Merge "Improve crasher." (dbfb20bd) · Commits · e / os / android_system_core

debuggerd/Android.mk

+3 −4

Original line number	Diff line number	Diff line
		@@ -52,7 +52,7 @@ LOCAL_MULTILIB := both

		include $(BUILD_EXECUTABLE)

		crasher_cppflags := $(common_cppflags) -fstack-protector-all -Wno-free-nonheap-object -Wno-date-time
		crasher_cppflags := $(common_cppflags) -O0 -fstack-protector-all -Wno-free-nonheap-object

		include $(CLEAR_VARS)
		LOCAL_SRC_FILES := crasher.cpp
		@@ -65,7 +65,7 @@ LOCAL_SRC_FILES_x86_64 := x86_64/crashglue.S
		LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
		LOCAL_MODULE_TAGS := optional
		LOCAL_CPPFLAGS := $(crasher_cppflags)
		LOCAL_SHARED_LIBRARIES := libcutils liblog
		LOCAL_SHARED_LIBRARIES := libbase liblog

		# The arm emulator has VFP but not VFPv3-D32.
		ifeq ($(ARCH_ARM_HAVE_VFP_D32),true)
		@@ -91,7 +91,6 @@ LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
		LOCAL_MODULE_TAGS := optional
		LOCAL_CPPFLAGS := $(crasher_cppflags) -DSTATIC_CRASHER
		LOCAL_FORCE_STATIC_EXECUTABLE := true
		LOCAL_SHARED_LIBRARIES := libcutils liblog

		# The arm emulator has VFP but not VFPv3-D32.
		ifeq ($(ARCH_ARM_HAVE_VFP_D32),true)
		@@ -103,7 +102,7 @@ LOCAL_MODULE_STEM_32 := static_crasher
		LOCAL_MODULE_STEM_64 := static_crasher64
		LOCAL_MULTILIB := both

		LOCAL_STATIC_LIBRARIES := libdebuggerd_client libcutils liblog
		LOCAL_STATIC_LIBRARIES := libdebuggerd_client libbase liblog

		include $(BUILD_EXECUTABLE)

debuggerd/crasher.cpp

+117 −122

Original line number	Diff line number	Diff line
		@@ -17,47 +17,43 @@
		#define LOG_TAG "crasher"

		#include <assert.h>
		#include <dirent.h>
		#include <errno.h>
		#include <fcntl.h>
		#include <pthread.h>
		#include <sched.h>
		#include <signal.h>
		#include <stdio.h>
		#include <stdlib.h>
		#include <string.h>
		#include <sys/cdefs.h>
		#include <sys/mman.h>
		#include <sys/ptrace.h>
		#include <sys/socket.h>
		#include <sys/wait.h>
		#include <unistd.h>

		// We test both kinds of logging.
		#include <android/log.h>
		#include <cutils/sockets.h>
		#include <android-base/logging.h>

		#if defined(STATIC_CRASHER)
		#include "debuggerd/client.h"
		#endif

		#ifndef __unused
		#define __unused __attribute__((__unused__))
		#endif
		#define noinline __attribute__((__noinline__))

		extern const char* __progname;
		// Avoid name mangling so that stacks are more readable.
		extern "C" {

		extern "C" void crash1(void);
		extern "C" void crashnostack(void);
		void crash1(void);
		void crashnostack(void);

		static int do_action(const char* arg);
		int do_action(const char* arg);

		static void maybe_abort() {
		noinline void maybe_abort() {
		if (time(0) != 42) {
		abort();
		}
		}

		static char* smash_stack_dummy_buf;
		__attribute__ ((noinline)) static void smash_stack_dummy_function(volatile int* plen) {
		char* smash_stack_dummy_buf;
		noinline void smash_stack_dummy_function(volatile int* plen) {
		smash_stack_dummy_buf[*plen] = 0;
		}

		@@ -65,8 +61,8 @@ __attribute__ ((noinline)) static void smash_stack_dummy_function(volatile int*
		// compiler generates the proper stack guards around this function.
		// Assign local array address to global variable to force stack guards.
		// Use another noinline function to corrupt the stack.
		__attribute__ ((noinline)) static int smash_stack(volatile int* plen) {
		printf("%s: deliberately corrupting stack...\n", __progname);
		noinline int smash_stack(volatile int* plen) {
		printf("%s: deliberately corrupting stack...\n", getprogname());

		char buf[128];
		smash_stack_dummy_buf = buf;
		@@ -75,91 +71,107 @@ __attribute__ ((noinline)) static int smash_stack(volatile int* plen) {
		return 0;
		}

		#if defined(__clang__)
		#pragma clang diagnostic push
		#pragma clang diagnostic ignored "-Winfinite-recursion"
		#endif

		static void* global = 0; // So GCC doesn't optimize the tail recursion out of overflow_stack.
		void* global = 0; // So GCC doesn't optimize the tail recursion out of overflow_stack.

		__attribute__((noinline)) static void overflow_stack(void* p) {
		noinline void overflow_stack(void* p) {
		void* buf[1];
		buf[0] = p;
		global = buf;
		overflow_stack(&buf);
		}

		#if defined(__clang__)
		#pragma clang diagnostic pop
		#endif

		static void noisy(void x)
		{
		char c = (uintptr_t) x;
		for(;;) {
		usleep(250*1000);
		write(2, &c, 1);
		if(c == 'C') ((volatile unsigned) 0) = 42;
		}
		return NULL;
		}

		static int ctest()
		{
		pthread_t thr;
		pthread_attr_t attr;
		pthread_attr_init(&attr);
		pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
		pthread_create(&thr, &attr, noisy, (void*) 'A');
		pthread_create(&thr, &attr, noisy, (void*) 'B');
		pthread_create(&thr, &attr, noisy, (void*) 'C');
		for(;;) ;
		return 0;
		}

		static void* thread_callback(void* raw_arg)
		{
		return (void) (uintptr_t) do_action((const char) raw_arg);
		noinline void* thread_callback(void* raw_arg) {
		const char* arg = reinterpret_cast<const char*>(raw_arg);
		return reinterpret_cast<void*>(static_cast<uintptr_t>(do_action(arg)));
		}

		static int do_action_on_thread(const char* arg)
		{
		noinline int do_action_on_thread(const char* arg) {
		pthread_t t;
		pthread_create(&t, NULL, thread_callback, (void*) arg);
		void* result = NULL;
		pthread_create(&t, nullptr, thread_callback, const_cast<char*>(arg));
		void* result = nullptr;
		pthread_join(t, &result);
		return (int) (uintptr_t) result;
		return reinterpret_cast<uintptr_t>(result);
		}

		__attribute__((noinline)) static int crash3(int a) {
		((int) 0xdead) = a;
		noinline int crash3(int a) {
		reinterpret_cast<int>(0xdead) = a;
		return a*4;
		}

		__attribute__((noinline)) static int crash2(int a) {
		noinline int crash2(int a) {
		a = crash3(a) + 2;
		return a*3;
		}

		__attribute__((noinline)) static int crash(int a) {
		noinline int crash(int a) {
		a = crash2(a) + 1;
		return a*2;
		}

		static void abuse_heap() {
		noinline void abuse_heap() {
		char buf[16];
		free((void*) buf); // GCC is smart enough to warn about this, but we're doing it deliberately.
		free(buf); // GCC is smart enough to warn about this, but we're doing it deliberately.
		}

		static void sigsegv_non_null() {
		noinline void sigsegv_non_null() {
		int* a = (int *)(&do_action);
		*a = 42;
		}

		static int do_action(const char* arg)
		{
		fprintf(stderr, "%s: init pid=%d tid=%d\n", __progname, getpid(), gettid());
		noinline void fprintf_null() {
		fprintf(nullptr, "oops");
		}

		noinline void readdir_null() {
		readdir(nullptr);
		}

		noinline int strlen_null() {
		char* sneaky_null = nullptr;
		return strlen(sneaky_null);
		}

		static int usage() {
		fprintf(stderr, "usage: %s KIND\n", getprogname());
		fprintf(stderr, "\n");
		fprintf(stderr, "where KIND is:\n");
		fprintf(stderr, " smash-stack overwrite a -fstack-protector guard\n");
		fprintf(stderr, " stack-overflow recurse until the stack overflows\n");
		fprintf(stderr, " heap-corruption cause a libc abort by corrupting the heap\n");
		fprintf(stderr, " heap-usage cause a libc abort by abusing a heap function\n");
		fprintf(stderr, " nostack crash with a NULL stack pointer\n");
		fprintf(stderr, " abort call abort()\n");
		fprintf(stderr, " assert call assert() without a function\n");
		fprintf(stderr, " assert2 call assert() with a function\n");
		fprintf(stderr, " exit call exit(1)\n");
		fprintf(stderr, " fortify fail a _FORTIFY_SOURCE check\n");
		fprintf(stderr, " LOG_ALWAYS_FATAL call liblog LOG_ALWAYS_FATAL\n");
		fprintf(stderr, " LOG_ALWAYS_FATAL_IF call liblog LOG_ALWAYS_FATAL_IF\n");
		fprintf(stderr, " LOG-FATAL call libbase LOG(FATAL)\n");
		fprintf(stderr, " SIGFPE cause a SIGFPE\n");
		fprintf(stderr, " SIGSEGV cause a SIGSEGV at address 0x0 (synonym: crash)\n");
		fprintf(stderr, " SIGSEGV-non-null cause a SIGSEGV at a non-zero address\n");
		fprintf(stderr, " SIGSEGV-unmapped mmap/munmap a region of memory and then attempt to access it\n");
		fprintf(stderr, " SIGTRAP cause a SIGTRAP\n");
		fprintf(stderr, " fprintf-NULL pass a null pointer to fprintf\n");
		fprintf(stderr, " readdir-NULL pass a null pointer to readdir\n");
		fprintf(stderr, " strlen-NULL pass a null pointer to strlen\n");
		fprintf(stderr, "\n");
		fprintf(stderr, "prefix any of the above with 'thread-' to run on a new thread\n");
		fprintf(stderr, "prefix any of the above with 'exhaustfd-' to exhaust\n");
		fprintf(stderr, "all available file descriptors before crashing.\n");
		fprintf(stderr, "prefix any of the above with 'wait-' to wait until input is received on stdin\n");

		return EXIT_FAILURE;
		}

		noinline int do_action(const char* arg) {
		// Prefixes.
		if (!strncmp(arg, "wait-", strlen("wait-"))) {
		char buf[1];
		TEMP_FAILURE_RETRY(read(STDIN_FILENO, buf, sizeof(buf)));
		@@ -172,82 +184,66 @@ static int do_action(const char* arg)
		return do_action(arg + strlen("exhaustfd-"));
		} else if (!strncmp(arg, "thread-", strlen("thread-"))) {
		return do_action_on_thread(arg + strlen("thread-"));
		} else if (!strcmp(arg, "SIGSEGV-non-null")) {
		}

		// Actions.
		if (!strcasecmp(arg, "SIGSEGV-non-null")) {
		sigsegv_non_null();
		} else if (!strcmp(arg, "smash-stack")) {
		} else if (!strcasecmp(arg, "smash-stack")) {
		volatile int len = 128;
		return smash_stack(&len);
		} else if (!strcmp(arg, "stack-overflow")) {
		overflow_stack(NULL);
		} else if (!strcmp(arg, "nostack")) {
		} else if (!strcasecmp(arg, "stack-overflow")) {
		overflow_stack(nullptr);
		} else if (!strcasecmp(arg, "nostack")) {
		crashnostack();
		} else if (!strcmp(arg, "ctest")) {
		return ctest();
		} else if (!strcmp(arg, "exit")) {
		} else if (!strcasecmp(arg, "exit")) {
		exit(1);
		} else if (!strcmp(arg, "crash") \|\| !strcmp(arg, "SIGSEGV")) {
		} else if (!strcasecmp(arg, "crash") \|\| !strcmp(arg, "SIGSEGV")) {
		return crash(42);
		} else if (!strcmp(arg, "abort")) {
		} else if (!strcasecmp(arg, "abort")) {
		maybe_abort();
		} else if (!strcmp(arg, "assert")) {
		} else if (!strcasecmp(arg, "assert")) {
		__assert("some_file.c", 123, "false");
		} else if (!strcmp(arg, "assert2")) {
		} else if (!strcasecmp(arg, "assert2")) {
		__assert2("some_file.c", 123, "some_function", "false");
		} else if (!strcmp(arg, "fortify")) {
		} else if (!strcasecmp(arg, "fortify")) {
		char buf[10];
		__read_chk(-1, buf, 32, 10);
		while (true) pause();
		} else if (!strcmp(arg, "LOG_ALWAYS_FATAL")) {
		} else if (!strcasecmp(arg, "LOG(FATAL)")) {
		LOG(FATAL) << "hello " << 123;
		} else if (!strcasecmp(arg, "LOG_ALWAYS_FATAL")) {
		LOG_ALWAYS_FATAL("hello %s", "world");
		} else if (!strcmp(arg, "LOG_ALWAYS_FATAL_IF")) {
		} else if (!strcasecmp(arg, "LOG_ALWAYS_FATAL_IF")) {
		LOG_ALWAYS_FATAL_IF(true, "hello %s", "world");
		} else if (!strcmp(arg, "SIGFPE")) {
		} else if (!strcasecmp(arg, "SIGFPE")) {
		raise(SIGFPE);
		return EXIT_SUCCESS;
		} else if (!strcmp(arg, "SIGTRAP")) {
		} else if (!strcasecmp(arg, "SIGTRAP")) {
		raise(SIGTRAP);
		return EXIT_SUCCESS;
		} else if (!strcmp(arg, "heap-usage")) {
		} else if (!strcasecmp(arg, "fprintf-NULL")) {
		fprintf_null();
		} else if (!strcasecmp(arg, "readdir-NULL")) {
		readdir_null();
		} else if (!strcasecmp(arg, "strlen-NULL")) {
		return strlen_null();
		} else if (!strcasecmp(arg, "heap-usage")) {
		abuse_heap();
		} else if (!strcmp(arg, "SIGSEGV-unmapped")) {
		char* map = reinterpret_cast<char*>(mmap(NULL, sizeof(int), PROT_READ \| PROT_WRITE, MAP_SHARED \| MAP_ANONYMOUS, -1, 0));
		} else if (!strcasecmp(arg, "SIGSEGV-unmapped")) {
		char* map = reinterpret_cast<char*>(mmap(nullptr, sizeof(int), PROT_READ \| PROT_WRITE,
		MAP_SHARED \| MAP_ANONYMOUS, -1, 0));
		munmap(map, sizeof(int));
		map[0] = '8';
		} else {
		return usage();
		}

		fprintf(stderr, "%s OP\n", __progname);
		fprintf(stderr, "where OP is:\n");
		fprintf(stderr, " smash-stack overwrite a stack-guard canary\n");
		fprintf(stderr, " stack-overflow recurse until the stack overflows\n");
		fprintf(stderr, " heap-corruption cause a libc abort by corrupting the heap\n");
		fprintf(stderr, " heap-usage cause a libc abort by abusing a heap function\n");
		fprintf(stderr, " nostack crash with a NULL stack pointer\n");
		fprintf(stderr, " ctest (obsoleted by thread-crash?)\n");
		fprintf(stderr, " exit call exit(1)\n");
		fprintf(stderr, " abort call abort()\n");
		fprintf(stderr, " assert call assert() without a function\n");
		fprintf(stderr, " assert2 call assert() with a function\n");
		fprintf(stderr, " fortify fail a _FORTIFY_SOURCE check\n");
		fprintf(stderr, " LOG_ALWAYS_FATAL call LOG_ALWAYS_FATAL\n");
		fprintf(stderr, " LOG_ALWAYS_FATAL_IF call LOG_ALWAYS_FATAL\n");
		fprintf(stderr, " SIGFPE cause a SIGFPE\n");
		fprintf(stderr, " SIGSEGV cause a SIGSEGV at address 0x0 (synonym: crash)\n");
		fprintf(stderr, " SIGSEGV-non-null cause a SIGSEGV at a non-zero address\n");
		fprintf(stderr, " SIGSEGV-unmapped mmap/munmap a region of memory and then attempt to access it\n");
		fprintf(stderr, " SIGTRAP cause a SIGTRAP\n");
		fprintf(stderr, "prefix any of the above with 'thread-' to not run\n");
		fprintf(stderr, "on the process' main thread.\n");
		fprintf(stderr, "prefix any of the above with 'exhaustfd-' to exhaust\n");
		fprintf(stderr, "all available file descriptors before crashing.\n");
		fprintf(stderr, "prefix any of the above with 'wait-' to wait until input is received on stdin\n");

		fprintf(stderr, "%s: exiting normally!\n", getprogname());
		return EXIT_SUCCESS;
		}

		int main(int argc, char **argv)
		{
		fprintf(stderr, "%s: built at " __TIME__ "!@\n", __progname);

		int main(int argc, char** argv) {
		#if defined(STATIC_CRASHER)
		debuggerd_callbacks_t callbacks = {
		.get_abort_message = []() {
		@@ -265,11 +261,10 @@ int main(int argc, char **argv)
		debuggerd_init(&callbacks);
		#endif

		if (argc > 1) {
		return do_action(argv[1]);
		} else {
		crash1();
		}
		if (argc == 1) crash1();
		else if (argc == 2) return do_action(argv[1]);

		return 0;
		return usage();
		}

		};