1 // SPDX-License-Identifier: GPL-2.0 2 #include <stdio.h> 3 #include <unistd.h> 4 #include <stdlib.h> 5 #include <errno.h> 6 #include <sys/types.h> 7 #include <sys/stat.h> 8 #include <fcntl.h> 9 #include <linux/kernel.h> 10 #include <linux/err.h> 11 #include <traceevent/event-parse.h> 12 #include <api/fs/tracing_path.h> 13 #include <api/fs/fs.h> 14 #include "trace-event.h" 15 #include "machine.h" 16 17 /* 18 * global trace_event object used by trace_event__tp_format 19 * 20 * TODO There's no cleanup call for this. Add some sort of 21 * __exit function support and call trace_event__cleanup 22 * there. 23 */ 24 static struct trace_event tevent; 25 static bool tevent_initialized; 26 27 int trace_event__init(struct trace_event *t) 28 { 29 struct tep_handle *pevent = tep_alloc(); 30 31 if (pevent) { 32 t->plugin_list = tep_load_plugins(pevent); 33 t->pevent = pevent; 34 } 35 36 return pevent ? 0 : -1; 37 } 38 39 static int trace_event__init2(void) 40 { 41 int be = tep_is_bigendian(); 42 struct tep_handle *pevent; 43 44 if (trace_event__init(&tevent)) 45 return -1; 46 47 pevent = tevent.pevent; 48 tep_set_flag(pevent, TEP_NSEC_OUTPUT); 49 tep_set_file_bigendian(pevent, be); 50 tep_set_local_bigendian(pevent, be); 51 tevent_initialized = true; 52 return 0; 53 } 54 55 int trace_event__register_resolver(struct machine *machine, 56 tep_func_resolver_t *func) 57 { 58 if (!tevent_initialized && trace_event__init2()) 59 return -1; 60 61 return tep_set_function_resolver(tevent.pevent, func, machine); 62 } 63 64 void trace_event__cleanup(struct trace_event *t) 65 { 66 tep_unload_plugins(t->plugin_list, t->pevent); 67 tep_free(t->pevent); 68 } 69 70 /* 71 * Returns pointer with encoded error via <linux/err.h> interface. 72 */ 73 static struct tep_event* 74 tp_format(const char *sys, const char *name) 75 { 76 char *tp_dir = get_events_file(sys); 77 struct tep_handle *pevent = tevent.pevent; 78 struct tep_event *event = NULL; 79 char path[PATH_MAX]; 80 size_t size; 81 char *data; 82 int err; 83 84 if (!tp_dir) 85 return ERR_PTR(-errno); 86 87 scnprintf(path, PATH_MAX, "%s/%s/format", tp_dir, name); 88 put_events_file(tp_dir); 89 90 err = filename__read_str(path, &data, &size); 91 if (err) 92 return ERR_PTR(err); 93 94 tep_parse_format(pevent, &event, data, size, sys); 95 96 free(data); 97 return event; 98 } 99 100 /* 101 * Returns pointer with encoded error via <linux/err.h> interface. 102 */ 103 struct tep_event* 104 trace_event__tp_format(const char *sys, const char *name) 105 { 106 if (!tevent_initialized && trace_event__init2()) 107 return ERR_PTR(-ENOMEM); 108 109 return tp_format(sys, name); 110 } 111 112 struct tep_event *trace_event__tp_format_id(int id) 113 { 114 if (!tevent_initialized && trace_event__init2()) 115 return ERR_PTR(-ENOMEM); 116 117 return tep_find_event(tevent.pevent, id); 118 } 119