summaryrefslogtreecommitdiffstats
path: root/tools/perf/util/probe-file.c
blob: bbb243717ec834f0548e9d5bf8a3ac0ff48f8c4b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
/*
 * probe-file.c : operate ftrace k/uprobe events files
 *
 * Written by Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */
#include "util.h"
#include "event.h"
#include "strlist.h"
#include "debug.h"
#include "cache.h"
#include "color.h"
#include "symbol.h"
#include "thread.h"
#include <api/fs/debugfs.h>
#include <api/fs/tracefs.h>
#include "probe-event.h"
#include "probe-file.h"
#include "session.h"

#define MAX_CMDLEN 256

static void print_open_warning(int err, bool uprobe)
{
	char sbuf[STRERR_BUFSIZE];

	if (err == -ENOENT) {
		const char *config;

		if (uprobe)
			config = "CONFIG_UPROBE_EVENTS";
		else
			config = "CONFIG_KPROBE_EVENTS";

		pr_warning("%cprobe_events file does not exist"
			   " - please rebuild kernel with %s.\n",
			   uprobe ? 'u' : 'k', config);
	} else if (err == -ENOTSUP)
		pr_warning("Tracefs or debugfs is not mounted.\n");
	else
		pr_warning("Failed to open %cprobe_events: %s\n",
			   uprobe ? 'u' : 'k',
			   strerror_r(-err, sbuf, sizeof(sbuf)));
}

static void print_both_open_warning(int kerr, int uerr)
{
	/* Both kprobes and uprobes are disabled, warn it. */
	if (kerr == -ENOTSUP && uerr == -ENOTSUP)
		pr_warning("Tracefs or debugfs is not mounted.\n");
	else if (kerr == -ENOENT && uerr == -ENOENT)
		pr_warning("Please rebuild kernel with CONFIG_KPROBE_EVENTS "
			   "or/and CONFIG_UPROBE_EVENTS.\n");
	else {
		char sbuf[STRERR_BUFSIZE];
		pr_warning("Failed to open kprobe events: %s.\n",
			   strerror_r(-kerr, sbuf, sizeof(sbuf)));
		pr_warning("Failed to open uprobe events: %s.\n",
			   strerror_r(-uerr, sbuf, sizeof(sbuf)));
	}
}

static int open_probe_events(const char *trace_file, bool readwrite)
{
	char buf[PATH_MAX];
	const char *__debugfs;
	const char *tracing_dir = "";
	int ret;

	__debugfs = tracefs_find_mountpoint();
	if (__debugfs == NULL) {
		tracing_dir = "tracing/";

		__debugfs = debugfs_find_mountpoint();
		if (__debugfs == NULL)
			return -ENOTSUP;
	}

	ret = e_snprintf(buf, PATH_MAX, "%s/%s%s",
			 __debugfs, tracing_dir, trace_file);
	if (ret >= 0) {
		pr_debug("Opening %s write=%d\n", buf, readwrite);
		if (readwrite && !probe_event_dry_run)
			ret = open(buf, O_RDWR | O_APPEND, 0);
		else
			ret = open(buf, O_RDONLY, 0);

		if (ret < 0)
			ret = -errno;
	}
	return ret;
}

static int open_kprobe_events(bool readwrite)
{
	return open_probe_events("kprobe_events", readwrite);
}

static int open_uprobe_events(bool readwrite)
{
	return open_probe_events("uprobe_events", readwrite);
}

int probe_file__open(int flag)
{
	int fd;

	if (flag & PF_FL_UPROBE)
		fd = open_uprobe_events(flag & PF_FL_RW);
	else
		fd = open_kprobe_events(flag & PF_FL_RW);
	if (fd < 0)
		print_open_warning(fd, flag & PF_FL_UPROBE);

	return fd;
}

int probe_file__open_both(int *kfd, int *ufd, int flag)
{
	if (!kfd || !ufd)
		return -EINVAL;

	*kfd = open_kprobe_events(flag & PF_FL_RW);
	*ufd = open_uprobe_events(flag & PF_FL_RW);
	if (*kfd < 0 && *ufd < 0) {
		print_both_open_warning(*kfd, *ufd);
		return *kfd;
	}

	return 0;
}

/* Get raw string list of current kprobe_events  or uprobe_events */
struct strlist *probe_file__get_rawlist(int fd)
{
	int ret, idx;
	FILE *fp;
	char buf[MAX_CMDLEN];
	char *p;
	struct strlist *sl;

	sl = strlist__new(NULL, NULL);

	fp = fdopen(dup(fd), "r");
	while (!feof(fp)) {
		p = fgets(buf, MAX_CMDLEN, fp);
		if (!p)
			break;

		idx = strlen(p) - 1;
		if (p[idx] == '\n')
			p[idx] = '\0';
		ret = strlist__add(sl, buf);
		if (ret < 0) {
			pr_debug("strlist__add failed (%d)\n", ret);
			strlist__delete(sl);
			return NULL;
		}
	}
	fclose(fp);

	return sl;
}

static struct strlist *__probe_file__get_namelist(int fd, bool include_group)
{
	char buf[128];
	struct strlist *sl, *rawlist;
	struct str_node *ent;
	struct probe_trace_event tev;
	int ret = 0;

	memset(&tev, 0, sizeof(tev));
	rawlist = probe_file__get_rawlist(fd);
	if (!rawlist)
		return NULL;
	sl = strlist__new(NULL, NULL);
	strlist__for_each(ent, rawlist) {
		ret = parse_probe_trace_command(ent->s, &tev);
		if (ret < 0)
			break;
		if (include_group) {
			ret = e_snprintf(buf, 128, "%s:%s", tev.group,
					tev.event);
			if (ret >= 0)
				ret = strlist__add(sl, buf);
		} else
			ret = strlist__add(sl, tev.event);
		clear_probe_trace_event(&tev);
		if (ret < 0)
			break;
	}
	strlist__delete(rawlist);

	if (ret < 0) {
		strlist__delete(sl);
		return NULL;
	}
	return sl;
}

/* Get current perf-probe event names */
struct strlist *probe_file__get_namelist(int fd)
{
	return __probe_file__get_namelist(fd, false);
}

int probe_file__add_event(int fd, struct probe_trace_event *tev)
{
	int ret = 0;
	char *buf = synthesize_probe_trace_command(tev);
	char sbuf[STRERR_BUFSIZE];

	if (!buf) {
		pr_debug("Failed to synthesize probe trace event.\n");
		return -EINVAL;
	}

	pr_debug("Writing event: %s\n", buf);
	if (!probe_event_dry_run) {
		ret = write(fd, buf, strlen(buf));
		if (ret <= 0) {
			ret = -errno;
			pr_warning("Failed to write event: %s\n",
				   strerror_r(errno, sbuf, sizeof(sbuf)));
		}
	}
	free(buf);

	return ret;
}

static int __del_trace_probe_event(int fd, struct str_node *ent)
{
	char *p;
	char buf[128];
	int ret;

	/* Convert from perf-probe event to trace-probe event */
	ret = e_snprintf(buf, 128, "-:%s", ent->s);
	if (ret < 0)
		goto error;

	p = strchr(buf + 2, ':');
	if (!p) {
		pr_debug("Internal error: %s should have ':' but not.\n",
			 ent->s);
		ret = -ENOTSUP;
		goto error;
	}
	*p = '/';

	pr_debug("Writing event: %s\n", buf);
	ret = write(fd, buf, strlen(buf));
	if (ret < 0) {
		ret = -errno;
		goto error;
	}

	pr_info("Removed event: %s\n", ent->s);
	return 0;
error:
	pr_warning("Failed to delete event: %s\n",
		   strerror_r(-ret, buf, sizeof(buf)));
	return ret;
}

int probe_file__del_events(int fd, struct strfilter *filter)
{
	struct strlist *namelist;
	struct str_node *ent;
	const char *p;
	int ret = -ENOENT;

	namelist = __probe_file__get_namelist(fd, true);
	if (!namelist)
		return -ENOENT;

	strlist__for_each(ent, namelist) {
		p = strchr(ent->s, ':');
		if ((p && strfilter__compare(filter, p + 1)) ||
		    strfilter__compare(filter, ent->s)) {
			ret = __del_trace_probe_event(fd, ent);
			if (ret < 0)
				break;
		}
	}
	strlist__delete(namelist);

	return ret;
}
OpenPOWER on IntegriCloud