1 /*
2 * Copyright (c) 2021-2024 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 #include "dfx_signal_local_handler.h"
17
18 #include <securec.h>
19 #include <csignal>
20 #include <sigchain.h>
21 #include <cstdint>
22 #include <cstdio>
23 #include <unistd.h>
24 #include <pthread.h>
25 #include <sched.h>
26 #include <sys/syscall.h>
27 #include <sys/mman.h>
28 #include <sys/prctl.h>
29 #include <sys/wait.h>
30 #include <linux/futex.h>
31 #include "dfx_allocator.h"
32 #include "dfx_crash_local_handler.h"
33 #include "dfx_cutil.h"
34 #include "dfx_log.h"
35
36 #ifdef LOG_DOMAIN
37 #undef LOG_DOMAIN
38 #define LOG_DOMAIN 0xD002D11
39 #endif
40
41 #ifdef LOG_TAG
42 #undef LOG_TAG
43 #define LOG_TAG "DfxSignalLocalHandler"
44 #endif
45
46 constexpr uint32_t FAULTLOGGERD_UID = 1202;
47
48 static CrashFdFunc g_crashFdFn = nullptr;
49 static SigAlarmFunc g_sigAlarmCallbackFn = nullptr;
50 #if !defined(__aarch64__) && !defined(__loongarch_lp64)
51 constexpr uint32_t LOCAL_HANDLER_STACK_SIZE = 128 * 1024; // 128K
52 static void *g_reservedChildStack = nullptr;
53 #endif
54 static struct ProcessDumpRequest g_request;
55 static pthread_mutex_t g_signalHandlerMutex = PTHREAD_MUTEX_INITIALIZER;
56
57 static constexpr int CATCHER_STACK_SIGNALS[] = {
58 SIGABRT, SIGBUS, SIGILL, SIGSEGV, SIGALRM,
59 };
60
61 #if !defined(__aarch64__) && !defined(__loongarch_lp64)
ReserveChildThreadSignalStack(void)62 static void ReserveChildThreadSignalStack(void)
63 {
64 // reserve stack for fork
65 g_reservedChildStack = mmap(nullptr, LOCAL_HANDLER_STACK_SIZE, \
66 PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, 1, 0);
67 if (g_reservedChildStack == MAP_FAILED) {
68 DFXLOGE("[%{public}d]: Failed to alloc memory for child stack.", __LINE__);
69 return;
70 }
71 g_reservedChildStack = static_cast<void *>(static_cast<uint8_t *>(g_reservedChildStack) +
72 LOCAL_HANDLER_STACK_SIZE - 1);
73 }
74 #endif
75
FutexWait(volatile void * ftx,int value)76 AT_UNUSED static void FutexWait(volatile void* ftx, int value)
77 {
78 syscall(__NR_futex, ftx, FUTEX_WAIT, value, NULL, NULL, 0);
79 }
80
DoCrashHandler(void * arg)81 static int DoCrashHandler(void* arg)
82 {
83 int sig = *(static_cast<int *>(arg));
84 RegisterAllocator();
85 DFXLOGI("DoCrashHandler::start handle sig(%d)", sig);
86 if (sig == SIGALRM) {
87 if (g_sigAlarmCallbackFn != nullptr) {
88 g_sigAlarmCallbackFn();
89 }
90 } else {
91 if (g_crashFdFn == nullptr) {
92 CrashLocalHandler(&g_request);
93 } else {
94 int fd = g_crashFdFn(&g_request);
95 CrashLocalHandlerFd(fd, &g_request);
96 if (fd >= 0) {
97 close(fd);
98 }
99 }
100 }
101 DFXLOGI("DoCrashHandler::finish handle sig(%d)", sig);
102 UnregisterAllocator();
103 pthread_mutex_unlock(&g_signalHandlerMutex);
104 _exit(0);
105 return 0;
106 }
107
DFX_SignalLocalHandler(int sig,siginfo_t * si,void * context)108 void DFX_SignalLocalHandler(int sig, siginfo_t *si, void *context)
109 {
110 pthread_mutex_lock(&g_signalHandlerMutex);
111 if (sig != SIGALRM) {
112 (void)memset_s(&g_request, sizeof(g_request), 0, sizeof(g_request));
113 g_request.tid = gettid();
114 g_request.pid = getpid();
115 g_request.uid = FAULTLOGGERD_UID;
116 g_request.timeStamp = GetTimeMilliseconds();
117 DFXLOGI("DFX_SignalLocalHandler :: sig(%{public}d), pid(%{public}d), tid(%{public}d).",
118 sig, g_request.pid, g_request.tid);
119
120 GetThreadNameByTid(g_request.tid, g_request.threadName, sizeof(g_request.threadName));
121 GetProcessName(g_request.processName, sizeof(g_request.processName));
122 (void)memcpy_s(&(g_request.siginfo), sizeof(siginfo_t), si, sizeof(siginfo_t));
123 (void)memcpy_s(&(g_request.context), sizeof(ucontext_t), context, sizeof(ucontext_t));
124 }
125 #if defined(__aarch64__) || defined(__loongarch_lp64)
126 DoCrashHandler(&sig);
127 #else
128 int pseudothreadTid = -1;
129 pid_t childTid = clone(DoCrashHandler, g_reservedChildStack, \
130 CLONE_THREAD | CLONE_SIGHAND | CLONE_VM | CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID, \
131 &sig, &pseudothreadTid, NULL, NULL, &pseudothreadTid);
132 if (childTid == -1) {
133 DFXLOGE("Failed to create thread for crash local handler");
134 pthread_mutex_unlock(&g_signalHandlerMutex);
135 return;
136 }
137
138 FutexWait(&pseudothreadTid, -1);
139 FutexWait(&pseudothreadTid, childTid);
140
141 DFXLOGI("child thread(%{public}d) exit.", childTid);
142 _exit(0);
143 #endif
144 }
145
DFX_GetCrashFdFunc(CrashFdFunc fn)146 void DFX_GetCrashFdFunc(CrashFdFunc fn)
147 {
148 g_crashFdFn = fn;
149 }
150
DFX_InstallLocalSignalHandler(void)151 void DFX_InstallLocalSignalHandler(void)
152 {
153 #if !defined(__aarch64__) && !defined(__loongarch_lp64)
154 ReserveChildThreadSignalStack();
155 #endif
156
157 sigset_t set;
158 sigemptyset(&set);
159 struct sigaction action;
160 (void)memset_s(&action, sizeof(action), 0, sizeof(action));
161 sigfillset(&action.sa_mask);
162 action.sa_sigaction = DFX_SignalLocalHandler;
163 action.sa_flags = SA_RESTART | SA_SIGINFO | SA_ONSTACK;
164
165 for (auto sig : CATCHER_STACK_SIGNALS) {
166 remove_all_special_handler(sig);
167 sigaddset(&set, sig);
168 if (sigaction(sig, &action, nullptr) != 0) {
169 DFXLOGE("Failed to register signal(%{public}d)", sig);
170 }
171 }
172 sigprocmask(SIG_UNBLOCK, &set, nullptr);
173 }
174
DFX_SetSigAlarmCallBack(SigAlarmFunc func)175 void DFX_SetSigAlarmCallBack(SigAlarmFunc func)
176 {
177 g_sigAlarmCallbackFn = func;
178 }