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Subject: Re: [PATCH 1/2] Add thread_info_cache_init() to all archs
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Sam Ravnborg <sam@ravnborg.org>
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Date: Wed, 21 May 2008 16:38:20 -0400
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Cc: Linux-Arch <linux-arch@vger.kernel.org>, linux-m32r@ml.linux-m32r.org,
	Luke Browning <LukeBrowning@us.ibm.com>, takata@linux-m32r.org,
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On Wed, 2008-05-21 at 21:06 +0200, Sam Ravnborg wrote:
> It was discussed to add some run-time checks for this issue.
> But the examples given were a bit fluffy so I never integrated
> anything
> i kbuild to detect this.
> 
> As this is only a bug for const weak functions they could be made
> non-const
> if they are seldomly used?

With the asm("") trick ?

I suppose, but I'm also happy to just reject the bad gcc...

It shouldn't be too hard to do a test case made of 2 files.

test_foo.c

int foo(void)
{
	printf("good\n");
}

test_bar.c

int foo(void) __weak
{
}

int main(void)
{
	foo();
	return 0;
}

And check for "good" in the output of said program..

Can somebody test that ? Luke, you have a broken compiler, can you make
up some test that could be integrated in the kernel build system
easily ?

(I'm travelling right now, no time to play much with it myself).

Cheers,
Ben.