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 #if defined(__ANDROID__)
18 #include <android-base/properties.h>
19 #endif
20
21 #include "command.h"
22 #include "environment.h"
23
24 using namespace simpleperf;
25
26 #if defined(__ANDROID__)
27
AndroidSecurityCheck()28 bool AndroidSecurityCheck() {
29 // Simpleperf can be executed by the shell, or by apps themselves. To avoid malicious apps
30 // exploiting perf_event_open interface via simpleperf, simpleperf needs proof that the user
31 // is expecting simpleperf to be ran:
32 // 1) On Android < R, perf_event_open is secured by perf_event_allow_path, which is controlled
33 // by security.perf_harden property. perf_event_open syscall can be used only after user setting
34 // security.perf_harden to 0 in shell. So we don't need to check security.perf_harden explicitly.
35 // 2) On Android R, perf_event_open may be controlled by selinux instead of
36 // perf_event_allow_path. So we need to check security.perf_harden explicitly. If simpleperf is
37 // running via shell, we already know the origin of the request is the user, so set the property
38 // ourselves for convenience. When started by the app, we won't have the permission to set the
39 // property, so the user will need to prove this intent by setting it manually via shell.
40 if (GetAndroidVersion() >= 11) {
41 std::string prop_name = "security.perf_harden";
42 if (android::base::GetProperty(prop_name, "") != "0") {
43 if (!android::base::SetProperty(prop_name, "0")) {
44 fprintf(stderr,
45 "failed to set system property security.perf_harden to 0.\n"
46 "Try using `adb shell setprop security.perf_harden 0` to allow profiling.\n");
47 return false;
48 }
49 }
50 }
51 return true;
52 }
53
54 #endif
55
main(int argc,char ** argv)56 int main(int argc, char** argv) {
57 #if defined(__ANDROID__)
58 if (!AndroidSecurityCheck()) {
59 return 1;
60 }
61 #endif
62 return RunSimpleperfCmd(argc, argv) ? 0 : 1;
63 }
64