From 8466fca2a074323a235ef38d425f994a2ff7e64f Mon Sep 17 00:00:00 2001 From: Victor Kamensky 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 --- 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