Add way to ensure we are at the front of the sigaction chain
Calling this after jni_on_load fixes the unity apps. This is
not exactly correct since we may already have the following chain.
Start up:
Us -> debuggerd
After app goes in front:
App -> us -> debuggerd
After we put ourself back at the front:
Us -> app -> us -> app -> .... stack overflow.
Bug: 17620677
Change-Id: I9183997e3d5ebd51c320b5d51425be5142e938f3
(cherry picked from commit 1f24296c7c8a6501ee2388c0d20b48f471b48660)
diff --git a/runtime/fault_handler.cc b/runtime/fault_handler.cc
index fede2f8..62e0609 100644
--- a/runtime/fault_handler.cc
+++ b/runtime/fault_handler.cc
@@ -95,16 +95,29 @@
FaultManager::~FaultManager() {
}
+static void SetUpArtAction(struct sigaction* action) {
+ action->sa_sigaction = art_fault_handler;
+ sigemptyset(&action->sa_mask);
+ action->sa_flags = SA_SIGINFO | SA_ONSTACK;
+#if !defined(__APPLE__) && !defined(__mips__)
+ action->sa_restorer = nullptr;
+#endif
+}
+
+void FaultManager::EnsureArtActionInFrontOfSignalChain() {
+ if (initialized_) {
+ struct sigaction action;
+ SetUpArtAction(&action);
+ EnsureFrontOfChain(SIGSEGV, &action);
+ } else {
+ LOG(WARNING) << "Can't call " << __FUNCTION__ << " due to unitialized fault manager";
+ }
+}
void FaultManager::Init() {
CHECK(!initialized_);
struct sigaction action;
- action.sa_sigaction = art_fault_handler;
- sigemptyset(&action.sa_mask);
- action.sa_flags = SA_SIGINFO | SA_ONSTACK;
-#if !defined(__APPLE__) && !defined(__mips__)
- action.sa_restorer = nullptr;
-#endif
+ SetUpArtAction(&action);
// Set our signal handler now.
int e = sigaction(SIGSEGV, &action, &oldaction_);
@@ -138,7 +151,6 @@
//
// If malloc calls abort, it will be holding its lock.
// If the handler tries to call malloc, it will deadlock.
-
VLOG(signals) << "Handling fault";
if (IsInGeneratedCode(info, context, true)) {
VLOG(signals) << "in generated code, looking for handler";