1 files changed, 88 insertions, 0 deletions
diff --git a/elf/dladdr.c b/elf/dladdr.c
new file mode 100644
index 0000000000..166952ac46
--- /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;
+}
+