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

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R=nealsid at http://breakpad.appspot.com/194001/show

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@693 4c0a9323-5329-0410-9bdc-e9ce6186880e
This commit is contained in:
ted.mielczarek 2010-09-17 13:36:11 +00:00
parent c40bcc74d9
commit efa30c13f2
5 changed files with 229 additions and 8 deletions
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9
Makefile.am
View file

@ -220,8 +220,13 @@ src_client_linux_linux_client_unittest_LDADD = \
src/common/md5.lo \
src/common/linux/file_id.lo \
src/common/linux/guid_creator.lo \
src/common/string_conversion.lo
src_client_linux_linux_client_unittest_DEPENDENCIES = src/client/linux/linux_dumper_unittest_helper src/client/linux/libbreakpad_client.la
src/common/string_conversion.lo \
src/processor/basic_code_modules.lo \
src/processor/logging.lo \
src/processor/minidump.lo \
src/processor/pathname_stripper.lo
src_client_linux_linux_client_unittest_DEPENDENCIES = src/client/linux/linux_dumper_unittest_helper src/client/linux/libbreakpad_client.la src/libbreakpad.la
endif
src_processor_address_map_unittest_SOURCES = \

8
Makefile.in
View file

@ -801,9 +801,13 @@ TESTS_ENVIRONMENT =
@LINUX_HOST_TRUE@ src/common/md5.lo \
@LINUX_HOST_TRUE@ src/common/linux/file_id.lo \
@LINUX_HOST_TRUE@ src/common/linux/guid_creator.lo \
@LINUX_HOST_TRUE@ src/common/string_conversion.lo
@LINUX_HOST_TRUE@ src/common/string_conversion.lo \
@LINUX_HOST_TRUE@ src/processor/basic_code_modules.lo \
@LINUX_HOST_TRUE@ src/processor/logging.lo \
@LINUX_HOST_TRUE@ src/processor/minidump.lo \
@LINUX_HOST_TRUE@ src/processor/pathname_stripper.lo
@LINUX_HOST_TRUE@src_client_linux_linux_client_unittest_DEPENDENCIES = src/client/linux/linux_dumper_unittest_helper src/client/linux/libbreakpad_client.la
@LINUX_HOST_TRUE@src_client_linux_linux_client_unittest_DEPENDENCIES = src/client/linux/linux_dumper_unittest_helper src/client/linux/libbreakpad_client.la src/libbreakpad.la
src_processor_address_map_unittest_SOURCES = \
src/processor/address_map_unittest.cc

123
src/client/linux/handler/exception_handler_unittest.cc
View file

@ -32,6 +32,7 @@
#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>
@ -42,6 +43,7 @@
#include "common/linux/eintr_wrapper.h"
#include "common/linux/linux_libc_support.h"
#include "third_party/lss/linux_syscall_support.h"
#include "google_breakpad/processor/minidump.h"
using namespace google_breakpad;
@ -126,6 +128,127 @@ TEST(ExceptionHandlerTest, ChildCrash) {
ASSERT_EQ(stat(minidump_filename.c_str(), &st), 0);
ASSERT_GT(st.st_size, 0u);
unlink(minidump_filename.c_str());
}
TEST(ExceptionHandlerTest, InstructionPointerMemory) {
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 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 };
const pid_t child = fork();
if (child == 0) {
close(fds[0]);
ExceptionHandler handler("/tmp", NULL, DoneCallback, (void*) fds[1],
true);
// 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();
}
close(fds[1]);
int status;
ASSERT_NE(HANDLE_EINTR(waitpid(child, &status, 0)), -1);
ASSERT_TRUE(WIFSIGNALED(status));
ASSERT_EQ(WTERMSIG(status), SIGILL);
struct pollfd pfd;
memset(&pfd, 0, sizeof(pfd));
pfd.fd = fds[0];
pfd.events = POLLIN | POLLERR;
const int r = HANDLE_EINTR(poll(&pfd, 1, 0));
ASSERT_EQ(r, 1);
ASSERT_TRUE(pfd.revents & POLLIN);
uint32_t len;
ASSERT_EQ(read(fds[0], &len, sizeof(len)), (ssize_t)sizeof(len));
ASSERT_LT(len, (uint32_t)2048);
char* filename = reinterpret_cast<char*>(malloc(len + 1));
ASSERT_EQ(read(fds[0], filename, len), len);
filename[len] = 0;
close(fds[0]);
const std::string minidump_filename = std::string("/tmp/") + filename +
".dmp";
struct stat st;
ASSERT_EQ(stat(minidump_filename.c_str(), &st), 0);
ASSERT_GT(st.st_size, 0u);
// 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_filename);
ASSERT_TRUE(minidump.Read());
MinidumpException* exception = minidump.GetException();
MinidumpMemoryList* memory_list = minidump.GetMemoryList();
ASSERT_TRUE(exception);
ASSERT_TRUE(memory_list);
ASSERT_LT(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);
ASSERT_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);
unlink(minidump_filename.c_str());
free(filename);
}

93
src/client/linux/minidump_writer/minidump_writer.cc
View file

@ -46,6 +46,8 @@
#include "client/linux/minidump_writer/minidump_writer.h"
#include "client/minidump_file_writer-inl.h"
#include <algorithm>
#include <errno.h>
#include <fcntl.h>
#include <link.h>
@ -367,7 +369,8 @@ class MinidumpWriter {
float_state_(NULL),
#endif
crashing_tid_(context->tid),
dumper_(crashing_pid) {
dumper_(crashing_pid),
memory_blocks_(dumper_.allocator()) {
}
bool Init() {
@ -400,7 +403,9 @@ class MinidumpWriter {
// A minidump file contains a number of tagged streams. This is the number
// of stream which we write.
const unsigned kNumWriters = 11 + !!r_debug;
unsigned kNumWriters = 12;
if (r_debug)
++kNumWriters;
TypedMDRVA<MDRawHeader> header(&minidump_writer_);
TypedMDRVA<MDRawDirectory> dir(&minidump_writer_);
@ -427,6 +432,10 @@ class MinidumpWriter {
return false;
dir.CopyIndex(dir_index++, &dirent);
if (!WriteMemoryListStream(&dirent))
return false;
dir.CopyIndex(dir_index++, &dirent);
if (!WriteExceptionStream(&dirent))
return false;
dir.CopyIndex(dir_index++, &dirent);
@ -635,6 +644,50 @@ class MinidumpWriter {
memory.Copy(stack_copy, stack_len);
thread.stack.start_of_memory_range = (uintptr_t) (stack);
thread.stack.memory = memory.location();
memory_blocks_.push_back(thread.stack);
// Copy 256 bytes around crashing instruction pointer to minidump.
const size_t kIPMemorySize = 256;
u_int64_t ip = GetInstructionPointer();
// Bound it to the upper and lower bounds of the memory map
// it's contained within. If it's not in mapped memory,
// don't bother trying to write it.
bool ip_is_mapped = false;
MDMemoryDescriptor ip_memory_d;
for (unsigned i = 0; i < dumper_.mappings().size(); ++i) {
const MappingInfo& mapping = *dumper_.mappings()[i];
if (ip >= mapping.start_addr &&
ip < mapping.start_addr + mapping.size) {
ip_is_mapped = true;
// Try to get 128 bytes before and after the IP, but
// settle for whatever's available.
ip_memory_d.start_of_memory_range =
std::min(mapping.start_addr,
uintptr_t(ip - (kIPMemorySize / 2)));
ip_memory_d.memory.data_size =
std::min(ptrdiff_t(kIPMemorySize),
ptrdiff_t(mapping.start_addr + mapping.size
- ip_memory_d.start_of_memory_range));
break;
}
}
if (ip_is_mapped) {
UntypedMDRVA ip_memory(&minidump_writer_);
if (!ip_memory.Allocate(ip_memory_d.memory.data_size))
return false;
uint8_t* memory_copy =
(uint8_t*) dumper_.allocator()->Alloc(ip_memory_d.memory.data_size);
dumper_.CopyFromProcess(
memory_copy,
thread.thread_id,
reinterpret_cast<void*>(ip_memory_d.start_of_memory_range),
ip_memory_d.memory.data_size);
ip_memory.Copy(memory_copy, ip_memory_d.memory.data_size);
ip_memory_d.memory = ip_memory.location();
memory_blocks_.push_back(ip_memory_d);
}
TypedMDRVA<RawContextCPU> cpu(&minidump_writer_);
if (!cpu.Allocate())
return false;
@ -657,6 +710,8 @@ class MinidumpWriter {
memory.Copy(stack_copy, info.stack_len);
thread.stack.start_of_memory_range = (uintptr_t)(info.stack);
thread.stack.memory = memory.location();
memory_blocks_.push_back(thread.stack);
TypedMDRVA<RawContextCPU> cpu(&minidump_writer_);
if (!cpu.Allocate())
return false;
@ -757,6 +812,24 @@ class MinidumpWriter {
return true;
}
bool WriteMemoryListStream(MDRawDirectory* dirent) {
TypedMDRVA<uint32_t> list(&minidump_writer_);
if (!list.AllocateObjectAndArray(memory_blocks_.size(),
sizeof(MDMemoryDescriptor)))
return false;
dirent->stream_type = MD_MEMORY_LIST_STREAM;
dirent->location = list.location();
*list.get() = memory_blocks_.size();
for (size_t i = 0; i < memory_blocks_.size(); ++i) {
list.CopyIndexAfterObject(i, &memory_blocks_[i],
sizeof(MDMemoryDescriptor));
}
return true;
}
bool WriteExceptionStream(MDRawDirectory* dirent) {
TypedMDRVA<MDRawExceptionStream> exc(&minidump_writer_);
if (!exc.Allocate())
@ -872,14 +945,26 @@ class MinidumpWriter {
uintptr_t GetStackPointer() {
return ucontext_->uc_mcontext.gregs[REG_ESP];
}
uintptr_t GetInstructionPointer() {
return ucontext_->uc_mcontext.gregs[REG_EIP];
}
#elif defined(__x86_64)
uintptr_t GetStackPointer() {
return ucontext_->uc_mcontext.gregs[REG_RSP];
}
uintptr_t GetInstructionPointer() {
return ucontext_->uc_mcontext.gregs[REG_RIP];
}
#elif defined(__ARM_EABI__)
uintptr_t GetStackPointer() {
return ucontext_->uc_mcontext.arm_sp;
}
uintptr_t GetInstructionPointer() {
return ucontext_->uc_mcontext.arm_ip;
}
#else
#error "This code has not been ported to your platform yet."
#endif
@ -1129,6 +1214,10 @@ popline:
LinuxDumper dumper_;
MinidumpFileWriter minidump_writer_;
MDLocationDescriptor crashing_thread_context_;
// Blocks of memory written to the dump. These are all currently
// written while writing the thread list stream, but saved here
// so a memory list stream can be written afterwards.
wasteful_vector<MDMemoryDescriptor> memory_blocks_;
};
bool WriteMinidump(const char* filename, pid_t crashing_process,