diff options
Diffstat (limited to 'elf/dl-addr.c')
| -rw-r--r-- | elf/dl-addr.c | 122 |
1 files changed, 67 insertions, 55 deletions
diff --git a/elf/dl-addr.c b/elf/dl-addr.c index 0b8328bf4d..ae97398bad 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) 1996-2000,2001,2002,2003 Free Software Foundation, Inc. + Copyright (C) 1996-2003, 2004 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 @@ -33,6 +33,9 @@ _dl_addr (const void *address, Dl_info *info, const char *strtab; ElfW(Word) strtabsize; + /* Protect against concurrent loads and unloads. */ + __rtld_lock_lock_recursive (GL(dl_load_lock)); + /* Find the highest-addressed object that ADDRESS is not below. */ match = NULL; for (l = GL(dl_loaded); l; l = l->l_next) @@ -56,62 +59,71 @@ _dl_addr (const void *address, Dl_info *info, break; } - if (match == NULL) - return 0; - - /* 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 (l->l_name[0], 'a') == '\0' - && l->l_type == lt_executable) - info->dli_fname = _dl_argv[0]; - - symtab = (const void *) D_PTR (match, l_info[DT_SYMTAB]); - strtab = (const void *) D_PTR (match, l_info[DT_STRTAB]); - - strtabsize = match->l_info[DT_STRSZ]->d_un.d_val; - - 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; - - /* We assume that the string table follows the symbol table, because - there is no way in ELF to know the size of the dynamic symbol table!! */ - for (matchsym = NULL; (void *) symtab < (void *) symtabend; ++symtab) - if (addr >= match->l_addr + symtab->st_value - && ((symtab->st_size == 0 && addr == match->l_addr + symtab->st_value) - || addr < match->l_addr + symtab->st_value + symtab->st_size) - && symtab->st_name < strtabsize - && (matchsym == NULL || matchsym->st_value < symtab->st_value) - && (ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL - || ELFW(ST_BIND) (symtab->st_info) == STB_WEAK)) - matchsym = (ElfW(Sym) *) symtab; - - if (mapp) - *mapp = match; - if (symbolp) - *symbolp = matchsym; - - if (matchsym) - { - /* We found a symbol close by. Fill in its name and exact address. */ - info->dli_sname = strtab + matchsym->st_name; - info->dli_saddr = (void *) (match->l_addr + matchsym->st_value); - } - else + int result = 0; + if (match != NULL) { - /* No symbol matches. We return only the containing object. */ - info->dli_sname = NULL; - info->dli_saddr = NULL; + /* 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 (l->l_name[0], 'a') == '\0' + && l->l_type == lt_executable) + info->dli_fname = _dl_argv[0]; + + symtab = (const void *) D_PTR (match, l_info[DT_SYMTAB]); + strtab = (const void *) D_PTR (match, l_info[DT_STRTAB]); + + strtabsize = match->l_info[DT_STRSZ]->d_un.d_val; + + 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; + + /* We assume that the string table follows the symbol table, + because there is no way in ELF to know the size of the + dynamic symbol table!! */ + for (matchsym = NULL; (void *) symtab < (void *) symtabend; ++symtab) + if (addr >= match->l_addr + symtab->st_value + && ((symtab->st_size == 0 + && addr == match->l_addr + symtab->st_value) + || addr < match->l_addr + symtab->st_value + symtab->st_size) + && symtab->st_name < strtabsize + && (matchsym == NULL || matchsym->st_value < symtab->st_value) + && (ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL + || ELFW(ST_BIND) (symtab->st_info) == STB_WEAK)) + matchsym = (ElfW(Sym) *) symtab; + + if (mapp) + *mapp = match; + if (symbolp) + *symbolp = matchsym; + + if (matchsym) + { + /* We found a symbol close by. Fill in its name and exact + address. */ + info->dli_sname = strtab + matchsym->st_name; + info->dli_saddr = (void *) (match->l_addr + matchsym->st_value); + } + else + { + /* No symbol matches. We return only the containing object. */ + info->dli_sname = NULL; + info->dli_saddr = NULL; + } + + result = 1; } - return 1; + __rtld_lock_unlock_recursive (GL(dl_load_lock)); + + return result; } libc_hidden_def (_dl_addr) |