Re: [PATCH 1/5] string.h: add array-wrappers for (v)memdup_user()

From: Andy Shevchenko
Date: Thu Aug 31 2023 - 09:16:58 EST


On Thu, Aug 31, 2023 at 3:22 PM Philipp Stanner <pstanner@xxxxxxxxxx> wrote:
> On Wed, 2023-08-30 at 17:11 +0300, Andy Shevchenko wrote:
> > On Wed, Aug 30, 2023 at 4:46 PM Philipp Stanner <pstanner@xxxxxxxxxx>
> > wrote:

...

> > I'm wondering if this has no side-effects as string.h/string.c IIRC
> > is used also for early stages where some of the APIs are not available.
>
> I forgot to address this point in my previous reply.
>
> Who's going to decide whether this is a problem or not?
>
> My personal guess is that this is unlikely to be a problem because
>
> A. either (v)memdup_user() is available, in which case
> (v)memdup_array_user() will always work –
> B. or (v)memdup_user() is not available, which would cause the code
> that currently uses (v)memdup_user() for copying arrays to fail
> anyways.

It also uses something from overflow.h. I don't remember if that
header was ever been used in early stage modules (like
boot/decompressor).

--
With Best Regards,
Andy Shevchenko