linux-kernel - Re: [PATCH] drm: nouveau: fix nvbe leakage

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Date:	Tue, 8 Oct 2013 06:15:35 -0300
From:	Geyslan Gregório Bem <geyslan@...il.com>
To:	Ben Skeggs <bskeggs@...hat.com>
Cc:	Felipe Pena <felipensp@...il.com>, airlied@...ux.ie,
	dri-devel@...ts.freedesktop.org,
	LKML <linux-kernel@...r.kernel.org>,
	kernel-br <kernel-br@...glegroups.com>
Subject: Re: [PATCH] drm: nouveau: fix nvbe leakage

Rather, the first member of nvbe is ttm (same address). Got it.

Please, disregard this patch. Thank you.

Geyslan Gregório Bem
hackingbits.com


2013/10/7 Ben Skeggs <bskeggs@...hat.com>:
> ----- Original Message -----
>> From: "Geyslan Gregório Bem" <geyslan@...il.com>
>> To: "Felipe Pena" <felipensp@...il.com>
>> Cc: "Ben Skeggs" <bskeggs@...hat.com>, airlied@...ux.ie, dri-devel@...ts.freedesktop.org,
>> linux-kernel@...r.kernel.org, "kernel-br" <kernel-br@...glegroups.com>
>> Sent: Tuesday, 8 October, 2013 9:39:02 AM
>> Subject: Re: [PATCH] drm: nouveau: fix nvbe leakage
>>
>> Felipe, thank you too.
>>
>> I realized this after a code review.
>>
>> Ben, what do you think?
>>
>> Geyslan Gregório Bem
>> hackingbits.com
>>
>>
>> 2013/10/7 Felipe Pena <felipensp@...il.com>:
>> > Hi,
>> >
>> > On Mon, Oct 7, 2013 at 7:35 PM, Ben Skeggs <bskeggs@...hat.com> wrote:
>> >> ----- Original Message -----
>> >>> From: "Geyslan G. Bem" <geyslan@...il.com>
>> >>> To: airlied@...ux.ie, bskeggs@...hat.com, dri-devel@...ts.freedesktop.org
>> >>> Cc: linux-kernel@...r.kernel.org, kernel-br@...glegroups.com, "Geyslan G.
>> >>> Bem" <geyslan@...il.com>
>> >>> Sent: Tuesday, 8 October, 2013 8:14:26 AM
>> >>> Subject: [PATCH] drm: nouveau: fix nvbe leakage
>> >>>
>> >>> Free memory allocated to nvbe when returning NULL.
>> >>>
>> >>> Signed-off-by: Geyslan G. Bem <geyslan@...il.com>
>> >> NACK.  ttm_dma_tt_init() calls the destructor if it fails, which frees the
>> >> memory.
>> >>
>> >> Ben.
>> >>
>> >
>> > But ttm_tt_destroy() just handles the ttm_tt part from nvbe, the nvbe
>> > pointer itself is not being free'd.
> Actually look at ttm_tt_destroy() and you'll see that right at the end it goes ttm->func->destroy(ttm), which is nouveau_sgdma_destroy().
>
> Ben.
>> >
>> >>> ---
>> >>>  drivers/gpu/drm/nouveau/nouveau_sgdma.c | 3 +++
>> >>>  1 file changed, 3 insertions(+)
>> >>>
>> >>> diff --git a/drivers/gpu/drm/nouveau/nouveau_sgdma.c
>> >>> b/drivers/gpu/drm/nouveau/nouveau_sgdma.c
>> >>> index 0843ebc..af8b66d 100644
>> >>> --- a/drivers/gpu/drm/nouveau/nouveau_sgdma.c
>> >>> +++ b/drivers/gpu/drm/nouveau/nouveau_sgdma.c
>> >>> @@ -105,6 +105,9 @@ nouveau_sgdma_create_ttm(struct ttm_bo_device *bdev,
>> >>>               nvbe->ttm.ttm.func = &nv50_sgdma_backend;
>> >>>
>> >>>       if (ttm_dma_tt_init(&nvbe->ttm, bdev, size, page_flags,
>> >>>       dummy_read_page))
>> >>> +     {
>> >>> +             kfree(nvbe);
>> >>>               return NULL;
>> >>> +     }
>> >>>       return &nvbe->ttm.ttm;
>> >>>  }
>> >>> --
>> >>> 1.8.4
>> >>>
>> >>>
>> >> --
>> >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>> >> the body of a message to majordomo@...r.kernel.org
>> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>> >> Please read the FAQ at  http://www.tux.org/lkml/
>> >
>> >
>> >
>> > --
>> > Regards,
>> > Felipe Pena
>>
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