5 files changed, 15 insertions, 9 deletions
diff --git a/lib/asan/asan_posix.cc b/lib/asan/asan_posix.cc
index 8acadd751..05892475d 100644
--- a/lib/asan/asan_posix.cc
+++ b/lib/asan/asan_posix.cc
@@ -37,7 +37,7 @@ void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
   ScopedDeadlySignal signal_scope(GetCurrentThread());
   StartReportDeadlySignal();
   SignalContext sig(siginfo, context);
-  if (IsStackOverflow(sig))
+  if (sig.IsStackOverflow())
     ReportStackOverflow(sig);
   else
     ReportDeadlySignal(sig);
diff --git a/lib/sanitizer_common/sanitizer_common.h b/lib/sanitizer_common/sanitizer_common.h
index 51c1f3575..988acb794 100644
--- a/lib/sanitizer_common/sanitizer_common.h
+++ b/lib/sanitizer_common/sanitizer_common.h
@@ -311,7 +311,6 @@ HandleSignalMode GetHandleSignalMode(int signum);
 void InstallDeadlySignalHandlers(SignalHandlerType handler);
 // Signal reporting.
 void StartReportDeadlySignal();
-bool IsStackOverflow(const SignalContext &sig);
 // FIXME: Hide after moving more signal handling code into common.
 void MaybeReportNonExecRegion(uptr pc);
 void MaybeDumpInstructionBytes(uptr pc);
@@ -827,6 +826,9 @@ struct SignalContext {
   // String description of the signal.
   const char *Describe() const;
 
+  // Returns true if signal is stack overflow.
+  bool IsStackOverflow() const;
+
  private:
   // Platform specific initialization.
   void InitPcSpBp();
diff --git a/lib/sanitizer_common/sanitizer_fuchsia.cc b/lib/sanitizer_common/sanitizer_fuchsia.cc
index 07190f150..4619f6f7c 100644
--- a/lib/sanitizer_common/sanitizer_fuchsia.cc
+++ b/lib/sanitizer_common/sanitizer_fuchsia.cc
@@ -97,6 +97,7 @@ void InitTlsSize() {}
 
 void PrintModuleMap() {}
 
+bool SignalContext::IsStackOverflow() const { return false; }
 void SignalContext::DumpAllRegisters(void *context) { UNIMPLEMENTED(); }
 const char *SignalContext::Describe() const { UNIMPLEMENTED(); }
 
diff --git a/lib/sanitizer_common/sanitizer_posix_libcdep.cc b/lib/sanitizer_common/sanitizer_posix_libcdep.cc
index e49101a7b..b4d0ce5bf 100644
--- a/lib/sanitizer_common/sanitizer_posix_libcdep.cc
+++ b/lib/sanitizer_common/sanitizer_posix_libcdep.cc
@@ -215,7 +215,7 @@ void InstallDeadlySignalHandlers(SignalHandlerType handler) {
   MaybeInstallSigaction(SIGILL, handler);
 }
 
-bool IsStackOverflow(const SignalContext &sig) {
+bool SignalContext::IsStackOverflow() const {
   // Access at a reasonable offset above SP, or slightly below it (to account
   // for x86_64 or PowerPC redzone, ARM push of multiple registers, etc) is
   // probably a stack overflow.
@@ -223,10 +223,9 @@ bool IsStackOverflow(const SignalContext &sig) {
   // On s390, the fault address in siginfo points to start of the page, not
   // to the precise word that was accessed.  Mask off the low bits of sp to
   // take it into account.
-  bool IsStackAccess =
-      sig.addr >= (sig.sp & ~0xFFF) && sig.addr < sig.sp + 0xFFFF;
+  bool IsStackAccess = sig.addr >= (sig.sp & ~0xFFF) && sig.addr < sp + 0xFFFF;
 #else
-  bool IsStackAccess = sig.addr + 512 > sig.sp && sig.addr < sig.sp + 0xFFFF;
+  bool IsStackAccess = addr + 512 > sp && addr < sp + 0xFFFF;
 #endif
 
 #if __powerpc__
@@ -236,8 +235,8 @@ bool IsStackOverflow(const SignalContext &sig) {
   // If the store faults then sp will not have been updated, so test above
   // will not work, because the fault address will be more than just "slightly"
   // below sp.
-  if (!IsStackAccess && IsAccessibleMemoryRange(sig.pc, 4)) {
-    u32 inst = *(unsigned *)sig.pc;
+  if (!IsStackAccess && IsAccessibleMemoryRange(pc, 4)) {
+    u32 inst = *(unsigned *)pc;
     u32 ra = (inst >> 16) & 0x1F;
     u32 opcd = inst >> 26;
     u32 xo = (inst >> 1) & 0x3FF;
@@ -257,7 +256,7 @@ bool IsStackOverflow(const SignalContext &sig) {
   // We also check si_code to filter out SEGV caused by something else other
   // then hitting the guard page or unmapped memory, like, for example,
   // unaligned memory access.
-  auto si = static_cast<const siginfo_t *>(sig.siginfo);
+  auto si = static_cast<const siginfo_t *>(siginfo);
   return IsStackAccess &&
          (si->si_code == si_SEGV_MAPERR || si->si_code == si_SEGV_ACCERR);
 }
diff --git a/lib/sanitizer_common/sanitizer_win.cc b/lib/sanitizer_common/sanitizer_win.cc
index ff3d4b94b..4d68f5610 100644
--- a/lib/sanitizer_common/sanitizer_win.cc
+++ b/lib/sanitizer_common/sanitizer_win.cc
@@ -915,6 +915,10 @@ bool IsAccessibleMemoryRange(uptr beg, uptr size) {
   return true;
 }
 
+bool SignalContext::IsStackOverflow() const {
+  return GetType() == EXCEPTION_STACK_OVERFLOW;
+}
+
 void SignalContext::InitPcSpBp() {
   EXCEPTION_RECORD *exception_record = (EXCEPTION_RECORD *)siginfo;
   CONTEXT *context_record = (CONTEXT *)context;