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From: Alexander Potapenko <glider@google.com>
To: Michael Ellerman <mpe@ellerman.id.au>
Cc: elver@google.com, akpm@linux-foundation.org,
	zhangpeng.00@bytedance.com,  linux-kernel@vger.kernel.org,
	linux-mm@kvack.org,  linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] mm: kfence: Fix false positives on big endian
Date: Fri, 5 May 2023 09:14:30 +0200	[thread overview]
Message-ID: <CAG_fn=WprOA21Ksc0Ty6S3KQ2pqj9vvPmDFOu1uqYW_oHmTBeA@mail.gmail.com> (raw)
In-Reply-To: <20230505035127.195387-1-mpe@ellerman.id.au>

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On Fri, May 5, 2023 at 5:51 AM Michael Ellerman <mpe@ellerman.id.au> wrote:

> Since commit 1ba3cbf3ec3b ("mm: kfence: improve the performance of
> __kfence_alloc() and __kfence_free()"), kfence reports failures in
> random places at boot on big endian machines.
>
> The problem is that the new KFENCE_CANARY_PATTERN_U64 encodes the
> address of each byte in its value, so it needs to be byte swapped on big
> endian machines.
>
> The compiler is smart enough to do the le64_to_cpu() at compile time, so
> there is no runtime overhead.
>
> Fixes: 1ba3cbf3ec3b ("mm: kfence: improve the performance of
> __kfence_alloc() and __kfence_free()")
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
>
Reviewed-by: Alexander Potapenko <glider@google.com>

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  reply	other threads:[~2023-05-05  7:15 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-05  3:51 Michael Ellerman
2023-05-05  7:14 ` Alexander Potapenko [this message]
2023-05-05  7:43 ` Marco Elver
2023-05-05 11:56   ` Michael Ellerman
2023-05-05 16:02 ` David Laight
2023-05-17 22:20   ` Andrew Morton
2023-05-19  5:14     ` Michael Ellerman
2023-05-19  6:29       ` Benjamin Gray
2023-05-19  5:40     ` Christophe Leroy

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