1 /*
2  * Copyright (C) 2014 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 <errno.h>
18 #include <jni.h>
19 #include <string.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <unistd.h>
23 #include <cutils/log.h>
24 #include <inttypes.h>
25 
isAddressExecutable(uintptr_t address)26 static jboolean isAddressExecutable(uintptr_t address) {
27     char line[1024];
28     jboolean retval = false;
29     FILE *fp = fopen("/proc/self/maps", "re");
30     if (fp == NULL) {
31         ALOGE("Unable to open /proc/self/maps: %s", strerror(errno));
32         return false;
33     }
34     while(fgets(line, sizeof(line), fp) != NULL) {
35         uintptr_t start;
36         uintptr_t end;
37         char permissions[10];
38         int scan = sscanf(line, "%" SCNxPTR "-%" SCNxPTR " %9s ", &start, &end, permissions);
39         if ((scan == 3) && (start <= address) && (address < end)) {
40             retval = (permissions[2] == 'x');
41             break;
42         }
43     }
44     fclose(fp);
45     return retval;
46 }
47 
android_os_cts_NoExecutePermissionTest_isStackExecutable(JNIEnv *,jobject)48 static jboolean android_os_cts_NoExecutePermissionTest_isStackExecutable(JNIEnv*, jobject)
49 {
50     unsigned int foo;
51     return isAddressExecutable((uintptr_t) &foo);
52 }
53 
54 
android_os_cts_NoExecutePermissionTest_isHeapExecutable(JNIEnv *,jobject)55 static jboolean android_os_cts_NoExecutePermissionTest_isHeapExecutable(JNIEnv*, jobject)
56 {
57     unsigned int* foo = (unsigned int *) malloc(sizeof(unsigned int));
58     if (foo == NULL) {
59         ALOGE("Unable to allocate memory");
60         return false;
61     }
62     jboolean result = isAddressExecutable((uintptr_t) foo);
63     free(foo);
64     return result;
65 }
66 
67 static JNINativeMethod gMethods[] = {
68     {  "isStackExecutable", "()Z",
69             (void *) android_os_cts_NoExecutePermissionTest_isStackExecutable  },
70     {  "isHeapExecutable", "()Z",
71             (void *) android_os_cts_NoExecutePermissionTest_isHeapExecutable  }
72 };
73 
register_android_os_cts_NoExecutePermissionTest(JNIEnv * env)74 int register_android_os_cts_NoExecutePermissionTest(JNIEnv* env)
75 {
76     jclass clazz = env->FindClass("android/os/cts/NoExecutePermissionTest");
77 
78     return env->RegisterNatives(clazz, gMethods,
79             sizeof(gMethods) / sizeof(JNINativeMethod));
80 }
81