Re: [PATCH 1/3] mm: get_cmdline use arg_lock instead of mmap_sem

From: Kirill Tkhai
Date: Tue Apr 30 2019 - 05:54:05 EST


On 30.04.2019 12:38, Cyrill Gorcunov wrote:
> On Tue, Apr 30, 2019 at 12:09:57PM +0300, Kirill Tkhai wrote:
>>
>> This looks OK for me.
>>
>> But speaking about existing code it's a secret for me, why we ignore arg_lock
>> in binfmt code, e.g. in load_elf_binary().
>
> Well, strictly speaking we probably should but you know setup of
> the @arg_start by kernel's elf loader doesn't cause any side
> effects as far as I can tell (its been working this lockless
> way for years, mmap_sem is taken later in the loader code).
> Though for consistency sake we probably should set it up
> under the spinlock.

Ok, so elf loader doesn't change these parameters. Thanks for the explanation.