]>
Commit | Line | Data |
---|---|---|
afe61f67 CW |
1 | #include "util.h" |
2 | #include "debugfs.h" | |
3 | #include "cache.h" | |
4 | ||
ebf294bf | 5 | #include <linux/kernel.h> |
c168fbfb ACM |
6 | #include <sys/mount.h> |
7 | ||
afe61f67 | 8 | static int debugfs_premounted; |
ebf294bf ACM |
9 | char debugfs_mountpoint[PATH_MAX + 1] = "/sys/kernel/debug"; |
10 | char tracing_events_path[PATH_MAX + 1] = "/sys/kernel/debug/tracing/events"; | |
afe61f67 CW |
11 | |
12 | static const char *debugfs_known_mountpoints[] = { | |
13 | "/sys/kernel/debug/", | |
14 | "/debug/", | |
15 | 0, | |
16 | }; | |
17 | ||
afe61f67 CW |
18 | static int debugfs_found; |
19 | ||
20 | /* find the path to the mounted debugfs */ | |
21 | const char *debugfs_find_mountpoint(void) | |
22 | { | |
23 | const char **ptr; | |
24 | char type[100]; | |
25 | FILE *fp; | |
26 | ||
27 | if (debugfs_found) | |
28 | return (const char *) debugfs_mountpoint; | |
29 | ||
30 | ptr = debugfs_known_mountpoints; | |
31 | while (*ptr) { | |
32 | if (debugfs_valid_mountpoint(*ptr) == 0) { | |
33 | debugfs_found = 1; | |
34 | strcpy(debugfs_mountpoint, *ptr); | |
35 | return debugfs_mountpoint; | |
36 | } | |
37 | ptr++; | |
38 | } | |
39 | ||
40 | /* give up and parse /proc/mounts */ | |
41 | fp = fopen("/proc/mounts", "r"); | |
42 | if (fp == NULL) | |
ebf294bf | 43 | return NULL; |
afe61f67 | 44 | |
c168fbfb | 45 | while (fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n", |
afe61f67 CW |
46 | debugfs_mountpoint, type) == 2) { |
47 | if (strcmp(type, "debugfs") == 0) | |
48 | break; | |
49 | } | |
50 | fclose(fp); | |
51 | ||
52 | if (strcmp(type, "debugfs") != 0) | |
53 | return NULL; | |
54 | ||
55 | debugfs_found = 1; | |
56 | ||
57 | return debugfs_mountpoint; | |
58 | } | |
59 | ||
60 | /* verify that a mountpoint is actually a debugfs instance */ | |
61 | ||
62 | int debugfs_valid_mountpoint(const char *debugfs) | |
63 | { | |
64 | struct statfs st_fs; | |
65 | ||
66 | if (statfs(debugfs, &st_fs) < 0) | |
67 | return -ENOENT; | |
68 | else if (st_fs.f_type != (long) DEBUGFS_MAGIC) | |
69 | return -ENOENT; | |
70 | ||
71 | return 0; | |
72 | } | |
73 | ||
ebf294bf ACM |
74 | static void debugfs_set_tracing_events_path(const char *mountpoint) |
75 | { | |
76 | snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s", | |
77 | mountpoint, "tracing/events"); | |
78 | } | |
79 | ||
29c52aa2 | 80 | /* mount the debugfs somewhere if it's not mounted */ |
afe61f67 | 81 | |
29c52aa2 | 82 | char *debugfs_mount(const char *mountpoint) |
afe61f67 | 83 | { |
afe61f67 CW |
84 | /* see if it's already mounted */ |
85 | if (debugfs_find_mountpoint()) { | |
86 | debugfs_premounted = 1; | |
ebf294bf | 87 | goto out; |
afe61f67 CW |
88 | } |
89 | ||
90 | /* if not mounted and no argument */ | |
91 | if (mountpoint == NULL) { | |
92 | /* see if environment variable set */ | |
93 | mountpoint = getenv(PERF_DEBUGFS_ENVIRONMENT); | |
94 | /* if no environment variable, use default */ | |
95 | if (mountpoint == NULL) | |
96 | mountpoint = "/sys/kernel/debug"; | |
97 | } | |
98 | ||
29c52aa2 XG |
99 | if (mount(NULL, mountpoint, "debugfs", 0, NULL) < 0) |
100 | return NULL; | |
101 | ||
afe61f67 | 102 | /* save the mountpoint */ |
61be3e59 | 103 | debugfs_found = 1; |
ebf294bf ACM |
104 | strncpy(debugfs_mountpoint, mountpoint, sizeof(debugfs_mountpoint)); |
105 | out: | |
106 | debugfs_set_tracing_events_path(debugfs_mountpoint); | |
29c52aa2 | 107 | return debugfs_mountpoint; |
afe61f67 CW |
108 | } |
109 | ||
ebf294bf ACM |
110 | void debugfs_set_path(const char *mountpoint) |
111 | { | |
112 | snprintf(debugfs_mountpoint, sizeof(debugfs_mountpoint), "%s", mountpoint); | |
113 | debugfs_set_tracing_events_path(mountpoint); | |
114 | } |