Merge "Better seccomp/kuser_helper diagnostics from debuggerd." (f4ae6203) · Commits · e / os / android_system_core

debuggerd/Android.bp

+4 −0

Original line number	Diff line number	Diff line
		@@ -195,3 +195,7 @@ cc_binary {

		init_rc: ["tombstoned/tombstoned.rc"]
		}

		subdirs = [
		"crasher",
		]

debuggerd/crasher/Android.bp

0 → 100644

+81 −0

Original line number	Diff line number	Diff line
		cc_defaults {
		name: "crasher-defaults",

		cppflags: [
		"-std=gnu++14",
		"-W",
		"-Wall",
		"-Wextra",
		"-Wunused",
		"-Werror",
		"-O0",
		"-fstack-protector-all",
		"-Wno-free-nonheap-object",
		"-Wno-date-time",
		],
		srcs: ["crasher.cpp"],
		arch: {
		arm: {
		srcs: ["arm/crashglue.S"],

		armv7_a_neon: {
		asflags: ["-DHAS_VFP_D32"],
		},
		},
		arm64: {
		srcs: ["arm64/crashglue.S"],
		},
		mips: {
		srcs: ["mips/crashglue.S"],
		},
		mips64: {
		srcs: ["mips64/crashglue.S"],
		},
		x86: {
		srcs: ["x86/crashglue.S"],
		},
		x86_64: {
		srcs: ["x86_64/crashglue.S"],
		},
		},
		compile_multilib: "both",
		}

		cc_binary {
		name: "crasher",

		defaults: ["crasher-defaults"],
		shared_libs: [
		"libbase",
		"liblog",
		],
		multilib: {
		lib32: {
		stem: "crasher",
		},
		lib64: {
		stem: "crasher64",
		},
		},
		}

		cc_binary {
		name: "static_crasher",

		defaults: ["crasher-defaults"],
		cppflags: ["-DSTATIC_CRASHER"],
		static_executable: true,
		static_libs: [
		"libdebuggerd_handler",
		"libbase",
		"liblog",
		],
		multilib: {
		lib32: {
		stem: "static_crasher",
		},
		lib64: {
		stem: "static_crasher64",
		},
		},
		}

debuggerd/crasher/Android.mk

deleted100644 → 0

+0 −66

Original line number	Diff line number	Diff line
		LOCAL_PATH := $(call my-dir)

		crasher_cppflags := \
		-std=gnu++14 \
		-W \
		-Wall \
		-Wextra \
		-Wunused \
		-Werror \
		-O0 \
		-fstack-protector-all \
		-Wno-free-nonheap-object \
		-Wno-date-time

		include $(CLEAR_VARS)
		LOCAL_SRC_FILES := crasher.cpp
		LOCAL_SRC_FILES_arm := arm/crashglue.S
		LOCAL_SRC_FILES_arm64 := arm64/crashglue.S
		LOCAL_SRC_FILES_mips := mips/crashglue.S
		LOCAL_SRC_FILES_mips64 := mips64/crashglue.S
		LOCAL_SRC_FILES_x86 := x86/crashglue.S
		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 := libbase liblog

		# The arm emulator has VFP but not VFPv3-D32.
		ifeq ($(ARCH_ARM_HAVE_VFP_D32),true)
		LOCAL_ASFLAGS_arm += -DHAS_VFP_D32
		endif

		LOCAL_MODULE := crasher
		LOCAL_MODULE_STEM_32 := crasher
		LOCAL_MODULE_STEM_64 := crasher64
		LOCAL_MULTILIB := both

		include $(BUILD_EXECUTABLE)

		include $(CLEAR_VARS)
		LOCAL_SRC_FILES := crasher.cpp
		LOCAL_SRC_FILES_arm := arm/crashglue.S
		LOCAL_SRC_FILES_arm64 := arm64/crashglue.S
		LOCAL_SRC_FILES_mips := mips/crashglue.S
		LOCAL_SRC_FILES_mips64 := mips64/crashglue.S
		LOCAL_SRC_FILES_x86 := x86/crashglue.S
		LOCAL_SRC_FILES_x86_64 := x86_64/crashglue.S
		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 := libbase liblog

		# The arm emulator has VFP but not VFPv3-D32.
		ifeq ($(ARCH_ARM_HAVE_VFP_D32),true)
		LOCAL_ASFLAGS_arm += -DHAS_VFP_D32
		endif

		LOCAL_MODULE := static_crasher
		LOCAL_MODULE_STEM_32 := static_crasher
		LOCAL_MODULE_STEM_64 := static_crasher64
		LOCAL_MULTILIB := both

		LOCAL_STATIC_LIBRARIES := libdebuggerd_handler libbase liblog

		include $(BUILD_EXECUTABLE)

debuggerd/crasher/crasher.cpp

+42 −1

Original line number	Diff line number	Diff line
		@@ -36,6 +36,19 @@
		#include "debuggerd/handler.h"
		#endif

		#if defined(__arm__)
		// See https://www.kernel.org/doc/Documentation/arm/kernel_user_helpers.txt for details.
		#define __kuser_helper_version ((int32_t) 0xffff0ffc)
		typedef void * (__kuser_get_tls_t)(void);
		#define __kuser_get_tls ((__kuser_get_tls_t) 0xffff0fe0)
		typedef int (__kuser_cmpxchg_t)(int oldval, int newval, volatile int *ptr);
		#define __kuser_cmpxchg ((__kuser_cmpxchg_t) 0xffff0fc0)
		typedef void (__kuser_dmb_t)(void);
		#define __kuser_dmb ((__kuser_dmb_t) 0xffff0fa0)
		typedef int (__kuser_cmpxchg64_t)(const int64_t, const int64_t, volatile int64_t*);
		#define __kuser_cmpxchg64 ((__kuser_cmpxchg64_t) 0xffff0f60)
		#endif

		#define noinline __attribute__((__noinline__))

		// Avoid name mangling so that stacks are more readable.
		@@ -142,22 +155,36 @@ static int usage() {
		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, " nostack crash with a NULL stack pointer\n");
		fprintf(stderr, "\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, "\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, "\n");
		fprintf(stderr, " fortify fail a _FORTIFY_SOURCE check\n");
		fprintf(stderr, " seccomp fail a seccomp check\n");
		#if defined(__arm__)
		fprintf(stderr, " kuser_helper_version call kuser_helper_version\n");
		fprintf(stderr, " kuser_get_tls call kuser_get_tls\n");
		fprintf(stderr, " kuser_cmpxchg call kuser_cmpxchg\n");
		fprintf(stderr, " kuser_memory_barrier call kuser_memory_barrier\n");
		fprintf(stderr, " kuser_cmpxchg64 call kuser_cmpxchg64\n");
		#endif
		fprintf(stderr, "\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, "\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, "\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");
		@@ -235,6 +262,20 @@ noinline int do_action(const char* arg) {
		MAP_SHARED \| MAP_ANONYMOUS, -1, 0));
		munmap(map, sizeof(int));
		map[0] = '8';
		} else if (!strcasecmp(arg, "seccomp")) {
		syscall(99999);
		#if defined(__arm__)
		} else if (!strcasecmp(arg, "kuser_helper_version")) {
		return __kuser_helper_version;
		} else if (!strcasecmp(arg, "kuser_get_tls")) {
		return !__kuser_get_tls();
		} else if (!strcasecmp(arg, "kuser_cmpxchg")) {
		return __kuser_cmpxchg(0, 0, 0);
		} else if (!strcasecmp(arg, "kuser_memory_barrier")) {
		__kuser_dmb();
		} else if (!strcasecmp(arg, "kuser_cmpxchg64")) {
		return __kuser_cmpxchg64(0, 0, 0);
		#endif
		} else {
		return usage();
		}

debuggerd/libdebuggerd/tombstone.cpp

+37 −11

Original line number	Diff line number	Diff line
		@@ -49,6 +49,8 @@
		#include "open_files_list.h"
		#include "tombstone.h"

		using android::base::StringPrintf;

		#define STACK_WORDS 16

		#define MAX_TOMBSTONES 10
		@@ -195,6 +197,29 @@ static void dump_header_info(log_t* log) {
		_LOG(log, logtype::HEADER, "ABI: '%s'\n", ABI_STRING);
		}

		static void dump_probable_cause(log_t* log, const siginfo_t& si) {
		std::string cause;
		if (si.si_signo == SIGSEGV && si.si_code == SEGV_MAPERR) {
		if (si.si_addr < reinterpret_cast<void*>(4096)) {
		cause = StringPrintf("null pointer dereference");
		} else if (si.si_addr == reinterpret_cast<void*>(0xffff0ffc)) {
		cause = "call to kuser_helper_version";
		} else if (si.si_addr == reinterpret_cast<void*>(0xffff0fe0)) {
		cause = "call to kuser_get_tls";
		} else if (si.si_addr == reinterpret_cast<void*>(0xffff0fc0)) {
		cause = "call to kuser_cmpxchg";
		} else if (si.si_addr == reinterpret_cast<void*>(0xffff0fa0)) {
		cause = "call to kuser_memory_barrier";
		} else if (si.si_addr == reinterpret_cast<void*>(0xffff0f60)) {
		cause = "call to kuser_cmpxchg64";
		}
		} else if (si.si_signo == SIGSYS && si.si_code == SYS_SECCOMP) {
		cause = StringPrintf("seccomp prevented call to disallowed system call %d", si.si_syscall);
		}

		if (!cause.empty()) _LOG(log, logtype::HEADER, "Cause: %s\n", cause.c_str());
		}

		static void dump_signal_info(log_t* log, pid_t tid) {
		siginfo_t si;
		memset(&si, 0, sizeof(si));
		@@ -212,6 +237,8 @@ static void dump_signal_info(log_t* log, pid_t tid) {

		_LOG(log, logtype::HEADER, "signal %d (%s), code %d (%s), fault addr %s\n", si.si_signo,
		get_signame(si.si_signo), si.si_code, get_sigcode(si.si_signo, si.si_code), addr_desc);

		dump_probable_cause(log, si);
		}

		static void dump_thread_info(log_t* log, pid_t pid, pid_t tid) {
		@@ -262,11 +289,11 @@ static void dump_stack_segment(
		line = " ";
		if (i == 0 && label >= 0) {
		// Print the label once.
		line += android::base::StringPrintf("#%02d ", label);
		line += StringPrintf("#%02d ", label);
		} else {
		line += " ";
		}
		line += android::base::StringPrintf("%" PRIPTR " %" PRIPTR, *sp, stack_data[i]);
		line += StringPrintf("%" PRIPTR " %" PRIPTR, *sp, stack_data[i]);

		backtrace_map_t map;
		backtrace->FillInMap(stack_data[i], &map);
		@@ -277,7 +304,7 @@ static void dump_stack_segment(
		if (!func_name.empty()) {
		line += " (" + func_name;
		if (offset) {
		line += android::base::StringPrintf("+%" PRIuPTR, offset);
		line += StringPrintf("+%" PRIuPTR, offset);
		}
		line += ')';
		}
		@@ -336,11 +363,11 @@ static void dump_stack(Backtrace* backtrace, log_t* log) {
		static std::string get_addr_string(uintptr_t addr) {
		std::string addr_str;
		#if defined(__LP64__)
		addr_str = android::base::StringPrintf("%08x'%08x",
		addr_str = StringPrintf("%08x'%08x",
		static_cast<uint32_t>(addr >> 32),
		static_cast<uint32_t>(addr & 0xffffffff));
		#else
		addr_str = android::base::StringPrintf("%08x", addr);
		addr_str = StringPrintf("%08x", addr);
		#endif
		return addr_str;
		}
		@@ -426,8 +453,7 @@ static void dump_all_maps(Backtrace* backtrace, BacktraceMap* map, log_t* log, p
		} else {
		line += '-';
		}
		line += android::base::StringPrintf(" %8" PRIxPTR " %8" PRIxPTR,
		it->offset, it->end - it->start);
		line += StringPrintf(" %8" PRIxPTR " %8" PRIxPTR, it->offset, it->end - it->start);
		bool space_needed = true;
		if (it->name.length() > 0) {
		space_needed = false;
		@@ -441,7 +467,7 @@ static void dump_all_maps(Backtrace* backtrace, BacktraceMap* map, log_t* log, p
		if (space_needed) {
		line += ' ';
		}
		line += android::base::StringPrintf(" (load base 0x%" PRIxPTR ")", it->load_base);
		line += StringPrintf(" (load base 0x%" PRIxPTR ")", it->load_base);
		}
		_LOG(log, logtype::MAPS, "%s\n", line.c_str());
		}