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 #include <stdio.h> 17 #include <string.h> 18 #include <errno.h> 19 #include <sys/stat.h> 20 #include <sys/types.h> 21 #include <fcntl.h> 22 #include <unistd.h> 23 24 // This is the pathname to the sysfs file that enables and disables 25 // tracing on the qemu emulator. 26 #define SYS_QEMU_TRACE_STATE "/sys/qemu_trace/state" 27 28 29 // This is the pathname to the sysfs file that adds new (address, symbol) 30 // pairs to the trace. 31 #define SYS_QEMU_TRACE_SYMBOL "/sys/qemu_trace/symbol" 32 33 // The maximum length of a symbol name 34 #define MAX_SYMBOL_NAME_LENGTH (4 * 1024) 35 36 // Allow space in the buffer for the address plus whitespace. 37 #define MAX_BUF_SIZE (MAX_SYMBOL_NAME_LENGTH + 20) 38 39 // return 0 on success, or an error if the qemu driver cannot be opened 40 int qemu_start_tracing() 41 { 42 int fd = open(SYS_QEMU_TRACE_STATE, O_WRONLY); 43 if (fd < 0) 44 return fd; 45 write(fd, "1\n", 2); 46 close(fd); 47 return 0; 48 } 49 50 int qemu_stop_tracing() 51 { 52 int fd = open(SYS_QEMU_TRACE_STATE, O_WRONLY); 53 if (fd < 0) 54 return fd; 55 write(fd, "0\n", 2); 56 close(fd); 57 return 0; 58 } 59 60 int qemu_add_mapping(unsigned int addr, const char *name) 61 { 62 char buf[MAX_BUF_SIZE]; 63 64 if (strlen(name) > MAX_SYMBOL_NAME_LENGTH) 65 return EINVAL; 66 int fd = open(SYS_QEMU_TRACE_SYMBOL, O_WRONLY); 67 if (fd < 0) 68 return fd; 69 sprintf(buf, "%x %s\n", addr, name); 70 write(fd, buf, strlen(buf)); 71 close(fd); 72 return 0; 73 } 74 75 int qemu_remove_mapping(unsigned int addr) 76 { 77 char buf[MAX_BUF_SIZE]; 78 79 int fd = open(SYS_QEMU_TRACE_SYMBOL, O_WRONLY); 80 if (fd < 0) 81 return fd; 82 sprintf(buf, "%x\n", addr); 83 write(fd, buf, strlen(buf)); 84 close(fd); 85 return 0; 86 } 87
