procfs: use an enum for possible hidepid values
Previously, the hidepid parameter was checked by comparing literal
integers 0, 1, 2. Let's add a proper enum for this, to make the
checking more expressive:
0 → HIDEPID_OFF
1 → HIDEPID_NO_ACCESS
2 → HIDEPID_INVISIBLE
This changes the internal labelling only, the userspace-facing interface
remains unmodified, and still works with literal integers 0, 1, 2.
No functional changes.
Link: http://lkml.kernel.org/r/1484572984-13388-2-git-send-email-djalal@gmail.com
Signed-off-by: Lafcadio Wluiki <wluikil@gmail.com>
Signed-off-by: Djalal Harouni <tixxdz@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/proc/root.c b/fs/proc/root.c
index 1988440..b90da88 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -58,7 +58,8 @@ int proc_parse_options(char *options, struct pid_namespace *pid)
case Opt_hidepid:
if (match_int(&args[0], &option))
return 0;
- if (option < 0 || option > 2) {
+ if (option < HIDEPID_OFF ||
+ option > HIDEPID_INVISIBLE) {
pr_err("proc: hidepid value must be between 0 and 2.\n");
return 0;
}