Re: [PATCH v2] drm/panfrost: Make sure a BO is only unmapped when appropriate

From: Rob Herring <robh+dt@kernel.org>
To: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Tomeu Vizoso <tomeu@tomeuvizoso.net>,
	dri-devel <dri-devel@lists.freedesktop.org>,
	stable <stable@vger.kernel.org>
Subject: Re: [PATCH v2] drm/panfrost: Make sure a BO is only unmapped when appropriate
Date: Tue, 18 Jun 2019 09:29:12 -0600	[thread overview]
Message-ID: <CAL_JsqJhUxtAjbwUDppA3opAK4h9ws0wVuFT66yYZ7NU1=GzPg@mail.gmail.com> (raw)
In-Reply-To: <20190618081343.16927-1-boris.brezillon@collabora.com>

On Tue, Jun 18, 2019 at 2:13 AM Boris Brezillon
<boris.brezillon@collabora.com> wrote:
>
> mmu_ops->unmap() will fail when called on a BO that has not been
> previously mapped, and the error path in panfrost_ioctl_create_bo()
> can call drm_gem_object_put_unlocked() (which in turn calls
> panfrost_mmu_unmap()) on a BO that has not been mapped yet.
>
> Keep track of the mapped/unmapped state to avoid such issues.
>
> Fixes: f3ba91228e8e ("drm/panfrost: Add initial panfrost driver")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
> ---
> Changes in v2:
> * Check is_mapped val in the caller and add WARN_ON() in the mmu code
>   (suggested by Tomeu)
> ---
>  drivers/gpu/drm/panfrost/panfrost_gem.c | 3 ++-
>  drivers/gpu/drm/panfrost/panfrost_gem.h | 1 +
>  drivers/gpu/drm/panfrost/panfrost_mmu.c | 8 ++++++++
>  3 files changed, 11 insertions(+), 1 deletion(-)

Applied.

Rob