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

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

On Sun, 2009-08-16 at 12:08 +0200, Ingo Molnar wrote:
> * Catalin Marinas <catalin.marinas@arm.com> wrote:
> > diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
> > index 676debf..cb690b3 100644
> > --- a/arch/x86/kernel/aperture_64.c
> > +++ b/arch/x86/kernel/aperture_64.c
> > @@ -94,6 +94,11 @@ 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);
> 
> i tried this in -tip, it causes this build error:
> 
> arch/x86/kernel/aperture_64.c: In function ‘allocate_aperture’:
> arch/x86/kernel/aperture_64.c:101: error: implicit declaration of function ‘kmemleak_ignore’

Missing the #include. Here's the updated patch:


kmemleak: Ignore the aperture memory hole on x86_64

From: Catalin Marinas <catalin.marinas@arm.com>

This block is allocated with alloc_bootmem() and scanned by kmemleak but
the kernel direct mapping may no longer exist. This patch tells kmemleak
to ignore this memory hole.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/aperture_64.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
index 676debf..128111d 100644
--- 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",

Thanks.

-- 
Catalin