platform_system_core/debuggerd/tombstoned_client.cpp
Josh Gao e1aa0ca58a debuggerd_handler: implement missing fallback functionality.
Allow the fallback implementation to dump traces and create tombstones
in seccomped processes.

Bug: http://b/35858739
Test: debuggerd -b `pidof media.codec`; killall -ABRT media.codec
Change-Id: I381b283de39a66d8900f1c320d32497d6f2b4ec4
2017-03-09 11:26:05 -08:00

86 lines
3 KiB
C++

/*
* Copyright 2017, 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 "debuggerd/tombstoned.h"
#include <fcntl.h>
#include <unistd.h>
#include <utility>
#include <android-base/unique_fd.h>
#include <cutils/sockets.h>
#include "debuggerd/protocol.h"
#include "debuggerd/util.h"
#include "private/libc_logging.h"
using android::base::unique_fd;
bool tombstoned_connect(pid_t pid, unique_fd* tombstoned_socket, unique_fd* output_fd) {
unique_fd sockfd(socket_local_client(kTombstonedCrashSocketName,
ANDROID_SOCKET_NAMESPACE_RESERVED, SOCK_SEQPACKET));
if (sockfd == -1) {
__libc_format_log(ANDROID_LOG_ERROR, "libc", "failed to connect to tombstoned: %s",
strerror(errno));
return false;
}
TombstonedCrashPacket packet = {};
packet.packet_type = CrashPacketType::kDumpRequest;
packet.packet.dump_request.pid = pid;
if (TEMP_FAILURE_RETRY(write(sockfd, &packet, sizeof(packet))) != sizeof(packet)) {
__libc_format_log(ANDROID_LOG_ERROR, "libc", "failed to write DumpRequest packet: %s",
strerror(errno));
return false;
}
unique_fd tmp_output_fd;
ssize_t rc = recv_fd(sockfd, &packet, sizeof(packet), &tmp_output_fd);
if (rc == -1) {
__libc_format_log(ANDROID_LOG_ERROR, "libc",
"failed to read response to DumpRequest packet: %s", strerror(errno));
return false;
} else if (rc != sizeof(packet)) {
__libc_format_log(
ANDROID_LOG_ERROR, "libc",
"received DumpRequest response packet of incorrect length (expected %zu, got %zd)",
sizeof(packet), rc);
return false;
}
// Make the fd O_APPEND so that our output is guaranteed to be at the end of a file.
// (This also makes selinux rules consistent, because selinux distinguishes between writing to
// a regular fd, and writing to an fd with O_APPEND).
int flags = fcntl(tmp_output_fd.get(), F_GETFL);
if (fcntl(tmp_output_fd.get(), F_SETFL, flags | O_APPEND) != 0) {
__libc_format_log(ANDROID_LOG_WARN, "libc", "failed to set output fd flags: %s",
strerror(errno));
}
*tombstoned_socket = std::move(sockfd);
*output_fd = std::move(tmp_output_fd);
return true;
}
bool tombstoned_notify_completion(int tombstoned_socket) {
TombstonedCrashPacket packet = {};
packet.packet_type = CrashPacketType::kCompletedDump;
if (TEMP_FAILURE_RETRY(write(tombstoned_socket, &packet, sizeof(packet))) != sizeof(packet)) {
return false;
}
return true;
}