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 * Interpretation depends on wether the event has the 'vcpu' property: 33 * - false: Boolean value indicating whether the event is active. 34 * - true : Integral counting the number of vCPUs that have this event enabled. 35 */ 36 uint16_t trace_events_dstate[TRACE_EVENT_COUNT]; 37 38 QemuOptsList qemu_trace_opts = { 39 .name = "trace", 40 .implied_opt_name = "enable", 41 .head = QTAILQ_HEAD_INITIALIZER(qemu_trace_opts.head), 42 .desc = { 43 { 44 .name = "enable", 45 .type = QEMU_OPT_STRING, 46 }, 47 { 48 .name = "events", 49 .type = QEMU_OPT_STRING, 50 },{ 51 .name = "file", 52 .type = QEMU_OPT_STRING, 53 }, 54 { /* end of list */ } 55 }, 56 }; 57 58 59 TraceEvent *trace_event_name(const char *name) 60 { 61 assert(name != NULL); 62 63 TraceEventID i; 64 for (i = 0; i < trace_event_count(); i++) { 65 TraceEvent *ev = trace_event_id(i); 66 if (strcmp(trace_event_get_name(ev), name) == 0) { 67 return ev; 68 } 69 } 70 return NULL; 71 } 72 73 static bool pattern_glob(const char *pat, const char *ev) 74 { 75 while (*pat != '\0' && *ev != '\0') { 76 if (*pat == *ev) { 77 pat++; 78 ev++; 79 } 80 else if (*pat == '*') { 81 if (pattern_glob(pat, ev+1)) { 82 return true; 83 } else if (pattern_glob(pat+1, ev)) { 84 return true; 85 } else { 86 return false; 87 } 88 } else { 89 return false; 90 } 91 } 92 93 while (*pat == '*') { 94 pat++; 95 } 96 97 if (*pat == '\0' && *ev == '\0') { 98 return true; 99 } else { 100 return false; 101 } 102 } 103 104 TraceEvent *trace_event_pattern(const char *pat, TraceEvent *ev) 105 { 106 assert(pat != NULL); 107 108 TraceEventID i; 109 110 if (ev == NULL) { 111 i = -1; 112 } else { 113 i = trace_event_get_id(ev); 114 } 115 i++; 116 117 while (i < trace_event_count()) { 118 TraceEvent *res = trace_event_id(i); 119 if (pattern_glob(pat, trace_event_get_name(res))) { 120 return res; 121 } 122 i++; 123 } 124 125 return NULL; 126 } 127 128 void trace_list_events(void) 129 { 130 int i; 131 for (i = 0; i < trace_event_count(); i++) { 132 TraceEvent *res = trace_event_id(i); 133 fprintf(stderr, "%s\n", trace_event_get_name(res)); 134 } 135 } 136 137 static void do_trace_enable_events(const char *line_buf) 138 { 139 const bool enable = ('-' != line_buf[0]); 140 const char *line_ptr = enable ? line_buf : line_buf + 1; 141 142 if (trace_event_is_pattern(line_ptr)) { 143 TraceEvent *ev = NULL; 144 while ((ev = trace_event_pattern(line_ptr, ev)) != NULL) { 145 if (trace_event_get_state_static(ev)) { 146 trace_event_set_state_dynamic_init(ev, enable); 147 } 148 } 149 } else { 150 TraceEvent *ev = trace_event_name(line_ptr); 151 if (ev == NULL) { 152 error_report("WARNING: trace event '%s' does not exist", 153 line_ptr); 154 } else if (!trace_event_get_state_static(ev)) { 155 error_report("WARNING: trace event '%s' is not traceable", 156 line_ptr); 157 } else { 158 trace_event_set_state_dynamic_init(ev, enable); 159 } 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 } 272 273 void trace_init_vcpu_events(void) 274 { 275 TraceEvent *ev = NULL; 276 while ((ev = trace_event_pattern("*", ev)) != NULL) { 277 if (trace_event_is_vcpu(ev) && 278 trace_event_get_state_static(ev) && 279 trace_event_get_state_dynamic(ev)) { 280 TraceEventID id = trace_event_get_id(ev); 281 /* check preconditions */ 282 assert(trace_events_dstate[id] == 1); 283 /* disable early-init state ... */ 284 trace_events_dstate[id] = 0; 285 trace_events_enabled_count--; 286 /* ... and properly re-enable */ 287 trace_event_set_state_dynamic(ev, true); 288 } 289 } 290 } 291