[compiler-rt] r305871 - Revert "[compiler-rt] Don't reset non-default user handler if allow_user_segv_handler is true."

[Vitaly Buka via llvm-commits]

Author: vitalybuka
Date: Tue Jun 20 20:10:23 2017
New Revision: 305871

URL: http://llvm.org/viewvc/llvm-project?rev=305871&view=rev
Log:
Revert "[compiler-rt] Don't reset non-default user handler if allow_user_segv_handler is true."

Summary:
On Android we still need to reset preinstalled handlers and allow use handlers later.

This reverts commit r304039.

Reviewers: eugenis

Subscribers: kubamracek, dberris, llvm-commits

Differential Revision: https://reviews.llvm.org/D34434

Modified:
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix_libcdep.cc
    compiler-rt/trunk/test/asan/TestCases/Linux/preinstalled_signal.cc

Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix_libcdep.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix_libcdep.cc?rev=305871&r1=305870&r2=305871&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix_libcdep.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix_libcdep.cc Tue Jun 20 20:10:23 2017
@@ -189,25 +189,7 @@ void UnsetAlternateSignalStack() {
 
 static void MaybeInstallSigaction(int signum,
                                   SignalHandlerType handler) {
-  switch (GetHandleSignalMode(signum)) {
-    case kHandleSignalNo:
-      return;
-    case kHandleSignalYes: {
-      struct sigaction sigact;
-      internal_memset(&sigact, 0, sizeof(sigact));
-      CHECK_EQ(0, internal_sigaction(signum, nullptr, &sigact));
-      if (sigact.sa_flags & SA_SIGINFO) {
-        if (sigact.sa_sigaction) return;
-      } else {
-        if (sigact.sa_handler != SIG_DFL && sigact.sa_handler != SIG_IGN &&
-            sigact.sa_handler != SIG_ERR)
-          return;
-      }
-      break;
-    }
-    case kHandleSignalExclusive:
-      break;
-  }
+  if (GetHandleSignalMode(signum) == kHandleSignalNo) return;
 
   struct sigaction sigact;
   internal_memset(&sigact, 0, sizeof(sigact));

Modified: compiler-rt/trunk/test/asan/TestCases/Linux/preinstalled_signal.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/asan/TestCases/Linux/preinstalled_signal.cc?rev=305871&r1=305870&r2=305871&view=diff
==============================================================================
--- compiler-rt/trunk/test/asan/TestCases/Linux/preinstalled_signal.cc (original)
+++ compiler-rt/trunk/test/asan/TestCases/Linux/preinstalled_signal.cc Tue Jun 20 20:10:23 2017
@@ -4,11 +4,13 @@
 // RUN: env LD_PRELOAD=%shared_libasan %env_asan_opts=handle_segv=2 not %run %t 2>&1 | FileCheck %s
 
 // RUN: %clangxx -std=c++11 -DTEST_INSTALL_SIG_HANDLER %s -o %t
-// RUN: env LD_PRELOAD=%shared_libasan %env_asan_opts=handle_segv=1 not %run %t 2>&1 | FileCheck --check-prefix=CHECK-HANDLER %s
+// RUN: env LD_PRELOAD=%shared_libasan %env_asan_opts=handle_segv=0 not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-HANDLER
+// RUN: env LD_PRELOAD=%shared_libasan %env_asan_opts=handle_segv=1 not %run %t 2>&1 | FileCheck %s
 // RUN: env LD_PRELOAD=%shared_libasan %env_asan_opts=handle_segv=2 not %run %t 2>&1 | FileCheck %s
 
 // RUN: %clangxx -std=c++11 -DTEST_INSTALL_SIG_ACTION %s -o %t
-// RUN: env LD_PRELOAD=%shared_libasan %env_asan_opts=handle_segv=1 not %run %t 2>&1 | FileCheck --check-prefix=CHECK-ACTION %s
+// RUN: env LD_PRELOAD=%shared_libasan %env_asan_opts=handle_segv=0 not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-ACTION
+// RUN: env LD_PRELOAD=%shared_libasan %env_asan_opts=handle_segv=1 not %run %t 2>&1 | FileCheck %s
 // RUN: env LD_PRELOAD=%shared_libasan %env_asan_opts=handle_segv=2 not %run %t 2>&1 | FileCheck %s
 
 // REQUIRES: asan-dynamic-runtime
@@ -51,22 +53,22 @@ int InternalSigaction(int sig, KernelSig
   return syscall(__NR_rt_sigaction, sig, act, oact, NSIG / 8);
 }
 
-struct KernelSigaction sigact = {};
+struct KernelSigaction pre_asan = {};
 
 static void Init() {
-  int res = InternalSigaction(SIGSEGV, nullptr, &sigact);
+  int res = InternalSigaction(SIGSEGV, nullptr, &pre_asan);
   assert(res >= 0);
-  assert(sigact.handler == SIG_DFL || sigact.handler == SIG_IGN);
+  assert(pre_asan.handler == SIG_DFL || pre_asan.handler == SIG_IGN);
 #if defined(TEST_INSTALL_SIG_HANDLER)
-  sigact = {};
-  sigact.handler = &SigHandler;
-  res = InternalSigaction(SIGSEGV, &sigact, nullptr);
+  pre_asan = {};
+  pre_asan.handler = &SigHandler;
+  res = InternalSigaction(SIGSEGV, &pre_asan, nullptr);
   assert(res >= 0);
 #elif defined(TEST_INSTALL_SIG_ACTION)
-  sigact = {};
-  sigact.flags = SA_SIGINFO | SA_NODEFER;
-  sigact.handler = (__sighandler_t)&SigAction;
-  res = InternalSigaction(SIGSEGV, &sigact, nullptr);
+  pre_asan = {};
+  pre_asan.flags = SA_SIGINFO | SA_NODEFER;
+  pre_asan.handler = (__sighandler_t)&SigAction;
+  res = InternalSigaction(SIGSEGV, &pre_asan, nullptr);
   assert(res >= 0);
 #endif
 }
@@ -74,21 +76,21 @@ static void Init() {
 __attribute__((section(".preinit_array"), used))
 void (*__local_test_preinit)(void) = Init;
 
-bool ShouldAsanInstallHandlers() {
+bool ExpectUserHandler() {
 #if defined(TEST_INSTALL_SIG_HANDLER) || defined(TEST_INSTALL_SIG_ACTION)
-  return !strcmp(getenv("ASAN_OPTIONS"), "handle_segv=2");
+  return !strcmp(getenv("ASAN_OPTIONS"), "handle_segv=0");
 #endif
-  return true;
+  return false;
 }
 
 int main(int argc, char *argv[]) {
-  KernelSigaction sigact_asan = {};
-  InternalSigaction(SIGSEGV, nullptr, &sigact_asan);
+  KernelSigaction post_asan = {};
+  InternalSigaction(SIGSEGV, nullptr, &post_asan);
 
-  assert(sigact_asan.handler != SIG_DFL);
-  assert(sigact_asan.handler != SIG_IGN);
-  assert(ShouldAsanInstallHandlers() ==
-         (sigact_asan.handler != sigact.handler));
+  assert(post_asan.handler != SIG_DFL);
+  assert(post_asan.handler != SIG_IGN);
+  assert(ExpectUserHandler() ==
+         (post_asan.handler == pre_asan.handler));
 
   raise(SIGSEGV);
   printf("%s\n", handler);