From: Steven Price <steven.price@arm.com>
To: Boris Brezillon <boris.brezillon@collabora.com>,
Rob Herring <robh+dt@kernel.org>,
Tomeu Vizoso <tomeu@tomeuvizoso.net>,
Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Cc: stable@vger.kernel.org, dri-devel@lists.freedesktop.org
Subject: Re: [PATCH 4/8] drm/panfrost: Fix a race in panfrost_gem_free_object()
Date: Fri, 29 Nov 2019 14:28:33 +0000 [thread overview]
Message-ID: <a30a18c7-e9de-a90d-97b5-f8f386b7f35d@arm.com> (raw)
In-Reply-To: <20191129135908.2439529-5-boris.brezillon@collabora.com>
On 29/11/2019 13:59, Boris Brezillon wrote:
> panfrost_gem_shrinker_scan() might purge a BO (release the sgt and
> kill the GPU mapping) that's being freed by panfrost_gem_free_object()
> if we don't remove the BO from the shrinker list at the beginning of
> panfrost_gem_free_object().
>
> Fixes: 013b65101315 ("drm/panfrost: Add madvise and shrinker support")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
> ---
> drivers/gpu/drm/panfrost/panfrost_gem.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
> index acb07fe06580..daf4c55a2863 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
> @@ -19,6 +19,16 @@ static void panfrost_gem_free_object(struct drm_gem_object *obj)
> struct panfrost_gem_object *bo = to_panfrost_bo(obj);
> struct panfrost_device *pfdev = obj->dev->dev_private;
>
> + /*
> + * Make sure the BO is no longer inserted in the shrinker list before
> + * taking care of the destruction itself. If we don't do that we have a
> + * race condition between this function and what's done in
> + * panfrost_gem_shrinker_scan().
> + */
> + mutex_lock(&pfdev->shrinker_lock);
> + list_del_init(&bo->base.madv_list);
> + mutex_unlock(&pfdev->shrinker_lock);
> +
> if (bo->sgts) {
> int i;
> int n_sgt = bo->base.base.size / SZ_2M;
> @@ -33,11 +43,6 @@ static void panfrost_gem_free_object(struct drm_gem_object *obj)
> kfree(bo->sgts);
> }
>
> - mutex_lock(&pfdev->shrinker_lock);
> - if (!list_empty(&bo->base.madv_list))
> - list_del(&bo->base.madv_list);
> - mutex_unlock(&pfdev->shrinker_lock);
> -
> drm_gem_shmem_free_object(obj);
> }
>
>
next prev parent reply other threads:[~2019-11-29 14:28 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20191129135908.2439529-1-boris.brezillon@collabora.com>
2019-11-29 13:59 ` [PATCH 1/8] drm/panfrost: Make panfrost_job_run() return an ERR_PTR() instead of NULL Boris Brezillon
2019-11-29 14:19 ` Steven Price
2019-11-29 14:31 ` Boris Brezillon
2019-11-29 14:38 ` Steven Price
2019-11-29 19:32 ` Boris Brezillon
2019-11-29 13:59 ` [PATCH 2/8] drm/panfrost: Fix a race in panfrost_ioctl_madvise() Boris Brezillon
2019-11-29 14:24 ` Steven Price
2019-11-29 14:33 ` Boris Brezillon
2019-11-29 14:40 ` Steven Price
2019-11-29 20:07 ` Daniel Vetter
2019-11-29 21:45 ` Boris Brezillon
2019-12-05 23:08 ` Rob Herring
2019-12-06 7:53 ` Boris Brezillon
2019-12-06 8:08 ` Boris Brezillon
2019-11-29 13:59 ` [PATCH 3/8] drm/panfrost: Fix a BO leak in panfrost_ioctl_mmap_bo() Boris Brezillon
2019-11-29 14:26 ` Steven Price
2019-11-29 13:59 ` [PATCH 4/8] drm/panfrost: Fix a race in panfrost_gem_free_object() Boris Brezillon
2019-11-29 14:28 ` Steven Price [this message]
2019-11-29 13:59 ` [PATCH 5/8] drm/panfrost: Open/close the perfcnt BO Boris Brezillon
2019-11-29 14:34 ` Steven Price
2019-11-29 13:59 ` [PATCH 6/8] drm/panfrost: Make sure imported/exported BOs are never purged Boris Brezillon
2019-11-29 14:14 ` Boris Brezillon
2019-11-29 14:45 ` Steven Price
2019-11-29 14:52 ` Boris Brezillon
2019-11-29 20:12 ` Daniel Vetter
2019-11-29 21:09 ` Boris Brezillon
2019-12-02 8:52 ` Daniel Vetter
2019-12-02 9:50 ` Boris Brezillon
2019-11-29 13:59 ` [PATCH 7/8] drm/panfrost: Add the panfrost_gem_mapping concept Boris Brezillon
2019-11-29 15:37 ` Steven Price
2019-11-29 20:14 ` Daniel Vetter
2019-11-29 21:36 ` Boris Brezillon
2019-12-02 8:55 ` Daniel Vetter
2019-12-02 9:13 ` Boris Brezillon
2019-12-02 9:44 ` Daniel Vetter
2019-12-04 11:41 ` Steven Price
2019-11-29 13:59 ` [PATCH 8/8] drm/panfrost: Make sure the shrinker does not reclaim referenced BOs Boris Brezillon
2019-11-29 15:48 ` Steven Price
2019-11-29 16:07 ` Boris Brezillon
2019-11-29 16:12 ` Steven Price
2019-12-02 12:50 ` Robin Murphy
2019-12-02 13:32 ` Boris Brezillon
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