xref: /linux/tools/perf/util/tp_pmu.c (revision ec714e371f22f716a04e6ecb2a24988c92b26911)
1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
2 #include "tp_pmu.h"
3 #include "pmus.h"
4 #include <api/fs/fs.h>
5 #include <api/fs/tracing_path.h>
6 #include <api/io_dir.h>
7 #include <linux/kernel.h>
8 #include <errno.h>
9 #include <string.h>
10 
tp_pmu__id(const char * sys,const char * name)11 int tp_pmu__id(const char *sys, const char *name)
12 {
13 	char *tp_dir = get_events_file(sys);
14 	char path[PATH_MAX];
15 	int id, err;
16 
17 	if (!tp_dir)
18 		return -1;
19 
20 	scnprintf(path, PATH_MAX, "%s/%s/id", tp_dir, name);
21 	put_events_file(tp_dir);
22 	err = filename__read_int(path, &id);
23 	if (err)
24 		return err;
25 
26 	return id;
27 }
28 
29 
tp_pmu__for_each_tp_event(const char * sys,void * state,tp_event_callback cb)30 int tp_pmu__for_each_tp_event(const char *sys, void *state, tp_event_callback cb)
31 {
32 	char *evt_path;
33 	struct io_dirent64 *evt_ent;
34 	struct io_dir evt_dir;
35 	int ret = 0;
36 
37 	evt_path = get_events_file(sys);
38 	if (!evt_path)
39 		return -errno;
40 
41 	io_dir__init(&evt_dir, open(evt_path, O_CLOEXEC | O_DIRECTORY | O_RDONLY));
42 	if (evt_dir.dirfd < 0) {
43 		ret = -errno;
44 		put_events_file(evt_path);
45 		return ret;
46 	}
47 	put_events_file(evt_path);
48 
49 	while (!ret && (evt_ent = io_dir__readdir(&evt_dir))) {
50 		if (!strcmp(evt_ent->d_name, ".")
51 		    || !strcmp(evt_ent->d_name, "..")
52 		    || !strcmp(evt_ent->d_name, "enable")
53 		    || !strcmp(evt_ent->d_name, "filter"))
54 			continue;
55 
56 		ret = cb(state, sys, evt_ent->d_name);
57 		if (ret)
58 			break;
59 	}
60 	close(evt_dir.dirfd);
61 	return ret;
62 }
63 
tp_pmu__for_each_tp_sys(void * state,tp_sys_callback cb)64 int tp_pmu__for_each_tp_sys(void *state, tp_sys_callback cb)
65 {
66 	struct io_dirent64 *events_ent;
67 	struct io_dir events_dir;
68 	int ret = 0;
69 	char *events_dir_path = get_tracing_file("events");
70 
71 	if (!events_dir_path)
72 		return -errno;
73 
74 	io_dir__init(&events_dir, open(events_dir_path, O_CLOEXEC | O_DIRECTORY | O_RDONLY));
75 	if (events_dir.dirfd < 0) {
76 		ret = -errno;
77 		put_events_file(events_dir_path);
78 		return ret;
79 	}
80 	put_events_file(events_dir_path);
81 
82 	while (!ret && (events_ent = io_dir__readdir(&events_dir))) {
83 		if (!strcmp(events_ent->d_name, ".") ||
84 		    !strcmp(events_ent->d_name, "..") ||
85 		    !strcmp(events_ent->d_name, "enable") ||
86 		    !strcmp(events_ent->d_name, "header_event") ||
87 		    !strcmp(events_ent->d_name, "header_page"))
88 			continue;
89 
90 		ret = cb(state, events_ent->d_name);
91 	}
92 	close(events_dir.dirfd);
93 	return ret;
94 }
95 
perf_pmu__is_tracepoint(const struct perf_pmu * pmu)96 bool perf_pmu__is_tracepoint(const struct perf_pmu *pmu)
97 {
98 	return pmu->type == PERF_TYPE_TRACEPOINT;
99 }
100 
101 struct for_each_event_args {
102 	void *state;
103 	pmu_event_callback cb;
104 	const struct perf_pmu *pmu;
105 };
106 
for_each_event_cb(void * state,const char * sys_name,const char * evt_name)107 static int for_each_event_cb(void *state, const char *sys_name, const char *evt_name)
108 {
109 	struct for_each_event_args *args = state;
110 	char name[2 * FILENAME_MAX + 2];
111 	/* 16 possible hex digits and 22 other characters and \0. */
112 	char encoding[16 + 22];
113 	char *format = NULL;
114 	size_t format_size;
115 	struct pmu_event_info info = {
116 		.pmu = args->pmu,
117 		.pmu_name = args->pmu->name,
118 		.event_type_desc = "Tracepoint event",
119 	};
120 	char *tp_dir = get_events_file(sys_name);
121 	char path[PATH_MAX];
122 	int id, err;
123 
124 	if (!tp_dir)
125 		return -1;
126 
127 	scnprintf(path, sizeof(path), "%s/%s/id", tp_dir, evt_name);
128 	err = filename__read_int(path, &id);
129 	if (err == 0) {
130 		snprintf(encoding, sizeof(encoding), "tracepoint/config=0x%x/", id);
131 		info.encoding_desc = encoding;
132 	}
133 
134 	scnprintf(path, sizeof(path), "%s/%s/format", tp_dir, evt_name);
135 	put_events_file(tp_dir);
136 	err = filename__read_str(path, &format, &format_size);
137 	if (err == 0) {
138 		info.long_desc = format;
139 		for (size_t i = 0 ; i < format_size; i++) {
140 			/* Swap tabs to spaces due to some rendering issues. */
141 			if (format[i] == '\t')
142 				format[i] = ' ';
143 		}
144 	}
145 	snprintf(name, sizeof(name), "%s:%s", sys_name, evt_name);
146 	info.name = name;
147 	err = args->cb(args->state, &info);
148 	free(format);
149 	return err;
150 }
151 
for_each_event_sys_cb(void * state,const char * sys_name)152 static int for_each_event_sys_cb(void *state, const char *sys_name)
153 {
154 	return tp_pmu__for_each_tp_event(sys_name, state, for_each_event_cb);
155 }
156 
tp_pmu__for_each_event(struct perf_pmu * pmu,void * state,pmu_event_callback cb)157 int tp_pmu__for_each_event(struct perf_pmu *pmu, void *state, pmu_event_callback cb)
158 {
159 	struct for_each_event_args args = {
160 		.state = state,
161 		.cb = cb,
162 		.pmu = pmu,
163 	};
164 
165 	return tp_pmu__for_each_tp_sys(&args, for_each_event_sys_cb);
166 }
167 
num_events_cb(void * state,const char * sys_name __maybe_unused,const char * evt_name __maybe_unused)168 static int num_events_cb(void *state, const char *sys_name __maybe_unused,
169 			 const char *evt_name __maybe_unused)
170 {
171 	size_t *count = state;
172 
173 	(*count)++;
174 	return 0;
175 }
176 
num_events_sys_cb(void * state,const char * sys_name)177 static int num_events_sys_cb(void *state, const char *sys_name)
178 {
179 	return tp_pmu__for_each_tp_event(sys_name, state, num_events_cb);
180 }
181 
tp_pmu__num_events(struct perf_pmu * pmu __maybe_unused)182 size_t tp_pmu__num_events(struct perf_pmu *pmu __maybe_unused)
183 {
184 	size_t count = 0;
185 
186 	tp_pmu__for_each_tp_sys(&count, num_events_sys_cb);
187 	return count;
188 }
189 
tp_pmu__have_event(struct perf_pmu * pmu __maybe_unused,const char * name)190 bool tp_pmu__have_event(struct perf_pmu *pmu __maybe_unused, const char *name)
191 {
192 	char *dup_name, *colon;
193 	int id;
194 
195 	colon = strchr(name, ':');
196 	if (colon == NULL)
197 		return false;
198 
199 	dup_name = strdup(name);
200 	if (!dup_name)
201 		return false;
202 
203 	colon = dup_name + (colon - name);
204 	*colon = '\0';
205 	id = tp_pmu__id(dup_name, colon + 1);
206 	free(dup_name);
207 	return id >= 0;
208 }
209