Re: [PATCH 2/2] kmemleak: Ignore the aperture memory hole on x86_64

[Catalin Marinas <catalin.marinas@arm.com>]

On Sat, 2009-08-29 at 15:31 +0200, Ingo Molnar wrote:
> * Catalin Marinas <catalin.marinas@arm.com> wrote:
> > --- a/arch/x86/kernel/aperture_64.c
> > +++ b/arch/x86/kernel/aperture_64.c
> > @@ -20,6 +20,7 @@
> >  #include <linux/bitops.h>
> >  #include <linux/ioport.h>
> >  #include <linux/suspend.h>
> > +#include <linux/kmemleak.h>
> >  #include <asm/e820.h>
> >  #include <asm/io.h>
> >  #include <asm/iommu.h>
> > @@ -94,6 +95,11 @@ static u32 __init allocate_aperture(void)
> >  	 * code for safe
> >  	 */
> >  	p = __alloc_bootmem_nopanic(aper_size, aper_size, 512ULL<<20);
> > +	/*
> > +	 * Kmemleak should not scan this block as it may not be mapped via the
> > +	 * kernel direct mapping.
> > +	 */
> > +	kmemleak_ignore(p);
> >  	if (!p || __pa(p)+aper_size > 0xffffffff) {
> >  		printk(KERN_ERR
> >  			"Cannot allocate aperture memory hole (%p,%uK)\n",
> 
> This sure does not look right for the rare but theoretically 
> possible !p case, does it?

All the kmemleak_* callbacks check for (p && !IS_ERR(p)), just to
simplify the calling site.

-- 
Catalin