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From: Richard Henderson <rth@twiddle.net>
To: "Randy.Dunlap" <rddunlap@osdl.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>,
	jakub@redhat.com, szepe@pinerecords.com, jamagallon@able.es,
	kwall@kurtwerks.com, lcapitulino@prefeitura.sp.gov.br,
	linux-kernel@vger.kernel.org, torvalds@osdl.org
Subject: Re: 2.6-test2: gcc-3.3.1 warning.
Date: Sat, 16 Aug 2003 18:25:51 -0700	[thread overview]
Message-ID: <20030817012551.GB22022@twiddle.net> (raw)
In-Reply-To: <20030729083507.3dd20485.rddunlap@osdl.org>

On Tue, Jul 29, 2003 at 08:35:07AM -0700, Randy.Dunlap wrote:
> I really hate to get this back to the original problem, but is
> the reported warning a gcc 3.3.x problem?  I don't see the assembly
> problem here.
> 
> | arch/i386/kernel/reboot.c: In function `machine_restart':
> | arch/i386/kernel/reboot.c:261: warning: use of memory input without
> | lvalue in asm operand 0 is deprecated


	static long no_idt[2];
	...
	__asm__ __volatile__("lidt %0": :"m" (no_idt));

Notice that no_idt is an array.  Therefore its identifier decays
into a pointer.  Therefore, what this statement is really asking
for is

	{
	  long *tmp = no_idt;
	  asm volatile ("lidt %0" : : "m" (*&tmp));
	}

which is clearly not what was intended.

Fixed by doing

	__asm__ __volatile__("lidt %0": :"m" (*no_idt));



r~

  reply	other threads:[~2003-08-17  1:26 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-07-28 12:40 2.6-test2: gcc-3.3.1 warning Luiz Capitulino
2003-07-28 20:29 ` Randy.Dunlap
2003-07-28 22:50 ` Tomas Szepe
2003-07-29  0:22   ` Kurt Wall
2003-07-29  4:55     ` Tomas Szepe
2003-07-29  9:28       ` J.A. Magallon
2003-07-29  9:35         ` Tomas Szepe
2003-07-29  9:48           ` J.A. Magallon
2003-07-29  9:58             ` Tomas Szepe
2003-07-29 10:11               ` J.A. Magallon
2003-07-29 10:20                 ` Tomas Szepe
2003-07-29 11:57                   ` Alan Cox
2003-07-29 15:35                     ` Randy.Dunlap
2003-08-17  1:25                       ` Richard Henderson [this message]
2003-08-17  1:34                         ` Linus Torvalds
2003-08-17  2:04                           ` Randy.Dunlap
2003-07-29 12:34                   ` Jakub Jelinek

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