1 /* 2 * Interface for configuring and controlling the state of tracing events. 3 * 4 * Copyright (C) 2011-2016 Lluís Vilanova <vilanova@ac.upc.edu> 5 * 6 * This work is licensed under the terms of the GNU GPL, version 2 or later. 7 * See the COPYING file in the top-level directory. 8 */ 9 10 #include "qemu/osdep.h" 11 #include "trace/control.h" 12 #include "qemu/help_option.h" 13 #ifdef CONFIG_TRACE_SIMPLE 14 #include "trace/simple.h" 15 #endif 16 #ifdef CONFIG_TRACE_FTRACE 17 #include "trace/ftrace.h" 18 #endif 19 #ifdef CONFIG_TRACE_LOG 20 #include "qemu/log.h" 21 #endif 22 #ifdef CONFIG_TRACE_SYSLOG 23 #include <syslog.h> 24 #endif 25 #include "qapi/error.h" 26 #include "qemu/error-report.h" 27 #include "qemu/config-file.h" 28 #include "monitor/monitor.h" 29 30 int trace_events_enabled_count; 31 32 QemuOptsList qemu_trace_opts = { 33 .name = "trace", 34 .implied_opt_name = "enable", 35 .head = QTAILQ_HEAD_INITIALIZER(qemu_trace_opts.head), 36 .desc = { 37 { 38 .name = "enable", 39 .type = QEMU_OPT_STRING, 40 }, 41 { 42 .name = "events", 43 .type = QEMU_OPT_STRING, 44 },{ 45 .name = "file", 46 .type = QEMU_OPT_STRING, 47 }, 48 { /* end of list */ } 49 }, 50 }; 51 52 53 TraceEvent *trace_event_name(const char *name) 54 { 55 assert(name != NULL); 56 57 TraceEventIter iter; 58 TraceEvent *ev; 59 trace_event_iter_init(&iter, NULL); 60 while ((ev = trace_event_iter_next(&iter)) != NULL) { 61 if (strcmp(trace_event_get_name(ev), name) == 0) { 62 return ev; 63 } 64 } 65 return NULL; 66 } 67 68 static bool pattern_glob(const char *pat, const char *ev) 69 { 70 while (*pat != '\0' && *ev != '\0') { 71 if (*pat == *ev) { 72 pat++; 73 ev++; 74 } 75 else if (*pat == '*') { 76 if (pattern_glob(pat, ev+1)) { 77 return true; 78 } else if (pattern_glob(pat+1, ev)) { 79 return true; 80 } else { 81 return false; 82 } 83 } else { 84 return false; 85 } 86 } 87 88 while (*pat == '*') { 89 pat++; 90 } 91 92 if (*pat == '\0' && *ev == '\0') { 93 return true; 94 } else { 95 return false; 96 } 97 } 98 99 100 void trace_event_iter_init(TraceEventIter *iter, const char *pattern) 101 { 102 iter->event = 0; 103 iter->pattern = pattern; 104 } 105 106 TraceEvent *trace_event_iter_next(TraceEventIter *iter) 107 { 108 while (trace_events[iter->event] != NULL) { 109 TraceEvent *ev = trace_events[iter->event]; 110 iter->event++; 111 if (!iter->pattern || 112 pattern_glob(iter->pattern, 113 trace_event_get_name(ev))) { 114 return ev; 115 } 116 } 117 118 return NULL; 119 } 120 121 void trace_list_events(void) 122 { 123 TraceEventIter iter; 124 TraceEvent *ev; 125 trace_event_iter_init(&iter, NULL); 126 while ((ev = trace_event_iter_next(&iter)) != NULL) { 127 fprintf(stderr, "%s\n", trace_event_get_name(ev)); 128 } 129 } 130 131 static void do_trace_enable_events(const char *line_buf) 132 { 133 const bool enable = ('-' != line_buf[0]); 134 const char *line_ptr = enable ? line_buf : line_buf + 1; 135 TraceEventIter iter; 136 TraceEvent *ev; 137 bool is_pattern = trace_event_is_pattern(line_ptr); 138 139 trace_event_iter_init(&iter, line_ptr); 140 while ((ev = trace_event_iter_next(&iter)) != NULL) { 141 if (!trace_event_get_state_static(ev)) { 142 if (!is_pattern) { 143 error_report("WARNING: trace event '%s' is not traceable", 144 line_ptr); 145 return; 146 } 147 continue; 148 } 149 150 /* start tracing */ 151 trace_event_set_state_dynamic(ev, enable); 152 if (!is_pattern) { 153 return; 154 } 155 } 156 157 if (!is_pattern) { 158 error_report("WARNING: trace event '%s' does not exist", 159 line_ptr); 160 } 161 } 162 163 void trace_enable_events(const char *line_buf) 164 { 165 if (is_help_option(line_buf)) { 166 trace_list_events(); 167 if (cur_mon == NULL) { 168 exit(0); 169 } 170 } else { 171 do_trace_enable_events(line_buf); 172 } 173 } 174 175 static void trace_init_events(const char *fname) 176 { 177 Location loc; 178 FILE *fp; 179 char line_buf[1024]; 180 size_t line_idx = 0; 181 182 if (fname == NULL) { 183 return; 184 } 185 186 loc_push_none(&loc); 187 loc_set_file(fname, 0); 188 fp = fopen(fname, "r"); 189 if (!fp) { 190 error_report("%s", strerror(errno)); 191 exit(1); 192 } 193 while (fgets(line_buf, sizeof(line_buf), fp)) { 194 loc_set_file(fname, ++line_idx); 195 size_t len = strlen(line_buf); 196 if (len > 1) { /* skip empty lines */ 197 line_buf[len - 1] = '\0'; 198 if ('#' == line_buf[0]) { /* skip commented lines */ 199 continue; 200 } 201 trace_enable_events(line_buf); 202 } 203 } 204 if (fclose(fp) != 0) { 205 loc_set_file(fname, 0); 206 error_report("%s", strerror(errno)); 207 exit(1); 208 } 209 loc_pop(&loc); 210 } 211 212 void trace_init_file(const char *file) 213 { 214 #ifdef CONFIG_TRACE_SIMPLE 215 st_set_trace_file(file); 216 #elif defined CONFIG_TRACE_LOG 217 /* If both the simple and the log backends are enabled, "-trace file" 218 * only applies to the simple backend; use "-D" for the log backend. 219 */ 220 if (file) { 221 qemu_set_log_filename(file, &error_fatal); 222 } 223 #else 224 if (file) { 225 fprintf(stderr, "error: -trace file=...: " 226 "option not supported by the selected tracing backends\n"); 227 exit(1); 228 } 229 #endif 230 } 231 232 bool trace_init_backends(void) 233 { 234 #ifdef CONFIG_TRACE_SIMPLE 235 if (!st_init()) { 236 fprintf(stderr, "failed to initialize simple tracing backend.\n"); 237 return false; 238 } 239 #endif 240 241 #ifdef CONFIG_TRACE_FTRACE 242 if (!ftrace_init()) { 243 fprintf(stderr, "failed to initialize ftrace backend.\n"); 244 return false; 245 } 246 #endif 247 248 #ifdef CONFIG_TRACE_SYSLOG 249 openlog(NULL, LOG_PID, LOG_DAEMON); 250 #endif 251 252 return true; 253 } 254 255 char *trace_opt_parse(const char *optarg) 256 { 257 char *trace_file; 258 QemuOpts *opts = qemu_opts_parse_noisily(qemu_find_opts("trace"), 259 optarg, true); 260 if (!opts) { 261 exit(1); 262 } 263 if (qemu_opt_get(opts, "enable")) { 264 trace_enable_events(qemu_opt_get(opts, "enable")); 265 } 266 trace_init_events(qemu_opt_get(opts, "events")); 267 trace_file = g_strdup(qemu_opt_get(opts, "file")); 268 qemu_opts_del(opts); 269 270 return trace_file; 271 } 272