summaryrefslogtreecommitdiffstats
path: root/tools/lib/api/fs/debugfs.c
diff options
context:
space:
mode:
authorBorislav Petkov <bp@suse.de>2013-12-09 17:14:23 +0100
committerArnaldo Carvalho de Melo <acme@redhat.com>2013-12-16 16:03:27 -0300
commit553873e1df63a20559ac9c336765dc7055cfc3d4 (patch)
treecdae36b2cbe9818bea7e6987a9e73baf9d79fd53 /tools/lib/api/fs/debugfs.c
parentb283d2f3b74bc98174e8453c0be41dfcda3cae1b (diff)
downloadlinux-553873e1df63a20559ac9c336765dc7055cfc3d4.tar.bz2
tools/: Convert to new topic libraries
Move debugfs.* to api/fs/. We have a common tools/lib/api/ place where the Makefile lives and then we place the headers in subdirs. For example, all the fs-related stuff goes to tools/lib/api/fs/ from which we get libapikfs.a (acme got almost the naming he wanted :-)) and we link it into the tools which need it - in this case perf and tools/vm/page-types. acme: "Looking at the implementation, I think some tools can even link directly to the .o files, avoiding the .a file altogether. But that is just an optimization/finer granularity tools/lib/ cherrypicking that toolers can make use of." Fixup documentation cleaning target while at it. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robert Richter <rric@kernel.org> Cc: Stanislav Fomichev <stfomichev@yandex-team.ru> Cc: Stephane Eranian <eranian@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1386605664-24041-2-git-send-email-bp@alien8.de Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/lib/api/fs/debugfs.c')
-rw-r--r--tools/lib/api/fs/debugfs.c100
1 files changed, 100 insertions, 0 deletions
diff --git a/tools/lib/api/fs/debugfs.c b/tools/lib/api/fs/debugfs.c
new file mode 100644
index 000000000000..7c4347962353
--- /dev/null
+++ b/tools/lib/api/fs/debugfs.c
@@ -0,0 +1,100 @@
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+#include <sys/vfs.h>
+#include <sys/mount.h>
+#include <linux/kernel.h>
+
+#include "debugfs.h"
+
+char debugfs_mountpoint[PATH_MAX + 1] = "/sys/kernel/debug";
+
+static const char * const debugfs_known_mountpoints[] = {
+ "/sys/kernel/debug/",
+ "/debug/",
+ 0,
+};
+
+static bool debugfs_found;
+
+/* find the path to the mounted debugfs */
+const char *debugfs_find_mountpoint(void)
+{
+ const char * const *ptr;
+ char type[100];
+ FILE *fp;
+
+ if (debugfs_found)
+ return (const char *)debugfs_mountpoint;
+
+ ptr = debugfs_known_mountpoints;
+ while (*ptr) {
+ if (debugfs_valid_mountpoint(*ptr) == 0) {
+ debugfs_found = true;
+ strcpy(debugfs_mountpoint, *ptr);
+ return debugfs_mountpoint;
+ }
+ ptr++;
+ }
+
+ /* give up and parse /proc/mounts */
+ fp = fopen("/proc/mounts", "r");
+ if (fp == NULL)
+ return NULL;
+
+ while (fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
+ debugfs_mountpoint, type) == 2) {
+ if (strcmp(type, "debugfs") == 0)
+ break;
+ }
+ fclose(fp);
+
+ if (strcmp(type, "debugfs") != 0)
+ return NULL;
+
+ debugfs_found = true;
+
+ return debugfs_mountpoint;
+}
+
+/* verify that a mountpoint is actually a debugfs instance */
+
+int debugfs_valid_mountpoint(const char *debugfs)
+{
+ struct statfs st_fs;
+
+ if (statfs(debugfs, &st_fs) < 0)
+ return -ENOENT;
+ else if (st_fs.f_type != (long) DEBUGFS_MAGIC)
+ return -ENOENT;
+
+ return 0;
+}
+
+/* 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 = "/sys/kernel/debug";
+ }
+
+ 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;
+}