Prevent crashes if a map cannot be created.
Under some conditions, /proc/<pid>/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
diff --git a/libbacktrace/BacktraceCurrent.cpp b/libbacktrace/BacktraceCurrent.cpp
index 14f04de..95cd4d1 100644
--- a/libbacktrace/BacktraceCurrent.cpp
+++ b/libbacktrace/BacktraceCurrent.cpp
@@ -65,6 +65,11 @@
}
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);
}