From: Mark Wielaard <mark@klomp.org>
Date: Tue, 12 Jun 2018 10:18:31 +0000 (+0200)
Subject: libdw: Make __libdw_dieabbrev more robust on failure.
X-Git-Tag: elfutils-0.173~18
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=29a3395004643c4e412a47cec5de10f63c23f13c;p=thirdparty%2Felfutils.git

libdw: Make __libdw_dieabbrev more robust on failure.

Make sure to always set die->abbrev to DWARF_END_ABBREV on failure.
DWARF_END_ABBREV is also what the function reports on failure. And it
will prevent trying to lookup the abbrev ever again.

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

diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 07a1346b3..783216540 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,8 @@
+2018-06-12  Mark Wielaard  <mark@klomp.org>
+
+	* libdw.h (__libdw_dieabbrev): Set die->abbrev to DWARF_END_ABBREV
+	on failure.
+
 2018-06-10  Mark Wielaard  <mark@klomp.org>
 
 	* dwarf_attr_integrate.c (dwarf_attr_integrate): Stop after 16 DIE
diff --git a/libdw/libdwP.h b/libdw/libdwP.h
index 3d8e145a9..eebb7d126 100644
--- a/libdw/libdwP.h
+++ b/libdw/libdwP.h
@@ -653,8 +653,9 @@ __libdw_dieabbrev (Dwarf_Die *die, const unsigned char **readp)
       /* Get the abbreviation code.  */
       unsigned int code;
       const unsigned char *addr = die->addr;
-      if (die->cu == NULL || addr >= (const unsigned char *) die->cu->endp)
-	return DWARF_END_ABBREV;
+      if (unlikely (die->cu == NULL
+		    || addr >= (const unsigned char *) die->cu->endp))
+	return die->abbrev = DWARF_END_ABBREV;
       get_uleb128 (code, addr, die->cu->endp);
       if (readp != NULL)
 	*readp = addr;