1 // SPDX-License-Identifier: GPL-2.0
9 #include <linux/string.h>
14 #include "tracing_path.h"
16 static char tracing_mnt[PATH_MAX] = "/sys/kernel/debug";
17 static char tracing_path[PATH_MAX] = "/sys/kernel/debug/tracing";
18 static char tracing_events_path[PATH_MAX] = "/sys/kernel/debug/tracing/events";
20 static void __tracing_path_set(const char *tracing, const char *mountpoint)
22 snprintf(tracing_mnt, sizeof(tracing_mnt), "%s", mountpoint);
23 snprintf(tracing_path, sizeof(tracing_path), "%s/%s",
25 snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s%s",
26 mountpoint, tracing, "events");
29 static const char *tracing_path_tracefs_mount(void)
33 mnt = tracefs__mount();
37 __tracing_path_set("", mnt);
42 static const char *tracing_path_debugfs_mount(void)
46 mnt = debugfs__mount();
50 __tracing_path_set("tracing/", mnt);
55 const char *tracing_path_mount(void)
59 mnt = tracing_path_tracefs_mount();
63 mnt = tracing_path_debugfs_mount();
68 void tracing_path_set(const char *mntpt)
70 __tracing_path_set("tracing/", mntpt);
73 char *get_tracing_file(const char *name)
77 if (asprintf(&file, "%s/%s", tracing_path_mount(), name) < 0)
83 void put_tracing_file(char *file)
88 char *get_events_file(const char *name)
92 if (asprintf(&file, "%s/events/%s", tracing_path_mount(), name) < 0)
98 void put_events_file(char *file)
103 DIR *tracing_events__opendir(void)
106 char *path = get_tracing_file("events");
110 put_events_file(path);
116 int tracing_path__strerror_open_tp(int err, char *buf, size_t size,
117 const char *sys, const char *name)
120 char filename[PATH_MAX];
122 snprintf(filename, PATH_MAX, "%s/%s", sys, name ?: "*");
127 * We will get here if we can't find the tracepoint, but one of
128 * debugfs or tracefs is configured, which means you probably
129 * want some tracepoint which wasn't compiled in your kernel.
132 if (debugfs__configured() || tracefs__configured()) {
134 if (!strncmp(filename, "sdt_", 4)) {
136 "Error:\tFile %s/%s not found.\n"
137 "Hint:\tSDT event cannot be directly recorded on.\n"
138 "\tPlease first use 'perf probe %s:%s' before recording it.\n",
139 tracing_events_path, filename, sys, name);
142 "Error:\tFile %s/%s not found.\n"
143 "Hint:\tPerhaps this kernel misses some CONFIG_ setting to enable this feature?.\n",
144 tracing_events_path, filename);
148 snprintf(buf, size, "%s",
149 "Error:\tUnable to find debugfs/tracefs\n"
150 "Hint:\tWas your kernel compiled with debugfs/tracefs support?\n"
151 "Hint:\tIs the debugfs/tracefs filesystem mounted?\n"
152 "Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'");
156 "Error:\tNo permissions to read %s/%s\n"
157 "Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n",
158 tracing_events_path, filename, tracing_path_mount());
162 snprintf(buf, size, "%s", str_error_r(err, sbuf, sizeof(sbuf)));