1 /*
2  * Copyright (C) 2023 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 #include "berberis/runtime_primitives/crash_reporter.h"
18 
19 #include <sys/syscall.h>  // SYS_rt_tgdigqueueinfo
20 #include <unistd.h>       // syscall
21 
22 #include <csignal>
23 
24 #include "berberis/base/gettid.h"
25 #include "berberis/base/tracing.h"
26 #include "berberis/instrument/crash.h"
27 
28 namespace berberis {
29 
30 namespace {
31 
32 struct sigaction g_orig_action[NSIG];
33 
HandleFatalSignal(int sig,siginfo_t * info,void * context)34 void HandleFatalSignal(int sig, siginfo_t* info, void* context) {
35   TRACE("fatal signal %d", sig);
36 
37   OnCrash(sig, info, context);
38 
39   // Let default crash reporter do the job.
40   // Restore original signal action, as default crash reporter can re-raise the signal.
41   sigaction(sig, &g_orig_action[sig], nullptr);
42   if (g_orig_action[sig].sa_flags & SA_SIGINFO) {
43     // Run original signal action manually and provide actual siginfo and context.
44     g_orig_action[sig].sa_sigaction(sig, info, context);
45   } else {
46     // This should be rare as debuggerd sets siginfo handlers for most signals!
47     // Original action doesn't accept siginfo and context :(
48     // Re-raise the signal as accurate as possible and hope for the best.
49     syscall(SYS_rt_tgsigqueueinfo, GetpidSyscall(), GettidSyscall(), sig, info);
50   }
51 }
52 
53 }  // namespace
54 
InitCrashReporter()55 void InitCrashReporter() {
56   struct sigaction action {};
57   action.sa_sigaction = HandleFatalSignal;
58   action.sa_flags = SA_SIGINFO | SA_ONSTACK;
59   sigfillset(&action.sa_mask);
60 
61   sigaction(SIGSEGV, &action, &g_orig_action[SIGSEGV]);
62   sigaction(SIGILL, &action, &g_orig_action[SIGILL]);
63   sigaction(SIGFPE, &action, &g_orig_action[SIGFPE]);
64   sigaction(SIGABRT, &action, &g_orig_action[SIGABRT]);
65 }
66 
67 }  // namespace berberis
68