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From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
To: Zhenyu Wang <zhenyuw@linux.intel.com>, Zhi Wang <zhi.a.wang@intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>, intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH] drm/i915/kvmgt: avoid dereferencing a potentially null info pointer
Date: Thu, 23 Mar 2017 16:11:00 +0200	[thread overview]
Message-ID: <1490278260.16902.12.camel@linux.intel.com> (raw)
In-Reply-To: <20170323123900.GL27773@nuc-i3427.alporthouse.com>

Dropping the irrelevant Cc's.

On to, 2017-03-23 at 12:39 +0000, Chris Wilson wrote:
> On Thu, Mar 23, 2017 at 12:22:30PM +0000, Colin King wrote:
> > 
> > From: Colin Ian King <colin.king@canonical.com>
> > 
> > info is being checked to see if it is a null pointer, however, vpgu is
> > dereferencing info before this check, leading to a potential null
> > pointer dereference.  If info is null, then the error message being
> > printed by macro gvt_vgpu_err and this requires vpgu to exist. We can
> > use a null vpgu as the macro has a sanity check to see if vpgu is null,
> > so this is OK.
>
> It is never NULL, it gets checked by its only caller.

Took me a while to make any sense of the code as gvt_vgpu_err depends
on a vgpu variable being declared in the scope without taking it as a
parameter and that is a one big no-no:

https://01.org/linuxgraphics/gfx-docs/drm/process/coding-style.html#macros-enums-and-rtl

Regards, Joonas
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

  reply	other threads:[~2017-03-23 14:11 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-23 12:22 [PATCH] drm/i915/kvmgt: avoid dereferencing a potentially null info pointer Colin King
2017-03-23 12:22 ` Colin King
2017-03-23 12:39 ` Chris Wilson
2017-03-23 12:39   ` Chris Wilson
2017-03-23 12:39   ` Chris Wilson
2017-03-23 14:11   ` Joonas Lahtinen [this message]
2017-03-24  3:06     ` Zhenyu Wang
2017-03-23 13:16 ` ✗ Fi.CI.BAT: warning for " Patchwork
2017-03-23 13:43 ` [PATCH] " Frans Klaver
2017-03-23 13:43   ` Frans Klaver
2017-03-24  3:38   ` Zhenyu Wang
2017-03-24  3:38     ` Zhenyu Wang
2017-03-24  3:38     ` Zhenyu Wang

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