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Message-ID: <14f1d3efc0bef057a51748db6fe95fcd22f3b34c.camel@redhat.com>
Subject: Re: [PATCH 1/2] drm/nouveau: fix stale locked mutex in
 nouveau_gem_ioctl_pushbuf
From: Lyude Paul <lyude@redhat.com>
To: Karol Herbst <kherbst@redhat.com>, linux-kernel@vger.kernel.org
Cc: Danilo Krummrich <dakr@redhat.com>, dri-devel@lists.freedesktop.org, 
	nouveau@lists.freedesktop.org
Date: Mon, 04 Mar 2024 14:30:08 -0500
In-Reply-To: <20240304183157.1587152-1-kherbst@redhat.com>
References: <20240304183157.1587152-1-kherbst@redhat.com>
Organization: Red Hat Inc.
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Reviewed-by: Lyude Paul <lyude@redhat.com>

On Mon, 2024-03-04 at 19:31 +0100, Karol Herbst wrote:
> If VM_BIND is enabled on the client the legacy submission ioctl can't be
> used, however if a client tries to do so regardless it will return an
> error. In this case the clients mutex remained unlocked leading to a
> deadlock inside nouveau_drm_postclose or any other nouveau ioctl call.
>=20
> Fixes: b88baab82871 ("drm/nouveau: implement new VM_BIND uAPI")
> Cc: Danilo Krummrich <dakr@redhat.com>
> Signed-off-by: Karol Herbst <kherbst@redhat.com>
> ---
>  drivers/gpu/drm/nouveau/nouveau_gem.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>=20
> diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouv=
eau/nouveau_gem.c
> index 49c2bcbef1299..5a887d67dc0e8 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_gem.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
> @@ -764,7 +764,7 @@ nouveau_gem_ioctl_pushbuf(struct drm_device *dev, voi=
d *data,
>  		return -ENOMEM;
> =20
>  	if (unlikely(nouveau_cli_uvmm(cli)))
> -		return -ENOSYS;
> +		return nouveau_abi16_put(abi16, -ENOSYS);
> =20
>  	list_for_each_entry(temp, &abi16->channels, head) {
>  		if (temp->chan->chid =3D=3D req->channel) {

--=20
Cheers,
 Lyude Paul (she/her)
 Software Engineer at Red Hat