From: David Laight <david.laight.linux@gmail.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: "Thomas Weißschuh" <thomas.weissschuh@linutronix.de>,
"Russell King" <linux@armlinux.org.uk>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Russell King" <rmk+kernel@armlinux.org.uk>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, "Arnd Bergmann" <arnd@arndb.de>,
stable@vger.kernel.org
Subject: Re: [PATCH] ARM: fix memset64() on big-endian
Date: Fri, 2 Jan 2026 23:05:33 +0000 [thread overview]
Message-ID: <20260102230533.4fb1d8ef@pumpkin> (raw)
In-Reply-To: <aVfirJvsYt0-jDRD@casper.infradead.org>
On Fri, 2 Jan 2026 15:22:20 +0000
Matthew Wilcox <willy@infradead.org> wrote:
> On Fri, Jan 02, 2026 at 08:15:46AM +0100, Thomas Weißschuh wrote:
> > On big-endian systems the 32-bit low and high halves need to be swapped,
> > for the underlying assembly implemenation to work correctly.
>
> Heh. In my heart, ARM will always be a litte-endian architecture.
> I'm not really surprised this bug took, er, 8 years to show up; big-endian
> arm is rare enough and memset64() isn't much used on 32-bit systems.
> And it turns out that many of the users pass a constant 0 as the value,
> which was kind of not the point, but it seems to be an easier API to
> use than memset, so whatever ;-)
I'd have thought that part of the point of memset64() was to remove
all the 'alignment' and 'tail handling' that a normal memset() has.
Clearly someone thought otherwise :-)
David
>
> > Fixes: fd1d362600e2 ("ARM: implement memset32 & memset64")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
>
> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
>
prev parent reply other threads:[~2026-01-02 23:05 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-02 7:15 [PATCH] ARM: fix memset64() on big-endian Thomas Weißschuh
2026-01-02 9:24 ` Arnd Bergmann
2026-01-02 9:34 ` Thomas Weißschuh
2026-01-02 15:22 ` Matthew Wilcox
2026-01-02 23:05 ` David Laight [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260102230533.4fb1d8ef@pumpkin \
--to=david.laight.linux@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=arnd@arndb.de \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=rmk+kernel@armlinux.org.uk \
--cc=stable@vger.kernel.org \
--cc=thomas.weissschuh@linutronix.de \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.