Re: [PATCH] vdpa/mlx5: Fix double release of debugfs entry
On Wed, Aug 30, 2023 at 1:40 AM Dragos Tatulea wrote:
>
> The error path in setup_driver deletes the debugfs entry but doesn't
> clear the pointer. During .dev_del the invalid pointer will be released
> again causing a crash.
>
> This patch fixes the issue by always clearing the debugfs entry in
> mlx5_vdpa_remove_debugfs. Also, stop removing the debugfs entry in
> .dev_del op: the debugfs entry is already handled within the
> setup_driver/teardown_driver scope.
>
> Fixes: f0417e72add5 ("vdpa/mlx5: Add and remove debugfs in setup/teardown
> driver")
> Signed-off-by: Dragos Tatulea
> Reviewed-by: Gal Pressman
Acked-by: Jason Wang
Thanks
> ---
> drivers/vdpa/mlx5/net/debug.c | 5 +++--
> drivers/vdpa/mlx5/net/mlx5_vnet.c | 7 ++-
> drivers/vdpa/mlx5/net/mlx5_vnet.h | 2 +-
> 3 files changed, 6 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/vdpa/mlx5/net/debug.c b/drivers/vdpa/mlx5/net/debug.c
> index 60d6ac68cdc4..9c85162c19fc 100644
> --- a/drivers/vdpa/mlx5/net/debug.c
> +++ b/drivers/vdpa/mlx5/net/debug.c
> @@ -146,7 +146,8 @@ void mlx5_vdpa_add_debugfs(struct mlx5_vdpa_net *ndev)
> ndev->rx_dent = debugfs_create_dir("rx", ndev->debugfs);
> }
>
> -void mlx5_vdpa_remove_debugfs(struct dentry *dbg)
> +void mlx5_vdpa_remove_debugfs(struct mlx5_vdpa_net *ndev)
> {
> - debugfs_remove_recursive(dbg);
> + debugfs_remove_recursive(ndev->debugfs);
> + ndev->debugfs = NULL;
> }
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index 37be945a0230..f91c938b4be1 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -2713,7 +2713,7 @@ static int setup_driver(struct mlx5_vdpa_dev *mvdev)
> err_rqt:
> teardown_virtqueues(ndev);
> err_setup:
> - mlx5_vdpa_remove_debugfs(ndev->debugfs);
> + mlx5_vdpa_remove_debugfs(ndev);
> out:
> return err;
> }
> @@ -2727,8 +2727,7 @@ static void teardown_driver(struct mlx5_vdpa_net *ndev)
> if (!ndev->setup)
> return;
>
> - mlx5_vdpa_remove_debugfs(ndev->debugfs);
> - ndev->debugfs = NULL;
> + mlx5_vdpa_remove_debugfs(ndev);
> teardown_steering(ndev);
> destroy_tir(ndev);
> destroy_rqt(ndev);
> @@ -3489,8 +3488,6 @@ static void mlx5_vdpa_dev_del(struct vdpa_mgmt_dev
> *v_mdev, struct vdpa_device *
> struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev);
> struct workqueue_struct *wq;
>
> - mlx5_vdpa_remove_debugfs(ndev->debugfs);
> - ndev->debugfs = NULL;
> unregister_link_notifier(ndev);
> _vdpa_unregister_device(dev);
> wq = mvdev->wq;
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.h
> b/drivers/vdpa/mlx5/net/mlx5_vnet.h
> index 36c44d9fdd16..60cdbc903037 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.h
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.h
> @@ -88,7 +88,7 @@ struct macvlan_node {
> };
>
> void mlx5_vdpa_add_debugfs(struct mlx5_vdpa_net *ndev);
> -void mlx5_vdpa_remove_debugfs(struct dentry *dbg);
> +void mlx5_vdpa_remove_debugfs(struct mlx5_vdpa_net *ndev);
> void mlx5_vdpa_add_rx_flow_table(struct mlx5_vdpa_net *ndev);
> void mlx5_vdpa_remove_rx_flow_table(struct mlx5_vdpa_net *ndev);
> void mlx5_vdpa_add_tirn(struct mlx5_vdpa_net *ndev);
> --
> 2.41.0
>
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Re: [PATCH] vdpa/mlx5: Fix double release of debugfs entry
On Tue, 2023-08-29 at 20:40 +0300, Dragos Tatulea wrote:
> The error path in setup_driver deletes the debugfs entry but doesn't
> clear the pointer. During .dev_del the invalid pointer will be released
> again causing a crash.
>
> This patch fixes the issue by always clearing the debugfs entry in
> mlx5_vdpa_remove_debugfs. Also, stop removing the debugfs entry in
> .dev_del op: the debugfs entry is already handled within the
> setup_driver/teardown_driver scope.
>
> Fixes: f0417e72add5 ("vdpa/mlx5: Add and remove debugfs in setup/teardown
> driver")
> Signed-off-by: Dragos Tatulea
> Reviewed-by: Gal Pressman
Gentle ping. Are there any comments on this patch?
Thanks,
Dragos
> ---
> drivers/vdpa/mlx5/net/debug.c | 5 +++--
> drivers/vdpa/mlx5/net/mlx5_vnet.c | 7 ++-
> drivers/vdpa/mlx5/net/mlx5_vnet.h | 2 +-
> 3 files changed, 6 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/vdpa/mlx5/net/debug.c b/drivers/vdpa/mlx5/net/debug.c
> index 60d6ac68cdc4..9c85162c19fc 100644
> --- a/drivers/vdpa/mlx5/net/debug.c
> +++ b/drivers/vdpa/mlx5/net/debug.c
> @@ -146,7 +146,8 @@ void mlx5_vdpa_add_debugfs(struct mlx5_vdpa_net *ndev)
> ndev->rx_dent = debugfs_create_dir("rx", ndev->debugfs);
> }
>
> -void mlx5_vdpa_remove_debugfs(struct dentry *dbg)
> +void mlx5_vdpa_remove_debugfs(struct mlx5_vdpa_net *ndev)
> {
> - debugfs_remove_recursive(dbg);
> + debugfs_remove_recursive(ndev->debugfs);
> + ndev->debugfs = NULL;
> }
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index 37be945a0230..f91c938b4be1 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -2713,7 +2713,7 @@ static int setup_driver(struct mlx5_vdpa_dev *mvdev)
> err_rqt:
> teardown_virtqueues(ndev);
> err_setup:
> - mlx5_vdpa_remove_debugfs(ndev->debugfs);
> + mlx5_vdpa_remove_debugfs(ndev);
> out:
> return err;
> }
> @@ -2727,8 +2727,7 @@ static void teardown_driver(struct mlx5_vdpa_net *ndev)
> if (!ndev->setup)
> return;
>
> - mlx5_vdpa_remove_debugfs(ndev->debugfs);
> - ndev->debugfs = NULL;
> + mlx5_vdpa_remove_debugfs(ndev);
> teardown_steering(ndev);
> destroy_tir(ndev);
> destroy_rqt(ndev);
> @@ -3489,8 +3488,6 @@ static void mlx5_vdpa_dev_del(struct vdpa_mgmt_dev
> *v_mdev, struct vdpa_device *
> struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev);
> struct workqueue_struct *wq;
>
> - mlx5_vdpa_remove_debugfs(ndev->debugfs);
> - ndev->debugfs = NULL;
> unregister_link_notifier(ndev);
> _vdpa_unregister_device(dev);
> wq = mvdev->wq;
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.h
> b/drivers/vdpa/mlx5/net/mlx5_vnet.h
> index 36c44d9fdd16..60cdbc903037 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.h
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.h
> @@ -88,7 +88,7 @@ struct macvlan_node {
> };
>
> void mlx5_vdpa_add_debugfs(struct mlx5_vdpa_net *ndev);
> -void mlx5_vdpa_remove_debugfs(struct dentry *dbg);
> +void mlx5_vdpa_remove_debugfs(struct mlx5_vdpa_net *ndev);
> void mlx5_vdpa_add_rx_flow_table(struct mlx5_vdpa_net *ndev);
> void mlx5_vdpa_remove_rx_flow_table(struct mlx5_vdpa_net *ndev);
> void mlx5_vdpa_add_tirn(struct mlx5_vdpa_net *ndev);
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