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authorRoland McGrath <roland@gnu.org>1996-06-04 09:29:39 +0000
committerRoland McGrath <roland@gnu.org>1996-06-04 09:29:39 +0000
commita2b934be254cad6c725baf738f0d97df985522c6 (patch)
tree11c9280fa0c9480cb4bf74a0a2d5432493bfafa1 /elf/dladdr.c
parent55f3aaff8c2a31288f9dde795b63b95d04fca341 (diff)
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* stdio-common/vfprintf.c [USE_IN_LIBIO] (size_t): Don't define ascvs/libc-960604
macro. _IO_size_t is just an alias for the real size_t anyway. * elf/Makefile (libdl-routines): Add dladdr. * elf/dladdr.c: New file. * elf/dlfcn.h (Dl_info): New typedef. (dladdr): Declare it.
Diffstat (limited to 'elf/dladdr.c')
-rw-r--r--elf/dladdr.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/elf/dladdr.c b/elf/dladdr.c
new file mode 100644
index 0000000..166952a
--- /dev/null
+++ b/elf/dladdr.c
@@ -0,0 +1,88 @@
+/* dladdr -- Locate the shared object symbol nearest a given address.
+Copyright (C) 1996 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.
+
+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.
+
+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., 675 Mass Ave,
+Cambridge, MA 02139, USA. */
+
+#include <stddef.h>
+#include <link.h>
+#include <dlfcn.h>
+#include <setjmp.h>
+
+
+int
+dladdr (void *address, Dl_info *info)
+{
+ const Elf32_Addr addr = (Elf32_Addr) address;
+ struct link_map *l, *match;
+ const Elf32_Sym *symtab, *matchsym;
+ const char *strtab;
+ Elf32_Word symidx;
+
+ /* 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)
+ {
+ /* 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;
+ }
+ 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;
+
+ 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);
+
+ /* 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 &&
+ ELF32_ST_BIND (symtab->st_info) == STB_GLOBAL ||
+ ELF32_ST_BIND (symtab->st_info) == STB_WEAK)
+ matchsym = symtab;
+
+ 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;
+ }
+
+ return 1;
+}
+