diff options
Diffstat (limited to 'elf/dl-addr.c')
| -rw-r--r-- | elf/dl-addr.c | 236 |
1 files changed, 113 insertions, 123 deletions
diff --git a/elf/dl-addr.c b/elf/dl-addr.c index 7dbf716..e55dc4b 100644 --- a/elf/dl-addr.c +++ b/elf/dl-addr.c @@ -1,5 +1,5 @@ /* Locate the shared object symbol nearest a given address. - Copyright (C) 1996-2004, 2005, 2006, 2007 Free Software Foundation, Inc. + Copyright (C) 1996-2004, 2005, 2006 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 @@ -22,149 +22,139 @@ #include <ldsodefs.h> -static void -__attribute ((always_inline)) -determine_info (const ElfW(Addr) addr, struct link_map *match, Dl_info *info, - struct link_map **mapp, const ElfW(Sym) **symbolp) +int +internal_function +_dl_addr (const void *address, Dl_info *info, + struct link_map **mapp, const ElfW(Sym) **symbolp) { - /* Now we know what object the address lies in. */ - info->dli_fname = match->l_name; - info->dli_fbase = (void *) match->l_map_start; - - /* If this is the main program the information is incomplete. */ - if (__builtin_expect (match->l_name[0], 'a') == '\0' - && match->l_type == lt_executable) - info->dli_fname = _dl_argv[0]; - - const ElfW(Sym) *symtab - = (const ElfW(Sym) *) D_PTR (match, l_info[DT_SYMTAB]); - const char *strtab = (const char *) D_PTR (match, l_info[DT_STRTAB]); + const ElfW(Addr) addr = DL_LOOKUP_ADDRESS (address); - ElfW(Word) strtabsize = match->l_info[DT_STRSZ]->d_un.d_val; + /* Protect against concurrent loads and unloads. */ + __rtld_lock_lock_recursive (GL(dl_load_lock)); - const ElfW(Sym) *matchsym = NULL; - if (match->l_info[DT_ADDRTAGIDX (DT_GNU_HASH) + DT_NUM + DT_THISPROCNUM - + DT_VERSIONTAGNUM + DT_EXTRANUM + DT_VALNUM] != NULL) - { - /* We look at all symbol table entries referenced by the hash - table. */ - for (Elf_Symndx bucket = 0; bucket < match->l_nbuckets; ++bucket) + /* Find the highest-addressed object that ADDRESS is not below. */ + struct link_map *match = NULL; + for (Lmid_t ns = 0; ns < DL_NNS; ++ns) + for (struct link_map *l = GL(dl_ns)[ns]._ns_loaded; l; l = l->l_next) + if (addr >= l->l_map_start && addr < l->l_map_end) { - Elf32_Word symndx = match->l_gnu_buckets[bucket]; - if (symndx != 0) + /* We know ADDRESS lies within L if in any shared object. + Make sure it isn't past the end of L's segments. */ + size_t n = l->l_phnum; + if (n > 0) { - const Elf32_Word *hasharr = &match->l_gnu_chain_zero[symndx]; - do - { - /* The hash table never references local symbols so - we can omit that test here. */ - if ((symtab[symndx].st_shndx != SHN_UNDEF - || symtab[symndx].st_value != 0) -#ifdef USE_TLS - && ELFW(ST_TYPE) (symtab[symndx].st_info) != STT_TLS -#endif - && DL_ADDR_SYM_MATCH (match, &symtab[symndx], - matchsym, addr) - && symtab[symndx].st_name < strtabsize) - matchsym = (ElfW(Sym) *) &symtab[symndx]; - - ++symndx; - } - while ((*hasharr++ & 1u) == 0); + --n; + while (l->l_phdr[n].p_type != PT_LOAD); + if (addr >= (l->l_addr + + l->l_phdr[n].p_vaddr + l->l_phdr[n].p_memsz)) + /* Off the end of the highest-addressed shared object. */ + continue; } + + match = l; + break; } - } - else + + int result = 0; + if (match != NULL) { - const ElfW(Sym) *symtabend; - if (match->l_info[DT_HASH] != NULL) - symtabend = (symtab - + ((Elf_Symndx *) D_PTR (match, l_info[DT_HASH]))[1]); - else - /* There is no direct way to determine the number of symbols in the - dynamic symbol table and no hash table is present. The ELF - binary is ill-formed but what shall we do? Use the beginning of - the string table which generally follows the symbol table. */ - symtabend = (const ElfW(Sym) *) strtab; - - for (; (void *) symtab < (void *) symtabend; ++symtab) - if ((ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL - || ELFW(ST_BIND) (symtab->st_info) == STB_WEAK) -#ifdef USE_TLS - && ELFW(ST_TYPE) (symtab->st_info) != STT_TLS -#endif - && (symtab->st_shndx != SHN_UNDEF - || symtab->st_value != 0) - && DL_ADDR_SYM_MATCH (match, symtab, matchsym, addr) - && symtab->st_name < strtabsize) - matchsym = (ElfW(Sym) *) symtab; - } + /* Now we know what object the address lies in. */ + info->dli_fname = match->l_name; + info->dli_fbase = (void *) match->l_map_start; - if (mapp) - *mapp = match; - if (symbolp) - *symbolp = matchsym; + /* If this is the main program the information is incomplete. */ + if (__builtin_expect (match->l_name[0], 'a') == '\0' + && match->l_type == lt_executable) + info->dli_fname = _dl_argv[0]; - if (matchsym) - { - /* We found a symbol close by. Fill in its name and exact - address. */ - lookup_t matchl = LOOKUP_VALUE (match); + const ElfW(Sym) *symtab + = (const ElfW(Sym) *) D_PTR (match, l_info[DT_SYMTAB]); + const char *strtab = (const char *) D_PTR (match, l_info[DT_STRTAB]); - info->dli_sname = strtab + matchsym->st_name; - info->dli_saddr = DL_SYMBOL_ADDRESS (matchl, matchsym); - } - else - { - /* No symbol matches. We return only the containing object. */ - info->dli_sname = NULL; - info->dli_saddr = NULL; - } -} + ElfW(Word) strtabsize = match->l_info[DT_STRSZ]->d_un.d_val; + const ElfW(Sym) *matchsym = NULL; + if (match->l_info[DT_ADDRTAGIDX (DT_GNU_HASH) + DT_NUM + DT_THISPROCNUM + + DT_VERSIONTAGNUM + DT_EXTRANUM + DT_VALNUM] != NULL) + { + /* We look at all symbol table entries referenced by the + hash table. */ + for (Elf_Symndx bucket = 0; bucket < match->l_nbuckets; ++bucket) + { + Elf32_Word symndx = match->l_gnu_buckets[bucket]; + if (symndx != 0) + { + const Elf32_Word *hasharr = &match->l_gnu_chain_zero[symndx]; + + do + { + /* The hash table never references local symbols + so we can omit that test here. */ + if ((symtab[symndx].st_shndx != SHN_UNDEF + || symtab[symndx].st_value != 0) + && ELFW(ST_TYPE) (symtab[symndx].st_info) != STT_TLS + && DL_ADDR_SYM_MATCH (match, &symtab[symndx], + matchsym, addr) + && symtab[symndx].st_name < strtabsize) + matchsym = (ElfW(Sym) *) &symtab[symndx]; + + ++symndx; + } + while ((*hasharr++ & 1u) == 0); + } + } + } + else + { + const ElfW(Sym) *symtabend; + if (match->l_info[DT_HASH] != NULL) + symtabend = (symtab + + ((Elf_Symndx *) D_PTR (match, l_info[DT_HASH]))[1]); + else + /* There is no direct way to determine the number of symbols in the + dynamic symbol table and no hash table is present. The ELF + binary is ill-formed but what shall we do? Use the beginning of + the string table which generally follows the symbol table. */ + symtabend = (const ElfW(Sym) *) strtab; + + for (; (void *) symtab < (void *) symtabend; ++symtab) + if ((ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL + || ELFW(ST_BIND) (symtab->st_info) == STB_WEAK) + && ELFW(ST_TYPE) (symtab->st_info) != STT_TLS + && (symtab->st_shndx != SHN_UNDEF + || symtab->st_value != 0) + && DL_ADDR_SYM_MATCH (match, symtab, matchsym, addr) + && symtab->st_name < strtabsize) + matchsym = (ElfW(Sym) *) symtab; + } -int -internal_function -_dl_addr (const void *address, Dl_info *info, - struct link_map **mapp, const ElfW(Sym) **symbolp) -{ - const ElfW(Addr) addr = DL_LOOKUP_ADDRESS (address); - int result = 0; + if (mapp) + *mapp = match; + if (symbolp) + *symbolp = matchsym; - /* Protect against concurrent loads and unloads. */ - __rtld_lock_lock_recursive (GL(dl_load_lock)); + if (matchsym) + { + /* We found a symbol close by. Fill in its name and exact + address. */ + lookup_t matchl = LOOKUP_VALUE (match); - /* Find the highest-addressed object that ADDRESS is not below. */ - for (Lmid_t ns = 0; ns < DL_NNS; ++ns) - for (struct link_map *l = GL(dl_ns)[ns]._ns_loaded; l; l = l->l_next) - if (addr >= l->l_map_start && addr < l->l_map_end - && (l->l_contiguous || _dl_addr_inside_object (l, addr))) + info->dli_sname = strtab + matchsym->st_name; + info->dli_saddr = DL_SYMBOL_ADDRESS (matchl, matchsym); + } + else { - determine_info (addr, l, info, mapp, symbolp); - result = 1; - goto out; + /* No symbol matches. We return only the containing object. */ + info->dli_sname = NULL; + info->dli_saddr = NULL; } - out: + result = 1; + } + __rtld_lock_unlock_recursive (GL(dl_load_lock)); return result; } libc_hidden_def (_dl_addr) - -/* Return non-zero if ADDR lies within one of L's segments. */ -int -internal_function -_dl_addr_inside_object (struct link_map *l, const ElfW(Addr) addr) -{ - int n = l->l_phnum; - const ElfW(Addr) reladdr = addr - l->l_addr; - - while (--n >= 0) - if (l->l_phdr[n].p_type == PT_LOAD - && reladdr - l->l_phdr[n].p_vaddr >= 0 - && reladdr - l->l_phdr[n].p_vaddr < l->l_phdr[n].p_memsz) - return 1; - return 0; -} |