dwarf_getlocation crash on NULL attribute.

A recent change added code in front of the attr_ok check.  This
breaks existing code that assumes it can pass NULL to the ATTR
parameter.  Move the attr_ok check back to the front.

diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 9f87652..0cc9769 100644 (file)
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,8 @@
+2010-05-28  Ulrich Drepper  <drepper@redhat.com>
+
+       * dwarf_getlocation.c (dwarf_getlocation): Move attr_ok call back to
+       the front.
+
 2010-05-27  Roland McGrath  <roland@redhat.com>
 
        * dwarf.h: Add DW_AT_enum_class, DW_AT_linkage_name,
@@ -1329,4 +1334,4 @@
 
 2003-08-11  Ulrich Drepper  <drepper@redhat.com>
 
-        * Moved to CVS archive.
+       * Moved to CVS archive.

diff --git a/libdw/dwarf_getlocation.c b/libdw/dwarf_getlocation.c
index ede8c3c..c89488b 100644 (file)
--- a/libdw/dwarf_getlocation.c
+++ b/libdw/dwarf_getlocation.c
@@ -541,13 +541,13 @@ dwarf_getlocation (attr, llbuf, listlen)
      Dwarf_Op **llbuf;
      size_t *listlen;
 {
+  if (! attr_ok (attr))
+    return -1;
+
   int result = check_constant_offset (attr, llbuf, listlen);
   if (result != 1)
     return result;
 
-  if (! attr_ok (attr))
-    return -1;
-
   /* If it has a block form, it's a single location expression.  */
   Dwarf_Block block;
   if (INTUSE(dwarf_formblock) (attr, &block) != 0)