Write a window of memory around the instruction pointer from the crashing thread to the minidump on OS X.

R=nealsid at http://breakpad.appspot.com/200001/show

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@699 4c0a9323-5329-0410-9bdc-e9ce6186880e
This commit is contained in:
ted.mielczarek 2010-09-23 14:55:50 +00:00
parent cec12872c4
commit 4621ee0691
14 changed files with 930 additions and 18 deletions

View file

@ -29,6 +29,7 @@
// exception_handler_test.cc: Unit tests for google_breakpad::ExceptionHandler
#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>
@ -36,6 +37,14 @@
#include "client/mac/handler/exception_handler.h"
#include "client/mac/tests/auto_tempdir.h"
#include "common/mac/MachIPC.h"
#include "google_breakpad/processor/minidump.h"
namespace google_breakpad {
// This acts as the log sink for INFO logging from the processor
// logging code. The logging output confuses XCode and makes it think
// there are unit test failures. testlogging.h handles the overriding.
std::ostringstream info_log;
}
namespace {
using std::string;
@ -44,6 +53,11 @@ using google_breakpad::ExceptionHandler;
using google_breakpad::MachPortSender;
using google_breakpad::MachReceiveMessage;
using google_breakpad::MachSendMessage;
using google_breakpad::Minidump;
using google_breakpad::MinidumpContext;
using google_breakpad::MinidumpException;
using google_breakpad::MinidumpMemoryList;
using google_breakpad::MinidumpMemoryRegion;
using google_breakpad::ReceivePort;
using testing::Test;
@ -80,7 +94,6 @@ static bool MDCallback(const char *dump_dir, const char *file_name,
}
TEST_F(ExceptionHandlerTest, InProcess) {
AutoTempDir tempDir;
// Give the child process a pipe to report back on.
int fds[2];
ASSERT_EQ(0, pipe(fds));
@ -167,8 +180,8 @@ TEST_F(ExceptionHandlerTest, DumpChildProcess) {
parent_recv_port.WaitForMessage(&child_message, kTimeoutMs));
mach_port_t child_task = child_message.GetTranslatedPort(0);
mach_port_t child_thread = child_message.GetTranslatedPort(1);
ASSERT_NE(MACH_PORT_NULL, child_task);
ASSERT_NE(MACH_PORT_NULL, child_thread);
ASSERT_NE((mach_port_t)MACH_PORT_NULL, child_task);
ASSERT_NE((mach_port_t)MACH_PORT_NULL, child_thread);
// Write a minidump of the child process.
bool result = ExceptionHandler::WriteMinidumpForChild(child_task,
@ -195,4 +208,390 @@ TEST_F(ExceptionHandlerTest, DumpChildProcess) {
EXPECT_EQ(0, WEXITSTATUS(ret));
}
// Test that memory around the instruction pointer is written
// to the dump as a MinidumpMemoryRegion.
TEST_F(ExceptionHandlerTest, InstructionPointerMemory) {
// Give the child process a pipe to report back on.
int fds[2];
ASSERT_EQ(0, pipe(fds));
// These are defined here so the parent can use them to check the
// data from the minidump afterwards.
const u_int32_t kMemorySize = 256; // bytes
const int kOffset = kMemorySize / 2;
// This crashes with SIGILL on x86/x86-64/arm.
const unsigned char instructions[] = { 0xff, 0xff, 0xff, 0xff };
pid_t pid = fork();
if (pid == 0) {
close(fds[0]);
ExceptionHandler eh(tempDir.path, NULL, MDCallback, &fds[1], true, NULL);
// 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, instructions, sizeof(instructions));
// Now execute the instructions, which should crash.
typedef void (*void_function)(void);
void_function memory_function =
reinterpret_cast<void_function>(memory + kOffset);
memory_function();
// not reached
exit(1);
}
// In the parent process.
ASSERT_NE(-1, pid);
close(fds[1]);
// Wait for the background process to return the minidump file.
close(fds[1]);
char minidump_file[PATH_MAX];
ssize_t nbytes = read(fds[0], minidump_file, sizeof(minidump_file));
ASSERT_NE(0, nbytes);
// Ensure that minidump file exists and is > 0 bytes.
struct stat st;
ASSERT_EQ(0, stat(minidump_file, &st));
ASSERT_LT(0, st.st_size);
// Child process should have exited with a zero status.
int ret;
ASSERT_EQ(pid, waitpid(pid, &ret, 0));
EXPECT_NE(0, WIFEXITED(ret));
EXPECT_EQ(0, WEXITSTATUS(ret));
// 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_file);
ASSERT_TRUE(minidump.Read());
MinidumpException* exception = minidump.GetException();
MinidumpMemoryList* memory_list = minidump.GetMemoryList();
ASSERT_TRUE(exception);
ASSERT_TRUE(memory_list);
ASSERT_NE((unsigned int)0, memory_list->region_count());
MinidumpContext* context = exception->GetContext();
ASSERT_TRUE(context);
u_int64_t instruction_pointer;
switch (context->GetContextCPU()) {
case MD_CONTEXT_X86:
instruction_pointer = context->GetContextX86()->eip;
break;
case MD_CONTEXT_AMD64:
instruction_pointer = context->GetContextAMD64()->rip;
break;
case MD_CONTEXT_ARM:
instruction_pointer = context->GetContextARM()->iregs[15];
break;
default:
FAIL() << "Unknown context CPU: " << context->GetContextCPU();
break;
}
MinidumpMemoryRegion* region =
memory_list->GetMemoryRegionForAddress(instruction_pointer);
EXPECT_TRUE(region);
EXPECT_EQ(kMemorySize, region->GetSize());
const u_int8_t* bytes = region->GetMemory();
ASSERT_TRUE(bytes);
u_int8_t prefix_bytes[kOffset];
u_int8_t suffix_bytes[kMemorySize - kOffset - sizeof(instructions)];
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, instructions, sizeof(instructions)) == 0);
EXPECT_TRUE(memcmp(bytes + kOffset + sizeof(instructions),
suffix_bytes, sizeof(suffix_bytes)) == 0);
}
// Test that the memory region around the instruction pointer is
// bounded correctly on the low end.
TEST_F(ExceptionHandlerTest, InstructionPointerMemoryMinBound) {
// Give the child process a pipe to report back on.
int fds[2];
ASSERT_EQ(0, pipe(fds));
// These are defined here so the parent can use them to check the
// data from the minidump afterwards.
const u_int32_t kMemorySize = 256; // bytes
const int kOffset = 0;
// This crashes with SIGILL on x86/x86-64/arm.
const unsigned char instructions[] = { 0xff, 0xff, 0xff, 0xff };
pid_t pid = fork();
if (pid == 0) {
close(fds[0]);
ExceptionHandler eh(tempDir.path, NULL, MDCallback, &fds[1], true, NULL);
// 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 at the start
// of the block of memory, to ensure that the memory bounding
// works properly.
memcpy(memory + kOffset, instructions, sizeof(instructions));
// Now execute the instructions, which should crash.
typedef void (*void_function)(void);
void_function memory_function =
reinterpret_cast<void_function>(memory + kOffset);
memory_function();
// not reached
exit(1);
}
// In the parent process.
ASSERT_NE(-1, pid);
close(fds[1]);
// Wait for the background process to return the minidump file.
close(fds[1]);
char minidump_file[PATH_MAX];
ssize_t nbytes = read(fds[0], minidump_file, sizeof(minidump_file));
ASSERT_NE(0, nbytes);
// Ensure that minidump file exists and is > 0 bytes.
struct stat st;
ASSERT_EQ(0, stat(minidump_file, &st));
ASSERT_LT(0, st.st_size);
// Child process should have exited with a zero status.
int ret;
ASSERT_EQ(pid, waitpid(pid, &ret, 0));
EXPECT_NE(0, WIFEXITED(ret));
EXPECT_EQ(0, WEXITSTATUS(ret));
// 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_file);
ASSERT_TRUE(minidump.Read());
MinidumpException* exception = minidump.GetException();
MinidumpMemoryList* memory_list = minidump.GetMemoryList();
ASSERT_TRUE(exception);
ASSERT_TRUE(memory_list);
ASSERT_NE((unsigned int)0, memory_list->region_count());
MinidumpContext* context = exception->GetContext();
ASSERT_TRUE(context);
u_int64_t instruction_pointer;
switch (context->GetContextCPU()) {
case MD_CONTEXT_X86:
instruction_pointer = context->GetContextX86()->eip;
break;
case MD_CONTEXT_AMD64:
instruction_pointer = context->GetContextAMD64()->rip;
break;
case MD_CONTEXT_ARM:
instruction_pointer = context->GetContextARM()->iregs[15];
break;
default:
FAIL() << "Unknown context CPU: " << context->GetContextCPU();
break;
}
MinidumpMemoryRegion* region =
memory_list->GetMemoryRegionForAddress(instruction_pointer);
EXPECT_TRUE(region);
EXPECT_EQ(kMemorySize / 2, region->GetSize());
const u_int8_t* bytes = region->GetMemory();
ASSERT_TRUE(bytes);
u_int8_t suffix_bytes[kMemorySize / 2 - sizeof(instructions)];
memset(suffix_bytes, 0, sizeof(suffix_bytes));
EXPECT_TRUE(memcmp(bytes + kOffset, instructions, sizeof(instructions)) == 0);
EXPECT_TRUE(memcmp(bytes + kOffset + sizeof(instructions),
suffix_bytes, sizeof(suffix_bytes)) == 0);
}
// Test that the memory region around the instruction pointer is
// bounded correctly on the high end.
TEST_F(ExceptionHandlerTest, InstructionPointerMemoryMaxBound) {
// Give the child process a pipe to report back on.
int fds[2];
ASSERT_EQ(0, pipe(fds));
// 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 u_int32_t kMemorySize = 4096; // bytes
// This crashes with SIGILL on x86/x86-64/arm.
const unsigned char instructions[] = { 0xff, 0xff, 0xff, 0xff };
const int kOffset = kMemorySize - sizeof(instructions);
pid_t pid = fork();
if (pid == 0) {
close(fds[0]);
ExceptionHandler eh(tempDir.path, NULL, MDCallback, &fds[1], true, NULL);
// 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 at the start
// of the block of memory, to ensure that the memory bounding
// works properly.
memcpy(memory + kOffset, instructions, sizeof(instructions));
// Now execute the instructions, which should crash.
typedef void (*void_function)(void);
void_function memory_function =
reinterpret_cast<void_function>(memory + kOffset);
memory_function();
// not reached
exit(1);
}
// In the parent process.
ASSERT_NE(-1, pid);
close(fds[1]);
// Wait for the background process to return the minidump file.
close(fds[1]);
char minidump_file[PATH_MAX];
ssize_t nbytes = read(fds[0], minidump_file, sizeof(minidump_file));
ASSERT_NE(0, nbytes);
// Ensure that minidump file exists and is > 0 bytes.
struct stat st;
ASSERT_EQ(0, stat(minidump_file, &st));
ASSERT_LT(0, st.st_size);
// Child process should have exited with a zero status.
int ret;
ASSERT_EQ(pid, waitpid(pid, &ret, 0));
EXPECT_NE(0, WIFEXITED(ret));
EXPECT_EQ(0, WEXITSTATUS(ret));
// 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_file);
ASSERT_TRUE(minidump.Read());
MinidumpException* exception = minidump.GetException();
MinidumpMemoryList* memory_list = minidump.GetMemoryList();
ASSERT_TRUE(exception);
ASSERT_TRUE(memory_list);
ASSERT_NE((unsigned int)0, memory_list->region_count());
MinidumpContext* context = exception->GetContext();
ASSERT_TRUE(context);
u_int64_t instruction_pointer;
switch (context->GetContextCPU()) {
case MD_CONTEXT_X86:
instruction_pointer = context->GetContextX86()->eip;
break;
case MD_CONTEXT_AMD64:
instruction_pointer = context->GetContextAMD64()->rip;
break;
case MD_CONTEXT_ARM:
instruction_pointer = context->GetContextARM()->iregs[15];
break;
default:
FAIL() << "Unknown context CPU: " << context->GetContextCPU();
break;
}
MinidumpMemoryRegion* region =
memory_list->GetMemoryRegionForAddress(instruction_pointer);
EXPECT_TRUE(region);
const size_t kPrefixSize = 128; // bytes
EXPECT_EQ(kPrefixSize + sizeof(instructions), region->GetSize());
const u_int8_t* bytes = region->GetMemory();
ASSERT_TRUE(bytes);
u_int8_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,
instructions, sizeof(instructions)) == 0);
}
// Ensure that an extra memory block doesn't get added when the
// instruction pointer is not in mapped memory.
TEST_F(ExceptionHandlerTest, InstructionPointerMemoryNullPointer) {
// Give the child process a pipe to report back on.
int fds[2];
ASSERT_EQ(0, pipe(fds));
pid_t pid = fork();
if (pid == 0) {
close(fds[0]);
ExceptionHandler eh(tempDir.path, NULL, MDCallback, &fds[1], true, NULL);
// Try calling a NULL pointer.
typedef void (*void_function)(void);
void_function memory_function =
reinterpret_cast<void_function>(NULL);
memory_function();
// not reached
exit(1);
}
// In the parent process.
ASSERT_NE(-1, pid);
close(fds[1]);
// Wait for the background process to return the minidump file.
close(fds[1]);
char minidump_file[PATH_MAX];
ssize_t nbytes = read(fds[0], minidump_file, sizeof(minidump_file));
ASSERT_NE(0, nbytes);
// Ensure that minidump file exists and is > 0 bytes.
struct stat st;
ASSERT_EQ(0, stat(minidump_file, &st));
ASSERT_LT(0, st.st_size);
// Child process should have exited with a zero status.
int ret;
ASSERT_EQ(pid, waitpid(pid, &ret, 0));
EXPECT_NE(0, WIFEXITED(ret));
EXPECT_EQ(0, WEXITSTATUS(ret));
// Read the minidump. Locate the exception record and the
// memory list, and then ensure that there is only one memory region
// in the memory list (the thread memory from the single thread).
Minidump minidump(minidump_file);
ASSERT_TRUE(minidump.Read());
MinidumpException* exception = minidump.GetException();
MinidumpMemoryList* memory_list = minidump.GetMemoryList();
ASSERT_TRUE(exception);
ASSERT_TRUE(memory_list);
ASSERT_EQ((unsigned int)1, memory_list->region_count());
}
}