From 37126fe7bdc305799c313783b495a3852bed5dba Mon Sep 17 00:00:00 2001
From: Vitaly Buka <vitalybuka@google.com>
Date: Fri, 10 Nov 2017 02:06:59 +0000
Subject: [msan] Deadly signal handler for msan

Summary: Part of https://github.com/google/sanitizers/issues/637

Reviewers: eugenis, alekseyshl

Subscribers: llvm-commits, kubamracek

Differential Revision: https://reviews.llvm.org/D39826

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@317864 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/msan/msan.cc              | 11 +++++++++++
 lib/msan/msan_interceptors.cc | 29 +++++++++++++++--------------
 2 files changed, 26 insertions(+), 14 deletions(-)

(limited to 'lib/msan')

diff --git a/lib/msan/msan.cc b/lib/msan/msan.cc
index 3f85a9a66..e6226ba76 100644
--- a/lib/msan/msan.cc
+++ b/lib/msan/msan.cc
@@ -369,6 +369,16 @@ void __msan_warning_noreturn() {
   Die();
 }
 
+static void OnStackUnwind(const SignalContext &sig, const void *,
+                          BufferedStackTrace *stack) {
+  GetStackTrace(stack, kStackTraceMax, sig.pc, sig.bp, sig.context,
+                common_flags()->fast_unwind_on_fatal);
+}
+
+static void MsanOnDeadlySignal(int signo, void *siginfo, void *context) {
+  HandleDeadlySignal(siginfo, context, GetTid(), &OnStackUnwind, nullptr);
+}
+
 void __msan_init() {
   CHECK(!msan_init_is_running);
   if (msan_inited) return;
@@ -384,6 +394,7 @@ void __msan_init() {
   __sanitizer_set_report_path(common_flags()->log_path);
 
   InitializeInterceptors();
+  InstallDeadlySignalHandlers(MsanOnDeadlySignal);
   InstallAtExitHandler(); // Needs __cxa_atexit interceptor.
 
   DisableCoreDumperIfNecessary();
diff --git a/lib/msan/msan_interceptors.cc b/lib/msan/msan_interceptors.cc
index feae876fd..f5822db28 100644
--- a/lib/msan/msan_interceptors.cc
+++ b/lib/msan/msan_interceptors.cc
@@ -1006,20 +1006,6 @@ static void read_sigaction(const __sanitizer_sigaction *act) {
   CHECK_UNPOISONED(&act->sa_mask, sizeof(act->sa_mask));
 }
 
-static int sigaction_impl(int signo, const __sanitizer_sigaction *act,
-                          __sanitizer_sigaction *oldact);
-static uptr signal_impl(int signo, uptr cb);
-
-INTERCEPTOR(int, sigaction, int signo, const __sanitizer_sigaction *act,
-            __sanitizer_sigaction *oldact) {
-  return sigaction_impl(signo, act, oldact);
-}
-
-INTERCEPTOR(int, signal, int signo, uptr cb) {
-  cb = signal_impl(signo, cb);
-  return REAL(signal)(signo, cb);
-}
-
 extern "C" int pthread_attr_init(void *attr);
 extern "C" int pthread_attr_destroy(void *attr);
 
@@ -1275,6 +1261,20 @@ int OnExit() {
 #include "sanitizer_common/sanitizer_platform_interceptors.h"
 #include "sanitizer_common/sanitizer_common_interceptors.inc"
 
+static uptr signal_impl(int signo, uptr cb);
+static int sigaction_impl(int signo, const __sanitizer_sigaction *act,
+                          __sanitizer_sigaction *oldact);
+
+#define SIGNAL_INTERCEPTOR_SIGACTION_IMPL(signo, act, oldact) \
+  { return sigaction_impl(signo, act, oldact); }
+
+#define SIGNAL_INTERCEPTOR_SIGNAL_IMPL(func, signo, handler) \
+  {                                                          \
+    handler = signal_impl(signo, handler);                   \
+    return REAL(func)(signo, handler);                       \
+  }
+
+#include "sanitizer_common/sanitizer_signal_interceptors.inc"
 
 static int sigaction_impl(int signo, const __sanitizer_sigaction *act,
                           __sanitizer_sigaction *oldact) {
@@ -1490,6 +1490,7 @@ void InitializeInterceptors() {
   static int inited = 0;
   CHECK_EQ(inited, 0);
   InitializeCommonInterceptors();
+  InitializeSignalInterceptors();
 
   INTERCEPT_FUNCTION(mmap);
   MSAN_MAYBE_INTERCEPT_MMAP64;
-- 
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