trace/control.c

   1 /*
   2  * Interface for configuring and controlling the state of tracing events.
   3  *
   4  * Copyright (C) 2011-2014 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 #include "qemu/error-report.h"
  23
  24 int trace_events_enabled_count;
  25 bool trace_events_dstate[TRACE_EVENT_COUNT];
  26
  27 TraceEvent *trace_event_name(const char *name)
  28 {
  29     assert(name != NULL);
  30
  31     TraceEventID i;
  32     for (i = 0; i < trace_event_count(); i++) {
  33         TraceEvent *ev = trace_event_id(i);
  34         if (strcmp(trace_event_get_name(ev), name) == 0) {
  35             return ev;
  36         }
  37     }
  38     return NULL;
  39 }
  40
  41 static bool pattern_glob(const char *pat, const char *ev)
  42 {
  43     while (*pat != '\0' && *ev != '\0') {
  44         if (*pat == *ev) {
  45             pat++;
  46             ev++;
  47         }
  48         else if (*pat == '*') {
  49             if (pattern_glob(pat, ev+1)) {
  50                 return true;
  51             } else if (pattern_glob(pat+1, ev)) {
  52                 return true;
  53             } else {
  54                 return false;
  55             }
  56         } else {
  57             return false;
  58         }
  59     }
  60
  61     while (*pat == '*') {
  62         pat++;
  63     }
  64
  65     if (*pat == '\0' && *ev == '\0') {
  66         return true;
  67     } else {
  68         return false;
  69     }
  70 }
  71
  72 TraceEvent *trace_event_pattern(const char *pat, TraceEvent *ev)
  73 {
  74     assert(pat != NULL);
  75
  76     TraceEventID i;
  77
  78     if (ev == NULL) {
  79         i = -1;
  80     } else {
  81         i = trace_event_get_id(ev);
  82     }
  83     i++;
  84
  85     while (i < trace_event_count()) {
  86         TraceEvent *res = trace_event_id(i);
  87         if (pattern_glob(pat, trace_event_get_name(res))) {
  88             return res;
  89         }
  90         i++;
  91     }
  92
  93     return NULL;
  94 }
  95
  96 void trace_list_events(void)
  97 {
  98     int i;
  99     for (i = 0; i < trace_event_count(); i++) {
 100         TraceEvent *res = trace_event_id(i);
 101         fprintf(stderr, "%s\n", trace_event_get_name(res));
 102     }
 103 }
 104
 105 static void do_trace_enable_events(const char *line_buf)
 106 {
 107     const bool enable = ('-' != line_buf[0]);
 108     const char *line_ptr = enable ? line_buf : line_buf + 1;
 109
 110     if (trace_event_is_pattern(line_ptr)) {
 111         TraceEvent *ev = NULL;
 112         while ((ev = trace_event_pattern(line_ptr, ev)) != NULL) {
 113             if (trace_event_get_state_static(ev)) {
 114                 trace_event_set_state_dynamic(ev, enable);
 115             }
 116         }
 117     } else {
 118         TraceEvent *ev = trace_event_name(line_ptr);
 119         if (ev == NULL) {
 120             error_report("WARNING: trace event '%s' does not exist",
 121                          line_ptr);
 122         } else if (!trace_event_get_state_static(ev)) {
 123             error_report("WARNING: trace event '%s' is not traceable",
 124                          line_ptr);
 125         } else {
 126             trace_event_set_state_dynamic(ev, enable);
 127         }
 128     }
 129 }
 130
 131 void trace_enable_events(const char *line_buf)
 132 {
 133     if (is_help_option(line_buf)) {
 134         trace_list_events();
 135         exit(0);
 136     } else {
 137         do_trace_enable_events(line_buf);
 138     }
 139 }
 140
 141 void trace_init_events(const char *fname)
 142 {
 143     Location loc;
 144     FILE *fp;
 145     char line_buf[1024];
 146     size_t line_idx = 0;
 147
 148     if (fname == NULL) {
 149         return;
 150     }
 151
 152     loc_push_none(&loc);
 153     loc_set_file(fname, 0);
 154     fp = fopen(fname, "r");
 155     if (!fp) {
 156         error_report("%s", strerror(errno));
 157         exit(1);
 158     }
 159     while (fgets(line_buf, sizeof(line_buf), fp)) {
 160         loc_set_file(fname, ++line_idx);
 161         size_t len = strlen(line_buf);
 162         if (len > 1) {              /* skip empty lines */
 163             line_buf[len - 1] = '\0';
 164             if ('#' == line_buf[0]) { /* skip commented lines */
 165                 continue;
 166             }
 167             trace_enable_events(line_buf);
 168         }
 169     }
 170     if (fclose(fp) != 0) {
 171         loc_set_file(fname, 0);
 172         error_report("%s", strerror(errno));
 173         exit(1);
 174     }
 175     loc_pop(&loc);
 176 }
 177
 178 void trace_init_file(const char *file)
 179 {
 180 #ifdef CONFIG_TRACE_SIMPLE
 181     st_set_trace_file(file);
 182 #elif defined CONFIG_TRACE_LOG
 183     /* If both the simple and the log backends are enabled, "-trace file"
 184      * only applies to the simple backend; use "-D" for the log backend.
 185      */
 186     if (file) {
 187         qemu_set_log_filename(file);
 188     }
 189 #else
 190     if (file) {
 191         fprintf(stderr, "error: -trace file=...: "
 192                 "option not supported by the selected tracing backends\n");
 193         exit(1);
 194     }
 195 #endif
 196 }
 197
 198 bool trace_init_backends(void)
 199 {
 200 #ifdef CONFIG_TRACE_SIMPLE
 201     if (!st_init()) {
 202         fprintf(stderr, "failed to initialize simple tracing backend.\n");
 203         return false;
 204     }
 205 #endif
 206
 207 #ifdef CONFIG_TRACE_FTRACE
 208     if (!ftrace_init()) {
 209         fprintf(stderr, "failed to initialize ftrace backend.\n");
 210         return false;
 211     }
 212 #endif
 213
 214     return true;
 215 }