control.c 4.2 KB

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  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. #include "trace/control.h"
  10. #ifdef CONFIG_TRACE_SIMPLE
  11. #include "trace/simple.h"
  12. #endif
  13. #ifdef CONFIG_TRACE_FTRACE
  14. #include "trace/ftrace.h"
  15. #endif
  16. #include "qemu/error-report.h"
  17. TraceEvent *trace_event_name(const char *name)
  18. {
  19. assert(name != NULL);
  20. TraceEventID i;
  21. for (i = 0; i < trace_event_count(); i++) {
  22. TraceEvent *ev = trace_event_id(i);
  23. if (strcmp(trace_event_get_name(ev), name) == 0) {
  24. return ev;
  25. }
  26. }
  27. return NULL;
  28. }
  29. static bool pattern_glob(const char *pat, const char *ev)
  30. {
  31. while (*pat != '\0' && *ev != '\0') {
  32. if (*pat == *ev) {
  33. pat++;
  34. ev++;
  35. }
  36. else if (*pat == '*') {
  37. if (pattern_glob(pat, ev+1)) {
  38. return true;
  39. } else if (pattern_glob(pat+1, ev)) {
  40. return true;
  41. } else {
  42. return false;
  43. }
  44. } else {
  45. return false;
  46. }
  47. }
  48. while (*pat == '*') {
  49. pat++;
  50. }
  51. if (*pat == '\0' && *ev == '\0') {
  52. return true;
  53. } else {
  54. return false;
  55. }
  56. }
  57. TraceEvent *trace_event_pattern(const char *pat, TraceEvent *ev)
  58. {
  59. assert(pat != NULL);
  60. TraceEventID i;
  61. if (ev == NULL) {
  62. i = -1;
  63. } else {
  64. i = trace_event_get_id(ev);
  65. }
  66. i++;
  67. while (i < trace_event_count()) {
  68. TraceEvent *res = trace_event_id(i);
  69. if (pattern_glob(pat, trace_event_get_name(res))) {
  70. return res;
  71. }
  72. i++;
  73. }
  74. return NULL;
  75. }
  76. static void trace_init_events(const char *fname)
  77. {
  78. Location loc;
  79. FILE *fp;
  80. char line_buf[1024];
  81. size_t line_idx = 0;
  82. if (fname == NULL) {
  83. return;
  84. }
  85. loc_push_none(&loc);
  86. loc_set_file(fname, 0);
  87. fp = fopen(fname, "r");
  88. if (!fp) {
  89. error_report("%s", strerror(errno));
  90. exit(1);
  91. }
  92. while (fgets(line_buf, sizeof(line_buf), fp)) {
  93. loc_set_file(fname, ++line_idx);
  94. size_t len = strlen(line_buf);
  95. if (len > 1) { /* skip empty lines */
  96. line_buf[len - 1] = '\0';
  97. if ('#' == line_buf[0]) { /* skip commented lines */
  98. continue;
  99. }
  100. const bool enable = ('-' != line_buf[0]);
  101. char *line_ptr = enable ? line_buf : line_buf + 1;
  102. if (trace_event_is_pattern(line_ptr)) {
  103. TraceEvent *ev = NULL;
  104. while ((ev = trace_event_pattern(line_ptr, ev)) != NULL) {
  105. if (trace_event_get_state_static(ev)) {
  106. trace_event_set_state_dynamic(ev, enable);
  107. }
  108. }
  109. } else {
  110. TraceEvent *ev = trace_event_name(line_ptr);
  111. if (ev == NULL) {
  112. error_report("WARNING: trace event '%s' does not exist",
  113. line_ptr);
  114. } else if (!trace_event_get_state_static(ev)) {
  115. error_report("WARNING: trace event '%s' is not traceable\n",
  116. line_ptr);
  117. } else {
  118. trace_event_set_state_dynamic(ev, enable);
  119. }
  120. }
  121. }
  122. }
  123. if (fclose(fp) != 0) {
  124. loc_set_file(fname, 0);
  125. error_report("%s", strerror(errno));
  126. exit(1);
  127. }
  128. loc_pop(&loc);
  129. }
  130. bool trace_init_backends(const char *events, const char *file)
  131. {
  132. #ifdef CONFIG_TRACE_SIMPLE
  133. if (!st_init(file)) {
  134. fprintf(stderr, "failed to initialize simple tracing backend.\n");
  135. return false;
  136. }
  137. #else
  138. if (file) {
  139. fprintf(stderr, "error: -trace file=...: "
  140. "option not supported by the selected tracing backends\n");
  141. return false;
  142. }
  143. #endif
  144. #ifdef CONFIG_TRACE_FTRACE
  145. if (!ftrace_init()) {
  146. fprintf(stderr, "failed to initialize ftrace backend.\n");
  147. return false;
  148. }
  149. #endif
  150. trace_init_events(events);
  151. return true;
  152. }