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Diffstat (limited to 'toolkit/crashreporter/google-breakpad/src/client/linux/handler/exception_handler_unittest.cc')
-rw-r--r-- | toolkit/crashreporter/google-breakpad/src/client/linux/handler/exception_handler_unittest.cc | 1179 |
1 files changed, 1179 insertions, 0 deletions
diff --git a/toolkit/crashreporter/google-breakpad/src/client/linux/handler/exception_handler_unittest.cc b/toolkit/crashreporter/google-breakpad/src/client/linux/handler/exception_handler_unittest.cc new file mode 100644 index 000000000..17d84cf7b --- /dev/null +++ b/toolkit/crashreporter/google-breakpad/src/client/linux/handler/exception_handler_unittest.cc @@ -0,0 +1,1179 @@ +// Copyright (c) 2010 Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#include <stdint.h> +#include <unistd.h> +#include <signal.h> +#include <sys/mman.h> +#include <sys/poll.h> +#include <sys/socket.h> +#include <sys/uio.h> +#include <sys/wait.h> +#if defined(__mips__) +#include <sys/cachectl.h> +#endif + +#include <string> + +#include "breakpad_googletest_includes.h" +#include "client/linux/handler/exception_handler.h" +#include "client/linux/minidump_writer/minidump_writer.h" +#include "common/linux/eintr_wrapper.h" +#include "common/linux/ignore_ret.h" +#include "common/linux/linux_libc_support.h" +#include "common/tests/auto_tempdir.h" +#include "common/using_std_string.h" +#include "third_party/lss/linux_syscall_support.h" +#include "google_breakpad/processor/minidump.h" + +using namespace google_breakpad; + +namespace { + +// Flush the instruction cache for a given memory range. +// Only required on ARM and mips. +void FlushInstructionCache(const char* memory, uint32_t memory_size) { +#if defined(__arm__) + long begin = reinterpret_cast<long>(memory); + long end = begin + static_cast<long>(memory_size); +# if defined(__ANDROID__) + // Provided by Android's <unistd.h> + cacheflush(begin, end, 0); +# elif defined(__linux__) + // GLibc/ARM doesn't provide a wrapper for it, do a direct syscall. +# ifndef __ARM_NR_cacheflush +# define __ARM_NR_cacheflush 0xf0002 +# endif + syscall(__ARM_NR_cacheflush, begin, end, 0); +# else +# error "Your operating system is not supported yet" +# endif +#elif defined(__mips__) +# if defined(__ANDROID__) + // Provided by Android's <unistd.h> + long begin = reinterpret_cast<long>(memory); + long end = begin + static_cast<long>(memory_size); +#if _MIPS_SIM == _ABIO32 + cacheflush(begin, end, 0); +#else + syscall(__NR_cacheflush, begin, end, ICACHE); +#endif +# elif defined(__linux__) + // See http://www.linux-mips.org/wiki/Cacheflush_Syscall. + cacheflush(const_cast<char*>(memory), memory_size, ICACHE); +# else +# error "Your operating system is not supported yet" +# endif +#endif +} + +void sigchld_handler(int signo) { } + +int CreateTMPFile(const string& dir, string* path) { + string file = dir + "/exception-handler-unittest.XXXXXX"; + const char* c_file = file.c_str(); + // Copy that string, mkstemp needs a C string it can modify. + char* c_path = strdup(c_file); + const int fd = mkstemp(c_path); + if (fd >= 0) + *path = c_path; + free(c_path); + return fd; +} + +class ExceptionHandlerTest : public ::testing::Test { + protected: + void SetUp() { + // We need to be able to wait for children, so SIGCHLD cannot be SIG_IGN. + struct sigaction sa; + memset(&sa, 0, sizeof(sa)); + sa.sa_handler = sigchld_handler; + ASSERT_NE(sigaction(SIGCHLD, &sa, &old_action), -1); + } + + void TearDown() { + sigaction(SIGCHLD, &old_action, NULL); + } + + struct sigaction old_action; +}; + + +void WaitForProcessToTerminate(pid_t process_id, int expected_status) { + int status; + ASSERT_NE(HANDLE_EINTR(waitpid(process_id, &status, 0)), -1); + ASSERT_TRUE(WIFSIGNALED(status)); + ASSERT_EQ(expected_status, WTERMSIG(status)); +} + +// Reads the minidump path sent over the pipe |fd| and sets it in |path|. +void ReadMinidumpPathFromPipe(int fd, string* path) { + struct pollfd pfd; + memset(&pfd, 0, sizeof(pfd)); + pfd.fd = fd; + pfd.events = POLLIN | POLLERR; + + const int r = HANDLE_EINTR(poll(&pfd, 1, 0)); + ASSERT_EQ(1, r); + ASSERT_TRUE(pfd.revents & POLLIN); + + int32_t len; + ASSERT_EQ(static_cast<ssize_t>(sizeof(len)), read(fd, &len, sizeof(len))); + ASSERT_LT(len, 2048); + char* filename = static_cast<char*>(malloc(len + 1)); + ASSERT_EQ(len, read(fd, filename, len)); + filename[len] = 0; + close(fd); + *path = filename; + free(filename); +} + +} // namespace + +TEST(ExceptionHandlerTest, SimpleWithPath) { + AutoTempDir temp_dir; + ExceptionHandler handler( + MinidumpDescriptor(temp_dir.path()), NULL, NULL, NULL, true, -1); + EXPECT_EQ(temp_dir.path(), handler.minidump_descriptor().directory()); + string temp_subdir = temp_dir.path() + "/subdir"; + handler.set_minidump_descriptor(MinidumpDescriptor(temp_subdir)); + EXPECT_EQ(temp_subdir, handler.minidump_descriptor().directory()); +} + +TEST(ExceptionHandlerTest, SimpleWithFD) { + AutoTempDir temp_dir; + string path; + const int fd = CreateTMPFile(temp_dir.path(), &path); + ExceptionHandler handler(MinidumpDescriptor(fd), NULL, NULL, NULL, true, -1); + close(fd); +} + +static bool DoneCallback(const MinidumpDescriptor& descriptor, + void* context, + bool succeeded) { + if (!succeeded) + return false; + + if (!descriptor.IsFD()) { + int fd = reinterpret_cast<intptr_t>(context); + uint32_t len = 0; + len = my_strlen(descriptor.path()); + IGNORE_RET(HANDLE_EINTR(sys_write(fd, &len, sizeof(len)))); + IGNORE_RET(HANDLE_EINTR(sys_write(fd, descriptor.path(), len))); + } + return true; +} + +#ifndef ADDRESS_SANITIZER + +// This is a replacement for "*reinterpret_cast<volatile int*>(NULL) = 0;" +// It is needed because GCC is allowed to assume that the program will +// not execute any undefined behavior (UB) operation. Further, when GCC +// observes that UB statement is reached, it can assume that all statements +// leading to the UB one are never executed either, and can completely +// optimize them out. In the case of ExceptionHandlerTest::ExternalDumper, +// GCC-4.9 optimized out the entire set up of ExceptionHandler, causing +// test failure. +volatile int *p_null; // external linkage, so GCC can't tell that it + // remains NULL. Volatile just for a good measure. +static void DoNullPointerDereference() { + *p_null = 1; +} + +void ChildCrash(bool use_fd) { + AutoTempDir temp_dir; + int fds[2] = {0}; + int minidump_fd = -1; + string minidump_path; + if (use_fd) { + minidump_fd = CreateTMPFile(temp_dir.path(), &minidump_path); + } else { + ASSERT_NE(pipe(fds), -1); + } + + const pid_t child = fork(); + if (child == 0) { + { + google_breakpad::scoped_ptr<ExceptionHandler> handler; + if (use_fd) { + handler.reset(new ExceptionHandler(MinidumpDescriptor(minidump_fd), + NULL, NULL, NULL, true, -1)); + } else { + close(fds[0]); // Close the reading end. + void* fd_param = reinterpret_cast<void*>(fds[1]); + handler.reset(new ExceptionHandler(MinidumpDescriptor(temp_dir.path()), + NULL, DoneCallback, fd_param, + true, -1)); + } + // Crash with the exception handler in scope. + DoNullPointerDereference(); + } + } + if (!use_fd) + close(fds[1]); // Close the writting end. + + ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGSEGV)); + + if (!use_fd) + ASSERT_NO_FATAL_FAILURE(ReadMinidumpPathFromPipe(fds[0], &minidump_path)); + + struct stat st; + ASSERT_EQ(0, stat(minidump_path.c_str(), &st)); + ASSERT_GT(st.st_size, 0); + unlink(minidump_path.c_str()); +} + +TEST(ExceptionHandlerTest, ChildCrashWithPath) { + ASSERT_NO_FATAL_FAILURE(ChildCrash(false)); +} + +TEST(ExceptionHandlerTest, ChildCrashWithFD) { + ASSERT_NO_FATAL_FAILURE(ChildCrash(true)); +} + +static bool DoneCallbackReturnFalse(const MinidumpDescriptor& descriptor, + void* context, + bool succeeded) { + return false; +} + +static bool DoneCallbackReturnTrue(const MinidumpDescriptor& descriptor, + void* context, + bool succeeded) { + return true; +} + +static bool DoneCallbackRaiseSIGKILL(const MinidumpDescriptor& descriptor, + void* context, + bool succeeded) { + raise(SIGKILL); + return true; +} + +static bool FilterCallbackReturnFalse(void* context) { + return false; +} + +static bool FilterCallbackReturnTrue(void* context) { + return true; +} + +// SIGKILL cannot be blocked and a handler cannot be installed for it. In the +// following tests, if the child dies with signal SIGKILL, then the signal was +// redelivered to this handler. If the child dies with SIGSEGV then it wasn't. +static void RaiseSIGKILL(int sig) { + raise(SIGKILL); +} + +static bool InstallRaiseSIGKILL() { + struct sigaction sa; + memset(&sa, 0, sizeof(sa)); + sa.sa_handler = RaiseSIGKILL; + return sigaction(SIGSEGV, &sa, NULL) != -1; +} + +static void CrashWithCallbacks(ExceptionHandler::FilterCallback filter, + ExceptionHandler::MinidumpCallback done, + string path) { + ExceptionHandler handler( + MinidumpDescriptor(path), filter, done, NULL, true, -1); + // Crash with the exception handler in scope. + DoNullPointerDereference(); +} + +TEST(ExceptionHandlerTest, RedeliveryOnFilterCallbackFalse) { + AutoTempDir temp_dir; + + const pid_t child = fork(); + if (child == 0) { + ASSERT_TRUE(InstallRaiseSIGKILL()); + CrashWithCallbacks(FilterCallbackReturnFalse, NULL, temp_dir.path()); + } + + ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGKILL)); +} + +TEST(ExceptionHandlerTest, RedeliveryOnDoneCallbackFalse) { + AutoTempDir temp_dir; + + const pid_t child = fork(); + if (child == 0) { + ASSERT_TRUE(InstallRaiseSIGKILL()); + CrashWithCallbacks(NULL, DoneCallbackReturnFalse, temp_dir.path()); + } + + ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGKILL)); +} + +TEST(ExceptionHandlerTest, NoRedeliveryOnDoneCallbackTrue) { + AutoTempDir temp_dir; + + const pid_t child = fork(); + if (child == 0) { + ASSERT_TRUE(InstallRaiseSIGKILL()); + CrashWithCallbacks(NULL, DoneCallbackReturnTrue, temp_dir.path()); + } + + ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGSEGV)); +} + +TEST(ExceptionHandlerTest, NoRedeliveryOnFilterCallbackTrue) { + AutoTempDir temp_dir; + + const pid_t child = fork(); + if (child == 0) { + ASSERT_TRUE(InstallRaiseSIGKILL()); + CrashWithCallbacks(FilterCallbackReturnTrue, NULL, temp_dir.path()); + } + + ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGSEGV)); +} + +TEST(ExceptionHandlerTest, RedeliveryToDefaultHandler) { + AutoTempDir temp_dir; + + const pid_t child = fork(); + if (child == 0) { + CrashWithCallbacks(FilterCallbackReturnFalse, NULL, temp_dir.path()); + } + + // As RaiseSIGKILL wasn't installed, the redelivery should just kill the child + // with SIGSEGV. + ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGSEGV)); +} + +// Check that saving and restoring the signal handler with 'signal' +// instead of 'sigaction' doesn't make the Breakpad signal handler +// crash. See comments in ExceptionHandler::SignalHandler for full +// details. +TEST(ExceptionHandlerTest, RedeliveryOnBadSignalHandlerFlag) { + AutoTempDir temp_dir; + const pid_t child = fork(); + if (child == 0) { + // Install the RaiseSIGKILL handler for SIGSEGV. + ASSERT_TRUE(InstallRaiseSIGKILL()); + + // Create a new exception handler, this installs a new SIGSEGV + // handler, after saving the old one. + ExceptionHandler handler( + MinidumpDescriptor(temp_dir.path()), NULL, + DoneCallbackReturnFalse, NULL, true, -1); + + // Install the default SIGSEGV handler, saving the current one. + // Then re-install the current one with 'signal', this loses the + // SA_SIGINFO flag associated with the Breakpad handler. + sighandler_t old_handler = signal(SIGSEGV, SIG_DFL); + ASSERT_NE(reinterpret_cast<void*>(old_handler), + reinterpret_cast<void*>(SIG_ERR)); + ASSERT_NE(reinterpret_cast<void*>(signal(SIGSEGV, old_handler)), + reinterpret_cast<void*>(SIG_ERR)); + + // Crash with the exception handler in scope. + DoNullPointerDereference(); + } + // SIGKILL means Breakpad's signal handler didn't crash. + ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGKILL)); +} + +TEST(ExceptionHandlerTest, StackedHandlersDeliveredToTop) { + AutoTempDir temp_dir; + + const pid_t child = fork(); + if (child == 0) { + ExceptionHandler bottom(MinidumpDescriptor(temp_dir.path()), + NULL, + NULL, + NULL, + true, + -1); + CrashWithCallbacks(NULL, DoneCallbackRaiseSIGKILL, temp_dir.path()); + } + ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGKILL)); +} + +TEST(ExceptionHandlerTest, StackedHandlersNotDeliveredToBottom) { + AutoTempDir temp_dir; + + const pid_t child = fork(); + if (child == 0) { + ExceptionHandler bottom(MinidumpDescriptor(temp_dir.path()), + NULL, + DoneCallbackRaiseSIGKILL, + NULL, + true, + -1); + CrashWithCallbacks(NULL, NULL, temp_dir.path()); + } + ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGSEGV)); +} + +TEST(ExceptionHandlerTest, StackedHandlersFilteredToBottom) { + AutoTempDir temp_dir; + + const pid_t child = fork(); + if (child == 0) { + ExceptionHandler bottom(MinidumpDescriptor(temp_dir.path()), + NULL, + DoneCallbackRaiseSIGKILL, + NULL, + true, + -1); + CrashWithCallbacks(FilterCallbackReturnFalse, NULL, temp_dir.path()); + } + ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGKILL)); +} + +TEST(ExceptionHandlerTest, StackedHandlersUnhandledToBottom) { + AutoTempDir temp_dir; + + const pid_t child = fork(); + if (child == 0) { + ExceptionHandler bottom(MinidumpDescriptor(temp_dir.path()), + NULL, + DoneCallbackRaiseSIGKILL, + NULL, + true, + -1); + CrashWithCallbacks(NULL, DoneCallbackReturnFalse, temp_dir.path()); + } + ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGKILL)); +} + +#endif // !ADDRESS_SANITIZER + +const unsigned char kIllegalInstruction[] = { +#if defined(__mips__) + // mfc2 zero,Impl - usually illegal in userspace. + 0x48, 0x00, 0x00, 0x48 +#else + // This crashes with SIGILL on x86/x86-64/arm. + 0xff, 0xff, 0xff, 0xff +#endif +}; + +// Test that memory around the instruction pointer is written +// to the dump as a MinidumpMemoryRegion. +TEST(ExceptionHandlerTest, InstructionPointerMemory) { + AutoTempDir temp_dir; + int fds[2]; + ASSERT_NE(pipe(fds), -1); + + // These are defined here so the parent can use them to check the + // data from the minidump afterwards. + const uint32_t kMemorySize = 256; // bytes + const int kOffset = kMemorySize / 2; + + const pid_t child = fork(); + if (child == 0) { + close(fds[0]); + ExceptionHandler handler(MinidumpDescriptor(temp_dir.path()), NULL, + DoneCallback, reinterpret_cast<void*>(fds[1]), + true, -1); + // Get some executable memory. + char* memory = + reinterpret_cast<char*>(mmap(NULL, + kMemorySize, + PROT_READ | PROT_WRITE | PROT_EXEC, + MAP_PRIVATE | MAP_ANON, + -1, + 0)); + if (!memory) + exit(0); + + // Write some instructions that will crash. Put them in the middle + // of the block of memory, because the minidump should contain 128 + // bytes on either side of the instruction pointer. + memcpy(memory + kOffset, kIllegalInstruction, sizeof(kIllegalInstruction)); + FlushInstructionCache(memory, kMemorySize); + + // Now execute the instructions, which should crash. + typedef void (*void_function)(void); + void_function memory_function = + reinterpret_cast<void_function>(memory + kOffset); + memory_function(); + } + close(fds[1]); + + ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGILL)); + + string minidump_path; + ASSERT_NO_FATAL_FAILURE(ReadMinidumpPathFromPipe(fds[0], &minidump_path)); + + struct stat st; + ASSERT_EQ(0, stat(minidump_path.c_str(), &st)); + ASSERT_GT(st.st_size, 0); + + // Read the minidump. Locate the exception record and the + // memory list, and then ensure that there is a memory region + // in the memory list that covers the instruction pointer from + // the exception record. + Minidump minidump(minidump_path); + ASSERT_TRUE(minidump.Read()); + + MinidumpException* exception = minidump.GetException(); + MinidumpMemoryList* memory_list = minidump.GetMemoryList(); + ASSERT_TRUE(exception); + ASSERT_TRUE(memory_list); + ASSERT_LT(0U, memory_list->region_count()); + + MinidumpContext* context = exception->GetContext(); + ASSERT_TRUE(context); + + uint64_t instruction_pointer; + ASSERT_TRUE(context->GetInstructionPointer(&instruction_pointer)); + + MinidumpMemoryRegion* region = + memory_list->GetMemoryRegionForAddress(instruction_pointer); + ASSERT_TRUE(region); + + EXPECT_EQ(kMemorySize, region->GetSize()); + const uint8_t* bytes = region->GetMemory(); + ASSERT_TRUE(bytes); + + uint8_t prefix_bytes[kOffset]; + uint8_t suffix_bytes[kMemorySize - kOffset - sizeof(kIllegalInstruction)]; + memset(prefix_bytes, 0, sizeof(prefix_bytes)); + memset(suffix_bytes, 0, sizeof(suffix_bytes)); + EXPECT_TRUE(memcmp(bytes, prefix_bytes, sizeof(prefix_bytes)) == 0); + EXPECT_TRUE(memcmp(bytes + kOffset, kIllegalInstruction, + sizeof(kIllegalInstruction)) == 0); + EXPECT_TRUE(memcmp(bytes + kOffset + sizeof(kIllegalInstruction), + suffix_bytes, sizeof(suffix_bytes)) == 0); + + unlink(minidump_path.c_str()); +} + +// Test that the memory region around the instruction pointer is +// bounded correctly on the low end. +TEST(ExceptionHandlerTest, InstructionPointerMemoryMinBound) { + AutoTempDir temp_dir; + int fds[2]; + ASSERT_NE(pipe(fds), -1); + + // These are defined here so the parent can use them to check the + // data from the minidump afterwards. + const uint32_t kMemorySize = 256; // bytes + const int kOffset = 0; + + const pid_t child = fork(); + if (child == 0) { + close(fds[0]); + ExceptionHandler handler(MinidumpDescriptor(temp_dir.path()), NULL, + DoneCallback, reinterpret_cast<void*>(fds[1]), + true, -1); + // Get some executable memory. + char* memory = + reinterpret_cast<char*>(mmap(NULL, + kMemorySize, + PROT_READ | PROT_WRITE | PROT_EXEC, + MAP_PRIVATE | MAP_ANON, + -1, + 0)); + if (!memory) + exit(0); + + // Write some instructions that will crash. Put them in the middle + // of the block of memory, because the minidump should contain 128 + // bytes on either side of the instruction pointer. + memcpy(memory + kOffset, kIllegalInstruction, sizeof(kIllegalInstruction)); + FlushInstructionCache(memory, kMemorySize); + + // Now execute the instructions, which should crash. + typedef void (*void_function)(void); + void_function memory_function = + reinterpret_cast<void_function>(memory + kOffset); + memory_function(); + } + close(fds[1]); + + ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGILL)); + + string minidump_path; + ASSERT_NO_FATAL_FAILURE(ReadMinidumpPathFromPipe(fds[0], &minidump_path)); + + struct stat st; + ASSERT_EQ(0, stat(minidump_path.c_str(), &st)); + ASSERT_GT(st.st_size, 0); + + // Read the minidump. Locate the exception record and the + // memory list, and then ensure that there is a memory region + // in the memory list that covers the instruction pointer from + // the exception record. + Minidump minidump(minidump_path); + ASSERT_TRUE(minidump.Read()); + + MinidumpException* exception = minidump.GetException(); + MinidumpMemoryList* memory_list = minidump.GetMemoryList(); + ASSERT_TRUE(exception); + ASSERT_TRUE(memory_list); + ASSERT_LT(0U, memory_list->region_count()); + + MinidumpContext* context = exception->GetContext(); + ASSERT_TRUE(context); + + uint64_t instruction_pointer; + ASSERT_TRUE(context->GetInstructionPointer(&instruction_pointer)); + + MinidumpMemoryRegion* region = + memory_list->GetMemoryRegionForAddress(instruction_pointer); + ASSERT_TRUE(region); + + EXPECT_EQ(kMemorySize / 2, region->GetSize()); + const uint8_t* bytes = region->GetMemory(); + ASSERT_TRUE(bytes); + + uint8_t suffix_bytes[kMemorySize / 2 - sizeof(kIllegalInstruction)]; + memset(suffix_bytes, 0, sizeof(suffix_bytes)); + EXPECT_TRUE(memcmp(bytes + kOffset, kIllegalInstruction, + sizeof(kIllegalInstruction)) == 0); + EXPECT_TRUE(memcmp(bytes + kOffset + sizeof(kIllegalInstruction), + suffix_bytes, sizeof(suffix_bytes)) == 0); + unlink(minidump_path.c_str()); +} + +// Test that the memory region around the instruction pointer is +// bounded correctly on the high end. +TEST(ExceptionHandlerTest, InstructionPointerMemoryMaxBound) { + AutoTempDir temp_dir; + int fds[2]; + ASSERT_NE(pipe(fds), -1); + + // These are defined here so the parent can use them to check the + // data from the minidump afterwards. + // Use 4k here because the OS will hand out a single page even + // if a smaller size is requested, and this test wants to + // test the upper bound of the memory range. + const uint32_t kMemorySize = 4096; // bytes + const int kOffset = kMemorySize - sizeof(kIllegalInstruction); + + const pid_t child = fork(); + if (child == 0) { + close(fds[0]); + ExceptionHandler handler(MinidumpDescriptor(temp_dir.path()), NULL, + DoneCallback, reinterpret_cast<void*>(fds[1]), + true, -1); + // Get some executable memory. + char* memory = + reinterpret_cast<char*>(mmap(NULL, + kMemorySize, + PROT_READ | PROT_WRITE | PROT_EXEC, + MAP_PRIVATE | MAP_ANON, + -1, + 0)); + if (!memory) + exit(0); + + // Write some instructions that will crash. Put them in the middle + // of the block of memory, because the minidump should contain 128 + // bytes on either side of the instruction pointer. + memcpy(memory + kOffset, kIllegalInstruction, sizeof(kIllegalInstruction)); + FlushInstructionCache(memory, kMemorySize); + + // Now execute the instructions, which should crash. + typedef void (*void_function)(void); + void_function memory_function = + reinterpret_cast<void_function>(memory + kOffset); + memory_function(); + } + close(fds[1]); + + ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGILL)); + + string minidump_path; + ASSERT_NO_FATAL_FAILURE(ReadMinidumpPathFromPipe(fds[0], &minidump_path)); + + struct stat st; + ASSERT_EQ(0, stat(minidump_path.c_str(), &st)); + ASSERT_GT(st.st_size, 0); + + // Read the minidump. Locate the exception record and the memory list, and + // then ensure that there is a memory region in the memory list that covers + // the instruction pointer from the exception record. + Minidump minidump(minidump_path); + ASSERT_TRUE(minidump.Read()); + + MinidumpException* exception = minidump.GetException(); + MinidumpMemoryList* memory_list = minidump.GetMemoryList(); + ASSERT_TRUE(exception); + ASSERT_TRUE(memory_list); + ASSERT_LT(0U, memory_list->region_count()); + + MinidumpContext* context = exception->GetContext(); + ASSERT_TRUE(context); + + uint64_t instruction_pointer; + ASSERT_TRUE(context->GetInstructionPointer(&instruction_pointer)); + + MinidumpMemoryRegion* region = + memory_list->GetMemoryRegionForAddress(instruction_pointer); + ASSERT_TRUE(region); + + const size_t kPrefixSize = 128; // bytes + EXPECT_EQ(kPrefixSize + sizeof(kIllegalInstruction), region->GetSize()); + const uint8_t* bytes = region->GetMemory(); + ASSERT_TRUE(bytes); + + uint8_t prefix_bytes[kPrefixSize]; + memset(prefix_bytes, 0, sizeof(prefix_bytes)); + EXPECT_TRUE(memcmp(bytes, prefix_bytes, sizeof(prefix_bytes)) == 0); + EXPECT_TRUE(memcmp(bytes + kPrefixSize, + kIllegalInstruction, sizeof(kIllegalInstruction)) == 0); + + unlink(minidump_path.c_str()); +} + +#ifndef ADDRESS_SANITIZER + +// Ensure that an extra memory block doesn't get added when the instruction +// pointer is not in mapped memory. +TEST(ExceptionHandlerTest, InstructionPointerMemoryNullPointer) { + AutoTempDir temp_dir; + int fds[2]; + ASSERT_NE(pipe(fds), -1); + + const pid_t child = fork(); + if (child == 0) { + close(fds[0]); + ExceptionHandler handler(MinidumpDescriptor(temp_dir.path()), NULL, + DoneCallback, reinterpret_cast<void*>(fds[1]), + true, -1); + // Try calling a NULL pointer. + typedef void (*void_function)(void); + // Volatile markings are needed to keep Clang from generating invalid + // opcodes. See http://crbug.com/498354 for details. + volatile void_function memory_function = + reinterpret_cast<void_function>(NULL); + memory_function(); + // not reached + exit(1); + } + close(fds[1]); + + ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGSEGV)); + + string minidump_path; + ASSERT_NO_FATAL_FAILURE(ReadMinidumpPathFromPipe(fds[0], &minidump_path)); + + struct stat st; + ASSERT_EQ(0, stat(minidump_path.c_str(), &st)); + ASSERT_GT(st.st_size, 0); + + // Read the minidump. Locate the exception record and the + // memory list, and then ensure that there is a memory region + // in the memory list that covers the instruction pointer from + // the exception record. + Minidump minidump(minidump_path); + ASSERT_TRUE(minidump.Read()); + + MinidumpException* exception = minidump.GetException(); + MinidumpMemoryList* memory_list = minidump.GetMemoryList(); + ASSERT_TRUE(exception); + ASSERT_TRUE(memory_list); + ASSERT_EQ(static_cast<unsigned int>(1), memory_list->region_count()); + + unlink(minidump_path.c_str()); +} + +#endif // !ADDRESS_SANITIZER + +// Test that anonymous memory maps can be annotated with names and IDs. +TEST(ExceptionHandlerTest, ModuleInfo) { + // These are defined here so the parent can use them to check the + // data from the minidump afterwards. + const uint32_t kMemorySize = sysconf(_SC_PAGESIZE); + const char* kMemoryName = "a fake module"; + const uint8_t kModuleGUID[sizeof(MDGUID)] = { + 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, + 0x88, 0x99, 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF + }; + const string module_identifier = "33221100554477668899AABBCCDDEEFF0"; + + // Get some memory. + char* memory = + reinterpret_cast<char*>(mmap(NULL, + kMemorySize, + PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANON, + -1, + 0)); + const uintptr_t kMemoryAddress = reinterpret_cast<uintptr_t>(memory); + ASSERT_TRUE(memory); + + AutoTempDir temp_dir; + ExceptionHandler handler( + MinidumpDescriptor(temp_dir.path()), NULL, NULL, NULL, true, -1); + + // Add info about the anonymous memory mapping. + handler.AddMappingInfo(kMemoryName, + kModuleGUID, + kMemoryAddress, + kMemorySize, + 0); + ASSERT_TRUE(handler.WriteMinidump()); + + const MinidumpDescriptor& minidump_desc = handler.minidump_descriptor(); + // Read the minidump. Load the module list, and ensure that the mmap'ed + // |memory| is listed with the given module name and debug ID. + Minidump minidump(minidump_desc.path()); + ASSERT_TRUE(minidump.Read()); + + MinidumpModuleList* module_list = minidump.GetModuleList(); + ASSERT_TRUE(module_list); + const MinidumpModule* module = + module_list->GetModuleForAddress(kMemoryAddress); + ASSERT_TRUE(module); + + EXPECT_EQ(kMemoryAddress, module->base_address()); + EXPECT_EQ(kMemorySize, module->size()); + EXPECT_EQ(kMemoryName, module->code_file()); + EXPECT_EQ(module_identifier, module->debug_identifier()); + + unlink(minidump_desc.path()); +} + +#ifndef ADDRESS_SANITIZER + +static const unsigned kControlMsgSize = + CMSG_SPACE(sizeof(int)) + CMSG_SPACE(sizeof(struct ucred)); + +static bool +CrashHandler(const void* crash_context, size_t crash_context_size, + void* context) { + const int fd = (intptr_t) context; + int fds[2]; + if (pipe(fds) == -1) { + // There doesn't seem to be any way to reliably handle + // this failure without the parent process hanging + // At least make sure that this process doesn't access + // unexpected file descriptors + fds[0] = -1; + fds[1] = -1; + } + struct kernel_msghdr msg = {0}; + struct kernel_iovec iov; + iov.iov_base = const_cast<void*>(crash_context); + iov.iov_len = crash_context_size; + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + char cmsg[kControlMsgSize]; + memset(cmsg, 0, kControlMsgSize); + msg.msg_control = cmsg; + msg.msg_controllen = sizeof(cmsg); + + struct cmsghdr *hdr = CMSG_FIRSTHDR(&msg); + hdr->cmsg_level = SOL_SOCKET; + hdr->cmsg_type = SCM_RIGHTS; + hdr->cmsg_len = CMSG_LEN(sizeof(int)); + *((int*) CMSG_DATA(hdr)) = fds[1]; + hdr = CMSG_NXTHDR((struct msghdr*) &msg, hdr); + hdr->cmsg_level = SOL_SOCKET; + hdr->cmsg_type = SCM_CREDENTIALS; + hdr->cmsg_len = CMSG_LEN(sizeof(struct ucred)); + struct ucred *cred = reinterpret_cast<struct ucred*>(CMSG_DATA(hdr)); + cred->uid = getuid(); + cred->gid = getgid(); + cred->pid = getpid(); + + ssize_t ret = HANDLE_EINTR(sys_sendmsg(fd, &msg, 0)); + sys_close(fds[1]); + if (ret <= 0) + return false; + + char b; + IGNORE_RET(HANDLE_EINTR(sys_read(fds[0], &b, 1))); + + return true; +} + +TEST(ExceptionHandlerTest, ExternalDumper) { + int fds[2]; + ASSERT_NE(socketpair(AF_UNIX, SOCK_DGRAM, 0, fds), -1); + static const int on = 1; + setsockopt(fds[0], SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)); + setsockopt(fds[1], SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)); + + const pid_t child = fork(); + if (child == 0) { + close(fds[0]); + ExceptionHandler handler(MinidumpDescriptor("/tmp1"), NULL, NULL, + reinterpret_cast<void*>(fds[1]), true, -1); + handler.set_crash_handler(CrashHandler); + DoNullPointerDereference(); + } + close(fds[1]); + struct msghdr msg = {0}; + struct iovec iov; + static const unsigned kCrashContextSize = + sizeof(ExceptionHandler::CrashContext); + char context[kCrashContextSize]; + char control[kControlMsgSize]; + iov.iov_base = context; + iov.iov_len = kCrashContextSize; + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + msg.msg_control = control; + msg.msg_controllen = kControlMsgSize; + + const ssize_t n = HANDLE_EINTR(recvmsg(fds[0], &msg, 0)); + ASSERT_EQ(static_cast<ssize_t>(kCrashContextSize), n); + ASSERT_EQ(kControlMsgSize, msg.msg_controllen); + ASSERT_EQ(static_cast<__typeof__(msg.msg_flags)>(0), msg.msg_flags); + ASSERT_EQ(0, close(fds[0])); + + pid_t crashing_pid = -1; + int signal_fd = -1; + for (struct cmsghdr *hdr = CMSG_FIRSTHDR(&msg); hdr; + hdr = CMSG_NXTHDR(&msg, hdr)) { + if (hdr->cmsg_level != SOL_SOCKET) + continue; + if (hdr->cmsg_type == SCM_RIGHTS) { + const unsigned len = hdr->cmsg_len - + (((uint8_t*)CMSG_DATA(hdr)) - (uint8_t*)hdr); + ASSERT_EQ(sizeof(int), len); + signal_fd = *(reinterpret_cast<int*>(CMSG_DATA(hdr))); + } else if (hdr->cmsg_type == SCM_CREDENTIALS) { + const struct ucred *cred = + reinterpret_cast<struct ucred*>(CMSG_DATA(hdr)); + crashing_pid = cred->pid; + } + } + + ASSERT_NE(crashing_pid, -1); + ASSERT_NE(signal_fd, -1); + + AutoTempDir temp_dir; + string templ = temp_dir.path() + "/exception-handler-unittest"; + ASSERT_TRUE(WriteMinidump(templ.c_str(), crashing_pid, context, + kCrashContextSize)); + static const char b = 0; + ASSERT_EQ(1, (HANDLE_EINTR(write(signal_fd, &b, 1)))); + ASSERT_EQ(0, close(signal_fd)); + + ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGSEGV)); + + struct stat st; + ASSERT_EQ(0, stat(templ.c_str(), &st)); + ASSERT_GT(st.st_size, 0); + unlink(templ.c_str()); +} + +#endif // !ADDRESS_SANITIZER + +TEST(ExceptionHandlerTest, WriteMinidumpExceptionStream) { + AutoTempDir temp_dir; + ExceptionHandler handler(MinidumpDescriptor(temp_dir.path()), NULL, NULL, + NULL, false, -1); + ASSERT_TRUE(handler.WriteMinidump()); + + string minidump_path = handler.minidump_descriptor().path(); + + // Read the minidump and check the exception stream. + Minidump minidump(minidump_path); + ASSERT_TRUE(minidump.Read()); + MinidumpException* exception = minidump.GetException(); + ASSERT_TRUE(exception); + const MDRawExceptionStream* raw = exception->exception(); + ASSERT_TRUE(raw); + EXPECT_EQ(MD_EXCEPTION_CODE_LIN_DUMP_REQUESTED, + raw->exception_record.exception_code); +} + +TEST(ExceptionHandlerTest, GenerateMultipleDumpsWithFD) { + AutoTempDir temp_dir; + string path; + const int fd = CreateTMPFile(temp_dir.path(), &path); + ExceptionHandler handler(MinidumpDescriptor(fd), NULL, NULL, NULL, false, -1); + ASSERT_TRUE(handler.WriteMinidump()); + // Check by the size of the data written to the FD that a minidump was + // generated. + off_t size = lseek(fd, 0, SEEK_CUR); + ASSERT_GT(size, 0); + + // Generate another minidump. + ASSERT_TRUE(handler.WriteMinidump()); + size = lseek(fd, 0, SEEK_CUR); + ASSERT_GT(size, 0); +} + +TEST(ExceptionHandlerTest, GenerateMultipleDumpsWithPath) { + AutoTempDir temp_dir; + ExceptionHandler handler(MinidumpDescriptor(temp_dir.path()), NULL, NULL, + NULL, false, -1); + ASSERT_TRUE(handler.WriteMinidump()); + + const MinidumpDescriptor& minidump_1 = handler.minidump_descriptor(); + struct stat st; + ASSERT_EQ(0, stat(minidump_1.path(), &st)); + ASSERT_GT(st.st_size, 0); + string minidump_1_path(minidump_1.path()); + // Check it is a valid minidump. + Minidump minidump1(minidump_1_path); + ASSERT_TRUE(minidump1.Read()); + unlink(minidump_1.path()); + + // Generate another minidump, it should go to a different file. + ASSERT_TRUE(handler.WriteMinidump()); + const MinidumpDescriptor& minidump_2 = handler.minidump_descriptor(); + ASSERT_EQ(0, stat(minidump_2.path(), &st)); + ASSERT_GT(st.st_size, 0); + string minidump_2_path(minidump_2.path()); + // Check it is a valid minidump. + Minidump minidump2(minidump_2_path); + ASSERT_TRUE(minidump2.Read()); + unlink(minidump_2.path()); + + // 2 distinct files should be produced. + ASSERT_STRNE(minidump_1_path.c_str(), minidump_2_path.c_str()); +} + +// Test that an additional memory region can be added to the minidump. +TEST(ExceptionHandlerTest, AdditionalMemory) { + const uint32_t kMemorySize = sysconf(_SC_PAGESIZE); + + // Get some heap memory. + uint8_t* memory = new uint8_t[kMemorySize]; + const uintptr_t kMemoryAddress = reinterpret_cast<uintptr_t>(memory); + ASSERT_TRUE(memory); + + // Stick some data into the memory so the contents can be verified. + for (uint32_t i = 0; i < kMemorySize; ++i) { + memory[i] = i % 255; + } + + AutoTempDir temp_dir; + ExceptionHandler handler( + MinidumpDescriptor(temp_dir.path()), NULL, NULL, NULL, true, -1); + + // Add the memory region to the list of memory to be included. + handler.RegisterAppMemory(memory, kMemorySize); + handler.WriteMinidump(); + + const MinidumpDescriptor& minidump_desc = handler.minidump_descriptor(); + + // Read the minidump. Ensure that the memory region is present + Minidump minidump(minidump_desc.path()); + ASSERT_TRUE(minidump.Read()); + + MinidumpMemoryList* dump_memory_list = minidump.GetMemoryList(); + ASSERT_TRUE(dump_memory_list); + const MinidumpMemoryRegion* region = + dump_memory_list->GetMemoryRegionForAddress(kMemoryAddress); + ASSERT_TRUE(region); + + EXPECT_EQ(kMemoryAddress, region->GetBase()); + EXPECT_EQ(kMemorySize, region->GetSize()); + + // Verify memory contents. + EXPECT_EQ(0, memcmp(region->GetMemory(), memory, kMemorySize)); + + delete[] memory; +} + +// Test that a memory region that was previously registered +// can be unregistered. +TEST(ExceptionHandlerTest, AdditionalMemoryRemove) { + const uint32_t kMemorySize = sysconf(_SC_PAGESIZE); + + // Get some heap memory. + uint8_t* memory = new uint8_t[kMemorySize]; + const uintptr_t kMemoryAddress = reinterpret_cast<uintptr_t>(memory); + ASSERT_TRUE(memory); + + AutoTempDir temp_dir; + ExceptionHandler handler( + MinidumpDescriptor(temp_dir.path()), NULL, NULL, NULL, true, -1); + + // Add the memory region to the list of memory to be included. + handler.RegisterAppMemory(memory, kMemorySize); + + // ...and then remove it + handler.UnregisterAppMemory(memory); + handler.WriteMinidump(); + + const MinidumpDescriptor& minidump_desc = handler.minidump_descriptor(); + + // Read the minidump. Ensure that the memory region is not present. + Minidump minidump(minidump_desc.path()); + ASSERT_TRUE(minidump.Read()); + + MinidumpMemoryList* dump_memory_list = minidump.GetMemoryList(); + ASSERT_TRUE(dump_memory_list); + const MinidumpMemoryRegion* region = + dump_memory_list->GetMemoryRegionForAddress(kMemoryAddress); + EXPECT_FALSE(region); + + delete[] memory; +} + +static bool SimpleCallback(const MinidumpDescriptor& descriptor, + void* context, + bool succeeded) { + string* filename = reinterpret_cast<string*>(context); + *filename = descriptor.path(); + return true; +} + +TEST(ExceptionHandlerTest, WriteMinidumpForChild) { + int fds[2]; + ASSERT_NE(-1, pipe(fds)); + + const pid_t child = fork(); + if (child == 0) { + close(fds[1]); + char b; + HANDLE_EINTR(read(fds[0], &b, sizeof(b))); + close(fds[0]); + syscall(__NR_exit); + } + close(fds[0]); + + AutoTempDir temp_dir; + string minidump_filename; + ASSERT_TRUE( + ExceptionHandler::WriteMinidumpForChild(child, child, + temp_dir.path(), SimpleCallback, + (void*)&minidump_filename)); + + Minidump minidump(minidump_filename); + ASSERT_TRUE(minidump.Read()); + // Check that the crashing thread is the main thread of |child| + MinidumpException* exception = minidump.GetException(); + ASSERT_TRUE(exception); + uint32_t thread_id; + ASSERT_TRUE(exception->GetThreadID(&thread_id)); + EXPECT_EQ(child, static_cast<int32_t>(thread_id)); + + const MDRawExceptionStream* raw = exception->exception(); + ASSERT_TRUE(raw); + EXPECT_EQ(MD_EXCEPTION_CODE_LIN_DUMP_REQUESTED, + raw->exception_record.exception_code); + + close(fds[1]); + unlink(minidump_filename.c_str()); +} |