1 /* 2 * Copyright (C) 2008 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 <string.h> 18 #include <cutils/process_name.h> 19 #include <cutils/properties.h> 20 #include <unistd.h> 21 #include <sys/types.h> 22 #include <sys/stat.h> 23 #include <fcntl.h> 24 25 #if defined(HAVE_PRCTL) 26 #include <sys/prctl.h> 27 #endif 28 29 #define PROCESS_NAME_DEVICE "/sys/qemu_trace/process_name" 30 31 static const char* process_name = "unknown"; 32 static int running_in_emulator = -1; 33 34 void set_process_name(const char* new_name) { 35 char propBuf[PROPERTY_VALUE_MAX]; 36 37 if (new_name == NULL) { 38 return; 39 } 40 41 // We never free the old name. Someone else could be using it. 42 int len = strlen(new_name); 43 char* copy = (char*) malloc(len + 1); 44 strcpy(copy, new_name); 45 process_name = (const char*) copy; 46 47 #if defined(HAVE_PRCTL) 48 if (len < 16) { 49 prctl(PR_SET_NAME, (unsigned long) new_name, 0, 0, 0); 50 } else { 51 prctl(PR_SET_NAME, (unsigned long) new_name + len - 15, 0, 0, 0); 52 } 53 #endif 54 55 // If we know we are not running in the emulator, then return. 56 if (running_in_emulator == 0) { 57 return; 58 } 59 60 // If the "running_in_emulator" variable has not been initialized, 61 // then do it now. 62 if (running_in_emulator == -1) { 63 property_get("ro.kernel.qemu", propBuf, ""); 64 if (propBuf[0] == '1') { 65 running_in_emulator = 1; 66 } else { 67 running_in_emulator = 0; 68 return; 69 } 70 } 71 72 // If the emulator was started with the "-trace file" command line option 73 // then we want to record the process name in the trace even if we are 74 // not currently tracing instructions (so that we will know the process 75 // name when we do start tracing instructions). We do not need to execute 76 // this code if we are just running in the emulator without the "-trace" 77 // command line option, but we don't know that here and this function 78 // isn't called frequently enough to bother optimizing that case. 79 int fd = open(PROCESS_NAME_DEVICE, O_RDWR); 80 if (fd < 0) 81 return; 82 write(fd, process_name, strlen(process_name) + 1); 83 close(fd); 84 } 85 86 const char* get_process_name(void) { 87 return process_name; 88 } 89
