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/base.c b/fs/proc/base.c
index 4ecb5ed..b8f0627 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -697,11 +697,11 @@ static int proc_pid_permission(struct inode *inode, int mask)
task = get_proc_task(inode);
if (!task)
return -ESRCH;
- has_perms = has_pid_permissions(pid, task, 1);
+ has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS);
put_task_struct(task);
if (!has_perms) {
- if (pid->hide_pid == 2) {
+ if (pid->hide_pid == HIDEPID_INVISIBLE) {
/*
* Let's make getdents(), stat(), and open()
* consistent with each other. If a process
@@ -1737,7 +1737,7 @@ int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
stat->gid = GLOBAL_ROOT_GID;
task = pid_task(proc_pid(inode), PIDTYPE_PID);
if (task) {
- if (!has_pid_permissions(pid, task, 2)) {
+ if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) {
rcu_read_unlock();
/*
* This doesn't prevent learning whether PID exists,
@@ -3168,7 +3168,7 @@ int proc_pid_readdir(struct file *file, struct dir_context *ctx)
int len;
cond_resched();
- if (!has_pid_permissions(ns, iter.task, 2))
+ if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE))
continue;
len = snprintf(name, sizeof(name), "%d", iter.tgid);