8 #include <linux/magic.h>
9 #include <linux/kernel.h>
13 char debugfs_mountpoint[PATH_MAX + 1] = "/sys/kernel/debug";
15 static const char * const debugfs_known_mountpoints[] = {
21 static bool debugfs_found;
23 /* find the path to the mounted debugfs */
24 const char *debugfs_find_mountpoint(void)
26 const char * const *ptr;
31 return (const char *)debugfs_mountpoint;
33 ptr = debugfs_known_mountpoints;
35 if (debugfs_valid_mountpoint(*ptr) == 0) {
37 strcpy(debugfs_mountpoint, *ptr);
38 return debugfs_mountpoint;
43 /* give up and parse /proc/mounts */
44 fp = fopen("/proc/mounts", "r");
48 while (fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
49 debugfs_mountpoint, type) == 2) {
50 if (strcmp(type, "debugfs") == 0)
55 if (strcmp(type, "debugfs") != 0)
60 return debugfs_mountpoint;
63 /* verify that a mountpoint is actually a debugfs instance */
65 int debugfs_valid_mountpoint(const char *debugfs)
69 if (statfs(debugfs, &st_fs) < 0)
71 else if (st_fs.f_type != (long) DEBUGFS_MAGIC)
77 /* mount the debugfs somewhere if it's not mounted */
78 char *debugfs_mount(const char *mountpoint)
80 /* see if it's already mounted */
81 if (debugfs_find_mountpoint())
84 /* if not mounted and no argument */
85 if (mountpoint == NULL) {
86 /* see if environment variable set */
87 mountpoint = getenv(PERF_DEBUGFS_ENVIRONMENT);
88 /* if no environment variable, use default */
89 if (mountpoint == NULL)
90 mountpoint = "/sys/kernel/debug";
93 if (mount(NULL, mountpoint, "debugfs", 0, NULL) < 0)
96 /* save the mountpoint */
98 strncpy(debugfs_mountpoint, mountpoint, sizeof(debugfs_mountpoint));
100 return debugfs_mountpoint;