From 30c942cf1024bf791c28ab9b67a1f752de72248c Mon Sep 17 00:00:00 2001 From: Christopher Ferris Date: Thu, 14 May 2015 15:39:52 -0700 Subject: Prevent crashes if a map cannot be created. Under some conditions, /proc//maps might return nothing. If we try and unwind in this case, we'll crash. Check this case and fail the unwind. Add checks that no other functions try and use map_ without checking for nullptr. Add logging when an unwind fails so it's clear what happened. Bug: 21162746 Change-Id: I56ce51dda0cfc9db20475a441f118108196aa07c --- libbacktrace/BacktraceCurrent.cpp | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'libbacktrace/BacktraceCurrent.cpp') diff --git a/libbacktrace/BacktraceCurrent.cpp b/libbacktrace/BacktraceCurrent.cpp index 14f04de5e..95cd4d1a6 100644 --- a/libbacktrace/BacktraceCurrent.cpp +++ b/libbacktrace/BacktraceCurrent.cpp @@ -65,6 +65,11 @@ size_t BacktraceCurrent::Read(uintptr_t addr, uint8_t* buffer, size_t bytes) { } bool BacktraceCurrent::Unwind(size_t num_ignore_frames, ucontext_t* ucontext) { + if (GetMap() == nullptr) { + // Without a map object, we can't do anything. + return false; + } + if (ucontext) { return UnwindFromContext(num_ignore_frames, ucontext); } -- cgit v1.2.3