linux-kernel - x86_64 has 2 x arch_vma_name()

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Date:	Wed, 25 Jul 2007 20:31:32 +0200
From:	Sam Ravnborg <sam@...nborg.org>
To:	Andi Kleen <ak@...e.de>, LKML <linux-kernel@...r.kernel.org>
Cc:	Nathan Lynch <ntl@...ox.com>, Andy Whitcroft <apw@...dowen.org>
Subject: x86_64 has 2 x arch_vma_name() - can we drop one?

In include/linux/mm.h arch_vma_name() is declared __weak.
This hide the fact that x86_64 has 2 implementations of
said function.

In arch/x86_64/mm/init.c:
const char *arch_vma_name(struct vm_area_struct *vma)
{
	if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
		return "[vdso]";
	if (vma == &gate_vma)
		return "[vsyscall]";
	return NULL;
}

And in arch/x86_64/ia32/syscall32.c:
const char *arch_vma_name(struct vm_area_struct *vma)
{
	if (vma->vm_start == VSYSCALL32_BASE &&
	    vma->vm_mm && vma->vm_mm->task_size == IA32_PAGE_OFFSET)
		return "[vdso]";
	return NULL;
}

As no comment were preceeding the fucntions this seems not to be on
purpose.
If I am correct which one should die?

The reason why this popped up is that the __weak definition in mm.h
causes problems on at least powerpc (trigger a binutils bug).
A similar bug is present at ia64 - but I have not confirmed if the
same fix is needed.

	Sam
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