diff --git a/debuggerd/Android.mk b/debuggerd/Android.mk index 607745dd3..e3bdd43c3 100644 --- a/debuggerd/Android.mk +++ b/debuggerd/Android.mk @@ -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) diff --git a/debuggerd/crasher.cpp b/debuggerd/crasher.cpp index b0e8b175f..e650f2274 100644 --- a/debuggerd/crasher.cpp +++ b/debuggerd/crasher.cpp @@ -17,47 +17,43 @@ #define LOG_TAG "crasher" #include +#include #include #include #include -#include #include #include #include #include -#include #include -#include -#include -#include #include +// We test both kinds of logging. #include -#include +#include #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; +noinline void* thread_callback(void* raw_arg) { + const char* arg = reinterpret_cast(raw_arg); + return reinterpret_cast(static_cast(do_action(arg))); } -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); -} - -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(arg)); + void* result = nullptr; pthread_join(t, &result); - return (int) (uintptr_t) result; + return reinterpret_cast(result); } -__attribute__((noinline)) static int crash3(int a) { - *((int*) 0xdead) = a; +noinline int crash3(int a) { + *reinterpret_cast(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(mmap(NULL, sizeof(int), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0)); + } else if (!strcasecmp(arg, "SIGSEGV-unmapped")) { + char* map = reinterpret_cast(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(); } + +};