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* Re: [PATCH 2/2] vdpa/mlx5: Fix possible failure in umem size calculation
       [not found] <20210530063214.183335-1-elic@nvidia.com>
@ 2021-05-30  8:05 ` Michael S. Tsirkin
       [not found]   ` <20210530081721.GB119906@mtl-vdi-166.wap.labs.mlnx>
  0 siblings, 1 reply; 3+ messages in thread
From: Michael S. Tsirkin @ 2021-05-30  8:05 UTC (permalink / raw)
  To: Eli Cohen; +Cc: linux-kernel, virtualization

On Sun, May 30, 2021 at 09:32:14AM +0300, Eli Cohen wrote:
> umem size is a 32 bit unsigned value so assigning it to an int could
> cause false failures. Set the calculated value inside the function and
> modify function name to reflect the fact it updates the size.
> 
> Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices")
> Signed-off-by: Eli Cohen <elic@nvidia.com>

could you clarify the impact of the bug please?


> ---
>  drivers/vdpa/mlx5/net/mlx5_vnet.c | 15 +++++----------
>  1 file changed, 5 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index 53312f0460ad..fdf3e74bffbd 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -610,8 +610,8 @@ static void cq_destroy(struct mlx5_vdpa_net *ndev, u16 idx)
>  	mlx5_db_free(ndev->mvdev.mdev, &vcq->db);
>  }
>  
> -static int umem_size(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq, int num,
> -		     struct mlx5_vdpa_umem **umemp)
> +static void set_umem_size(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq, int num,
> +			  struct mlx5_vdpa_umem **umemp)
>  {
>  	struct mlx5_core_dev *mdev = ndev->mvdev.mdev;
>  	int p_a;
> @@ -634,7 +634,7 @@ static int umem_size(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq
>  		*umemp = &mvq->umem3;
>  		break;
>  	}
> -	return p_a * mvq->num_ent + p_b;
> +	(*umemp)->size = p_a * mvq->num_ent + p_b;
>  }
>  
>  static void umem_frag_buf_free(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_umem *umem)
> @@ -650,15 +650,10 @@ static int create_umem(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *m
>  	void *in;
>  	int err;
>  	__be64 *pas;
> -	int size;
>  	struct mlx5_vdpa_umem *umem;
>  
> -	size = umem_size(ndev, mvq, num, &umem);
> -	if (size < 0)
> -		return size;
> -
> -	umem->size = size;
> -	err = umem_frag_buf_alloc(ndev, umem, size);
> +	set_umem_size(ndev, mvq, num, &umem);
> +	err = umem_frag_buf_alloc(ndev, umem, umem->size);
>  	if (err)
>  		return err;
>  
> -- 
> 2.31.1

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^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH 2/2] vdpa/mlx5: Fix possible failure in umem size calculation
       [not found]   ` <20210530081721.GB119906@mtl-vdi-166.wap.labs.mlnx>
@ 2021-05-30  8:21     ` Michael S. Tsirkin
       [not found]       ` <20210530082748.GB120333@mtl-vdi-166.wap.labs.mlnx>
  0 siblings, 1 reply; 3+ messages in thread
From: Michael S. Tsirkin @ 2021-05-30  8:21 UTC (permalink / raw)
  To: Eli Cohen; +Cc: linux-kernel, virtualization

On Sun, May 30, 2021 at 11:17:21AM +0300, Eli Cohen wrote:
> On Sun, May 30, 2021 at 04:05:57AM -0400, Michael S. Tsirkin wrote:
> > On Sun, May 30, 2021 at 09:32:14AM +0300, Eli Cohen wrote:
> > > umem size is a 32 bit unsigned value so assigning it to an int could
> > > cause false failures. Set the calculated value inside the function and
> > > modify function name to reflect the fact it updates the size.
> > > 
> > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices")
> > > Signed-off-by: Eli Cohen <elic@nvidia.com>
> > 
> > could you clarify the impact of the bug please?
> > 
> 
> This was found by code revew. I did not see it causing trouble becuase
> umem sizes are small enough to fit in int. Nevertheless it's a bug that
> deserves a fix.

ok pls include this info in the commit log.

> > 
> > > ---
> > >  drivers/vdpa/mlx5/net/mlx5_vnet.c | 15 +++++----------
> > >  1 file changed, 5 insertions(+), 10 deletions(-)
> > > 
> > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > index 53312f0460ad..fdf3e74bffbd 100644
> > > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > @@ -610,8 +610,8 @@ static void cq_destroy(struct mlx5_vdpa_net *ndev, u16 idx)
> > >  	mlx5_db_free(ndev->mvdev.mdev, &vcq->db);
> > >  }
> > >  
> > > -static int umem_size(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq, int num,
> > > -		     struct mlx5_vdpa_umem **umemp)
> > > +static void set_umem_size(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq, int num,
> > > +			  struct mlx5_vdpa_umem **umemp)
> > >  {
> > >  	struct mlx5_core_dev *mdev = ndev->mvdev.mdev;
> > >  	int p_a;
> > > @@ -634,7 +634,7 @@ static int umem_size(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq
> > >  		*umemp = &mvq->umem3;
> > >  		break;
> > >  	}
> > > -	return p_a * mvq->num_ent + p_b;
> > > +	(*umemp)->size = p_a * mvq->num_ent + p_b;
> > >  }
> > >  
> > >  static void umem_frag_buf_free(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_umem *umem)
> > > @@ -650,15 +650,10 @@ static int create_umem(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *m
> > >  	void *in;
> > >  	int err;
> > >  	__be64 *pas;
> > > -	int size;
> > >  	struct mlx5_vdpa_umem *umem;
> > >  
> > > -	size = umem_size(ndev, mvq, num, &umem);
> > > -	if (size < 0)
> > > -		return size;
> > > -
> > > -	umem->size = size;
> > > -	err = umem_frag_buf_alloc(ndev, umem, size);
> > > +	set_umem_size(ndev, mvq, num, &umem);
> > > +	err = umem_frag_buf_alloc(ndev, umem, umem->size);
> > >  	if (err)
> > >  		return err;
> > >  
> > > -- 
> > > 2.31.1
> > 

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Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH 2/2] vdpa/mlx5: Fix possible failure in umem size calculation
       [not found]       ` <20210530082748.GB120333@mtl-vdi-166.wap.labs.mlnx>
@ 2021-05-30  8:36         ` Michael S. Tsirkin
  0 siblings, 0 replies; 3+ messages in thread
From: Michael S. Tsirkin @ 2021-05-30  8:36 UTC (permalink / raw)
  To: Eli Cohen; +Cc: linux-kernel, virtualization

On Sun, May 30, 2021 at 11:27:48AM +0300, Eli Cohen wrote:
> On Sun, May 30, 2021 at 04:21:07AM -0400, Michael S. Tsirkin wrote:
> > On Sun, May 30, 2021 at 11:17:21AM +0300, Eli Cohen wrote:
> > > On Sun, May 30, 2021 at 04:05:57AM -0400, Michael S. Tsirkin wrote:
> > > > On Sun, May 30, 2021 at 09:32:14AM +0300, Eli Cohen wrote:
> > > > > umem size is a 32 bit unsigned value so assigning it to an int could
> > > > > cause false failures. Set the calculated value inside the function and
> > > > > modify function name to reflect the fact it updates the size.
> > > > > 
> > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices")
> > > > > Signed-off-by: Eli Cohen <elic@nvidia.com>
> > > > 
> > > > could you clarify the impact of the bug please?
> > > > 
> > > 
> > > This was found by code revew. I did not see it causing trouble becuase
> > > umem sizes are small enough to fit in int. Nevertheless it's a bug that
> > > deserves a fix.
> > 
> > ok pls include this info in the commit log.
> > 
> 
> Not sure what info do you want me to include. Seems to me that the
> changelog already provides the required information.


that this was found by code review and has no practical impact.

> > > > 
> > > > > ---
> > > > >  drivers/vdpa/mlx5/net/mlx5_vnet.c | 15 +++++----------
> > > > >  1 file changed, 5 insertions(+), 10 deletions(-)
> > > > > 
> > > > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > index 53312f0460ad..fdf3e74bffbd 100644
> > > > > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > @@ -610,8 +610,8 @@ static void cq_destroy(struct mlx5_vdpa_net *ndev, u16 idx)
> > > > >  	mlx5_db_free(ndev->mvdev.mdev, &vcq->db);
> > > > >  }
> > > > >  
> > > > > -static int umem_size(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq, int num,
> > > > > -		     struct mlx5_vdpa_umem **umemp)
> > > > > +static void set_umem_size(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq, int num,
> > > > > +			  struct mlx5_vdpa_umem **umemp)
> > > > >  {
> > > > >  	struct mlx5_core_dev *mdev = ndev->mvdev.mdev;
> > > > >  	int p_a;
> > > > > @@ -634,7 +634,7 @@ static int umem_size(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq
> > > > >  		*umemp = &mvq->umem3;
> > > > >  		break;
> > > > >  	}
> > > > > -	return p_a * mvq->num_ent + p_b;
> > > > > +	(*umemp)->size = p_a * mvq->num_ent + p_b;
> > > > >  }
> > > > >  
> > > > >  static void umem_frag_buf_free(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_umem *umem)
> > > > > @@ -650,15 +650,10 @@ static int create_umem(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *m
> > > > >  	void *in;
> > > > >  	int err;
> > > > >  	__be64 *pas;
> > > > > -	int size;
> > > > >  	struct mlx5_vdpa_umem *umem;
> > > > >  
> > > > > -	size = umem_size(ndev, mvq, num, &umem);
> > > > > -	if (size < 0)
> > > > > -		return size;
> > > > > -
> > > > > -	umem->size = size;
> > > > > -	err = umem_frag_buf_alloc(ndev, umem, size);
> > > > > +	set_umem_size(ndev, mvq, num, &umem);
> > > > > +	err = umem_frag_buf_alloc(ndev, umem, umem->size);
> > > > >  	if (err)
> > > > >  		return err;
> > > > >  
> > > > > -- 
> > > > > 2.31.1
> > > > 
> > 

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2021-05-30  8:37 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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     [not found] <20210530063214.183335-1-elic@nvidia.com>
2021-05-30  8:05 ` [PATCH 2/2] vdpa/mlx5: Fix possible failure in umem size calculation Michael S. Tsirkin
     [not found]   ` <20210530081721.GB119906@mtl-vdi-166.wap.labs.mlnx>
2021-05-30  8:21     ` Michael S. Tsirkin
     [not found]       ` <20210530082748.GB120333@mtl-vdi-166.wap.labs.mlnx>
2021-05-30  8:36         ` Michael S. Tsirkin

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