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

[Michal Koutný]

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].

Michal

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