linux-kernel - Re: [PATCH 2.6.18-rc4 00/10] Kernel memory leak detector 0.9

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Date:	Sat, 19 Aug 2006 14:25:50 +0100
From:	"Catalin Marinas" <catalin.marinas@...il.com>
To:	"Antonino A. Daplas" <adaplas@....net>
Cc:	"Michal Piotrowski" <michal.k.k.piotrowski@...il.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2.6.18-rc4 00/10] Kernel memory leak detector 0.9

On 19/08/06, Antonino A. Daplas <adaplas@....net> wrote:
> On Sat, 2006-08-19 at 11:07 +0100, Catalin Marinas wrote:
> > On 18/08/06, Michal Piotrowski <michal.k.k.piotrowski@...il.com> wrote:
> > > orphan pointer 0xc6110000 (size 12288):
> > >   c017480e: <__kmalloc>
> > >   c024dda4: <vc_resize>
> > >   c020ed9c: <fbcon_startup>
> > >   c0251028: <register_con_driver>
> > >   c02511e0: <take_over_console>
> > >   c020e21e: <fbcon_takeover>
> > >   c0212b08: <fbcon_fb_registered>
> > >   c0212ce1: <fbcon_event_notify>
>
> On boot, vc->vc_screenbuf is allocated by alloc_bootmem() (vc->kmalloced
> == 0), so yes, there's a leak in there . But I don't think we have a way
> to deallocate this type of memory, so we just let it go.

It's not the leak caused by alloc_bootmem as kmemleak doesn't track
this kind of allocations. The block allocated via kmalloc in
vc_resize() is reported as unreferenced. However, I think that's a
false positive because it looks like the vc_screenbuf pointer is
stored in vc_cons[].d->vc_screenbuf which is allocated by
alloc_bootmem in con_init() and kmemleak doesn't track the
alloc_bootmem blocks. I'll fix kmemleak.

Thanks.

-- 
Catalin
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