From efa30c13f2e0bf2cb60a9d00010e8cdc162c872a Mon Sep 17 00:00:00 2001 From: "ted.mielczarek" Date: Fri, 17 Sep 2010 13:36:11 +0000 Subject: Write a window of memory around the instruction pointer from the crashing thread to the minidump on Linux. 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 --- .../linux/handler/exception_handler_unittest.cc | 123 +++++++++++++++++++++ 1 file changed, 123 insertions(+) (limited to 'src/client/linux/handler') diff --git a/src/client/linux/handler/exception_handler_unittest.cc b/src/client/linux/handler/exception_handler_unittest.cc index 731207a8..3fea1159 100644 --- a/src/client/linux/handler/exception_handler_unittest.cc +++ b/src/client/linux/handler/exception_handler_unittest.cc @@ -32,6 +32,7 @@ #include #include #include +#include #include #include #include @@ -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(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(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(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); } -- cgit v1.2.1