debugfs: return error values, not NULL
authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 23 Jan 2019 10:28:14 +0000 (11:28 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 29 Jan 2019 20:28:35 +0000 (21:28 +0100)
commitff9fb72bc07705c00795ca48631f7fffe24d2c6b
tree843e8ed33a99d526773470109426188e50aed3c9
parentd88c93f090f708c18195553b352b9f205e65418f
debugfs: return error values, not NULL

When an error happens, debugfs should return an error pointer value, not
NULL.  This will prevent the totally theoretical error where a debugfs
call fails due to lack of memory, returning NULL, and that dentry value
is then passed to another debugfs call, which would end up succeeding,
creating a file at the root of the debugfs tree, but would then be
impossible to remove (because you can not remove the directory NULL).

So, to make everyone happy, always return errors, this makes the users
of debugfs much simpler (they do not have to ever check the return
value), and everyone can rest easy.

Reported-by: Gary R Hook <ghook@amd.com>
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Reported-by: Michal Hocko <mhocko@kernel.org>
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reported-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/debugfs/inode.c