Contributors: 18
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Jiri Olsa |
835 |
40.22% |
14 |
36.84% |
| Arnaldo Carvalho de Melo |
554 |
26.69% |
6 |
15.79% |
| Ian Rogers |
245 |
11.80% |
2 |
5.26% |
| Cody P Schafer |
145 |
6.98% |
1 |
2.63% |
| Alexander Shishkin |
93 |
4.48% |
1 |
2.63% |
| Kan Liang |
89 |
4.29% |
1 |
2.63% |
| Ingo Molnar |
42 |
2.02% |
1 |
2.63% |
| Joe Stringer |
21 |
1.01% |
1 |
2.63% |
| Wang Nan |
17 |
0.82% |
1 |
2.63% |
| Irina Tirdea |
9 |
0.43% |
1 |
2.63% |
| Masami Hiramatsu |
6 |
0.29% |
1 |
2.63% |
| Borislav Petkov |
6 |
0.29% |
1 |
2.63% |
| Stéphane Eranian |
5 |
0.24% |
2 |
5.26% |
| Alexey Brodkin |
3 |
0.14% |
1 |
2.63% |
| Andrey Zhizhikin |
3 |
0.14% |
1 |
2.63% |
| Mauro Carvalho Chehab |
1 |
0.05% |
1 |
2.63% |
| Kefeng Wang |
1 |
0.05% |
1 |
2.63% |
| Greg Kroah-Hartman |
1 |
0.05% |
1 |
2.63% |
| Total |
2076 |
|
38 |
|
// SPDX-License-Identifier: GPL-2.0
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/vfs.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <pthread.h>
#include <unistd.h>
#include <sys/mount.h>
#include "fs.h"
#include "debug-internal.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
#ifndef HUGETLBFS_MAGIC
#define HUGETLBFS_MAGIC 0x958458f6
#endif
#ifndef BPF_FS_MAGIC
#define BPF_FS_MAGIC 0xcafe4a11
#endif
static const char * const sysfs__known_mountpoints[] = {
"/sys",
0,
};
static const char * const procfs__known_mountpoints[] = {
"/proc",
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,
};
static const char * const hugetlbfs__known_mountpoints[] = {
0,
};
static const char * const bpf_fs__known_mountpoints[] = {
"/sys/fs/bpf",
0,
};
struct fs {
const char * const name;
const char * const * const mounts;
char *path;
pthread_mutex_t mount_mutex;
const long magic;
};
#ifndef TRACEFS_MAGIC
#define TRACEFS_MAGIC 0x74726163
#endif
static void fs__init_once(struct fs *fs);
static const char *fs__mountpoint(const struct fs *fs);
static const char *fs__mount(struct fs *fs);
#define FS(lower_name, fs_name, upper_name) \
static struct fs fs__##lower_name = { \
.name = #fs_name, \
.mounts = lower_name##__known_mountpoints, \
.magic = upper_name##_MAGIC, \
.mount_mutex = PTHREAD_MUTEX_INITIALIZER, \
}; \
\
static void lower_name##_init_once(void) \
{ \
struct fs *fs = &fs__##lower_name; \
\
fs__init_once(fs); \
} \
\
const char *lower_name##__mountpoint(void) \
{ \
static pthread_once_t init_once = PTHREAD_ONCE_INIT; \
struct fs *fs = &fs__##lower_name; \
\
pthread_once(&init_once, lower_name##_init_once); \
return fs__mountpoint(fs); \
} \
\
const char *lower_name##__mount(void) \
{ \
const char *mountpoint = lower_name##__mountpoint(); \
struct fs *fs = &fs__##lower_name; \
\
if (mountpoint) \
return mountpoint; \
\
return fs__mount(fs); \
} \
\
bool lower_name##__configured(void) \
{ \
return lower_name##__mountpoint() != NULL; \
}
FS(sysfs, sysfs, SYSFS);
FS(procfs, procfs, PROC_SUPER);
FS(debugfs, debugfs, DEBUGFS);
FS(tracefs, tracefs, TRACEFS);
FS(hugetlbfs, hugetlbfs, HUGETLBFS);
FS(bpf_fs, bpf, BPF_FS);
static bool fs__read_mounts(struct fs *fs)
{
char type[100];
FILE *fp;
char path[PATH_MAX + 1];
fp = fopen("/proc/mounts", "r");
if (fp == NULL)
return false;
while (fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
path, type) == 2) {
if (strcmp(type, fs->name) == 0) {
fs->path = strdup(path);
fclose(fp);
return fs->path != NULL;
}
}
fclose(fp);
return false;
}
static int fs__valid_mount(const char *fs, long magic)
{
struct statfs st_fs;
if (statfs(fs, &st_fs) < 0)
return -ENOENT;
else if ((long)st_fs.f_type != magic)
return -ENOENT;
return 0;
}
static bool fs__check_mounts(struct fs *fs)
{
const char * const *ptr;
ptr = fs->mounts;
while (*ptr) {
if (fs__valid_mount(*ptr, fs->magic) == 0) {
fs->path = strdup(*ptr);
if (!fs->path)
return false;
return true;
}
ptr++;
}
return false;
}
static void mem_toupper(char *f, size_t len)
{
while (len) {
*f = toupper(*f);
f++;
len--;
}
}
/*
* Check for "NAME_PATH" environment variable to override fs location (for
* testing). This matches the recommendation in Documentation/admin-guide/sysfs-rules.rst
* for SYSFS_PATH.
*/
static bool fs__env_override(struct fs *fs)
{
char *override_path;
size_t name_len = strlen(fs->name);
/* name + "_PATH" + '\0' */
char upper_name[name_len + 5 + 1];
memcpy(upper_name, fs->name, name_len);
mem_toupper(upper_name, name_len);
strcpy(&upper_name[name_len], "_PATH");
override_path = getenv(upper_name);
if (!override_path)
return false;
fs->path = strdup(override_path);
if (!fs->path)
return false;
return true;
}
static void fs__init_once(struct fs *fs)
{
if (!fs__env_override(fs) &&
!fs__check_mounts(fs) &&
!fs__read_mounts(fs)) {
assert(!fs->path);
} else {
assert(fs->path);
}
}
static const char *fs__mountpoint(const struct fs *fs)
{
return fs->path;
}
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(struct fs *fs)
{
const char *mountpoint;
pthread_mutex_lock(&fs->mount_mutex);
/* Check if path found inside the mutex to avoid races with other callers of mount. */
mountpoint = fs__mountpoint(fs);
if (mountpoint)
goto out;
mountpoint = mount_overload(fs);
if (mount(NULL, mountpoint, fs->name, 0, NULL) == 0 &&
fs__valid_mount(mountpoint, fs->magic) == 0) {
fs->path = strdup(mountpoint);
mountpoint = fs->path;
}
out:
pthread_mutex_unlock(&fs->mount_mutex);
return mountpoint;
}
int filename__read_int(const char *filename, int *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 = atoi(line);
err = 0;
}
close(fd);
return err;
}
static int filename__read_ull_base(const char *filename,
unsigned long long *value, int base)
{
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, base);
if (*value != ULLONG_MAX)
err = 0;
}
close(fd);
return err;
}
/*
* Parses @value out of @filename with strtoull.
* By using 16 for base to treat the number as hex.
*/
int filename__read_xll(const char *filename, unsigned long long *value)
{
return filename__read_ull_base(filename, value, 16);
}
/*
* Parses @value out of @filename with strtoull.
* By using 0 for base, the strtoull detects the
* base automatically (see man strtoull).
*/
int filename__read_ull(const char *filename, unsigned long long *value)
{
return filename__read_ull_base(filename, value, 0);
}
#define STRERR_BUFSIZE 128 /* For the buffer size of strerror_r */
int filename__read_str(const char *filename, char **buf, size_t *sizep)
{
size_t size = 0, alloc_size = 0;
void *bf = NULL, *nbf;
int fd, n, err = 0;
char sbuf[STRERR_BUFSIZE];
fd = open(filename, O_RDONLY);
if (fd < 0)
return -errno;
do {
if (size == alloc_size) {
alloc_size += BUFSIZ;
nbf = realloc(bf, alloc_size);
if (!nbf) {
err = -ENOMEM;
break;
}
bf = nbf;
}
n = read(fd, bf + size, alloc_size - size);
if (n < 0) {
if (size) {
pr_warn("read failed %d: %s\n", errno,
strerror_r(errno, sbuf, sizeof(sbuf)));
err = 0;
} else
err = -errno;
break;
}
size += n;
} while (n > 0);
if (!err) {
*sizep = size;
*buf = bf;
} else
free(bf);
close(fd);
return err;
}
int filename__write_int(const char *filename, int value)
{
int fd = open(filename, O_WRONLY), err = -1;
char buf[64];
if (fd < 0)
return err;
sprintf(buf, "%d", value);
if (write(fd, buf, sizeof(buf)) == sizeof(buf))
err = 0;
close(fd);
return err;
}
int procfs__read_str(const char *entry, char **buf, size_t *sizep)
{
char path[PATH_MAX];
const char *procfs = procfs__mountpoint();
if (!procfs)
return -1;
snprintf(path, sizeof(path), "%s/%s", procfs, entry);
return filename__read_str(path, buf, sizep);
}
static int sysfs__read_ull_base(const char *entry,
unsigned long long *value, int base)
{
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_base(path, value, base);
}
int sysfs__read_xll(const char *entry, unsigned long long *value)
{
return sysfs__read_ull_base(entry, value, 16);
}
int sysfs__read_ull(const char *entry, unsigned long long *value)
{
return sysfs__read_ull_base(entry, value, 0);
}
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 sysfs__read_str(const char *entry, char **buf, size_t *sizep)
{
char path[PATH_MAX];
const char *sysfs = sysfs__mountpoint();
if (!sysfs)
return -1;
snprintf(path, sizeof(path), "%s/%s", sysfs, entry);
return filename__read_str(path, buf, sizep);
}
int sysfs__read_bool(const char *entry, bool *value)
{
char *buf;
size_t size;
int ret;
ret = sysfs__read_str(entry, &buf, &size);
if (ret < 0)
return ret;
switch (buf[0]) {
case '1':
case 'y':
case 'Y':
*value = true;
break;
case '0':
case 'n':
case 'N':
*value = false;
break;
default:
ret = -1;
}
free(buf);
return ret;
}
int sysctl__read_int(const char *sysctl, int *value)
{
char path[PATH_MAX];
const char *procfs = procfs__mountpoint();
if (!procfs)
return -1;
snprintf(path, sizeof(path), "%s/sys/%s", procfs, sysctl);
return filename__read_int(path, value);
}
int sysfs__write_int(const char *entry, int value)
{
char path[PATH_MAX];
const char *sysfs = sysfs__mountpoint();
if (!sysfs)
return -1;
if (snprintf(path, sizeof(path), "%s/%s", sysfs, entry) >= PATH_MAX)
return -1;
return filename__write_int(path, value);
}