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From: Jan Kiszka <jan.kiszka@web.de>
To: linux-kernel@vger.kernel.org, Willy Tarreau <wtarreau@hera.kernel.org>
Subject: 2.4.x: i386/x86_64 bitops clobberings
Date: Sun, 08 Oct 2006 23:42:07 +0200	[thread overview]
Message-ID: <452970AF.8020605@web.de> (raw)

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Hi,

after going through debugging hell with some out-of-tree code, I
realised that this patch

http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=92934bcbf96bc9dc931c40ca5f1a57685b7b813b

makes a difference: current 2.6 works with the following code sequence
as expected (printk is executed), 2.4 fails.


#include <asm/bitops.h>
#include <linux/module.h>

unsigned long a = 1;

int module_init(void)
{
	unsigned long b = 0;
	int x;

	x = __test_and_set_bit(0, &b);
	if (__test_and_set_bit(0, &a))
		printk("x = %d\n", x);

	return -1;
}


There will likely be a way to work around my issue. Nevertheless, I
wondered if that patch was already considered for 2.4 inclusion. Or is
there no risk that in-tree code is affected?

Jan



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             reply	other threads:[~2006-10-08 21:43 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-10-08 21:42 Jan Kiszka [this message]
2006-10-08 22:44 ` 2.4.x: i386/x86_64 bitops clobberings Willy Tarreau
2006-10-08 22:53   ` Jan Kiszka
2006-10-08 23:36     ` Willy Tarreau
2006-10-09  6:27       ` Jan Kiszka
2006-10-14 19:50         ` Willy Tarreau
2006-10-15  9:56           ` Jan Kiszka
2006-10-15 10:12             ` Willy Tarreau

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