1 /* vi: set sw=4 ts=4: */
3 * This file contains the helper routines to load an ELF shared
4 * library into memory and add the symbol table info to the chain.
6 * Copyright (C) 2000-2006 by Erik Andersen <andersen@codepoet.org>
7 * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
8 * David Engel, Hongjiu Lu and Mitch D'Souza
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. The name of the above contributors may not be
16 * used to endorse or promote products derived from this software
17 * without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 #ifdef __LDSO_CACHE_SUPPORT__
37 static caddr_t _dl_cache_addr = NULL;
38 static size_t _dl_cache_size = 0;
40 int _dl_map_cache(void)
48 if (_dl_cache_addr == MAP_FAILED)
50 else if (_dl_cache_addr != NULL)
53 if (_dl_stat(LDSO_CACHE, &st)
54 || (fd = _dl_open(LDSO_CACHE, O_RDONLY|O_CLOEXEC, 0)) < 0) {
55 _dl_cache_addr = MAP_FAILED; /* so we won't try again */
59 _dl_cache_size = st.st_size;
60 _dl_cache_addr = _dl_mmap(0, _dl_cache_size, PROT_READ, LDSO_CACHE_MMAP_FLAGS, fd, 0);
62 if (_dl_mmap_check_error(_dl_cache_addr)) {
63 _dl_dprintf(2, "%s:%i: can't map '%s'\n",
64 _dl_progname, __LINE__, LDSO_CACHE);
68 header = (header_t *) _dl_cache_addr;
70 if (_dl_cache_size < sizeof(header_t) ||
71 _dl_memcmp(header->magic, LDSO_CACHE_MAGIC, LDSO_CACHE_MAGIC_LEN)
72 || _dl_memcmp(header->version, LDSO_CACHE_VER, LDSO_CACHE_VER_LEN)
74 (sizeof(header_t) + header->nlibs * sizeof(libentry_t))
75 || _dl_cache_addr[_dl_cache_size - 1] != '\0')
77 _dl_dprintf(2, "%s: cache '%s' is corrupt\n", _dl_progname,
82 strtabsize = _dl_cache_size - sizeof(header_t) -
83 header->nlibs * sizeof(libentry_t);
84 libent = (libentry_t *) & header[1];
86 for (i = 0; i < header->nlibs; i++) {
87 if (libent[i].sooffset >= strtabsize ||
88 libent[i].liboffset >= strtabsize)
90 _dl_dprintf(2, "%s: cache '%s' is corrupt\n", _dl_progname, LDSO_CACHE);
98 _dl_munmap(_dl_cache_addr, _dl_cache_size);
99 _dl_cache_addr = MAP_FAILED;
103 int _dl_unmap_cache(void)
105 if (_dl_cache_addr == NULL || _dl_cache_addr == MAP_FAILED)
109 _dl_munmap(_dl_cache_addr, _dl_cache_size);
110 _dl_cache_addr = NULL;
119 _dl_protect_relro (struct elf_resolve *l)
121 ElfW(Addr) base = (ElfW(Addr)) DL_RELOC_ADDR(l->loadaddr, l->relro_addr);
122 ElfW(Addr) start = (base & PAGE_ALIGN);
123 ElfW(Addr) end = ((base + l->relro_size) & PAGE_ALIGN);
124 _dl_if_debug_dprint("RELRO protecting %s: start:%x, end:%x\n", l->libname, start, end);
126 _dl_mprotect ((void *) start, end - start, PROT_READ) < 0) {
127 _dl_dprintf(2, "%s: cannot apply additional memory protection after relocation", l->libname);
132 /* This function's behavior must exactly match that
133 * in uClibc/ldso/util/ldd.c */
134 static struct elf_resolve *
135 search_for_named_library(const char *name, unsigned rflags, const char *path_list,
136 struct dyn_elf **rpnt)
138 char *path, *path_n, *mylibname;
139 struct elf_resolve *tpnt;
145 /* We need a writable copy of this string, but we don't
146 * need this allocated permanently since we don't want
147 * to leak memory, so use alloca to put path on the stack */
148 done = _dl_strlen(path_list);
149 path = alloca(done + 1);
151 /* another bit of local storage */
152 mylibname = alloca(2050);
154 _dl_memcpy(path, path_list, done+1);
156 /* Unlike ldd.c, don't bother to eliminate double //s */
158 /* Replace colons with zeros in path_list */
159 /* : at the beginning or end of path maps to CWD */
160 /* :: anywhere maps CWD */
172 _dl_strcpy(mylibname, path_n);
174 _dl_strcpy(mylibname, "."); /* Assume current dir if empty path */
175 _dl_strcat(mylibname, "/");
176 _dl_strcat(mylibname, name);
177 if ((tpnt = _dl_load_elf_shared_library(rflags, rpnt, mylibname)) != NULL)
186 /* Used to return error codes back to dlopen et. al. */
187 unsigned long _dl_error_number;
188 unsigned long _dl_internal_error_number;
190 struct elf_resolve *_dl_load_shared_library(unsigned rflags, struct dyn_elf **rpnt,
191 struct elf_resolve *tpnt, char *full_libname, int attribute_unused trace_loaded_objects)
194 struct elf_resolve *tpnt1;
197 _dl_internal_error_number = 0;
198 libname = full_libname;
200 /* quick hack to ensure mylibname buffer doesn't overflow. don't
201 allow full_libname or any directory to be longer than 1024. */
202 if (_dl_strlen(full_libname) > 1024)
205 /* Skip over any initial initial './' and '/' stuff to
206 * get the short form libname with no path garbage */
207 pnt = _dl_strrchr(libname, '/');
212 _dl_if_debug_dprint("\tfind library='%s'; searching\n", libname);
213 /* If the filename has any '/', try it straight and leave it at that.
214 For IBCS2 compatibility under linux, we substitute the string
215 /usr/i486-sysv4/lib for /usr/lib in library names. */
217 if (libname != full_libname) {
218 _dl_if_debug_dprint("\ttrying file='%s'\n", full_libname);
219 tpnt1 = _dl_load_elf_shared_library(rflags, rpnt, full_libname);
226 * The ABI specifies that RPATH is searched before LD_LIBRARY_PATH or
227 * the default path of /usr/lib. Check in rpath directories.
229 #ifdef __LDSO_RUNPATH__
230 pnt = (tpnt ? (char *) tpnt->dynamic_info[DT_RPATH] : NULL);
232 pnt += (unsigned long) tpnt->dynamic_info[DT_STRTAB];
233 _dl_if_debug_dprint("\tsearching RPATH='%s'\n", pnt);
234 if ((tpnt1 = search_for_named_library(libname, rflags, pnt, rpnt)) != NULL)
239 #ifdef __LDSO_LD_LIBRARY_PATH__
240 /* Check in LD_{ELF_}LIBRARY_PATH, if specified and allowed */
241 if (_dl_library_path) {
242 _dl_if_debug_dprint("\tsearching LD_LIBRARY_PATH='%s'\n", _dl_library_path);
243 if ((tpnt1 = search_for_named_library(libname, rflags, _dl_library_path, rpnt)) != NULL)
250 * The ABI specifies that RUNPATH is searched after LD_LIBRARY_PATH.
252 #ifdef __LDSO_RUNPATH__
253 pnt = (tpnt ? (char *)tpnt->dynamic_info[DT_RUNPATH] : NULL);
255 pnt += (unsigned long) tpnt->dynamic_info[DT_STRTAB];
256 _dl_if_debug_dprint("\tsearching RUNPATH='%s'\n", pnt);
257 if ((tpnt1 = search_for_named_library(libname, rflags, pnt, rpnt)) != NULL)
263 * Where should the cache be searched? There is no such concept in the
264 * ABI, so we have some flexibility here. For now, search it before
265 * the hard coded paths that follow (i.e before /lib and /usr/lib).
267 #ifdef __LDSO_CACHE_SUPPORT__
268 if (_dl_cache_addr != NULL && _dl_cache_addr != MAP_FAILED) {
270 header_t *header = (header_t *) _dl_cache_addr;
271 libentry_t *libent = (libentry_t *) & header[1];
272 char *strs = (char *) &libent[header->nlibs];
274 _dl_if_debug_dprint("\tsearching cache='%s'\n", LDSO_CACHE);
275 for (i = 0; i < header->nlibs; i++) {
276 if ((libent[i].flags == LIB_ELF
277 || libent[i].flags == LIB_ELF_LIBC0
278 || libent[i].flags == LIB_ELF_LIBC5)
279 && _dl_strcmp(libname, strs + libent[i].sooffset) == 0
280 && (tpnt1 = _dl_load_elf_shared_library(rflags, rpnt, strs + libent[i].liboffset))
287 #if defined SHARED && defined __LDSO_SEARCH_INTERP_PATH__
288 /* Look for libraries wherever the shared library loader
290 _dl_if_debug_dprint("\tsearching ldso dir='%s'\n", _dl_ldsopath);
291 tpnt1 = search_for_named_library(libname, rflags, _dl_ldsopath, rpnt);
295 /* Lastly, search the standard list of paths for the library.
296 This list must exactly match the list in uClibc/ldso/util/ldd.c */
297 _dl_if_debug_dprint("\tsearching full lib path list\n");
298 tpnt1 = search_for_named_library(libname, rflags,
299 UCLIBC_RUNTIME_PREFIX "lib:"
300 UCLIBC_RUNTIME_PREFIX "usr/lib"
301 #ifndef __LDSO_CACHE_SUPPORT__
302 ":" UCLIBC_RUNTIME_PREFIX "usr/X11R6/lib"
309 /* Well, we shot our wad on that one. All we can do now is punt */
310 if (_dl_internal_error_number)
311 _dl_error_number = _dl_internal_error_number;
313 _dl_error_number = LD_ERROR_NOFILE;
314 _dl_if_debug_dprint("Bummer: could not find '%s'!\n", libname);
318 /* Define the _dl_library_offset for the architectures that need it */
322 * Make a writeable mapping of a segment, regardless of whether PF_W is
326 map_writeable (int infile, ElfW(Phdr) *ppnt, int piclib, int flags,
327 unsigned long libaddr)
329 int prot_flags = ppnt->p_flags | PF_W;
330 char *status, *retval;
333 unsigned long map_size;
335 char *piclib2map = NULL;
338 /* We might be able to avoid this call if memsz doesn't
339 require an additional page, but this would require mmap
340 to always return page-aligned addresses and a whole
341 number of pages allocated. Unfortunately on uClinux
342 may return misaligned addresses and may allocate
343 partial pages, so we may end up doing unnecessary mmap
346 This is what we could do if we knew mmap would always
347 return aligned pages:
349 ((ppnt->p_vaddr + ppnt->p_filesz + ADDR_ALIGN) &
350 PAGE_ALIGN) < ppnt->p_vaddr + ppnt->p_memsz)
352 Instead, we have to do this: */
353 ppnt->p_filesz < ppnt->p_memsz)
355 piclib2map = (char *)
356 _dl_mmap(0, (ppnt->p_vaddr & ADDR_ALIGN) + ppnt->p_memsz,
357 LXFLAGS(prot_flags), flags | MAP_ANONYMOUS, -1, 0);
358 if (_dl_mmap_check_error(piclib2map))
362 tryaddr = piclib == 2 ? piclib2map
363 : ((char *) (piclib ? libaddr : DL_GET_LIB_OFFSET()) +
364 (ppnt->p_vaddr & PAGE_ALIGN));
366 size = (ppnt->p_vaddr & ADDR_ALIGN) + ppnt->p_filesz;
368 /* For !MMU, mmap to fixed address will fail.
369 So instead of desperately call mmap and fail,
370 we set status to MAP_FAILED to save a call
372 #ifndef __ARCH_USE_MMU__
375 status = (char *) _dl_mmap
376 (tryaddr, size, LXFLAGS(prot_flags),
377 flags | (piclib2map ? MAP_FIXED : 0),
378 infile, ppnt->p_offset & OFFS_ALIGN);
379 #ifndef __ARCH_USE_MMU__
384 if (_dl_mmap_check_error(status) && piclib2map
385 && (_DL_PREAD (infile, tryaddr, size,
386 ppnt->p_offset & OFFS_ALIGN) == size))
389 if (_dl_mmap_check_error(status) || (tryaddr && tryaddr != status))
397 /* Now we want to allocate and zero-out any data from the end
398 of the region we mapped in from the file (filesz) to the
399 end of the loadable segment (memsz). We may need
400 additional pages for memsz, that we map in below, and we
401 can count on the kernel to zero them out, but we have to
402 zero out stuff in the last page that we mapped in from the
403 file. However, we can't assume to have actually obtained
404 full pages from the kernel, since we didn't ask for them,
405 and uClibc may not give us full pages for small
406 allocations. So only zero out up to memsz or the end of
407 the page, whichever comes first. */
409 /* CPNT is the beginning of the memsz portion not backed by
411 cpnt = (char *) (status + size);
413 /* MAP_SIZE is the address of the
414 beginning of the next page. */
415 map_size = (ppnt->p_vaddr + ppnt->p_filesz
416 + ADDR_ALIGN) & PAGE_ALIGN;
425 if (map_size < ppnt->p_vaddr + ppnt->p_memsz && !piclib2map) {
426 tryaddr = map_size + (char*)(piclib ? libaddr : 0);
427 status = (char *) _dl_mmap(tryaddr,
428 ppnt->p_vaddr + ppnt->p_memsz - map_size,
430 flags | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
431 if (_dl_mmap_check_error(status) || tryaddr != status)
438 * Read one ELF library into memory, mmap it into the correct locations and
439 * add the symbol info to the symbol chain. Perform any relocations that
443 struct elf_resolve *_dl_load_elf_shared_library(unsigned rflags,
444 struct dyn_elf **rpnt, const char *libname)
447 unsigned long dynamic_addr = 0;
449 struct elf_resolve *tpnt;
451 #if defined(USE_TLS) && USE_TLS
452 ElfW(Phdr) *tlsppnt = NULL;
454 char *status, *header;
455 unsigned long dynamic_info[DYNAMIC_SIZE];
457 unsigned long libaddr;
458 unsigned long minvma = 0xffffffff, maxvma = 0;
459 unsigned int rtld_flags;
460 int i, flags, piclib, infile;
461 ElfW(Addr) relro_addr = 0;
462 size_t relro_size = 0;
465 DL_LOADADDR_TYPE lib_loadaddr;
466 DL_INIT_LOADADDR_EXTRA_DECLS
469 infile = _dl_open(libname, O_RDONLY, 0);
471 _dl_internal_error_number = LD_ERROR_NOFILE;
475 if (_dl_fstat(infile, &st) < 0) {
476 _dl_internal_error_number = LD_ERROR_NOFILE;
480 /* If we are in secure mode (i.e. a setuid/gid binary using LD_PRELOAD),
481 we don't load the library if it isn't setuid. */
482 if (rflags & DL_RESOLVE_SECURE) {
483 if (!(st.st_mode & S_ISUID)) {
489 /* Check if file is already loaded */
490 for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
491 if (tpnt->st_dev == st.st_dev && tpnt->st_ino == st.st_ino) {
498 if (rflags & DL_RESOLVE_NOLOAD) {
502 header = _dl_mmap((void *) 0, _dl_pagesize, PROT_READ | PROT_WRITE,
503 MAP_PRIVATE | MAP_ANONYMOUS | MAP_UNINITIALIZE, -1, 0);
504 if (_dl_mmap_check_error(header)) {
505 _dl_dprintf(2, "%s:%i: can't map '%s'\n", _dl_progname, __LINE__, libname);
506 _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
511 _dl_read(infile, header, _dl_pagesize);
512 epnt = (ElfW(Ehdr) *) (intptr_t) header;
513 p32 = (uint32_t*)&epnt->e_ident;
514 if (*p32 != ELFMAG_U32) {
515 _dl_dprintf(2, "%s: '%s' is not an ELF file\n", _dl_progname,
517 _dl_internal_error_number = LD_ERROR_NOTELF;
519 _dl_munmap(header, _dl_pagesize);
523 if ((epnt->e_type != ET_DYN
524 #ifdef __LDSO_STANDALONE_SUPPORT__
525 && epnt->e_type != ET_EXEC
527 ) || (epnt->e_machine != MAGIC1
529 && epnt->e_machine != MAGIC2
533 _dl_internal_error_number =
534 (epnt->e_type != ET_DYN ? LD_ERROR_NOTDYN : LD_ERROR_NOTMAGIC);
535 _dl_dprintf(2, "%s: '%s' is not an ELF executable for " ELF_TARGET
536 "\n", _dl_progname, libname);
538 _dl_munmap(header, _dl_pagesize);
542 ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
545 for (i = 0; i < epnt->e_phnum; i++) {
547 if (ppnt->p_type == PT_DYNAMIC) {
549 _dl_dprintf(2, "%s: '%s' has more than one dynamic section\n",
550 _dl_progname, libname);
551 dynamic_addr = ppnt->p_vaddr;
554 if (ppnt->p_type == PT_LOAD) {
555 /* See if this is a PIC library. */
556 if (minvma == 0xffffffff && ppnt->p_vaddr > 0x1000000) {
558 minvma = ppnt->p_vaddr;
560 if (piclib && ppnt->p_vaddr < minvma) {
561 minvma = ppnt->p_vaddr;
563 if (((unsigned long) ppnt->p_vaddr + ppnt->p_memsz) > maxvma) {
564 maxvma = ppnt->p_vaddr + ppnt->p_memsz;
567 if (ppnt->p_type == PT_TLS) {
568 #if defined(USE_TLS) && USE_TLS
569 if (ppnt->p_memsz == 0)
570 /* Nothing to do for an empty segment. */
573 /* Save for after 'tpnt' is actually allocated. */
577 * Yup, the user was an idiot and tried to sneak in a library with
578 * TLS in it and we don't support it. Let's fall on our own sword
579 * and scream at the luser while we die.
581 _dl_dprintf(2, "%s: '%s' library contains unsupported TLS\n",
582 _dl_progname, libname);
583 _dl_internal_error_number = LD_ERROR_TLS_FAILED;
585 _dl_munmap(header, _dl_pagesize);
592 #ifdef __LDSO_STANDALONE_SUPPORT__
593 if (epnt->e_type == ET_EXEC)
597 DL_CHECK_LIB_TYPE (epnt, piclib, _dl_progname, libname);
599 maxvma = (maxvma + ADDR_ALIGN) & PAGE_ALIGN;
600 minvma = minvma & ~ADDR_ALIGN;
602 flags = MAP_PRIVATE /*| MAP_DENYWRITE */ ;
604 if (piclib == 0 || piclib == 1) {
605 status = (char *) _dl_mmap((char *) (piclib ? 0 : minvma),
606 maxvma - minvma, PROT_NONE, flags | MAP_ANONYMOUS, -1, 0);
607 if (_dl_mmap_check_error(status)) {
609 _dl_dprintf(2, "%s:%i: can't map '%s'\n", _dl_progname, __LINE__, libname);
610 _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
612 _dl_munmap(header, _dl_pagesize);
615 libaddr = (unsigned long) status;
619 /* Get the memory to store the library */
620 ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
622 DL_INIT_LOADADDR(lib_loadaddr, libaddr - minvma, ppnt, epnt->e_phnum);
623 /* Set _dl_library_offset to lib_loadaddr or 0. */
624 DL_SET_LIB_OFFSET(lib_loadaddr);
626 for (i = 0; i < epnt->e_phnum; i++) {
627 if (DL_IS_SPECIAL_SEGMENT (epnt, ppnt)) {
630 addr = DL_MAP_SEGMENT (epnt, ppnt, infile, flags);
633 DL_LOADADDR_UNMAP (lib_loadaddr, maxvma - minvma);
637 DL_INIT_LOADADDR_HDR (lib_loadaddr, addr, ppnt);
641 if (ppnt->p_type == PT_GNU_RELRO) {
642 relro_addr = ppnt->p_vaddr;
643 relro_size = ppnt->p_memsz;
645 if (ppnt->p_type == PT_LOAD) {
649 if (ppnt->p_flags & PF_W) {
650 status = map_writeable (infile, ppnt, piclib, flags, libaddr);
654 tryaddr = (piclib == 2 ? 0
655 : (char *) (ppnt->p_vaddr & PAGE_ALIGN)
656 + (piclib ? libaddr : DL_GET_LIB_OFFSET()));
657 size = (ppnt->p_vaddr & ADDR_ALIGN) + ppnt->p_filesz;
658 status = (char *) _dl_mmap
659 (tryaddr, size, LXFLAGS(ppnt->p_flags),
660 flags | (piclib == 2 ? MAP_EXECUTABLE
661 | MAP_DENYWRITE : 0),
662 infile, ppnt->p_offset & OFFS_ALIGN);
663 if (_dl_mmap_check_error(status)
664 || (tryaddr && tryaddr != status))
667 DL_INIT_LOADADDR_HDR(lib_loadaddr,
668 status + (ppnt->p_vaddr & ADDR_ALIGN),
671 /* if (libaddr == 0 && piclib) {
672 libaddr = (unsigned long) status;
680 * The dynamic_addr must be take into acount lib_loadaddr value, to note
681 * it is zero when the SO has been mapped to the elf's physical addr
683 #ifdef __LDSO_PRELINK_SUPPORT__
684 if (DL_GET_LIB_OFFSET()) {
688 dynamic_addr = (unsigned long) DL_RELOC_ADDR(lib_loadaddr, dynamic_addr);
692 * OK, the ELF library is now loaded into VM in the correct locations
693 * The next step is to go through and do the dynamic linking (if needed).
696 /* Start by scanning the dynamic section to get all of the pointers */
699 _dl_internal_error_number = LD_ERROR_NODYNAMIC;
700 _dl_dprintf(2, "%s: '%s' is missing a dynamic section\n",
701 _dl_progname, libname);
702 _dl_munmap(header, _dl_pagesize);
707 dpnt = (ElfW(Dyn) *) dynamic_addr;
708 _dl_memset(dynamic_info, 0, sizeof(dynamic_info));
709 rtld_flags = _dl_parse_dynamic_info(dpnt, dynamic_info, NULL, lib_loadaddr);
710 /* If the TEXTREL is set, this means that we need to make the pages
711 writable before we perform relocations. Do this now. They get set
714 if (dynamic_info[DT_TEXTREL]) {
715 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
716 ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
717 for (i = 0; i < epnt->e_phnum; i++, ppnt++) {
718 if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W)) {
719 #ifdef __ARCH_USE_MMU__
720 _dl_mprotect((void *) ((piclib ? libaddr : DL_GET_LIB_OFFSET()) +
721 (ppnt->p_vaddr & PAGE_ALIGN)),
722 (ppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) ppnt->p_filesz,
723 PROT_READ | PROT_WRITE | PROT_EXEC);
726 new_addr = map_writeable (infile, ppnt, piclib, flags, libaddr);
728 _dl_dprintf(_dl_debug_file, "Can't modify %s's text section.",
732 DL_UPDATE_LOADADDR_HDR(lib_loadaddr,
733 new_addr + (ppnt->p_vaddr & ADDR_ALIGN),
735 /* This has invalidated all pointers into the previously readonly segment.
736 Update any them to point into the remapped segment. */
737 _dl_parse_dynamic_info(dpnt, dynamic_info, NULL, lib_loadaddr);
742 _dl_dprintf(_dl_debug_file, "Can't modify %s's text section."
743 " Use GCC option -fPIC for shared objects, please.\n",
751 tpnt = _dl_add_elf_hash_table(libname, lib_loadaddr, dynamic_info,
753 tpnt->mapaddr = libaddr;
754 tpnt->relro_addr = relro_addr;
755 tpnt->relro_size = relro_size;
756 tpnt->st_dev = st.st_dev;
757 tpnt->st_ino = st.st_ino;
758 tpnt->ppnt = (ElfW(Phdr) *)
759 DL_RELOC_ADDR(DL_GET_RUN_ADDR(tpnt->loadaddr, tpnt->mapaddr),
761 tpnt->n_phent = epnt->e_phnum;
762 tpnt->rtld_flags |= rtld_flags;
763 #ifdef __LDSO_STANDALONE_SUPPORT__
764 tpnt->l_entry = epnt->e_entry;
767 #if defined(USE_TLS) && USE_TLS
769 _dl_debug_early("Found TLS header for %s\n", libname);
770 # if NO_TLS_OFFSET != 0
771 tpnt->l_tls_offset = NO_TLS_OFFSET;
773 tpnt->l_tls_blocksize = tlsppnt->p_memsz;
774 tpnt->l_tls_align = tlsppnt->p_align;
775 if (tlsppnt->p_align == 0)
776 tpnt->l_tls_firstbyte_offset = 0;
778 tpnt->l_tls_firstbyte_offset = tlsppnt->p_vaddr &
779 (tlsppnt->p_align - 1);
780 tpnt->l_tls_initimage_size = tlsppnt->p_filesz;
781 tpnt->l_tls_initimage = (void *) tlsppnt->p_vaddr;
783 /* Assign the next available module ID. */
784 tpnt->l_tls_modid = _dl_next_tls_modid ();
786 /* We know the load address, so add it to the offset. */
787 #ifdef __LDSO_STANDALONE_SUPPORT__
788 if ((tpnt->l_tls_initimage != NULL) && piclib)
790 if (tpnt->l_tls_initimage != NULL)
793 # ifdef __SUPPORT_LD_DEBUG_EARLY__
794 unsigned int tmp = (unsigned int) tpnt->l_tls_initimage;
795 tpnt->l_tls_initimage = (char *) tlsppnt->p_vaddr + tpnt->loadaddr;
796 _dl_debug_early("Relocated TLS initial image from %x to %x (size = %x)\n", tmp, tpnt->l_tls_initimage, tpnt->l_tls_initimage_size);
799 tpnt->l_tls_initimage = (char *) tlsppnt->p_vaddr + tpnt->loadaddr;
806 * Add this object into the symbol chain
809 #ifdef __LDSO_STANDALONE_SUPPORT__
810 /* Do not create a new chain entry for the main executable */
814 (*rpnt)->next = _dl_malloc(sizeof(struct dyn_elf));
815 _dl_memset((*rpnt)->next, 0, sizeof(struct dyn_elf));
816 (*rpnt)->next->prev = (*rpnt);
817 *rpnt = (*rpnt)->next;
820 /* When statically linked, the first time we dlopen a DSO
821 * the *rpnt is NULL, so we need to allocate memory for it,
822 * and initialize the _dl_symbol_table.
825 *rpnt = _dl_symbol_tables = _dl_malloc(sizeof(struct dyn_elf));
826 _dl_memset(*rpnt, 0, sizeof(struct dyn_elf));
831 #ifdef __LDSO_STANDALONE_SUPPORT__
832 tpnt->libtype = (epnt->e_type == ET_DYN) ? elf_lib : elf_executable;
834 tpnt->libtype = elf_lib;
838 * OK, the next thing we need to do is to insert the dynamic linker into
839 * the proper entry in the GOT so that the PLT symbols can be properly
843 lpnt = (unsigned long *) dynamic_info[DT_PLTGOT];
846 lpnt = (unsigned long *) (dynamic_info[DT_PLTGOT]);
847 INIT_GOT(lpnt, tpnt);
851 /* Handle DSBT initialization */
853 struct elf_resolve *t, *ref;
854 int idx = tpnt->dsbt_index;
855 void **dsbt = tpnt->dsbt_table;
858 * It is okay (required actually) to have zero idx for an executable.
859 * This is the case when running ldso standalone and the program
860 * is being mapped in via _dl_load_shared_library().
862 if (idx == 0 && tpnt->libtype != elf_executable) {
863 if (!dynamic_info[DT_TEXTREL]) {
864 /* This DSO has not been assigned an index. */
865 _dl_dprintf(2, "%s: '%s' is missing a dsbt index assignment!\n",
866 _dl_progname, libname);
869 /* Find a dsbt table from another module. */
871 for (t = _dl_loaded_modules; t; t = t->next) {
872 if (ref == NULL && t != tpnt) {
877 idx = tpnt->dsbt_size;
879 if (!ref || ref->dsbt_table[idx] == NULL)
882 _dl_dprintf(2, "%s: '%s' caused DSBT table overflow!\n",
883 _dl_progname, libname);
886 _dl_if_debug_dprint("\n\tfile='%s'; assigned index %d\n",
888 tpnt->dsbt_index = idx;
891 /* make sure index is not already used */
892 if (_dl_ldso_dsbt[idx]) {
893 struct elf_resolve *dup;
894 const char *dup_name;
896 for (dup = _dl_loaded_modules; dup; dup = dup->next)
897 if (dup != tpnt && dup->dsbt_index == idx)
900 dup_name = dup->libname;
902 dup_name = "runtime linker";
904 dup_name = "unknown library";
905 _dl_dprintf(2, "%s: '%s' dsbt index %d already used by %s!\n",
906 _dl_progname, libname, idx, dup_name);
911 * Setup dsbt slot for this module in dsbt of all modules.
913 for (t = _dl_loaded_modules; t; t = t->next)
914 t->dsbt_table[idx] = dsbt;
915 _dl_ldso_dsbt[idx] = dsbt;
916 _dl_memcpy(dsbt, _dl_ldso_dsbt,
917 tpnt->dsbt_size * sizeof(tpnt->dsbt_table[0]));
920 _dl_if_debug_dprint("\n\tfile='%s'; generating link map\n", libname);
921 _dl_if_debug_dprint("\t\tdynamic: %x base: %x\n", dynamic_addr, DL_LOADADDR_BASE(lib_loadaddr));
922 _dl_if_debug_dprint("\t\t entry: %x phdr: %x phnum: %x\n\n",
923 DL_RELOC_ADDR(lib_loadaddr, epnt->e_entry), tpnt->ppnt, tpnt->n_phent);
925 _dl_munmap(header, _dl_pagesize);
930 /* now_flag must be RTLD_NOW or zero */
931 int _dl_fixup(struct dyn_elf *rpnt, struct r_scope_elem *scope, int now_flag)
934 struct elf_resolve *tpnt;
935 ElfW(Word) reloc_size, relative_count;
936 ElfW(Addr) reloc_addr;
939 goof = _dl_fixup(rpnt->next, scope, now_flag);
944 if (!(tpnt->init_flag & RELOCS_DONE))
945 _dl_if_debug_dprint("relocation processing: %s\n", tpnt->libname);
947 if (unlikely(tpnt->dynamic_info[UNSUPPORTED_RELOC_TYPE])) {
948 _dl_if_debug_dprint("%s: can't handle %s relocation records\n",
949 _dl_progname, UNSUPPORTED_RELOC_STR);
954 reloc_size = tpnt->dynamic_info[DT_RELOC_TABLE_SIZE];
955 /* On some machines, notably SPARC & PPC, DT_REL* includes DT_JMPREL in its
956 range. Note that according to the ELF spec, this is completely legal! */
957 #ifdef ELF_MACHINE_PLTREL_OVERLAP
958 reloc_size -= tpnt->dynamic_info [DT_PLTRELSZ];
960 if (tpnt->dynamic_info[DT_RELOC_TABLE_ADDR] &&
961 !(tpnt->init_flag & RELOCS_DONE)) {
962 reloc_addr = tpnt->dynamic_info[DT_RELOC_TABLE_ADDR];
963 relative_count = tpnt->dynamic_info[DT_RELCONT_IDX];
964 if (relative_count) { /* Optimize the XX_RELATIVE relocations if possible */
965 reloc_size -= relative_count * sizeof(ELF_RELOC);
966 #ifdef __LDSO_PRELINK_SUPPORT__
967 if (tpnt->loadaddr || (!tpnt->dynamic_info[DT_GNU_PRELINKED_IDX]))
969 elf_machine_relative(tpnt->loadaddr, reloc_addr, relative_count);
970 reloc_addr += relative_count * sizeof(ELF_RELOC);
972 goof += _dl_parse_relocation_information(rpnt, scope,
975 tpnt->init_flag |= RELOCS_DONE;
977 if (tpnt->dynamic_info[DT_BIND_NOW])
979 if (tpnt->dynamic_info[DT_JMPREL] &&
980 (!(tpnt->init_flag & JMP_RELOCS_DONE) ||
981 (now_flag && !(tpnt->rtld_flags & now_flag)))) {
982 tpnt->rtld_flags |= now_flag;
983 if (!(tpnt->rtld_flags & RTLD_NOW)) {
984 _dl_parse_lazy_relocation_information(rpnt,
985 tpnt->dynamic_info[DT_JMPREL],
986 tpnt->dynamic_info [DT_PLTRELSZ]);
988 goof += _dl_parse_relocation_information(rpnt, scope,
989 tpnt->dynamic_info[DT_JMPREL],
990 tpnt->dynamic_info[DT_PLTRELSZ]);
992 tpnt->init_flag |= JMP_RELOCS_DONE;
996 /* _dl_add_to_slotinfo is called by init_tls() for initial DSO
997 or by dlopen() for dynamically loaded DSO. */
998 #if defined(USE_TLS) && USE_TLS
999 /* Add object to slot information data if necessasy. */
1000 if (tpnt->l_tls_blocksize != 0 && tls_init_tp_called)
1001 _dl_add_to_slotinfo ((struct link_map *) tpnt);
1007 /* Minimal printf which handles only %s, %d, and %x */
1008 void _dl_dprintf(int fd, const char *fmt, ...)
1016 char *start, *ptr, *string;
1022 buf = _dl_mmap((void *) 0, _dl_pagesize, PROT_READ | PROT_WRITE,
1023 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
1024 if (_dl_mmap_check_error(buf)) {
1025 _dl_write(fd, "mmap of a spare page failed!\n", 29);
1031 if (_dl_strlen(fmt) >= (_dl_pagesize - 1)) {
1032 _dl_write(fd, "overflow\n", 11);
1036 _dl_strcpy(buf, fmt);
1037 va_start(args, fmt);
1040 while (*ptr != '%' && *ptr) {
1046 _dl_write(fd, start, _dl_strlen(start));
1050 string = va_arg(args, char *);
1053 _dl_write(fd, "(null)", 6);
1055 _dl_write(fd, string, _dl_strlen(string));
1063 num = va_arg(args, long int);
1065 num = va_arg(args, int);
1067 string = _dl_simple_ltoa(tmp, num);
1068 _dl_write(fd, string, _dl_strlen(string));
1076 num = va_arg(args, long int);
1078 num = va_arg(args, int);
1080 string = _dl_simple_ltoahex(tmp, num);
1081 _dl_write(fd, string, _dl_strlen(string));
1085 _dl_write(fd, "(null)", 6);
1091 _dl_write(fd, start, _dl_strlen(start));
1095 _dl_munmap(buf, _dl_pagesize);
1099 char *_dl_strdup(const char *string)
1104 len = _dl_strlen(string);
1105 retval = _dl_malloc(len + 1);
1106 _dl_strcpy(retval, string);
1110 unsigned int _dl_parse_dynamic_info(ElfW(Dyn) *dpnt, unsigned long dynamic_info[],
1111 void *debug_addr, DL_LOADADDR_TYPE load_off)
1113 return __dl_parse_dynamic_info(dpnt, dynamic_info, debug_addr, load_off);