Merge "ART: Pass ucontext to Backtrace in Stack Dump"

3 files changed, 12 insertions, 5 deletions

diff --git a/runtime/runtime_linux.cc b/runtime/runtime_linux.cc
index 1de035c..a5a0204 100644
--- a/runtime/runtime_linux.cc
+++ b/runtime/runtime_linux.cc
@@ -35,9 +35,16 @@ namespace art {
 static constexpr bool kDumpHeapObjectOnSigsevg = false;
 
 struct Backtrace {
+ public:
+  explicit Backtrace(void* raw_context) : raw_context_(raw_context) {}
   void Dump(std::ostream& os) const {
-    DumpNativeStack(os, GetTid(), "\t");
+    DumpNativeStack(os, GetTid(), "\t", nullptr, raw_context_);
   }
+ private:
+  // Stores the context of the signal that was unexpected and will terminate the runtime. The
+  // DumpNativeStack code will take care of casting it to the expected type. This is required
+  // as our signal handler runs on an alternate stack.
+  void* raw_context_;
 };
 
 struct OsInfo {
@@ -298,7 +305,7 @@ void HandleUnexpectedSignal(int signal_number, siginfo_t* info, void* raw_contex
   pid_t tid = GetTid();
   std::string thread_name(GetThreadName(tid));
   UContext thread_context(raw_context);
-  Backtrace thread_backtrace;
+  Backtrace thread_backtrace(raw_context);
 
   LOG(INTERNAL_FATAL) << "*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***\n"
                       << StringPrintf("Fatal signal %d (%s), code %d (%s)",
diff --git a/runtime/utils.cc b/runtime/utils.cc
index 1211547..7234ec0 100644
--- a/runtime/utils.cc
+++ b/runtime/utils.cc
@@ -1118,7 +1118,7 @@ std::string GetSchedulerGroupName(pid_t tid) {
 }
 
 void DumpNativeStack(std::ostream& os, pid_t tid, const char* prefix,
-    mirror::ArtMethod* current_method) {
+    mirror::ArtMethod* current_method, void* ucontext_ptr) {
 #if __linux__
   // b/18119146
   if (RUNNING_ON_VALGRIND != 0) {
@@ -1134,7 +1134,7 @@ void DumpNativeStack(std::ostream& os, pid_t tid, const char* prefix,
 #endif
 
   std::unique_ptr<Backtrace> backtrace(Backtrace::Create(BACKTRACE_CURRENT_PROCESS, tid));
-  if (!backtrace->Unwind(0)) {
+  if (!backtrace->Unwind(0, reinterpret_cast<ucontext*>(ucontext_ptr))) {
     os << prefix << "(backtrace::Unwind failed for thread " << tid << ")\n";
     return;
   } else if (backtrace->NumFrames() == 0) {
diff --git a/runtime/utils.h b/runtime/utils.h
index f9622b7..b5413e7 100644
--- a/runtime/utils.h
+++ b/runtime/utils.h
@@ -465,7 +465,7 @@ void SetThreadName(const char* thread_name);
 
 // Dumps the native stack for thread 'tid' to 'os'.
 void DumpNativeStack(std::ostream& os, pid_t tid, const char* prefix = "",
-    mirror::ArtMethod* current_method = nullptr)
+    mirror::ArtMethod* current_method = nullptr, void* ucontext = nullptr)
     NO_THREAD_SAFETY_ANALYSIS;
 
 // Dumps the kernel stack for thread 'tid' to 'os'. Note that this is only available on linux-x86.