Loading...
1// SPDX-License-Identifier: GPL-2.0
2#ifndef _GNU_SOURCE
3# define _GNU_SOURCE
4#endif
5
6#include <stdio.h>
7#include <stdlib.h>
8#include <string.h>
9#include <linux/string.h>
10#include <errno.h>
11#include <unistd.h>
12#include "fs.h"
13
14#include "tracing_path.h"
15
16static char tracing_mnt[PATH_MAX] = "/sys/kernel/debug";
17static char tracing_path[PATH_MAX] = "/sys/kernel/debug/tracing";
18static char tracing_events_path[PATH_MAX] = "/sys/kernel/debug/tracing/events";
19
20static void __tracing_path_set(const char *tracing, const char *mountpoint)
21{
22 snprintf(tracing_mnt, sizeof(tracing_mnt), "%s", mountpoint);
23 snprintf(tracing_path, sizeof(tracing_path), "%s/%s",
24 mountpoint, tracing);
25 snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s%s",
26 mountpoint, tracing, "events");
27}
28
29static const char *tracing_path_tracefs_mount(void)
30{
31 const char *mnt;
32
33 mnt = tracefs__mount();
34 if (!mnt)
35 return NULL;
36
37 __tracing_path_set("", mnt);
38
39 return tracing_path;
40}
41
42static const char *tracing_path_debugfs_mount(void)
43{
44 const char *mnt;
45
46 mnt = debugfs__mount();
47 if (!mnt)
48 return NULL;
49
50 __tracing_path_set("tracing/", mnt);
51
52 return tracing_path;
53}
54
55const char *tracing_path_mount(void)
56{
57 const char *mnt;
58
59 mnt = tracing_path_tracefs_mount();
60 if (mnt)
61 return mnt;
62
63 mnt = tracing_path_debugfs_mount();
64
65 return mnt;
66}
67
68void tracing_path_set(const char *mntpt)
69{
70 __tracing_path_set("tracing/", mntpt);
71}
72
73char *get_tracing_file(const char *name)
74{
75 char *file;
76
77 if (asprintf(&file, "%s/%s", tracing_path_mount(), name) < 0)
78 return NULL;
79
80 return file;
81}
82
83void put_tracing_file(char *file)
84{
85 free(file);
86}
87
88char *get_events_file(const char *name)
89{
90 char *file;
91
92 if (asprintf(&file, "%s/events/%s", tracing_path_mount(), name) < 0)
93 return NULL;
94
95 return file;
96}
97
98void put_events_file(char *file)
99{
100 free(file);
101}
102
103DIR *tracing_events__opendir(void)
104{
105 DIR *dir = NULL;
106 char *path = get_tracing_file("events");
107
108 if (path) {
109 dir = opendir(path);
110 put_events_file(path);
111 }
112
113 return dir;
114}
115
116int tracing_events__scandir_alphasort(struct dirent ***namelist)
117{
118 char *path = get_tracing_file("events");
119 int ret;
120
121 if (!path) {
122 *namelist = NULL;
123 return 0;
124 }
125
126 ret = scandir(path, namelist, NULL, alphasort);
127 put_events_file(path);
128
129 return ret;
130}
131
132int tracing_path__strerror_open_tp(int err, char *buf, size_t size,
133 const char *sys, const char *name)
134{
135 char sbuf[128];
136 char filename[PATH_MAX];
137
138 snprintf(filename, PATH_MAX, "%s/%s", sys, name ?: "*");
139
140 switch (err) {
141 case ENOENT:
142 /*
143 * We will get here if we can't find the tracepoint, but one of
144 * debugfs or tracefs is configured, which means you probably
145 * want some tracepoint which wasn't compiled in your kernel.
146 * - jirka
147 */
148 if (debugfs__configured() || tracefs__configured()) {
149 /* sdt markers */
150 if (!strncmp(filename, "sdt_", 4)) {
151 snprintf(buf, size,
152 "Error:\tFile %s/%s not found.\n"
153 "Hint:\tSDT event cannot be directly recorded on.\n"
154 "\tPlease first use 'perf probe %s:%s' before recording it.\n",
155 tracing_events_path, filename, sys, name);
156 } else {
157 snprintf(buf, size,
158 "Error:\tFile %s/%s not found.\n"
159 "Hint:\tPerhaps this kernel misses some CONFIG_ setting to enable this feature?.\n",
160 tracing_events_path, filename);
161 }
162 break;
163 }
164 snprintf(buf, size, "%s",
165 "Error:\tUnable to find debugfs/tracefs\n"
166 "Hint:\tWas your kernel compiled with debugfs/tracefs support?\n"
167 "Hint:\tIs the debugfs/tracefs filesystem mounted?\n"
168 "Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'");
169 break;
170 case EACCES: {
171 snprintf(buf, size,
172 "Error:\tNo permissions to read %s/%s\n"
173 "Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n",
174 tracing_events_path, filename, tracing_path_mount());
175 }
176 break;
177 default:
178 snprintf(buf, size, "%s", str_error_r(err, sbuf, sizeof(sbuf)));
179 break;
180 }
181
182 return 0;
183}
1// SPDX-License-Identifier: GPL-2.0
2#ifndef _GNU_SOURCE
3# define _GNU_SOURCE
4#endif
5
6#include <stdio.h>
7#include <stdlib.h>
8#include <string.h>
9#include <linux/string.h>
10#include <errno.h>
11#include <unistd.h>
12#include "fs.h"
13
14#include "tracing_path.h"
15
16
17char tracing_mnt[PATH_MAX] = "/sys/kernel/debug";
18char tracing_path[PATH_MAX] = "/sys/kernel/debug/tracing";
19char tracing_events_path[PATH_MAX] = "/sys/kernel/debug/tracing/events";
20
21
22static void __tracing_path_set(const char *tracing, const char *mountpoint)
23{
24 snprintf(tracing_mnt, sizeof(tracing_mnt), "%s", mountpoint);
25 snprintf(tracing_path, sizeof(tracing_path), "%s/%s",
26 mountpoint, tracing);
27 snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s%s",
28 mountpoint, tracing, "events");
29}
30
31static const char *tracing_path_tracefs_mount(void)
32{
33 const char *mnt;
34
35 mnt = tracefs__mount();
36 if (!mnt)
37 return NULL;
38
39 __tracing_path_set("", mnt);
40
41 return mnt;
42}
43
44static const char *tracing_path_debugfs_mount(void)
45{
46 const char *mnt;
47
48 mnt = debugfs__mount();
49 if (!mnt)
50 return NULL;
51
52 __tracing_path_set("tracing/", mnt);
53
54 return mnt;
55}
56
57const char *tracing_path_mount(void)
58{
59 const char *mnt;
60
61 mnt = tracing_path_tracefs_mount();
62 if (mnt)
63 return mnt;
64
65 mnt = tracing_path_debugfs_mount();
66
67 return mnt;
68}
69
70void tracing_path_set(const char *mntpt)
71{
72 __tracing_path_set("tracing/", mntpt);
73}
74
75char *get_tracing_file(const char *name)
76{
77 char *file;
78
79 if (asprintf(&file, "%s/%s", tracing_path, name) < 0)
80 return NULL;
81
82 return file;
83}
84
85void put_tracing_file(char *file)
86{
87 free(file);
88}
89
90int tracing_path__strerror_open_tp(int err, char *buf, size_t size,
91 const char *sys, const char *name)
92{
93 char sbuf[128];
94 char filename[PATH_MAX];
95
96 snprintf(filename, PATH_MAX, "%s/%s", sys, name ?: "*");
97
98 switch (err) {
99 case ENOENT:
100 /*
101 * We will get here if we can't find the tracepoint, but one of
102 * debugfs or tracefs is configured, which means you probably
103 * want some tracepoint which wasn't compiled in your kernel.
104 * - jirka
105 */
106 if (debugfs__configured() || tracefs__configured()) {
107 /* sdt markers */
108 if (!strncmp(filename, "sdt_", 4)) {
109 snprintf(buf, size,
110 "Error:\tFile %s/%s not found.\n"
111 "Hint:\tSDT event cannot be directly recorded on.\n"
112 "\tPlease first use 'perf probe %s:%s' before recording it.\n",
113 tracing_events_path, filename, sys, name);
114 } else {
115 snprintf(buf, size,
116 "Error:\tFile %s/%s not found.\n"
117 "Hint:\tPerhaps this kernel misses some CONFIG_ setting to enable this feature?.\n",
118 tracing_events_path, filename);
119 }
120 break;
121 }
122 snprintf(buf, size, "%s",
123 "Error:\tUnable to find debugfs/tracefs\n"
124 "Hint:\tWas your kernel compiled with debugfs/tracefs support?\n"
125 "Hint:\tIs the debugfs/tracefs filesystem mounted?\n"
126 "Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'");
127 break;
128 case EACCES: {
129 snprintf(buf, size,
130 "Error:\tNo permissions to read %s/%s\n"
131 "Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n",
132 tracing_events_path, filename, tracing_mnt);
133 }
134 break;
135 default:
136 snprintf(buf, size, "%s", str_error_r(err, sbuf, sizeof(sbuf)));
137 break;
138 }
139
140 return 0;
141}