From 99534e80401c96180c6797ccc4097a7ae12ebbd8 Mon Sep 17 00:00:00 2001
From: Vitaly Buka <vitalybuka@google.com>
Date: Sat, 20 May 2017 01:04:59 +0000
Subject: [PATCH] [compiler-rt] Change default of allow_user_segv_handler to
 true

Reviewers: eugenis

Subscribers: srhines, kubamracek, llvm-commits

Differential Revision: https://reviews.llvm.org/D32443

llvm-svn: 303476
---
 compiler-rt/lib/asan/scripts/asan_device_setup      |  5 -----
 compiler-rt/lib/asan/tests/asan_test.cc             | 21 +++++++++++++--------
 .../lib/sanitizer_common/sanitizer_flags.inc        |  2 +-
 3 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/compiler-rt/lib/asan/scripts/asan_device_setup b/compiler-rt/lib/asan/scripts/asan_device_setup
index fdfc46f..c807df3 100755
--- a/compiler-rt/lib/asan/scripts/asan_device_setup
+++ b/compiler-rt/lib/asan/scripts/asan_device_setup
@@ -327,11 +327,6 @@ exec $_to \$@
 EOF
 }
 
-# On Android-L not allowing user segv handler breaks some applications.
-if [[ PRE_L -eq 0 ]]; then
-    ASAN_OPTIONS="$ASAN_OPTIONS,allow_user_segv_handler=1"
-fi
-
 if [[ x$extra_options != x ]] ; then
     ASAN_OPTIONS="$ASAN_OPTIONS,$extra_options"
 fi
diff --git a/compiler-rt/lib/asan/tests/asan_test.cc b/compiler-rt/lib/asan/tests/asan_test.cc
index 7ac7295..d0128e3 100644
--- a/compiler-rt/lib/asan/tests/asan_test.cc
+++ b/compiler-rt/lib/asan/tests/asan_test.cc
@@ -251,7 +251,8 @@ TEST(AddressSanitizer, BitFieldNegativeTest) {
 namespace {
 
 const char kSEGVCrash[] = "AddressSanitizer: SEGV on unknown address";
-const char kOverriddenHandler[] = "ASan signal handler has been overridden\n";
+const char kOverriddenSigactionHandler[] = "Test sigaction handler\n";
+const char kOverriddenSignalHandler[] = "Test signal handler\n";
 
 TEST(AddressSanitizer, WildAddressTest) {
   char *c = (char*)0x123;
@@ -259,12 +260,12 @@ TEST(AddressSanitizer, WildAddressTest) {
 }
 
 void my_sigaction_sighandler(int, siginfo_t*, void*) {
-  fprintf(stderr, kOverriddenHandler);
+  fprintf(stderr, kOverriddenSigactionHandler);
   exit(1);
 }
 
 void my_signal_sighandler(int signum) {
-  fprintf(stderr, kOverriddenHandler);
+  fprintf(stderr, kOverriddenSignalHandler);
   exit(1);
 }
 
@@ -273,16 +274,20 @@ TEST(AddressSanitizer, SignalTest) {
   memset(&sigact, 0, sizeof(sigact));
   sigact.sa_sigaction = my_sigaction_sighandler;
   sigact.sa_flags = SA_SIGINFO;
-  // ASan should silently ignore sigaction()...
+  char *c = (char *)0x123;
+
+  EXPECT_DEATH(*c = 0, kSEGVCrash);
+
+  // ASan should allow to set sigaction()...
   EXPECT_EQ(0, sigaction(SIGSEGV, &sigact, 0));
 #ifdef __APPLE__
   EXPECT_EQ(0, sigaction(SIGBUS, &sigact, 0));
 #endif
-  char *c = (char*)0x123;
-  EXPECT_DEATH(*c = 0, kSEGVCrash);
+  EXPECT_DEATH(*c = 0, kOverriddenSigactionHandler);
+
   // ... and signal().
-  EXPECT_EQ(0, signal(SIGSEGV, my_signal_sighandler));
-  EXPECT_DEATH(*c = 0, kSEGVCrash);
+  EXPECT_NE(SIG_ERR, signal(SIGSEGV, my_signal_sighandler));
+  EXPECT_DEATH(*c = 0, kOverriddenSignalHandler);
 }
 }  // namespace
 #endif
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_flags.inc b/compiler-rt/lib/sanitizer_common/sanitizer_flags.inc
index c5aaf41..1972bda 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_flags.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_flags.inc
@@ -92,7 +92,7 @@ COMMON_FLAG(HandleSignalMode, handle_sigill, kHandleSignalNo,
 COMMON_FLAG(HandleSignalMode, handle_sigfpe, kHandleSignalYes,
             COMMON_FLAG_HANDLE_SIGNAL_HELP(SIGFPE))
 #undef COMMON_FLAG_HANDLE_SIGNAL_HELP
-COMMON_FLAG(bool, allow_user_segv_handler, false,
+COMMON_FLAG(bool, allow_user_segv_handler, true,
             "If set, allows user to register a SEGV handler even if the tool "
             "registers one.")
 COMMON_FLAG(bool, use_sigaltstack, true,
-- 
2.7.4