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From 8466fca2a074323a235ef38d425f994a2ff7e64f Mon Sep 17 00:00:00 2001
From: Victor Kamensky <kamensky@cisco.com>
Date: Mon, 9 Jul 2018 09:31:19 -0700
Subject: [PATCH] dwflpp::function_entrypc avoid usage of uninitialized memory
Failure on 3.3 release was observed. Failure was elusive and
disappeared after seemingly random configure option change, or when
code was compiled with -O1 or -O0 (vs default -O2). Running failing
test case under valgrind memcheck pointed to couple places where
'Conditional jump or move depends on uninitialised value(s)' occured.
After addressing these in two places in dwflpp::function_entrypc,
valgrind memcheck run is clean and original issue got fixed.
Upstream-Status: Backport
Signed-off-by: Victor Kamensky <kamensky@cisco.com>
---
dwflpp.cxx | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/dwflpp.cxx b/dwflpp.cxx
index bfbb6b096..2172e705a 100644
--- a/dwflpp.cxx
+++ b/dwflpp.cxx
@@ -2465,13 +2465,17 @@ bool
dwflpp::function_entrypc (Dwarf_Addr * addr)
{
assert (function);
+
+ // assign default value
+ *addr = 0;
+
// PR10574: reject 0, which tends to be eliminated COMDAT
if (dwarf_entrypc (function, addr) == 0 && *addr != 0)
return true;
/* Assume the entry pc is the base address, or (if zero)
the first address of the ranges covering this DIE. */
- Dwarf_Addr start, end;
+ Dwarf_Addr start = 0, end;
if (dwarf_ranges (function, 0, addr, &start, &end) >= 0)
{
if (*addr == 0)
--
2.17.1
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