1 // SPDX-License-Identifier: GPL-2.0 2 3 #include <stdio.h> 4 #include <unistd.h> 5 #include <stdlib.h> 6 #include <errno.h> 7 #include <sys/types.h> 8 #include <sys/stat.h> 9 #include <fcntl.h> 10 #include <linux/kernel.h> 11 #include <linux/err.h> 12 #include <traceevent/event-parse.h> 13 #include <api/fs/tracing_path.h> 14 #include <api/fs/fs.h> 15 #include "trace-event.h" 16 #include "machine.h" 17 18 /* 19 * global trace_event object used by trace_event__tp_format 20 * 21 * TODO There's no cleanup call for this. Add some sort of 22 * __exit function support and call trace_event__cleanup 23 * there. 24 */ 25 static struct trace_event tevent; 26 static bool tevent_initialized; 27 28 int trace_event__init(struct trace_event *t) 29 { 30 struct tep_handle *pevent = tep_alloc(); 31 32 if (pevent) { 33 t->plugin_list = tep_load_plugins(pevent); 34 t->pevent = pevent; 35 } 36 37 return pevent ? 0 : -1; 38 } 39 40 static int trace_event__init2(void) 41 { 42 int be = tep_is_bigendian(); 43 struct tep_handle *pevent; 44 45 if (trace_event__init(&tevent)) 46 return -1; 47 48 pevent = tevent.pevent; 49 tep_set_flag(pevent, TEP_NSEC_OUTPUT); 50 tep_set_file_bigendian(pevent, be); 51 tep_set_local_bigendian(pevent, be); 52 tevent_initialized = true; 53 return 0; 54 } 55 56 int trace_event__register_resolver(struct machine *machine, 57 tep_func_resolver_t *func) 58 { 59 if (!tevent_initialized && trace_event__init2()) 60 return -1; 61 62 return tep_set_function_resolver(tevent.pevent, func, machine); 63 } 64 65 void trace_event__cleanup(struct trace_event *t) 66 { 67 tep_unload_plugins(t->plugin_list, t->pevent); 68 tep_free(t->pevent); 69 } 70 71 /* 72 * Returns pointer with encoded error via <linux/err.h> interface. 73 */ 74 static struct tep_event* 75 tp_format(const char *sys, const char *name) 76 { 77 char *tp_dir = get_events_file(sys); 78 struct tep_handle *pevent = tevent.pevent; 79 struct tep_event *event = NULL; 80 char path[PATH_MAX]; 81 size_t size; 82 char *data; 83 int err; 84 85 if (!tp_dir) 86 return ERR_PTR(-errno); 87 88 scnprintf(path, PATH_MAX, "%s/%s/format", tp_dir, name); 89 put_events_file(tp_dir); 90 91 err = filename__read_str(path, &data, &size); 92 if (err) 93 return ERR_PTR(err); 94 95 tep_parse_format(pevent, &event, data, size, sys); 96 97 free(data); 98 return event; 99 } 100 101 /* 102 * Returns pointer with encoded error via <linux/err.h> interface. 103 */ 104 struct tep_event* 105 trace_event__tp_format(const char *sys, const char *name) 106 { 107 if (!tevent_initialized && trace_event__init2()) 108 return ERR_PTR(-ENOMEM); 109 110 return tp_format(sys, name); 111 } 112 113 struct tep_event *trace_event__tp_format_id(int id) 114 { 115 if (!tevent_initialized && trace_event__init2()) 116 return ERR_PTR(-ENOMEM); 117 118 return tep_find_event(tevent.pevent, id); 119 } 120