Merge "libdebuggerd_handler: in-process crash dumping for seccomped processes." (c7cd48af) · Commits · e / os / android_system_core

debuggerd/Android.bp

+45 −5

Original line number	Diff line number	Diff line
		@@ -12,14 +12,48 @@ cc_defaults {
		}

		cc_library_static {
		name: "libdebuggerd_handler",
		name: "libdebuggerd_handler_core",
		defaults: ["debuggerd_defaults"],
		srcs: ["handler/debuggerd_handler.cpp"],

		// libdebuggerd_handler gets async signal safe logging via libc_logging,
		// which defines its interface in bionic private headers.
		include_dirs: ["bionic/libc"],
		static_libs: ["libc_logging"],
		whole_static_libs: [
		"libc_logging",
		"libdebuggerd",
		],

		export_include_dirs: ["include"],
		}

		cc_library_static {
		name: "libdebuggerd_handler",
		defaults: ["debuggerd_defaults"],
		srcs: ["handler/debuggerd_fallback_nop.cpp"],

		whole_static_libs: [
		"libdebuggerd_handler_core",
		],

		export_include_dirs: ["include"],
		}

		cc_library_static {
		name: "libdebuggerd_handler_fallback",
		defaults: ["debuggerd_defaults"],
		srcs: ["handler/debuggerd_fallback.cpp"],

		// libdebuggerd_handler gets async signal safe logging via libc_logging,
		// which defines its interface in bionic private headers.
		include_dirs: ["bionic/libc"],
		static_libs: [
		"libdebuggerd",
		"libbacktrace",
		"libunwind",
		"liblzma",
		"libcutils",
		],

		export_include_dirs: ["include"],
		}
		@@ -39,7 +73,7 @@ cc_library {
		export_include_dirs: ["include"],
		}

		cc_library {
		cc_library_static {
		name: "libdebuggerd",
		defaults: ["debuggerd_defaults"],

		@@ -75,8 +109,10 @@ cc_library {
		local_include_dirs: ["libdebuggerd/include"],
		export_include_dirs: ["libdebuggerd/include"],

		shared_libs: [
		static_libs: [
		"libbacktrace",
		"libunwind",
		"liblzma",
		"libbase",
		"libcutils",
		"liblog",
		@@ -150,10 +186,14 @@ cc_binary {
		},
		},

		static_libs: [
		"libdebuggerd",
		"libcutils",
		],

		shared_libs: [
		"libbacktrace",
		"libbase",
		"libdebuggerd",
		"liblog",
		"libprocinfo",
		"libselinux",

debuggerd/crash_dump.cpp

+2 −2

Original line number	Diff line number	Diff line
		@@ -395,8 +395,8 @@ int main(int argc, char** argv) {
		if (backtrace) {
		dump_backtrace(output_fd.get(), backtrace_map.get(), target, main_tid, attached_siblings, 0);
		} else {
		engrave_tombstone(output_fd.get(), backtrace_map.get(), open_files, target, main_tid,
		attached_siblings, abort_address, fatal_signal ? &amfd_data : nullptr);
		engrave_tombstone(output_fd.get(), backtrace_map.get(), &open_files, target, main_tid,
		&attached_siblings, abort_address, fatal_signal ? &amfd_data : nullptr);
		}

		// We don't actually need to PTRACE_DETACH, as long as our tracees aren't in

debuggerd/handler/debuggerd_fallback.cpp

0 → 100644

+48 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2017 The Android Open Source Project
		* All rights reserved.
		*
		* Redistribution and use in source and binary forms, with or without
		* modification, are permitted provided that the following conditions
		* are met:
		* * Redistributions of source code must retain the above copyright
		* notice, this list of conditions and the following disclaimer.
		* * Redistributions in binary form must reproduce the above copyright
		* notice, this list of conditions and the following disclaimer in
		* the documentation and/or other materials provided with the
		* distribution.
		*
		* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
		* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
		* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
		* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
		* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
		* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
		* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
		* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
		* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
		* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
		* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
		* SUCH DAMAGE.
		*/

		#include <stddef.h>
		#include <sys/ucontext.h>
		#include <unistd.h>

		#include "tombstone.h"

		extern "C" void __linker_use_fallback_allocator();

		extern "C" bool debuggerd_fallback(ucontext_t* ucontext, siginfo_t* siginfo, void* abort_message) {
		// This is incredibly sketchy to do inside of a signal handler, especially when libbacktrace
		// uses the C++ standard library throughout, but this code runs in the linker, so we'll be using
		// the linker's malloc instead of the libc one. Switch it out for a replacement, just in case.
		//
		// This isn't the default method of dumping because it can fail in cases such as memory space
		// exhaustion.
		__linker_use_fallback_allocator();
		engrave_tombstone_ucontext(-1, getpid(), gettid(), reinterpret_cast<uintptr_t>(abort_message),
		siginfo, ucontext);
		return true;
		}

debuggerd/handler/debuggerd_fallback_nop.cpp

0 → 100644

+35 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2017 The Android Open Source Project
		* All rights reserved.
		*
		* Redistribution and use in source and binary forms, with or without
		* modification, are permitted provided that the following conditions
		* are met:
		* * Redistributions of source code must retain the above copyright
		* notice, this list of conditions and the following disclaimer.
		* * Redistributions in binary form must reproduce the above copyright
		* notice, this list of conditions and the following disclaimer in
		* the documentation and/or other materials provided with the
		* distribution.
		*
		* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
		* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
		* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
		* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
		* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
		* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
		* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
		* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
		* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
		* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
		* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
		* SUCH DAMAGE.
		*/

		#include <stddef.h>
		#include <sys/ucontext.h>
		#include <unistd.h>

		extern "C" bool debuggerd_fallback(ucontext_t, siginfo_t, void*) {
		return false;
		}

debuggerd/handler/debuggerd_handler.cpp

+14 −8

Original line number	Diff line number	Diff line
		@@ -62,6 +62,8 @@

		#define CRASH_DUMP_PATH "/system/bin/" CRASH_DUMP_NAME

		extern "C" bool debuggerd_fallback(ucontext_t, siginfo_t, void*);

		static debuggerd_callbacks_t g_callbacks;

		// Mutex to ensure only one crashing thread dumps itself.
		@@ -329,7 +331,7 @@ static void resend_signal(siginfo_t* info, bool crash_dump_started) {

		// Handler that does crash dumping by forking and doing the processing in the child.
		// Do this by ptracing the relevant thread, and then execing debuggerd to do the actual dump.
		static void debuggerd_signal_handler(int signal_number, siginfo_t* info, void*) {
		static void debuggerd_signal_handler(int signal_number, siginfo_t* info, void* context) {
		int ret = pthread_mutex_lock(&crash_mutex);
		if (ret != 0) {
		__libc_format_log(ANDROID_LOG_INFO, "libc", "pthread_mutex_lock failed: %s", strerror(ret));
		@@ -359,18 +361,22 @@ static void debuggerd_signal_handler(int signal_number, siginfo_t* info, void*)

		log_signal_summary(signal_number, info);

		void* abort_message = nullptr;
		if (g_callbacks.get_abort_message) {
		abort_message = g_callbacks.get_abort_message();
		}

		if (prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0) == 1) {
		ucontext_t* ucontext = static_cast<ucontext_t*>(context);
		if (signal_number == DEBUGGER_SIGNAL \|\| !debuggerd_fallback(ucontext, info, abort_message)) {
		// The process has NO_NEW_PRIVS enabled, so we can't transition to the crash_dump context.
		__libc_format_log(ANDROID_LOG_INFO, "libc",
		"Suppressing debuggerd output because prctl(PR_GET_NO_NEW_PRIVS)==1");
		}
		resend_signal(info, false);
		return;
		}

		void* abort_message = nullptr;
		if (g_callbacks.get_abort_message) {
		abort_message = g_callbacks.get_abort_message();
		}
		// Populate si_value with the abort message address, if found.
		if (abort_message) {
		info->si_value.sival_ptr = abort_message;