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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
commitb4b7ff4b08e691656c9d77c758fc355833128ac0 (patch)
tree82fcb00e6b918026dc9f2d1f05ed8eee83874cc0 /tools/lib/api
parent35acfa0fc609f2a2cd95cef4a6a9c3a5c38f1778 (diff)
Linux-libre 4.4-gnupck-4.4-gnu
Diffstat (limited to 'tools/lib/api')
-rw-r--r--tools/lib/api/Build1
-rw-r--r--tools/lib/api/Makefile6
-rw-r--r--tools/lib/api/cpu.c18
-rw-r--r--tools/lib/api/cpu.h6
-rw-r--r--tools/lib/api/fs/Build4
-rw-r--r--tools/lib/api/fs/debugfs.c129
-rw-r--r--tools/lib/api/fs/debugfs.h23
-rw-r--r--tools/lib/api/fs/findfs.c63
-rw-r--r--tools/lib/api/fs/findfs.h23
-rw-r--r--tools/lib/api/fs/fs.c165
-rw-r--r--tools/lib/api/fs/fs.h30
-rw-r--r--tools/lib/api/fs/tracefs.c78
-rw-r--r--tools/lib/api/fs/tracefs.h21
-rw-r--r--tools/lib/api/fs/tracing_path.c135
-rw-r--r--tools/lib/api/fs/tracing_path.h16
15 files changed, 357 insertions, 361 deletions
diff --git a/tools/lib/api/Build b/tools/lib/api/Build
index 3653965cf..e8b8a23b9 100644
--- a/tools/lib/api/Build
+++ b/tools/lib/api/Build
@@ -1,2 +1,3 @@
libapi-y += fd/
libapi-y += fs/
+libapi-y += cpu.o
diff --git a/tools/lib/api/Makefile b/tools/lib/api/Makefile
index fe1b02c2c..d85904dc9 100644
--- a/tools/lib/api/Makefile
+++ b/tools/lib/api/Makefile
@@ -21,12 +21,14 @@ CFLAGS += -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64
RM = rm -f
-build := -f $(srctree)/tools/build/Makefile.build dir=. obj
API_IN := $(OUTPUT)libapi-in.o
+all:
+
export srctree OUTPUT CC LD CFLAGS V
+include $(srctree)/tools/build/Makefile.include
-all: $(LIBFILE)
+all: fixdep $(LIBFILE)
$(API_IN): FORCE
@$(MAKE) $(build)=libapi
diff --git a/tools/lib/api/cpu.c b/tools/lib/api/cpu.c
new file mode 100644
index 000000000..8c6489356
--- /dev/null
+++ b/tools/lib/api/cpu.c
@@ -0,0 +1,18 @@
+#include <stdio.h>
+
+#include "cpu.h"
+#include "fs/fs.h"
+
+int cpu__get_max_freq(unsigned long long *freq)
+{
+ char entry[PATH_MAX];
+ int cpu;
+
+ if (sysfs__read_int("devices/system/cpu/online", &cpu) < 0)
+ return -1;
+
+ snprintf(entry, sizeof(entry),
+ "devices/system/cpu/cpu%d/cpufreq/cpuinfo_max_freq", cpu);
+
+ return sysfs__read_ull(entry, freq);
+}
diff --git a/tools/lib/api/cpu.h b/tools/lib/api/cpu.h
new file mode 100644
index 000000000..81e9d3955
--- /dev/null
+++ b/tools/lib/api/cpu.h
@@ -0,0 +1,6 @@
+#ifndef __API_CPU__
+#define __API_CPU__
+
+int cpu__get_max_freq(unsigned long long *freq);
+
+#endif /* __API_CPU__ */
diff --git a/tools/lib/api/fs/Build b/tools/lib/api/fs/Build
index 6de5a4f0b..f4ed9629a 100644
--- a/tools/lib/api/fs/Build
+++ b/tools/lib/api/fs/Build
@@ -1,4 +1,2 @@
libapi-y += fs.o
-libapi-y += debugfs.o
-libapi-y += findfs.o
-libapi-y += tracefs.o
+libapi-y += tracing_path.o
diff --git a/tools/lib/api/fs/debugfs.c b/tools/lib/api/fs/debugfs.c
deleted file mode 100644
index eb7cf4d18..000000000
--- a/tools/lib/api/fs/debugfs.c
+++ /dev/null
@@ -1,129 +0,0 @@
-#define _GNU_SOURCE
-#include <errno.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <stdbool.h>
-#include <sys/vfs.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/mount.h>
-#include <linux/kernel.h>
-
-#include "debugfs.h"
-#include "tracefs.h"
-
-#ifndef DEBUGFS_DEFAULT_PATH
-#define DEBUGFS_DEFAULT_PATH "/sys/kernel/debug"
-#endif
-
-char debugfs_mountpoint[PATH_MAX + 1] = DEBUGFS_DEFAULT_PATH;
-
-static const char * const debugfs_known_mountpoints[] = {
- DEBUGFS_DEFAULT_PATH,
- "/debug",
- 0,
-};
-
-static bool debugfs_found;
-
-bool debugfs_configured(void)
-{
- return debugfs_find_mountpoint() != NULL;
-}
-
-/* find the path to the mounted debugfs */
-const char *debugfs_find_mountpoint(void)
-{
- const char *ret;
-
- if (debugfs_found)
- return (const char *)debugfs_mountpoint;
-
- ret = find_mountpoint("debugfs", (long) DEBUGFS_MAGIC,
- debugfs_mountpoint, PATH_MAX + 1,
- debugfs_known_mountpoints);
- if (ret)
- debugfs_found = true;
-
- return ret;
-}
-
-/* mount the debugfs somewhere if it's not mounted */
-char *debugfs_mount(const char *mountpoint)
-{
- /* see if it's already mounted */
- if (debugfs_find_mountpoint())
- goto out;
-
- /* if not mounted and no argument */
- if (mountpoint == NULL) {
- /* see if environment variable set */
- mountpoint = getenv(PERF_DEBUGFS_ENVIRONMENT);
- /* if no environment variable, use default */
- if (mountpoint == NULL)
- mountpoint = DEBUGFS_DEFAULT_PATH;
- }
-
- if (mount(NULL, mountpoint, "debugfs", 0, NULL) < 0)
- return NULL;
-
- /* save the mountpoint */
- debugfs_found = true;
- strncpy(debugfs_mountpoint, mountpoint, sizeof(debugfs_mountpoint));
-out:
- return debugfs_mountpoint;
-}
-
-int debugfs__strerror_open(int err, char *buf, size_t size, const char *filename)
-{
- char sbuf[128];
-
- switch (err) {
- case ENOENT:
- if (debugfs_found) {
- snprintf(buf, size,
- "Error:\tFile %s/%s not found.\n"
- "Hint:\tPerhaps this kernel misses some CONFIG_ setting to enable this feature?.\n",
- debugfs_mountpoint, filename);
- break;
- }
- snprintf(buf, size, "%s",
- "Error:\tUnable to find debugfs\n"
- "Hint:\tWas your kernel compiled with debugfs support?\n"
- "Hint:\tIs the debugfs filesystem mounted?\n"
- "Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'");
- break;
- case EACCES: {
- const char *mountpoint = debugfs_mountpoint;
-
- if (!access(debugfs_mountpoint, R_OK) && strncmp(filename, "tracing/", 8) == 0) {
- const char *tracefs_mntpoint = tracefs_find_mountpoint();
-
- if (tracefs_mntpoint)
- mountpoint = tracefs_mntpoint;
- }
-
- snprintf(buf, size,
- "Error:\tNo permissions to read %s/%s\n"
- "Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n",
- debugfs_mountpoint, filename, mountpoint);
- }
- break;
- default:
- snprintf(buf, size, "%s", strerror_r(err, sbuf, sizeof(sbuf)));
- break;
- }
-
- return 0;
-}
-
-int debugfs__strerror_open_tp(int err, char *buf, size_t size, const char *sys, const char *name)
-{
- char path[PATH_MAX];
-
- snprintf(path, PATH_MAX, "tracing/events/%s/%s", sys, name ?: "*");
-
- return debugfs__strerror_open(err, buf, size, path);
-}
diff --git a/tools/lib/api/fs/debugfs.h b/tools/lib/api/fs/debugfs.h
deleted file mode 100644
index 455023698..000000000
--- a/tools/lib/api/fs/debugfs.h
+++ /dev/null
@@ -1,23 +0,0 @@
-#ifndef __API_DEBUGFS_H__
-#define __API_DEBUGFS_H__
-
-#include "findfs.h"
-
-#ifndef DEBUGFS_MAGIC
-#define DEBUGFS_MAGIC 0x64626720
-#endif
-
-#ifndef PERF_DEBUGFS_ENVIRONMENT
-#define PERF_DEBUGFS_ENVIRONMENT "PERF_DEBUGFS_DIR"
-#endif
-
-bool debugfs_configured(void);
-const char *debugfs_find_mountpoint(void);
-char *debugfs_mount(const char *mountpoint);
-
-extern char debugfs_mountpoint[];
-
-int debugfs__strerror_open(int err, char *buf, size_t size, const char *filename);
-int debugfs__strerror_open_tp(int err, char *buf, size_t size, const char *sys, const char *name);
-
-#endif /* __API_DEBUGFS_H__ */
diff --git a/tools/lib/api/fs/findfs.c b/tools/lib/api/fs/findfs.c
deleted file mode 100644
index 49946cb6d..000000000
--- a/tools/lib/api/fs/findfs.c
+++ /dev/null
@@ -1,63 +0,0 @@
-#include <errno.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdbool.h>
-#include <sys/vfs.h>
-
-#include "findfs.h"
-
-/* verify that a mountpoint is actually the type we want */
-
-int valid_mountpoint(const char *mount, long magic)
-{
- struct statfs st_fs;
-
- if (statfs(mount, &st_fs) < 0)
- return -ENOENT;
- else if ((long)st_fs.f_type != magic)
- return -ENOENT;
-
- return 0;
-}
-
-/* find the path to a mounted file system */
-const char *find_mountpoint(const char *fstype, long magic,
- char *mountpoint, int len,
- const char * const *known_mountpoints)
-{
- const char * const *ptr;
- char format[128];
- char type[100];
- FILE *fp;
-
- if (known_mountpoints) {
- ptr = known_mountpoints;
- while (*ptr) {
- if (valid_mountpoint(*ptr, magic) == 0) {
- strncpy(mountpoint, *ptr, len - 1);
- mountpoint[len-1] = 0;
- return mountpoint;
- }
- ptr++;
- }
- }
-
- /* give up and parse /proc/mounts */
- fp = fopen("/proc/mounts", "r");
- if (fp == NULL)
- return NULL;
-
- snprintf(format, 128, "%%*s %%%ds %%99s %%*s %%*d %%*d\n", len);
-
- while (fscanf(fp, format, mountpoint, type) == 2) {
- if (strcmp(type, fstype) == 0)
- break;
- }
- fclose(fp);
-
- if (strcmp(type, fstype) != 0)
- return NULL;
-
- return mountpoint;
-}
diff --git a/tools/lib/api/fs/findfs.h b/tools/lib/api/fs/findfs.h
deleted file mode 100644
index b6f5d05ac..000000000
--- a/tools/lib/api/fs/findfs.h
+++ /dev/null
@@ -1,23 +0,0 @@
-#ifndef __API_FINDFS_H__
-#define __API_FINDFS_H__
-
-#include <stdbool.h>
-
-#define _STR(x) #x
-#define STR(x) _STR(x)
-
-/*
- * On most systems <limits.h> would have given us this, but not on some systems
- * (e.g. GNU/Hurd).
- */
-#ifndef PATH_MAX
-#define PATH_MAX 4096
-#endif
-
-const char *find_mountpoint(const char *fstype, long magic,
- char *mountpoint, int len,
- const char * const *known_mountpoints);
-
-int valid_mountpoint(const char *mount, long magic);
-
-#endif /* __API_FINDFS_H__ */
diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c
index 128ef6332..459599d1b 100644
--- a/tools/lib/api/fs/fs.c
+++ b/tools/lib/api/fs/fs.c
@@ -1,7 +1,6 @@
-/* TODO merge/factor in debugfs.c here */
-
#include <ctype.h>
#include <errno.h>
+#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
@@ -11,10 +10,29 @@
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
+#include <sys/mount.h>
-#include "debugfs.h"
#include "fs.h"
+#define _STR(x) #x
+#define STR(x) _STR(x)
+
+#ifndef SYSFS_MAGIC
+#define SYSFS_MAGIC 0x62656572
+#endif
+
+#ifndef PROC_SUPER_MAGIC
+#define PROC_SUPER_MAGIC 0x9fa0
+#endif
+
+#ifndef DEBUGFS_MAGIC
+#define DEBUGFS_MAGIC 0x64626720
+#endif
+
+#ifndef TRACEFS_MAGIC
+#define TRACEFS_MAGIC 0x74726163
+#endif
+
static const char * const sysfs__fs_known_mountpoints[] = {
"/sys",
0,
@@ -25,19 +43,48 @@ static const char * const procfs__known_mountpoints[] = {
0,
};
+#ifndef DEBUGFS_DEFAULT_PATH
+#define DEBUGFS_DEFAULT_PATH "/sys/kernel/debug"
+#endif
+
+static const char * const debugfs__known_mountpoints[] = {
+ DEBUGFS_DEFAULT_PATH,
+ "/debug",
+ 0,
+};
+
+
+#ifndef TRACEFS_DEFAULT_PATH
+#define TRACEFS_DEFAULT_PATH "/sys/kernel/tracing"
+#endif
+
+static const char * const tracefs__known_mountpoints[] = {
+ TRACEFS_DEFAULT_PATH,
+ "/sys/kernel/debug/tracing",
+ "/tracing",
+ "/trace",
+ 0,
+};
+
struct fs {
const char *name;
const char * const *mounts;
- char path[PATH_MAX + 1];
+ char path[PATH_MAX];
bool found;
long magic;
};
enum {
- FS__SYSFS = 0,
- FS__PROCFS = 1,
+ FS__SYSFS = 0,
+ FS__PROCFS = 1,
+ FS__DEBUGFS = 2,
+ FS__TRACEFS = 3,
};
+#ifndef TRACEFS_MAGIC
+#define TRACEFS_MAGIC 0x74726163
+#endif
+
static struct fs fs__entries[] = {
[FS__SYSFS] = {
.name = "sysfs",
@@ -49,6 +96,16 @@ static struct fs fs__entries[] = {
.mounts = procfs__known_mountpoints,
.magic = PROC_SUPER_MAGIC,
},
+ [FS__DEBUGFS] = {
+ .name = "debugfs",
+ .mounts = debugfs__known_mountpoints,
+ .magic = DEBUGFS_MAGIC,
+ },
+ [FS__TRACEFS] = {
+ .name = "tracefs",
+ .mounts = tracefs__known_mountpoints,
+ .magic = TRACEFS_MAGIC,
+ },
};
static bool fs__read_mounts(struct fs *fs)
@@ -159,14 +216,54 @@ static const char *fs__mountpoint(int idx)
return fs__get_mountpoint(fs);
}
-#define FS__MOUNTPOINT(name, idx) \
-const char *name##__mountpoint(void) \
-{ \
- return fs__mountpoint(idx); \
+static const char *mount_overload(struct fs *fs)
+{
+ size_t name_len = strlen(fs->name);
+ /* "PERF_" + name + "_ENVIRONMENT" + '\0' */
+ char upper_name[5 + name_len + 12 + 1];
+
+ snprintf(upper_name, name_len, "PERF_%s_ENVIRONMENT", fs->name);
+ mem_toupper(upper_name, name_len);
+
+ return getenv(upper_name) ?: *fs->mounts;
+}
+
+static const char *fs__mount(int idx)
+{
+ struct fs *fs = &fs__entries[idx];
+ const char *mountpoint;
+
+ if (fs__mountpoint(idx))
+ return (const char *)fs->path;
+
+ mountpoint = mount_overload(fs);
+
+ if (mount(NULL, mountpoint, fs->name, 0, NULL) < 0)
+ return NULL;
+
+ return fs__check_mounts(fs) ? fs->path : NULL;
+}
+
+#define FS(name, idx) \
+const char *name##__mountpoint(void) \
+{ \
+ return fs__mountpoint(idx); \
+} \
+ \
+const char *name##__mount(void) \
+{ \
+ return fs__mount(idx); \
+} \
+ \
+bool name##__configured(void) \
+{ \
+ return name##__mountpoint() != NULL; \
}
-FS__MOUNTPOINT(sysfs, FS__SYSFS);
-FS__MOUNTPOINT(procfs, FS__PROCFS);
+FS(sysfs, FS__SYSFS);
+FS(procfs, FS__PROCFS);
+FS(debugfs, FS__DEBUGFS);
+FS(tracefs, FS__TRACEFS);
int filename__read_int(const char *filename, int *value)
{
@@ -185,6 +282,50 @@ int filename__read_int(const char *filename, int *value)
return err;
}
+int filename__read_ull(const char *filename, unsigned long long *value)
+{
+ char line[64];
+ int fd = open(filename, O_RDONLY), err = -1;
+
+ if (fd < 0)
+ return -1;
+
+ if (read(fd, line, sizeof(line)) > 0) {
+ *value = strtoull(line, NULL, 10);
+ if (*value != ULLONG_MAX)
+ err = 0;
+ }
+
+ close(fd);
+ return err;
+}
+
+int sysfs__read_ull(const char *entry, unsigned long long *value)
+{
+ char path[PATH_MAX];
+ const char *sysfs = sysfs__mountpoint();
+
+ if (!sysfs)
+ return -1;
+
+ snprintf(path, sizeof(path), "%s/%s", sysfs, entry);
+
+ return filename__read_ull(path, value);
+}
+
+int sysfs__read_int(const char *entry, int *value)
+{
+ char path[PATH_MAX];
+ const char *sysfs = sysfs__mountpoint();
+
+ if (!sysfs)
+ return -1;
+
+ snprintf(path, sizeof(path), "%s/%s", sysfs, entry);
+
+ return filename__read_int(path, value);
+}
+
int sysctl__read_int(const char *sysctl, int *value)
{
char path[PATH_MAX];
diff --git a/tools/lib/api/fs/fs.h b/tools/lib/api/fs/fs.h
index 6caa2bbc6..d024a7f68 100644
--- a/tools/lib/api/fs/fs.h
+++ b/tools/lib/api/fs/fs.h
@@ -1,17 +1,33 @@
#ifndef __API_FS__
#define __API_FS__
-#ifndef SYSFS_MAGIC
-#define SYSFS_MAGIC 0x62656572
-#endif
+#include <stdbool.h>
-#ifndef PROC_SUPER_MAGIC
-#define PROC_SUPER_MAGIC 0x9fa0
+/*
+ * On most systems <limits.h> would have given us this, but not on some systems
+ * (e.g. GNU/Hurd).
+ */
+#ifndef PATH_MAX
+#define PATH_MAX 4096
#endif
-const char *sysfs__mountpoint(void);
-const char *procfs__mountpoint(void);
+#define FS(name) \
+ const char *name##__mountpoint(void); \
+ const char *name##__mount(void); \
+ bool name##__configured(void); \
+
+FS(sysfs)
+FS(procfs)
+FS(debugfs)
+FS(tracefs)
+
+#undef FS
+
int filename__read_int(const char *filename, int *value);
+int filename__read_ull(const char *filename, unsigned long long *value);
+
int sysctl__read_int(const char *sysctl, int *value);
+int sysfs__read_int(const char *entry, int *value);
+int sysfs__read_ull(const char *entry, unsigned long long *value);
#endif /* __API_FS__ */
diff --git a/tools/lib/api/fs/tracefs.c b/tools/lib/api/fs/tracefs.c
deleted file mode 100644
index e4aa9688b..000000000
--- a/tools/lib/api/fs/tracefs.c
+++ /dev/null
@@ -1,78 +0,0 @@
-#include <errno.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <stdbool.h>
-#include <sys/vfs.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/mount.h>
-#include <linux/kernel.h>
-
-#include "tracefs.h"
-
-#ifndef TRACEFS_DEFAULT_PATH
-#define TRACEFS_DEFAULT_PATH "/sys/kernel/tracing"
-#endif
-
-char tracefs_mountpoint[PATH_MAX + 1] = TRACEFS_DEFAULT_PATH;
-
-static const char * const tracefs_known_mountpoints[] = {
- TRACEFS_DEFAULT_PATH,
- "/sys/kernel/debug/tracing",
- "/tracing",
- "/trace",
- 0,
-};
-
-static bool tracefs_found;
-
-bool tracefs_configured(void)
-{
- return tracefs_find_mountpoint() != NULL;
-}
-
-/* find the path to the mounted tracefs */
-const char *tracefs_find_mountpoint(void)
-{
- const char *ret;
-
- if (tracefs_found)
- return (const char *)tracefs_mountpoint;
-
- ret = find_mountpoint("tracefs", (long) TRACEFS_MAGIC,
- tracefs_mountpoint, PATH_MAX + 1,
- tracefs_known_mountpoints);
-
- if (ret)
- tracefs_found = true;
-
- return ret;
-}
-
-/* mount the tracefs somewhere if it's not mounted */
-char *tracefs_mount(const char *mountpoint)
-{
- /* see if it's already mounted */
- if (tracefs_find_mountpoint())
- goto out;
-
- /* if not mounted and no argument */
- if (mountpoint == NULL) {
- /* see if environment variable set */
- mountpoint = getenv(PERF_TRACEFS_ENVIRONMENT);
- /* if no environment variable, use default */
- if (mountpoint == NULL)
- mountpoint = TRACEFS_DEFAULT_PATH;
- }
-
- if (mount(NULL, mountpoint, "tracefs", 0, NULL) < 0)
- return NULL;
-
- /* save the mountpoint */
- tracefs_found = true;
- strncpy(tracefs_mountpoint, mountpoint, sizeof(tracefs_mountpoint));
-out:
- return tracefs_mountpoint;
-}
diff --git a/tools/lib/api/fs/tracefs.h b/tools/lib/api/fs/tracefs.h
deleted file mode 100644
index da780ac49..000000000
--- a/tools/lib/api/fs/tracefs.h
+++ /dev/null
@@ -1,21 +0,0 @@
-#ifndef __API_TRACEFS_H__
-#define __API_TRACEFS_H__
-
-#include "findfs.h"
-
-#ifndef TRACEFS_MAGIC
-#define TRACEFS_MAGIC 0x74726163
-#endif
-
-#ifndef PERF_TRACEFS_ENVIRONMENT
-#define PERF_TRACEFS_ENVIRONMENT "PERF_TRACEFS_DIR"
-#endif
-
-bool tracefs_configured(void);
-const char *tracefs_find_mountpoint(void);
-int tracefs_valid_mountpoint(const char *debugfs);
-char *tracefs_mount(const char *mountpoint);
-
-extern char tracefs_mountpoint[];
-
-#endif /* __API_DEBUGFS_H__ */
diff --git a/tools/lib/api/fs/tracing_path.c b/tools/lib/api/fs/tracing_path.c
new file mode 100644
index 000000000..a26bb5ea8
--- /dev/null
+++ b/tools/lib/api/fs/tracing_path.c
@@ -0,0 +1,135 @@
+#ifndef _GNU_SOURCE
+# define _GNU_SOURCE
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include "fs.h"
+
+#include "tracing_path.h"
+
+
+char tracing_mnt[PATH_MAX] = "/sys/kernel/debug";
+char tracing_path[PATH_MAX] = "/sys/kernel/debug/tracing";
+char tracing_events_path[PATH_MAX] = "/sys/kernel/debug/tracing/events";
+
+
+static void __tracing_path_set(const char *tracing, const char *mountpoint)
+{
+ snprintf(tracing_mnt, sizeof(tracing_mnt), "%s", mountpoint);
+ snprintf(tracing_path, sizeof(tracing_path), "%s/%s",
+ mountpoint, tracing);
+ snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s%s",
+ mountpoint, tracing, "events");
+}
+
+static const char *tracing_path_tracefs_mount(void)
+{
+ const char *mnt;
+
+ mnt = tracefs__mount();
+ if (!mnt)
+ return NULL;
+
+ __tracing_path_set("", mnt);
+
+ return mnt;
+}
+
+static const char *tracing_path_debugfs_mount(void)
+{
+ const char *mnt;
+
+ mnt = debugfs__mount();
+ if (!mnt)
+ return NULL;
+
+ __tracing_path_set("tracing/", mnt);
+
+ return mnt;
+}
+
+const char *tracing_path_mount(void)
+{
+ const char *mnt;
+
+ mnt = tracing_path_tracefs_mount();
+ if (mnt)
+ return mnt;
+
+ mnt = tracing_path_debugfs_mount();
+
+ return mnt;
+}
+
+void tracing_path_set(const char *mntpt)
+{
+ __tracing_path_set("tracing/", mntpt);
+}
+
+char *get_tracing_file(const char *name)
+{
+ char *file;
+
+ if (asprintf(&file, "%s/%s", tracing_path, name) < 0)
+ return NULL;
+
+ return file;
+}
+
+void put_tracing_file(char *file)
+{
+ free(file);
+}
+
+static int strerror_open(int err, char *buf, size_t size, const char *filename)
+{
+ char sbuf[128];
+
+ switch (err) {
+ case ENOENT:
+ /*
+ * We will get here if we can't find the tracepoint, but one of
+ * debugfs or tracefs is configured, which means you probably
+ * want some tracepoint which wasn't compiled in your kernel.
+ * - jirka
+ */
+ if (debugfs__configured() || tracefs__configured()) {
+ snprintf(buf, size,
+ "Error:\tFile %s/%s not found.\n"
+ "Hint:\tPerhaps this kernel misses some CONFIG_ setting to enable this feature?.\n",
+ tracing_events_path, filename);
+ break;
+ }
+ snprintf(buf, size, "%s",
+ "Error:\tUnable to find debugfs/tracefs\n"
+ "Hint:\tWas your kernel compiled with debugfs/tracefs support?\n"
+ "Hint:\tIs the debugfs/tracefs filesystem mounted?\n"
+ "Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'");
+ break;
+ case EACCES: {
+ snprintf(buf, size,
+ "Error:\tNo permissions to read %s/%s\n"
+ "Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n",
+ tracing_events_path, filename, tracing_mnt);
+ }
+ break;
+ default:
+ snprintf(buf, size, "%s", strerror_r(err, sbuf, sizeof(sbuf)));
+ break;
+ }
+
+ return 0;
+}
+
+int tracing_path__strerror_open_tp(int err, char *buf, size_t size, const char *sys, const char *name)
+{
+ char path[PATH_MAX];
+
+ snprintf(path, PATH_MAX, "%s/%s", sys, name ?: "*");
+
+ return strerror_open(err, buf, size, path);
+}
diff --git a/tools/lib/api/fs/tracing_path.h b/tools/lib/api/fs/tracing_path.h
new file mode 100644
index 000000000..3f233ac70
--- /dev/null
+++ b/tools/lib/api/fs/tracing_path.h
@@ -0,0 +1,16 @@
+#ifndef __API_FS_TRACING_PATH_H
+#define __API_FS_TRACING_PATH_H
+
+#include <linux/types.h>
+
+extern char tracing_path[];
+extern char tracing_events_path[];
+
+void tracing_path_set(const char *mountpoint);
+const char *tracing_path_mount(void);
+
+char *get_tracing_file(const char *name);
+void put_tracing_file(char *file);
+
+int tracing_path__strerror_open_tp(int err, char *buf, size_t size, const char *sys, const char *name);
+#endif /* __API_FS_TRACING_PATH_H */