Re: [PATCH] mm: get_cmdline use arg_lock instead of mmap_sem

From: Michal Hocko
Date: Wed Apr 17 2019 - 10:55:52 EST


On Wed 17-04-19 16:41:42, Michal Koutny wrote:
> On Wed, Apr 17, 2019 at 03:41:52PM +0200, Michal Hocko <mhocko@xxxxxxxxxx> wrote:
> > Don't we need to use the lock in prctl_set_mm as well then?
>
> Correct. The patch alone just moves the race from
> get_cmdline/prctl_set_mm_map to get_cmdline/prctl_set_mm.
>
> arg_lock could be used in prctl_set_mm but the better idea (IMO) is
> complete removal of that code in favor of prctl_set_mm_map [1].

Ohh, I have missed that patch. As long as both are merged together then
no objections from me and you can add

Acked-by: Michal Hocko <mhocko@xxxxxxxx>

> Michal
>
> [1] https://lore.kernel.org/lkml/20180405182651.GM15783@xxxxxxxxxx/

--
Michal Hocko
SUSE Labs