/* Locate the shared object symbol nearest a given address.
- Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+ Copyright (C) 1996-2016 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 Library General Public License as
- published by the Free Software Foundation; either version 2 of the
- License, or (at your option) any later version.
+ 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
- Library General Public License for more details.
+ Lesser General Public License for more details.
- You should have received a copy of the GNU Library General Public
- License along with the GNU C Library; see the file COPYING.LIB. If not,
- write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ 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 <stddef.h>
-#include <link.h>
#include <dlfcn.h>
+#include <stddef.h>
+#include <ldsodefs.h>
-int
-_dl_addr (const void *address, Dl_info *info)
+static inline 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)
{
- const ElfW(Addr) addr = (ElfW(Addr)) address;
- struct link_map *l, *match;
- const ElfW(Sym) *symtab, *matchsym;
- const char *strtab;
-
- /* Find the highest-addressed object that ADDRESS is not below. */
- match = NULL;
- for (l = _dl_loaded; l; l = l->l_next)
- if (addr >= l->l_addr && !match || match->l_addr < l->l_addr)
- match = l;
-
- if (match)
+ /* 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]);
+
+ 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 know ADDRESS lies within MATCH if in any shared object.
- Make sure it isn't past the end of MATCH's segments. */
- size_t n = match->l_phnum;
- do
- --n;
- while (match->l_phdr[n].p_type != PT_LOAD);
- if (addr >= (match->l_addr +
- match->l_phdr[n].p_vaddr + match->l_phdr[n].p_memsz))
- /* Off the end of the highest-addressed shared object. */
- return 0;
+ /* 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
- return 0;
-
- /* Now we know what object the address lies in. */
- info->dli_fname = match->l_name;
- info->dli_fbase = (void *) match->l_addr;
+ {
+ 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;
- symtab = ((void *) match->l_addr + match->l_info[DT_SYMTAB]->d_un.d_ptr);
- strtab = ((void *) match->l_addr + match->l_info[DT_STRTAB]->d_un.d_ptr);
+ 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;
+ }
- /* 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 *) strtab; ++symtab)
- if (addr >= match->l_addr + symtab->st_value && !matchsym ||
- matchsym->st_value < symtab->st_value &&
- ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL ||
- ELFW(ST_BIND) (symtab->st_info) == STB_WEAK)
- matchsym = symtab;
+ if (mapp)
+ *mapp = match;
+ if (symbolp)
+ *symbolp = matchsym;
if (matchsym)
{
- /* We found a symbol close by. Fill in its name and exact address. */
+ /* We found a symbol close by. Fill in its name and exact
+ address. */
+ lookup_t matchl = LOOKUP_VALUE (match);
+
info->dli_sname = strtab + matchsym->st_name;
- info->dli_saddr = (void *) (match->l_addr + matchsym->st_value);
+ info->dli_saddr = DL_SYMBOL_ADDRESS (matchl, matchsym);
}
else
{
info->dli_sname = NULL;
info->dli_saddr = NULL;
}
+}
+
+
+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;
+
+ /* Protect against concurrent loads and unloads. */
+ __rtld_lock_lock_recursive (GL(dl_load_lock));
+
+ struct link_map *l = _dl_find_dso_for_object (addr);
+
+ if (l)
+ {
+ determine_info (addr, l, info, mapp, symbolp);
+ 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;
- return 1;
+ 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;
}
projects / thirdparty / glibc.git / blobdiff