Re-add backtrace note about unreadable elf. (fe751c5a) · Commits · e / os / android_system_core

debuggerd/Android.bp

+10 −0

Original line number	Diff line number	Diff line
		@@ -276,6 +276,12 @@ cc_binary {
		],
		}

		cc_test_library {
		name: "libcrash_test",
		defaults: ["debuggerd_defaults"],
		srcs: ["crash_test.cpp"],
		}

		cc_test {
		name: "debuggerd_test",
		defaults: ["debuggerd_defaults"],
		@@ -341,6 +347,10 @@ cc_test {
		},
		},

		data: [
		":libcrash_test",
		],

		test_suites: ["device-tests"],
		}

debuggerd/crash_test.cpp

0 → 100644

+21 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright 2021, The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		#include <stdint.h>

		extern "C" void crash() {
		reinterpret_cast<volatile char>(0xdead) = '1';
		}

debuggerd/debuggerd_test.cpp

+56 −0

Original line number	Diff line number	Diff line
		@@ -15,6 +15,7 @@
		*/

		#include <dirent.h>
		#include <dlfcn.h>
		#include <err.h>
		#include <fcntl.h>
		#include <malloc.h>
		@@ -30,6 +31,7 @@

		#include <chrono>
		#include <regex>
		#include <string>
		#include <thread>

		#include <android/fdsan.h>
		@@ -1510,6 +1512,60 @@ TEST_F(CrasherTest, stack_overflow) {
		ASSERT_MATCH(result, R"(Cause: stack pointer[^\n]*stack overflow.\n)");
		}

		static bool CopySharedLibrary(const char* tmp_dir, std::string* tmp_so_name) {
		std::string test_lib(testing::internal::GetArgvs()[0]);
		auto const value = test_lib.find_last_of('/');
		if (value == std::string::npos) {
		test_lib = "./";
		} else {
		test_lib = test_lib.substr(0, value + 1) + "./";
		}
		test_lib += "libcrash_test.so";

		*tmp_so_name = std::string(tmp_dir) + "/libcrash_test.so";
		std::string cp_cmd = android::base::StringPrintf("cp %s %s", test_lib.c_str(), tmp_dir);

		// Copy the shared so to a tempory directory.
		return system(cp_cmd.c_str()) == 0;
		}

		TEST_F(CrasherTest, unreadable_elf) {
		int intercept_result;
		unique_fd output_fd;
		StartProcess([]() {
		TemporaryDir td;
		std::string tmp_so_name;
		if (!CopySharedLibrary(td.path, &tmp_so_name)) {
		_exit(1);
		}
		void* handle = dlopen(tmp_so_name.c_str(), RTLD_NOW);
		if (handle == nullptr) {
		_exit(1);
		}
		// Delete the original shared library so that we get the warning
		// about unreadable elf files.
		if (unlink(tmp_so_name.c_str()) == -1) {
		_exit(1);
		}
		void (crash_func)() = reinterpret_cast<void ()()>(dlsym(handle, "crash"));
		if (crash_func == nullptr) {
		_exit(1);
		}
		crash_func();
		});

		StartIntercept(&output_fd);
		FinishCrasher();
		AssertDeath(SIGSEGV);
		FinishIntercept(&intercept_result);

		ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";

		std::string result;
		ConsumeFd(std::move(output_fd), &result);
		ASSERT_MATCH(result, R"(NOTE: Function names and BuildId information is missing )");
		}

		TEST(tombstoned, proto) {
		const pid_t self = getpid();
		unique_fd tombstoned_socket, text_fd, proto_fd;

debuggerd/libdebuggerd/tombstone_proto.cpp

+9 −0

Original line number	Diff line number	Diff line
		@@ -395,6 +395,15 @@ static void dump_thread(Tombstone* tombstone, unwindstack::Unwinder* unwinder,
		unwinder->LastErrorAddress());
		}
		} else {
		if (unwinder->elf_from_memory_not_file()) {
		auto backtrace_note = thread.mutable_backtrace_note();
		*backtrace_note->Add() =
		"Function names and BuildId information is missing for some frames due";
		*backtrace_note->Add() =
		"to unreadable libraries. For unwinds of apps, only shared libraries";
		*backtrace_note->Add() = "found under the lib/ directory are readable.";
		*backtrace_note->Add() = "On this device, run setenforce 0 to make the libraries readable.";
		}
		unwinder->SetDisplayBuildID(true);
		for (const auto& frame : unwinder->frames()) {
		BacktraceFrame* f = thread.add_current_backtrace();

debuggerd/libdebuggerd/tombstone_proto_to_text.cpp

+4 −0

Original line number	Diff line number	Diff line
		@@ -171,6 +171,10 @@ static void print_thread_backtrace(CallbackType callback, const Tombstone& tombs
		const Thread& thread, bool should_log) {
		CBS("");
		CB(should_log, "backtrace:");
		if (!thread.backtrace_note().empty()) {
		CB(should_log, " NOTE: %s",
		android::base::Join(thread.backtrace_note(), "\n NOTE: ").c_str());
		}
		print_backtrace(callback, tombstone, thread.current_backtrace(), should_log);
		}