Home | History | Annotate | Download | only in jni 
      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 
     18 #define LOG_TAG "MMapExecutableTest"
     19 
     20 #include <android/log.h>
     21 #include <cutils/log.h>
     22 #include <fcntl.h>
     23 #include <jni.h>
     24 #include <nativehelper/JNIHelp.h>
     25 #include <nativehelper/ScopedUtfChars.h>
     26 #include <string.h>
     27 #include <sys/mman.h>
     28 #include <sys/stat.h>
     29 #include <sys/types.h>
     30 #include <unistd.h>
     31 
     32 const size_t kOffset = 4096;
     33 
     34 // Verify that we can mmap a region of a file with a non-zero offset executable
     35 static jboolean mmap_executable(JNIEnv *env, jobject, jstring jfilename) {
     36     if (jfilename == NULL) {
     37         jniThrowNullPointerException(env, NULL);
     38         return false;
     39     }
     40 
     41     ScopedUtfChars filename(env, jfilename);
     42     int fd = open(filename.c_str(), O_RDONLY);
     43     if (fd == -1) {
     44         ALOGE("open %s: %s", filename.c_str(), strerror(errno));
     45         return false;
     46     }
     47 
     48     struct stat stat_buf;
     49     if (fstat(fd, &stat_buf) == -1) {
     50         ALOGE("fstat %s: %s", filename.c_str(), strerror(errno));
     51         return false;
     52     }
     53 
     54     if (stat_buf.st_size < kOffset) {
     55         ALOGE("file %s is too small", filename.c_str());
     56         return false;
     57     }
     58 
     59     void * mem =
     60             mmap(NULL, stat_buf.st_size - kOffset,
     61                  PROT_EXEC | PROT_READ, MAP_PRIVATE, fd, kOffset);
     62     if (mem == MAP_FAILED) {
     63         ALOGE("mmap %s: %s", filename.c_str(), strerror(errno));
     64         return false;
     65     }
     66 
     67     if (munmap(mem, stat_buf.st_size - kOffset) == -1) {
     68         ALOGE("munmap %s: %s", filename.c_str(), strerror(errno));
     69         return false;
     70     }
     71 
     72     return true;
     73 }
     74 
     75 static JNINativeMethod gMethods[] = {
     76     { (char*)"mmapExecutable",
     77       (char*)"(Ljava/lang/String;)Z", (void *)mmap_executable }
     78 };
     79 
     80 int register_android_security_cts_MMapExecutableTest(JNIEnv* env) {
     81     jclass clazz = env->FindClass("android/security/cts/MMapExecutableTest");
     82     return env->RegisterNatives(
     83             clazz, gMethods, sizeof(gMethods) / sizeof(JNINativeMethod));
     84 }
     85