[PATCH v2] drm/amdgpu: add a missing lock for AMDGPU_SCHED

[Christian König]

Am 26.04.23 um 08:17 schrieb Chia-I Wu:
> mgr->ctx_handles should be protected by mgr->lock.
>
> v2: improve commit message
>
> Signed-off-by: Chia-I Wu <olvaffe at gmail.com>
> Cc: stable at vger.kernel.org

Please don't manually CC stable at vger.kernel.org while sending patches 
out, let us maintainers push that upstream with the appropriate tag and 
Greg picking it up from there.

A Fixes tag and figuring out to which stable versions this needs to be 
backported are nice to have as well, but Alex and I can take care of 
that as well.

Apart from that the technical side of the patch is Reviewed-by: 
Christian König <christian.koenig at amd.com>.

Regards,
Christian.

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c
> index e9b45089a28a6..863b2a34b2d64 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c
> @@ -38,6 +38,7 @@ static int amdgpu_sched_process_priority_override(struct amdgpu_device *adev,
>   {
>   	struct fd f = fdget(fd);
>   	struct amdgpu_fpriv *fpriv;
> +	struct amdgpu_ctx_mgr *mgr;
>   	struct amdgpu_ctx *ctx;
>   	uint32_t id;
>   	int r;
> @@ -51,8 +52,11 @@ static int amdgpu_sched_process_priority_override(struct amdgpu_device *adev,
>   		return r;
>   	}
>   
> -	idr_for_each_entry(&fpriv->ctx_mgr.ctx_handles, ctx, id)
> +	mgr = &fpriv->ctx_mgr;
> +	mutex_lock(&mgr->lock);
> +	idr_for_each_entry(&mgr->ctx_handles, ctx, id)
>   		amdgpu_ctx_priority_override(ctx, priority);
> +	mutex_unlock(&mgr->lock);
>   
>   	fdput(f);
>   	return 0;