1 /* 2 ** Copyright 2010, 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 #define LOG_TAG "Watchdog_N" 18 #include <utils/Log.h> 19 20 #include <sys/stat.h> 21 #include <sys/types.h> 22 #include <fcntl.h> 23 #include <dirent.h> 24 #include <string.h> 25 #include <errno.h> 26 27 #include "jni.h" 28 #include "JNIHelp.h" 29 #include <android_runtime/AndroidRuntime.h> 30 31 static void dumpOneStack(int tid, int outFd) { 32 char buf[64]; 33 34 snprintf(buf, sizeof(buf), "/proc/%d/stack", tid); 35 int stackFd = open(buf, O_RDONLY); 36 if (stackFd >= 0) { 37 // header for readability 38 strncat(buf, ":\n", sizeof(buf) - strlen(buf) - 1); 39 write(outFd, buf, strlen(buf)); 40 41 // copy the stack dump text 42 int nBytes; 43 while ((nBytes = read(stackFd, buf, sizeof(buf))) > 0) { 44 write(outFd, buf, nBytes); 45 } 46 47 // footer and done 48 write(outFd, "\n", 1); 49 close(stackFd); 50 } else { 51 ALOGE("Unable to open stack of tid %d : %d (%s)", tid, errno, strerror(errno)); 52 } 53 } 54 55 static void dumpKernelStacks(JNIEnv* env, jobject clazz, jstring pathStr) { 56 char buf[128]; 57 DIR* taskdir; 58 59 ALOGI("dumpKernelStacks"); 60 if (!pathStr) { 61 jniThrowException(env, "java/lang/IllegalArgumentException", "Null path"); 62 return; 63 } 64 65 const char *path = env->GetStringUTFChars(pathStr, NULL); 66 67 int outFd = open(path, O_WRONLY | O_APPEND | O_CREAT, 68 S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH); 69 if (outFd < 0) { 70 ALOGE("Unable to open stack dump file: %d (%s)", errno, strerror(errno)); 71 goto done; 72 } 73 74 snprintf(buf, sizeof(buf), "\n----- begin pid %d kernel stacks -----\n", getpid()); 75 write(outFd, buf, strlen(buf)); 76 77 // look up the list of all threads in this process 78 snprintf(buf, sizeof(buf), "/proc/%d/task", getpid()); 79 taskdir = opendir(buf); 80 if (taskdir != NULL) { 81 struct dirent * ent; 82 while ((ent = readdir(taskdir)) != NULL) { 83 int tid = atoi(ent->d_name); 84 if (tid > 0 && tid <= 65535) { 85 // dump each stack trace 86 dumpOneStack(tid, outFd); 87 } 88 } 89 closedir(taskdir); 90 } 91 92 snprintf(buf, sizeof(buf), "----- end pid %d kernel stacks -----\n", getpid()); 93 write(outFd, buf, strlen(buf)); 94 95 close(outFd); 96 done: 97 env->ReleaseStringUTFChars(pathStr, path); 98 } 99 100 // ---------------------------------------- 101 102 namespace android { 103 104 static const JNINativeMethod g_methods[] = { 105 { "native_dumpKernelStacks", "(Ljava/lang/String;)V", (void*)dumpKernelStacks }, 106 }; 107 108 int register_android_server_Watchdog(JNIEnv* env) { 109 return AndroidRuntime::registerNativeMethods(env, "com/android/server/Watchdog", 110 g_methods, NELEM(g_methods)); 111 } 112 113 } 114