1/*
2 * Copyright (c) 2022 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_exit_hook.h"
17
18#include <dlfcn.h>
19#include <signal.h>
20#include <stdbool.h>
21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
24#include <syscall.h>
25#include <unistd.h>
26
27#include "dfx_log.h"
28#include "dfx_hook_utils.h"
29
30#ifdef LOG_DOMAIN
31#undef LOG_DOMAIN
32#define LOG_DOMAIN 0xD002D11
33#endif
34
35#ifdef LOG_TAG
36#undef LOG_TAG
37#define LOG_TAG "DfxExitHook"
38#endif
39
40typedef int (*KillFunc)(pid_t pid, int sig);
41typedef __attribute__((noreturn)) void (*ExitFunc)(int code);
42static KillFunc g_hookedKill = NULL;
43static ExitFunc g_hookedExit = NULL;
44static ExitFunc g_hookedExitEx = NULL;
45static bool g_abortWhenExit = false;
46
47static void __attribute__((constructor)) InitExitHook(void)
48{
49    char* str = getenv("ABORT_EXIT");
50    if (str != NULL && strlen(str) > 0) {
51        printf("AbortExit:%s\n", str);
52        g_abortWhenExit = true;
53    }
54
55    StartHookExitFunc();
56}
57
58int kill(pid_t pid, int sig)
59{
60    DFXLOGF("%{public}d send signal(%{public}d) to %{public}d", getpid(), sig, pid);
61    if ((sig == SIGKILL) && (pid == getpid())) {
62        abort();
63    } else if (sig == SIGKILL) {
64        LogBacktrace();
65    }
66
67    if (g_hookedKill == NULL) {
68        DFXLOGE("hooked kill is NULL?\n");
69        return syscall(SYS_kill, pid, sig);
70    }
71    return g_hookedKill(pid, sig);
72}
73
74void exit(int code)
75{
76    DFXLOGF("%{public}d call exit with code %{public}d", getpid(), code);
77    if (!g_abortWhenExit) {
78        LogBacktrace();
79    }
80
81    if ((!g_abortWhenExit) && (g_hookedExit != NULL)) {
82        g_hookedExit(code);
83    } else if (g_abortWhenExit) {
84        abort();
85    }
86
87    quick_exit(code);
88}
89
90void _exit(int code)
91{
92    DFXLOGF("%{public}d call exit with code %{public}d", getpid(), code);
93    if (!g_abortWhenExit) {
94        LogBacktrace();
95    }
96
97    if ((!g_abortWhenExit) && (g_hookedExitEx != NULL)) {
98        g_hookedExitEx(code);
99    } else if (g_abortWhenExit) {
100        abort();
101    }
102
103    quick_exit(code);
104}
105
106GEN_HOOK_FUNC(StartHookKillFunction, KillFunc, "kill", g_hookedKill)
107GEN_HOOK_FUNC(StartHookExitFunction, ExitFunc, "exit", g_hookedExit)
108GEN_HOOK_FUNC(StartHookExitExFunction, ExitFunc, "_exit", g_hookedExitEx)
109
110void StartHookExitFunc(void)
111{
112    StartHookKillFunction();
113    StartHookExitFunction();
114    StartHookExitExFunction();
115}
116