * library, since the dynamic resolver is not yet ready.
325 _dl_progname = argv[0];
328 if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
329 _dl_dprintf(_dl_debug_file, "Standalone execution is not supported yet\n");
333 /* Start to build the tables of the modules that are required for
334 * this beast to run. We start with the basic executable, and then
335 * go from there. Eventually we will run across ourself, and we
336 * will need to properly deal with that as well.
339 if (_dl_getenv("LD_BIND_NOW", envp))
342 /* Now we need to figure out what kind of options are selected.
343 * Note that for SUID programs we ignore the settings in
346 if ((auxvt[AT_UID].a_un.a_val == (size_t)-1 && _dl_suid_ok()) ||
347 (auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
348 auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
349 auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
351 _dl_preload = _dl_getenv("LD_PRELOAD", envp);
352 _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
354 static const char unsecure_envvars[] =
355 #ifdef EXTRA_UNSECURE_ENVVARS
356 EXTRA_UNSECURE_ENVVARS
362 nextp = unsecure_envvars;
364 _dl_unsetenv (nextp, envp);
365 /* We could use rawmemchr but this need not be fast. */
366 nextp = _dl_strchr(nextp, '\0') + 1;
367 } while (*nextp != '\0');
369 _dl_library_path = NULL;
370 /* SUID binaries can be exploited if they do LAZY relocation. */
375 _dl_error_catch_tsd = &_dl_initial_error_catch_tsd;
376 _dl_init_static_tls = &_dl_nothread_init_static_tls;
379 #ifdef __UCLIBC_HAS_SSP__
380 /* Set up the stack checker's canary. */
381 stack_chk_guard = _dl_setup_stack_chk_guard ();
382 # ifdef THREAD_SET_STACK_GUARD
383 THREAD_SET_STACK_GUARD (stack_chk_guard);
384 # ifdef __UCLIBC_HAS_SSP_COMPAT__
385 __guard = stack_chk_guard;
388 __stack_chk_guard = stack_chk_guard;
392 /* At this point we are now free to examine the user application,
393 * and figure out which libraries are supposed to be called. Until
394 * we have this list, we will not be completely ready for dynamic
398 /* Find the runtime load address of the main executable. This may be
399 * different from what the ELF header says for ET_DYN/PIE executables.
403 ElfW(Phdr) *phdr = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
405 for (idx = 0; idx < auxvt[AT_PHNUM].a_un.a_val; idx++, phdr++)
406 if (phdr->p_type == PT_PHDR) {
407 DL_INIT_LOADADDR_PROG(app_tpnt->loadaddr, auxvt[AT_PHDR].a_un.a_val - phdr->p_vaddr);
411 if (DL_LOADADDR_BASE(app_tpnt->loadaddr))
412 _dl_debug_early("Position Independent Executable: "
413 "app_tpnt->loadaddr=%x\n", DL_LOADADDR_BASE(app_tpnt->loadaddr));
417 * This is used by gdb to locate the chain of shared libraries that are
420 debug_addr = _dl_zalloc(sizeof(struct r_debug));
422 ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
423 for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
424 if (ppnt->p_type == PT_GNU_RELRO) {
425 relro_addr = ppnt->p_vaddr;
426 relro_size = ppnt->p_memsz;
428 if (!app_mapaddr && (ppnt->p_type == PT_LOAD)) {
429 app_mapaddr = DL_RELOC_ADDR (app_tpnt->loadaddr, ppnt->p_vaddr);
431 if (ppnt->p_type == PT_DYNAMIC) {
432 dpnt = (ElfW(Dyn) *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
433 _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
434 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
435 /* Ugly, ugly. We need to call mprotect to change the
436 * protection of the text pages so that we can do the
437 * dynamic linking. We can set the protection back
438 * again once we are done.
440 _dl_debug_early("calling mprotect on the application program\n");
441 /* Now cover the application program. */
442 if (app_tpnt->dynamic_info[DT_TEXTREL]) {
443 ElfW(Phdr) *ppnt_outer = ppnt;
444 ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
445 for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
446 if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
447 _dl_mprotect((void *) (DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr) & PAGE_ALIGN),
448 (DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr) & ADDR_ALIGN) +
449 (unsigned long) ppnt->p_filesz,
450 PROT_READ | PROT_WRITE | PROT_EXEC);
455 if (app_tpnt->dynamic_info[DT_TEXTREL]) {
456 _dl_dprintf(_dl_debug_file, "Can't modify application's text section; use the GCC option -fPIE for position-independent executables.\n");
461 #ifndef ALLOW_ZERO_PLTGOT
462 /* make sure it's really there. */
463 if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
466 /* OK, we have what we need - slip this one into the list. */
467 app_tpnt = _dl_add_elf_hash_table(_dl_progname, app_tpnt->loadaddr,
468 app_tpnt->dynamic_info,
469 (unsigned long) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr),
471 _dl_loaded_modules->libtype = elf_executable;
472 _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
473 _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
474 _dl_symbol_tables = rpnt = _dl_zalloc(sizeof(struct dyn_elf));
475 rpnt->dyn = _dl_loaded_modules;
476 app_tpnt->mapaddr = app_mapaddr;
477 app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
478 app_tpnt->usage_count++;
479 app_tpnt->symbol_scope = _dl_symbol_tables;
480 lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
481 #ifdef ALLOW_ZERO_PLTGOT
484 INIT_GOT(lpnt, _dl_loaded_modules);
487 /* OK, fill this in - we did not have this before */
488 if (ppnt->p_type == PT_INTERP) {
491 tpnt->libname = (char *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
493 #ifdef __LDSO_SEARCH_INTERP_PATH__
494 /* Store the path where the shared lib loader was found
497 _dl_ldsopath = _dl_strdup(tpnt->libname);
498 ptmp = _dl_strrchr(_dl_ldsopath, '/');
499 if (ptmp != _dl_ldsopath)
502 _dl_debug_early("Lib Loader: (%x) %s\n", (unsigned) DL_LOADADDR_BASE(tpnt->loadaddr), tpnt->libname);
506 /* Discover any TLS sections if the target supports them. */
507 if (ppnt->p_type == PT_TLS) {
509 if (ppnt->p_memsz > 0) {
510 app_tpnt->l_tls_blocksize = ppnt->p_memsz;
511 app_tpnt->l_tls_align = ppnt->p_align;
512 if (ppnt->p_align == 0)
513 app_tpnt->l_tls_firstbyte_offset = 0;
515 app_tpnt->l_tls_firstbyte_offset =
516 (ppnt->p_vaddr & (ppnt->p_align - 1));
517 app_tpnt->l_tls_initimage_size = ppnt->p_filesz;
518 app_tpnt->l_tls_initimage = (void *) ppnt->p_vaddr;
520 /* This image gets the ID one. */
521 _dl_tls_max_dtv_idx = app_tpnt->l_tls_modid = 1;
524 _dl_debug_early("Found TLS header for appplication program\n");
527 _dl_dprintf(_dl_debug_file, "Program uses unsupported TLS data!\n");
532 app_tpnt->relro_addr = relro_addr;
533 app_tpnt->relro_size = relro_size;
537 * Adjust the address of the TLS initialization image in
538 * case the executable is actually an ET_DYN object.
540 if (app_tpnt->l_tls_initimage != NULL) {
541 app_tpnt->l_tls_initimage =
542 (char *) app_tpnt->l_tls_initimage + app_tpnt->loadaddr;
543 _dl_debug_early("Relocated TLS initial image from %x to %x (size = %x)\n",
544 (unsigned int)app_tpnt->l_tls_initimage,
545 app_tpnt->l_tls_initimage, app_tpnt->l_tls_initimage_size);
549 #ifdef __SUPPORT_LD_DEBUG__
550 _dl_debug = _dl_getenv("LD_DEBUG", envp);
552 if (_dl_strstr(_dl_debug, "all")) {
553 _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
554 = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
556 _dl_debug_detail = _dl_strstr(_dl_debug, "detail");
557 _dl_debug_move = _dl_strstr(_dl_debug, "move");
558 _dl_debug_symbols = _dl_strstr(_dl_debug, "sym");
559 _dl_debug_reloc = _dl_strstr(_dl_debug, "reloc");
560 _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
561 _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
566 const char *dl_debug_output;
568 dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
570 if (dl_debug_output) {
571 char tmp[22], *tmp1, *filename;
574 _dl_memset(tmp, 0, sizeof(tmp));
575 tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
577 len1 = _dl_strlen(dl_debug_output);
578 len2 = _dl_strlen(tmp1);
580 filename = _dl_malloc(len1 + len2 + 2);
583 _dl_strcpy (filename, dl_debug_output);
584 filename[len1] = '.';
585 _dl_strcpy (&filename[len1+1], tmp1);
587 _dl_debug_file = _dl_open(filename, O_WRONLY|O_CREAT, 0644);
588 if (_dl_debug_file < 0) {
590 _dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
597 if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
598 trace_loaded_objects++;
601 #ifndef __LDSO_LDD_SUPPORT__
602 if (trace_loaded_objects) {
603 _dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
609 * OK, fix one more thing - set up debug_addr so it will point
610 * to our chain. Later we may need to fill in more fields, but this
611 * should be enough for now.
613 debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
614 debug_addr->r_version = 1;
615 debug_addr->r_ldbase = (ElfW(Addr)) DL_LOADADDR_BASE(load_addr);
616 debug_addr->r_brk = (unsigned long) &_dl_debug_state;
617 _dl_debug_addr = debug_addr;
619 /* Do not notify the debugger until the interpreter is in the list */
621 /* OK, we now have the application in the list, and we have some
622 * basic stuff in place. Now search through the list for other shared
623 * libraries that should be loaded, and insert them on the list in the
633 while (*str == ':' || *str == ' ' || *str == '\t')
638 while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
643 if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
644 _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", str, _dl_progname);
646 tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
648 #ifdef __LDSO_LDD_SUPPORT__
649 if (trace_loaded_objects)
650 _dl_dprintf(1, "\t%s => not found\n", str);
654 _dl_dprintf(_dl_debug_file, "%s: can't load " "library '%s'\n", _dl_progname, str);
658 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
660 _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
662 #ifdef __LDSO_LDD_SUPPORT__
663 if (trace_loaded_objects &&
664 tpnt1->usage_count == 1) {
665 /* This is a real hack to make
666 * ldd not print the library
667 * itself when run on a
670 if (_dl_strcmp(_dl_progname, str) != 0)
671 _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
672 DL_LOADADDR_BASE(tpnt1->loadaddr));
680 while (*str == ':' || *str == ' ' || *str == '\t')
685 #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
692 if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
696 if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
697 _dl_dprintf(_dl_debug_file, "%s: can't open file '%s'\n",
698 _dl_progname, LDSO_PRELOAD);
702 preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
703 PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
705 if (preload == (caddr_t) -1) {
706 _dl_dprintf(_dl_debug_file, "%s:%i: can't map '%s'\n",
707 _dl_progname, __LINE__, LDSO_PRELOAD);
711 /* convert all separators and comments to spaces */
712 for (cp = preload; *cp; /*nada */ ) {
713 if (*cp == ':' || *cp == '\t' || *cp == '\n') {
715 } else if (*cp == '#') {
718 } while (*cp != '\n' && *cp != '\0');
724 /* find start of first library */
725 for (cp = preload; *cp && *cp == ' '; cp++)
729 /* find end of library */
730 for (cp2 = cp; *cp && *cp != ' '; cp++)
735 _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", cp2, _dl_progname);
737 tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
739 #ifdef __LDSO_LDD_SUPPORT__
740 if (trace_loaded_objects)
741 _dl_dprintf(1, "\t%s => not found\n", cp2);
745 _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, cp2);
749 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
751 _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
753 #ifdef __LDSO_LDD_SUPPORT__
754 if (trace_loaded_objects &&
755 tpnt1->usage_count == 1) {
756 _dl_dprintf(1, "\t%s => %s (%x)\n",
758 DL_LOADADDR_BASE(tpnt1->loadaddr));
763 /* find start of next library */
765 for ( /*nada */ ; *cp && *cp == ' '; cp++)
769 _dl_munmap(preload, st.st_size + 1);
771 #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
774 for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
775 ElfW(Dyn) *this_dpnt;
778 for (this_dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; this_dpnt->d_tag; this_dpnt++) {
779 if (this_dpnt->d_tag == DT_NEEDED) {
781 struct init_fini_list *tmp;
783 lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + this_dpnt->d_un.d_val);
784 name = _dl_get_last_path_component(lpntstr);
785 if (_dl_strcmp(name, UCLIBC_LDSO) == 0)
788 _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", lpntstr, _dl_progname);
790 if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects))) {
791 #ifdef __LDSO_LDD_SUPPORT__
792 if (trace_loaded_objects) {
793 _dl_dprintf(1, "\t%s => not found\n", lpntstr);
798 _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
803 tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
805 tmp->next = tcurr->init_fini;
806 tcurr->init_fini = tmp;
808 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
810 _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
812 #ifdef __LDSO_LDD_SUPPORT__
813 if (trace_loaded_objects &&
814 tpnt1->usage_count == 1) {
815 _dl_dprintf(1, "\t%s => %s (%x)\n",
816 lpntstr, tpnt1->libname,
817 DL_LOADADDR_BASE(tpnt1->loadaddr));
825 --nlist; /* Exclude the application. */
826 init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
828 for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
829 init_fini_list[i++] = tcurr;
832 /* Sort the INIT/FINI list in dependency order. */
833 for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
836 for (j = 0; init_fini_list[j] != tcurr; ++j)
838 for (k = j + 1; k < nlist; ++k) {
839 struct init_fini_list *runp = init_fini_list[k]->init_fini;
841 for (; runp; runp = runp->next) {
842 if (runp->tpnt == tcurr) {
843 struct elf_resolve *here = init_fini_list[k];
844 _dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
845 for (i = (k - j); i; --i)
846 init_fini_list[i+j] = init_fini_list[i+j-1];
847 init_fini_list[j] = here;
854 #ifdef __SUPPORT_LD_DEBUG__
856 _dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
857 for (i = 0; i < nlist; i++) {
858 struct init_fini_list *tmp;
860 _dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
861 init_fini_list[i]->libname);
862 tmp = init_fini_list[i]->init_fini;
863 for (; tmp; tmp = tmp->next)
864 _dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
865 _dl_dprintf(_dl_debug_file, "\n");
871 * If the program interpreter is not in the module chain, add it.
872 * This will be required for dlopen to be able to access the internal
873 * functions in the dynamic linker and to relocate the interpreter
874 * again once all libs are loaded.
877 ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val;
878 ElfW(Phdr) *myppnt = (ElfW(Phdr) *) DL_RELOC_ADDR(load_addr, epnt->e_phoff);
881 tpnt = _dl_add_elf_hash_table(tpnt->libname, load_addr,
883 (unsigned long)tpnt->dynamic_addr,
886 if (_dl_stat(tpnt->libname, &st) >= 0) {
887 tpnt->st_dev = st.st_dev;
888 tpnt->st_ino = st.st_ino;
890 tpnt->n_phent = epnt->e_phnum;
892 for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
893 if (myppnt->p_type == PT_GNU_RELRO) {
894 tpnt->relro_addr = myppnt->p_vaddr;
895 tpnt->relro_size = myppnt->p_memsz;
899 tpnt->libtype = program_interpreter;
901 tpnt->symbol_scope = _dl_symbol_tables;
903 rpnt->next = _dl_zalloc(sizeof(struct dyn_elf));
904 rpnt->next->prev = rpnt;
907 rpnt = _dl_zalloc(sizeof(struct dyn_elf));
910 tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
911 #ifdef RERELOCATE_LDSO
912 /* Only rerelocate functions for now. */
913 tpnt->init_flag = RELOCS_DONE;
914 lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
915 # ifdef ALLOW_ZERO_PLTGOT
916 if (tpnt->dynamic_info[DT_PLTGOT])
918 INIT_GOT(lpnt, tpnt);
920 tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
925 #ifdef __LDSO_LDD_SUPPORT__
926 /* End of the line for ldd.... */
927 if (trace_loaded_objects) {
928 _dl_dprintf(1, "\t%s => %s (%x)\n",
929 rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
930 rpnt->dyn->libname, DL_LOADADDR_BASE(rpnt->dyn->loadaddr));
936 /* We do not initialize any of the TLS functionality unless any of the
937 * initial modules uses TLS. This makes dynamic loading of modules with
938 * TLS impossible, but to support it requires either eagerly doing setup
939 * now or lazily doing it later. Doing it now makes us incompatible with
940 * an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
941 * used. Trying to do it lazily is too hairy to try when there could be
942 * multiple threads (from a non-TLS-using libpthread). */
943 bool was_tls_init_tp_called = tls_init_tp_called;
945 _dl_debug_early("Calling init_tls()!\n");
950 _dl_debug_early("Beginning relocation fixups\n");
954 * Relocation of the GOT entries for MIPS have to be done
955 * after all the libraries have been loaded.
957 _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
961 * OK, now all of the kids are tucked into bed in their proper
962 * addresses. Now we go through and look for REL and RELA records that
963 * indicate fixups to the GOT tables. We need to do this in reverse
964 * order so that COPY directives work correctly.
966 if (_dl_symbol_tables)
967 if (_dl_fixup(_dl_symbol_tables, unlazy))
970 for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
971 if (tpnt->relro_size)
972 _dl_protect_relro (tpnt);
976 if (!was_tls_init_tp_called && _dl_tls_max_dtv_idx > 0)
977 ++_dl_tls_generation;
979 _dl_debug_early("Calling _dl_allocate_tls_init()!\n");
981 /* Now that we have completed relocation, the initializer data
982 for the TLS blocks has its final values and we can copy them
983 into the main thread's TLS area, which we allocated above. */
984 _dl_allocate_tls_init (tcbp);
986 /* And finally install it for the main thread. If ld.so itself uses
987 TLS we know the thread pointer was initialized earlier. */
988 if (! tls_init_tp_called) {
989 const char *lossage = (char *) TLS_INIT_TP (tcbp, USE___THREAD);
990 if (__builtin_expect (lossage != NULL, 0)) {
991 _dl_debug_early("cannot set up thread-local storage: %s\n", lossage);
997 /* OK, at this point things are pretty much ready to run. Now we need
998 * to touch up a few items that are required, and then we can let the
999 * user application have at it. Note that the dynamic linker itself
1000 * is not guaranteed to be fully dynamicly linked if we are using
1001 * ld.so.1, so we have to look up each symbol individually.
1004 _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "__environ", _dl_symbol_tables, NULL, 0, NULL);
1006 *_dl_envp = (unsigned long) envp;
1008 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
1013 /* We had to set the protections of all pages to R/W for
1014 * dynamic linking. Set text pages back to R/O.
1016 for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
1017 for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
1018 if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
1019 _dl_mprotect((void *) (DL_RELOC_ADDR(tpnt->loadaddr, myppnt->p_vaddr) & PAGE_ALIGN),
1020 (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
1027 /* Notify the debugger we have added some objects. */
1028 _dl_debug_addr->r_state = RT_ADD;
1031 /* Run pre-initialization functions for the executable. */
1032 _dl_run_array_forward(_dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAY],
1033 _dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAYSZ],
1034 _dl_loaded_modules->loadaddr);
1036 /* Run initialization functions for loaded objects. For the
1037 main executable, they will be run from __uClibc_main. */
1038 for (i = nlist; i; --i) {
1039 tpnt = init_fini_list[i-1];
1040 tpnt->init_fini = NULL; /* Clear, since alloca was used */
1041 if (tpnt->init_flag & INIT_FUNCS_CALLED)
1043 tpnt->init_flag |= INIT_FUNCS_CALLED;
1045 if (tpnt->dynamic_info[DT_INIT]) {
1046 void (*dl_elf_func) (void);
1048 dl_elf_func = (void (*)(void)) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_INIT]);
1050 _dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);
1052 DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
1055 _dl_run_init_array(tpnt);
1058 /* Find the real malloc function and make ldso functions use that from now on */
1059 _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "malloc",
1060 _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1063 /* Find the real functions and make ldso functions use them from now on */
1064 _dl_calloc_function = (void* (*)(size_t, size_t)) (intptr_t)
1065 _dl_find_hash(__C_SYMBOL_PREFIX__ "calloc", _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1067 _dl_realloc_function = (void* (*)(void *, size_t)) (intptr_t)
1068 _dl_find_hash(__C_SYMBOL_PREFIX__ "realloc", _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1070 _dl_free_function = (void (*)(void *)) (intptr_t)
1071 _dl_find_hash(__C_SYMBOL_PREFIX__ "free", _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1073 _dl_memalign_function = (void* (*)(size_t, size_t)) (intptr_t)
1074 _dl_find_hash(__C_SYMBOL_PREFIX__ "memalign", _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1078 /* Notify the debugger that all objects are now mapped in. */
1079 _dl_debug_addr->r_state = RT_CONSISTENT;
1083 #include "dl-hash.c"