linux-kernel - Re: [PATCH] futex: improve user space accesses

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Message-ID: <87bjxkzoz0.fsf@igel.home>
Date: Mon, 09 Dec 2024 19:32:51 +0100
From: Andreas Schwab <schwab@...ux-m68k.org>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Josh Poimboeuf <jpoimboe@...nel.org>,  LKML
 <linux-kernel@...r.kernel.org>,  x86@...nel.org,
  linuxppc-dev@...ts.ozlabs.org
Subject: Re: [PATCH] futex: improve user space accesses

On Dez 08 2024, Linus Torvalds wrote:

> IOW, does this one-liner fix it for you?
>
>   --- a/kernel/futex/futex.h
>   +++ b/kernel/futex/futex.h
>   @@ -265,7 +265,7 @@
>         else if (!user_read_access_begin(from, sizeof(*from)))
>                 return -EFAULT;
>         unsafe_get_user(val, from, Efault);
>   -     user_access_end();
>   +     user_read_access_end();
>         *dest = val;
>         return 0;
>    Efault:

Thanks, I can confirm that this fixed the crash (changing both arms as
pointed out by Christophe).

-- 
Andreas Schwab, schwab@...ux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
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