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
|
#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;
}
|
