procfs: make errno values consistent when open pident vs exit(2) race occurs
proc_pident_instantiate() has following call flow.
proc_pident_lookup()
proc_pident_instantiate()
proc_pid_make_inode()
And, proc_pident_lookup() has following error handling.
const struct pid_entry *p, *last;
error = ERR_PTR(-ENOENT);
if (!task)
goto out_no_task;
Then, proc_pident_instantiate should return ENOENT too when racing against
exit(2) occur.
EINAL has two bad reason.
- it implies caller is wrong. bad the race isn't caller's mistake.
- man 2 open don't explain EINVAL. user often don't handle it.
Note: Other proc_pid_make_inode() caller already use ENOENT properly.
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
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 fb45615..3326bbf 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1956,7 +1956,7 @@
const struct pid_entry *p = ptr;
struct inode *inode;
struct proc_inode *ei;
- struct dentry *error = ERR_PTR(-EINVAL);
+ struct dentry *error = ERR_PTR(-ENOENT);
inode = proc_pid_make_inode(dir->i_sb, task);
if (!inode)