diff options
Diffstat (limited to 'elf/dl-reloc.c')
| -rw-r--r-- | elf/dl-reloc.c | 363 |
1 files changed, 0 insertions, 363 deletions
diff --git a/elf/dl-reloc.c b/elf/dl-reloc.c deleted file mode 100644 index b3c3a9bbf9..0000000000 --- a/elf/dl-reloc.c +++ /dev/null @@ -1,363 +0,0 @@ -/* Relocate a shared object and resolve its references to other loaded objects. - Copyright (C) 1995-2017 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - <http://www.gnu.org/licenses/>. */ - -#include <errno.h> -#include <libintl.h> -#include <stdlib.h> -#include <unistd.h> -#include <ldsodefs.h> -#include <sys/mman.h> -#include <sys/param.h> -#include <sys/types.h> -#include <_itoa.h> -#include <libc-pointer-arith.h> -#include "dynamic-link.h" - -/* Statistics function. */ -#ifdef SHARED -# define bump_num_cache_relocations() ++GL(dl_num_cache_relocations) -#else -# define bump_num_cache_relocations() ((void) 0) -#endif - - -/* We are trying to perform a static TLS relocation in MAP, but it was - dynamically loaded. This can only work if there is enough surplus in - the static TLS area already allocated for each running thread. If this - object's TLS segment is too big to fit, we fail. If it fits, - we set MAP->l_tls_offset and return. - This function intentionally does not return any value but signals error - directly, as static TLS should be rare and code handling it should - not be inlined as much as possible. */ -int -internal_function -_dl_try_allocate_static_tls (struct link_map *map) -{ - /* If we've already used the variable with dynamic access, or if the - alignment requirements are too high, fail. */ - if (map->l_tls_offset == FORCED_DYNAMIC_TLS_OFFSET - || map->l_tls_align > GL(dl_tls_static_align)) - { - fail: - return -1; - } - -#if TLS_TCB_AT_TP - size_t freebytes = GL(dl_tls_static_size) - GL(dl_tls_static_used); - if (freebytes < TLS_TCB_SIZE) - goto fail; - freebytes -= TLS_TCB_SIZE; - - size_t blsize = map->l_tls_blocksize + map->l_tls_firstbyte_offset; - if (freebytes < blsize) - goto fail; - - size_t n = (freebytes - blsize) / map->l_tls_align; - - size_t offset = GL(dl_tls_static_used) + (freebytes - n * map->l_tls_align - - map->l_tls_firstbyte_offset); - - map->l_tls_offset = GL(dl_tls_static_used) = offset; -#elif TLS_DTV_AT_TP - /* dl_tls_static_used includes the TCB at the beginning. */ - size_t offset = (ALIGN_UP(GL(dl_tls_static_used) - - map->l_tls_firstbyte_offset, - map->l_tls_align) - + map->l_tls_firstbyte_offset); - size_t used = offset + map->l_tls_blocksize; - - if (used > GL(dl_tls_static_size)) - goto fail; - - map->l_tls_offset = offset; - map->l_tls_firstbyte_offset = GL(dl_tls_static_used); - GL(dl_tls_static_used) = used; -#else -# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined" -#endif - - /* If the object is not yet relocated we cannot initialize the - static TLS region. Delay it. */ - if (map->l_real->l_relocated) - { -#ifdef SHARED - if (__builtin_expect (THREAD_DTV()[0].counter != GL(dl_tls_generation), - 0)) - /* Update the slot information data for at least the generation of - the DSO we are allocating data for. */ - (void) _dl_update_slotinfo (map->l_tls_modid); -#endif - - GL(dl_init_static_tls) (map); - } - else - map->l_need_tls_init = 1; - - return 0; -} - -void -internal_function __attribute_noinline__ -_dl_allocate_static_tls (struct link_map *map) -{ - if (map->l_tls_offset == FORCED_DYNAMIC_TLS_OFFSET - || _dl_try_allocate_static_tls (map)) - { - _dl_signal_error (0, map->l_name, NULL, N_("\ -cannot allocate memory in static TLS block")); - } -} - -/* Initialize static TLS area and DTV for current (only) thread. - libpthread implementations should provide their own hook - to handle all threads. */ -void -_dl_nothread_init_static_tls (struct link_map *map) -{ -#if TLS_TCB_AT_TP - void *dest = (char *) THREAD_SELF - map->l_tls_offset; -#elif TLS_DTV_AT_TP - void *dest = (char *) THREAD_SELF + map->l_tls_offset + TLS_PRE_TCB_SIZE; -#else -# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined" -#endif - - /* Initialize the memory. */ - memset (__mempcpy (dest, map->l_tls_initimage, map->l_tls_initimage_size), - '\0', map->l_tls_blocksize - map->l_tls_initimage_size); -} - - -void -_dl_relocate_object (struct link_map *l, struct r_scope_elem *scope[], - int reloc_mode, int consider_profiling) -{ - struct textrels - { - caddr_t start; - size_t len; - int prot; - struct textrels *next; - } *textrels = NULL; - /* Initialize it to make the compiler happy. */ - const char *errstring = NULL; - int lazy = reloc_mode & RTLD_LAZY; - int skip_ifunc = reloc_mode & __RTLD_NOIFUNC; - -#ifdef SHARED - /* If we are auditing, install the same handlers we need for profiling. */ - if ((reloc_mode & __RTLD_AUDIT) == 0) - consider_profiling |= GLRO(dl_audit) != NULL; -#elif defined PROF - /* Never use dynamic linker profiling for gprof profiling code. */ -# define consider_profiling 0 -#endif - - if (l->l_relocated) - return; - - /* If DT_BIND_NOW is set relocate all references in this object. We - do not do this if we are profiling, of course. */ - // XXX Correct for auditing? - if (!consider_profiling - && __builtin_expect (l->l_info[DT_BIND_NOW] != NULL, 0)) - lazy = 0; - - if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_RELOC)) - _dl_debug_printf ("\nrelocation processing: %s%s\n", - DSO_FILENAME (l->l_name), lazy ? " (lazy)" : ""); - - /* DT_TEXTREL is now in level 2 and might phase out at some time. - But we rewrite the DT_FLAGS entry to a DT_TEXTREL entry to make - testing easier and therefore it will be available at all time. */ - if (__glibc_unlikely (l->l_info[DT_TEXTREL] != NULL)) - { - /* Bletch. We must make read-only segments writable - long enough to relocate them. */ - const ElfW(Phdr) *ph; - for (ph = l->l_phdr; ph < &l->l_phdr[l->l_phnum]; ++ph) - if (ph->p_type == PT_LOAD && (ph->p_flags & PF_W) == 0) - { - struct textrels *newp; - - newp = (struct textrels *) alloca (sizeof (*newp)); - newp->len = ALIGN_UP (ph->p_vaddr + ph->p_memsz, GLRO(dl_pagesize)) - - ALIGN_DOWN (ph->p_vaddr, GLRO(dl_pagesize)); - newp->start = PTR_ALIGN_DOWN (ph->p_vaddr, GLRO(dl_pagesize)) - + (caddr_t) l->l_addr; - - if (__mprotect (newp->start, newp->len, PROT_READ|PROT_WRITE) < 0) - { - errstring = N_("cannot make segment writable for relocation"); - call_error: - _dl_signal_error (errno, l->l_name, NULL, errstring); - } - -#if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7 - newp->prot = (PF_TO_PROT - >> ((ph->p_flags & (PF_R | PF_W | PF_X)) * 4)) & 0xf; -#else - newp->prot = 0; - if (ph->p_flags & PF_R) - newp->prot |= PROT_READ; - if (ph->p_flags & PF_W) - newp->prot |= PROT_WRITE; - if (ph->p_flags & PF_X) - newp->prot |= PROT_EXEC; -#endif - newp->next = textrels; - textrels = newp; - } - } - - { - /* Do the actual relocation of the object's GOT and other data. */ - - /* String table object symbols. */ - const char *strtab = (const void *) D_PTR (l, l_info[DT_STRTAB]); - - /* This macro is used as a callback from the ELF_DYNAMIC_RELOCATE code. */ -#define RESOLVE_MAP(ref, version, r_type) \ - ((ELFW(ST_BIND) ((*ref)->st_info) != STB_LOCAL \ - && __glibc_likely (!dl_symbol_visibility_binds_local_p (*ref))) \ - ? ((__builtin_expect ((*ref) == l->l_lookup_cache.sym, 0) \ - && elf_machine_type_class (r_type) == l->l_lookup_cache.type_class) \ - ? (bump_num_cache_relocations (), \ - (*ref) = l->l_lookup_cache.ret, \ - l->l_lookup_cache.value) \ - : ({ lookup_t _lr; \ - int _tc = elf_machine_type_class (r_type); \ - l->l_lookup_cache.type_class = _tc; \ - l->l_lookup_cache.sym = (*ref); \ - const struct r_found_version *v = NULL; \ - if ((version) != NULL && (version)->hash != 0) \ - v = (version); \ - _lr = _dl_lookup_symbol_x (strtab + (*ref)->st_name, l, (ref), \ - scope, v, _tc, \ - DL_LOOKUP_ADD_DEPENDENCY, NULL); \ - l->l_lookup_cache.ret = (*ref); \ - l->l_lookup_cache.value = _lr; })) \ - : l) - -#include "dynamic-link.h" - - ELF_DYNAMIC_RELOCATE (l, lazy, consider_profiling, skip_ifunc); - -#ifndef PROF - if (__glibc_unlikely (consider_profiling) - && l->l_info[DT_PLTRELSZ] != NULL) - { - /* Allocate the array which will contain the already found - relocations. If the shared object lacks a PLT (for example - if it only contains lead function) the l_info[DT_PLTRELSZ] - will be NULL. */ - size_t sizeofrel = l->l_info[DT_PLTREL]->d_un.d_val == DT_RELA - ? sizeof (ElfW(Rela)) - : sizeof (ElfW(Rel)); - size_t relcount = l->l_info[DT_PLTRELSZ]->d_un.d_val / sizeofrel; - l->l_reloc_result = calloc (sizeof (l->l_reloc_result[0]), relcount); - - if (l->l_reloc_result == NULL) - { - errstring = N_("\ -%s: out of memory to store relocation results for %s\n"); - _dl_fatal_printf (errstring, RTLD_PROGNAME, l->l_name); - } - } -#endif - } - - /* Mark the object so we know this work has been done. */ - l->l_relocated = 1; - - /* Undo the segment protection changes. */ - while (__builtin_expect (textrels != NULL, 0)) - { - if (__mprotect (textrels->start, textrels->len, textrels->prot) < 0) - { - errstring = N_("cannot restore segment prot after reloc"); - goto call_error; - } - -#ifdef CLEAR_CACHE - CLEAR_CACHE (textrels->start, textrels->start + textrels->len); -#endif - - textrels = textrels->next; - } - - /* In case we can protect the data now that the relocations are - done, do it. */ - if (l->l_relro_size != 0) - _dl_protect_relro (l); -} - - -void internal_function -_dl_protect_relro (struct link_map *l) -{ - ElfW(Addr) start = ALIGN_DOWN((l->l_addr - + l->l_relro_addr), - GLRO(dl_pagesize)); - ElfW(Addr) end = ALIGN_DOWN((l->l_addr - + l->l_relro_addr - + l->l_relro_size), - GLRO(dl_pagesize)); - if (start != end - && __mprotect ((void *) start, end - start, PROT_READ) < 0) - { - static const char errstring[] = N_("\ -cannot apply additional memory protection after relocation"); - _dl_signal_error (errno, l->l_name, NULL, errstring); - } -} - -void -internal_function __attribute_noinline__ -_dl_reloc_bad_type (struct link_map *map, unsigned int type, int plt) -{ -#define DIGIT(b) _itoa_lower_digits[(b) & 0xf]; - - /* XXX We cannot translate these messages. */ - static const char msg[2][32 -#if __ELF_NATIVE_CLASS == 64 - + 6 -#endif - ] = { "unexpected reloc type 0x", - "unexpected PLT reloc type 0x" }; - char msgbuf[sizeof (msg[0])]; - char *cp; - - cp = __stpcpy (msgbuf, msg[plt]); -#if __ELF_NATIVE_CLASS == 64 - if (__builtin_expect(type > 0xff, 0)) - { - *cp++ = DIGIT (type >> 28); - *cp++ = DIGIT (type >> 24); - *cp++ = DIGIT (type >> 20); - *cp++ = DIGIT (type >> 16); - *cp++ = DIGIT (type >> 12); - *cp++ = DIGIT (type >> 8); - } -#endif - *cp++ = DIGIT (type >> 4); - *cp++ = DIGIT (type); - *cp = '\0'; - - _dl_signal_error (0, map->l_name, NULL, msgbuf); -} |