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;
+}