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-rw-r--r--elf/dl-addr.c85
1 files changed, 85 insertions, 0 deletions
diff --git a/elf/dl-addr.c b/elf/dl-addr.c
new file mode 100644
index 0000000..d50cc4b
--- /dev/null
+++ b/elf/dl-addr.c
@@ -0,0 +1,85 @@
+/* Locate the shared object symbol nearest a given address.
+ Copyright (C) 1996, 1997 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., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include <stddef.h>
+#include <link.h>
+#include <dlfcn.h>
+
+
+int
+_dl_addr (const void *address, Dl_info *info)
+{
+ 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)
+ {
+ /* 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 &&
+ ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL ||
+ ELFW(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;
+}