1 /*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #define LOG_TAG "crash_dispatcher"
18
19 #include <vector>
20
21 #include <elf.h>
22 #include <errno.h>
23 #include <unistd.h>
24
25 #include <android-base/file.h>
26 #include <log/logger.h>
27
28 namespace {
29
30 const char kCrashCollector32Path[] = "/system/bin/crash_collector32";
31 const char kCrashCollector64Path[] = "/system/bin/crash_collector64";
32
33 } // namespace
34
35 // Reads the coredump from STDIN and checks whether it's 32-bit or 64-bit,
36 // and dispatches it to the appropriate version of crash_collector.
main(int argc,char ** argv)37 int main(int argc, char** argv) {
38 // Do not abort on a write error caused by a broken pipe.
39 signal(SIGPIPE, SIG_IGN);
40 // Read the ELF header until EI_CLASS.
41 char buf_head[EI_CLASS + 1];
42 if (!android::base::ReadFully(STDIN_FILENO, buf_head, sizeof(buf_head))) {
43 ALOGE("Failed to read. errno = %d", errno);
44 return 1;
45 }
46 // Set up pipe to feed coredump to crash_collector.
47 int pipe_fds[2];
48 if (pipe(pipe_fds) == -1) {
49 ALOGE("Failed to pipe. errno = %d", errno);
50 return 1;
51 }
52 // Prepare crash_collector arguments.
53 const char* crash_collector_path = buf_head[EI_CLASS] == ELFCLASS64 ?
54 kCrashCollector64Path : kCrashCollector32Path;
55 std::vector<const char*> args(argc + 1);
56 args[0] = crash_collector_path;
57 std::copy(argv + 1, argv + argc, args.begin() + 1);
58 args.back() = nullptr;
59 // Exec crash_collector.
60 const pid_t pid = fork();
61 if (pid == -1) {
62 ALOGE("Failed to fork. errno = %d", errno);
63 return 1;
64 }
65 if (pid == 0) {
66 if (close(pipe_fds[1]) != 0 && errno != EINTR) {
67 ALOGE("Failed to close the pipe's write end. errno = %d", errno);
68 _exit(1);
69 }
70 if (TEMP_FAILURE_RETRY(dup2(pipe_fds[0], STDIN_FILENO)) != 0) {
71 ALOGE("Failed to dup the pipe's read end. errno = %d", errno);
72 _exit(1);
73 }
74 execve(args[0], const_cast<char**>(&args[0]), environ);
75 ALOGE("Failed to execute crash_collector. errno = %d", errno);
76 _exit(1);
77 }
78 // Send buf_head to crash_collector.
79 if (close(pipe_fds[0]) != 0 && errno != EINTR) {
80 ALOGE("Failed to close the pipe's read end.");
81 return 1;
82 }
83 if (!android::base::WriteFully(pipe_fds[1], buf_head, sizeof(buf_head))) {
84 return 1;
85 }
86 // Send the rest of coredump to crash_collector.
87 const size_t kBufSize = 32768;
88 char buf[kBufSize];
89 while (true) {
90 int rv = TEMP_FAILURE_RETRY(read(STDIN_FILENO, buf, kBufSize));
91 if (rv == -1) {
92 ALOGE("Failed to read. errno = %d", errno);
93 return 1;
94 }
95 if (rv == 0)
96 break;
97 if (!android::base::WriteFully(pipe_fds[1], buf, rv)) {
98 return 1;
99 }
100 }
101 return 0;
102 }
103