v8/test/unittests/wasm/trap-handler-unittest.cc
Eric Holk ee4fe8963c [wasm] trap handlers: fall back on old signal handler
This is primarily needed to test D8 under ASan. ASan installs a signal handler
early in the process startup to show stack traces from crashes. We need to make
sure that if V8 does not handle a signal then the existing handler gets a
chance.

This change only applies when using V8's default signal handler. When
integrating with the embedder's signal handler the behavior is unchanged.

Bug: chromium:771948
Change-Id: Ifd560acf9700ec5f714f009530258fa92c83cabe
Reviewed-on: https://chromium-review.googlesource.com/705823
Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Commit-Queue: Eric Holk <eholk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48429}
2017-10-10 18:03:12 +00:00

69 lines
1.9 KiB
C++

// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/trap-handler/trap-handler.h"
#include "include/v8.h"
#include "testing/gtest/include/gtest/gtest.h"
#if V8_OS_POSIX
#include <setjmp.h>
#include <signal.h>
#endif
namespace {
void CrashOnPurpose() { *reinterpret_cast<volatile int*>(42); }
#if V8_OS_POSIX
// When using V8::RegisterDefaultSignalHandler, we save the old one to fall back
// on if V8 doesn't handle the signal. This allows tools like ASan to register a
// handler early on during the process startup and still generate stack traces
// on failures.
class SignalHandlerFallbackTest : public ::testing::Test {
protected:
virtual void SetUp() {
struct sigaction action;
action.sa_sigaction = SignalHandler;
sigemptyset(&action.sa_mask);
action.sa_flags = SA_SIGINFO;
sigaction(SIGSEGV, &action, &old_segv_action_);
sigaction(SIGBUS, &action, &old_bus_action_);
}
virtual void TearDown() {
// be a good citizen and restore the old signal handler.
sigaction(SIGSEGV, &old_segv_action_, nullptr);
sigaction(SIGBUS, &old_bus_action_, nullptr);
}
static sigjmp_buf continuation_;
private:
static void SignalHandler(int signal, siginfo_t* info, void*) {
siglongjmp(continuation_, 1);
}
struct sigaction old_segv_action_;
struct sigaction old_bus_action_; // We get SIGBUS on Mac sometimes.
};
sigjmp_buf SignalHandlerFallbackTest::continuation_;
TEST_F(SignalHandlerFallbackTest, DoTest) {
const int save_sigs = 1;
if (!sigsetjmp(continuation_, save_sigs)) {
v8::V8::RegisterDefaultSignalHandler();
CrashOnPurpose();
FAIL();
} else {
// Our signal handler ran.
v8::internal::trap_handler::RestoreOriginalSignalHandler();
SUCCEED();
return;
}
FAIL();
}
#endif
} // namespace