From: Jeremy Fitzhardinge <jeremy@goop.org>
To: the arch/x86 maintainers <x86@kernel.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Thomas Reitmayr <treitmayr@devbase.at>,
leigh123linux@googlemail.com, Dave Jones <davej@redhat.com>,
"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@elte.hu>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] Use correct byte-sized register constraint in __xchg_op()
Date: Fri, 06 Apr 2012 00:46:06 -0700 [thread overview]
Message-ID: <4F7E9F3E.3050301@goop.org> (raw)
In-Reply-To: <4F7A3315.501@goop.org>
PIng?
On 04/02/2012 04:15 PM, Jeremy Fitzhardinge wrote:
> x86-64 can access the low half of any register, but i386 can only do
> it with a subset of registers. 'r' causes compilation failures on i386,
> but 'q' expresses the constraint properly.
>
> Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
> Reported-by: Leigh Scott <leigh123linux@googlemail.com>
> Tested-by: Thomas Reitmayr <treitmayr@devbase.at>
>
> diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h
> index b3b7332..bc18d0e 100644
> --- a/arch/x86/include/asm/cmpxchg.h
> +++ b/arch/x86/include/asm/cmpxchg.h
> @@ -43,7 +43,7 @@ extern void __add_wrong_size(void)
> switch (sizeof(*(ptr))) { \
> case __X86_CASE_B: \
> asm volatile (lock #op "b %b0, %1\n" \
> - : "+r" (__ret), "+m" (*(ptr)) \
> + : "+q" (__ret), "+m" (*(ptr)) \
> : : "memory", "cc"); \
> break; \
> case __X86_CASE_W: \
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>
next prev parent reply other threads:[~2012-04-06 7:46 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-02 23:15 [PATCH] Use correct byte-sized register constraint in __xchg_op() Jeremy Fitzhardinge
2012-04-04 0:37 ` Josh Boyer
2012-04-05 20:27 ` Josh Boyer
2012-04-05 21:16 ` Thomas Reitmayr
2012-04-06 7:46 ` Jeremy Fitzhardinge [this message]
2012-04-06 16:52 ` [tip:x86/urgent] x86: " tip-bot for Jeremy Fitzhardinge
2012-04-06 16:53 ` [tip:x86/urgent] x86: Use correct byte-sized register constraint in __add() tip-bot for H. Peter Anvin
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=4F7E9F3E.3050301@goop.org \
--to=jeremy@goop.org \
--cc=davej@redhat.com \
--cc=hpa@zytor.com \
--cc=leigh123linux@googlemail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=tglx@linutronix.de \
--cc=treitmayr@devbase.at \
--cc=x86@kernel.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).