From: Mark Wielaard <mark@klomp.org>
Date: Fri, 8 Jun 2018 18:14:58 +0000 (+0200)
Subject: libdw: dwarf_get_units should handle existing failure to open Dwarf.
X-Git-Tag: elfutils-0.172~7
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b958e6b0fbe6aa246bbbbdec34487476b01d1f2e;p=thirdparty%2Felfutils.git

libdw: dwarf_get_units should handle existing failure to open Dwarf.

The other dwarf unit/cu iterators handle a NULL Dwarf handle as an
existing error and return NULL. Don't crash.

Signed-off-by: Mark Wielaard <mark@klomp.org>
---

diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 23e11b9de..21cb03c24 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,8 @@
+2018-06-08  Mark Wielaard  <mark@klomp.org>
+
+	* dwarf_get_units.c (dwarf_get_units): Handle existing error, no
+	dwarf.
+
 2018-06-08  Mark Wielaard  <mark@klomp.org>
 
 	* dwarf_getlocation.c (store_implicit_value): Return error when
diff --git a/libdw/dwarf_get_units.c b/libdw/dwarf_get_units.c
index aece17ef4..6215bf4bb 100644
--- a/libdw/dwarf_get_units.c
+++ b/libdw/dwarf_get_units.c
@@ -40,6 +40,10 @@ dwarf_get_units (Dwarf *dwarf, Dwarf_CU *cu, Dwarf_CU **next_cu,
 		 Dwarf_Half *version, uint8_t *unit_type,
 		 Dwarf_Die *cudie, Dwarf_Die *subdie)
 {
+  /* Handle existing error.  */
+  if (dwarf == NULL)
+    return -1;
+
   Dwarf_Off off;
   bool v4type;
   if (cu == NULL)