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";
diff --git a/runtime/fault_handler.h b/runtime/fault_handler.h
index 8b66a6f..adac4c2 100644
--- a/runtime/fault_handler.h
+++ b/runtime/fault_handler.h
@@ -45,6 +45,7 @@
// Unclaim signals and delete registered handlers.
void Shutdown();
+ void EnsureArtActionInFrontOfSignalChain();
void HandleFault(int sig, siginfo_t* info, void* context);
void HandleNestedSignal(int sig, siginfo_t* info, void* context);
@@ -128,7 +129,6 @@
DISALLOW_COPY_AND_ASSIGN(JavaStackTraceHandler);
};
-
// Statically allocated so the the signal handler can Get access to it.
extern FaultManager fault_manager;
diff --git a/runtime/java_vm_ext.cc b/runtime/java_vm_ext.cc
index 1444d97..fed8bf0 100644
--- a/runtime/java_vm_ext.cc
+++ b/runtime/java_vm_ext.cc
@@ -21,6 +21,7 @@
#include "base/mutex.h"
#include "base/stl_util.h"
#include "check_jni.h"
+#include "fault_handler.h"
#include "indirect_reference_table-inl.h"
#include "mirror/art_method.h"
#include "mirror/class-inl.h"
@@ -688,6 +689,10 @@
JNI_OnLoadFn jni_on_load = reinterpret_cast<JNI_OnLoadFn>(sym);
int version = (*jni_on_load)(this, nullptr);
+ if (runtime_->GetTargetSdkVersion() != 0 && runtime_->GetTargetSdkVersion() <= 21) {
+ fault_manager.EnsureArtActionInFrontOfSignalChain();
+ }
+
self->SetClassLoaderOverride(old_class_loader.get());
if (version == JNI_ERR) {
diff --git a/runtime/jni_internal.cc b/runtime/jni_internal.cc
index dea3014..361ab8d 100644
--- a/runtime/jni_internal.cc
+++ b/runtime/jni_internal.cc
@@ -30,6 +30,7 @@
#include "base/stl_util.h"
#include "class_linker-inl.h"
#include "dex_file-inl.h"
+#include "fault_handler.h"
#include "gc_root.h"
#include "gc/accounting/card_table-inl.h"
#include "indirect_reference_table-inl.h"