Re: [PATCH 13/29] IB/mlx4: Split a condition check in five functions

[Majd Dibbiny]

> On Feb 18, 2017, at 11:08 PM, SF Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx> wrote:
> 
> From: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
> Date: Sat, 18 Feb 2017 14:43:34 +0100
> 
> The kfree() function was called in up to two cases during error handling
> even if the passed variable contained a null pointer.
> 
> * Split a condition check for memory allocation failures.
> 
> * Adjust jump targets according to the Linux coding style convention.
> 
> * Delete initialisations for variables at the beginning
>  which became unnecessary with this refactoring.
> 
> Signed-off-by: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/infiniband/hw/mlx4/main.c | 90 +++++++++++++++++++++++++--------------
> 1 file changed, 59 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
> index b3b5ded85166..c0c299ffa0f6 100644
> --- a/drivers/infiniband/hw/mlx4/main.c
> +++ b/drivers/infiniband/hw/mlx4/main.c
> @@ -432,8 +432,8 @@ static int mlx4_ib_query_device(struct ib_device *ibdev,
>                struct ib_udata *uhw)
> {
>    struct mlx4_ib_dev *dev = to_mdev(ibdev);
> -    struct ib_smp *in_mad  = NULL;
> -    struct ib_smp *out_mad = NULL;
> +    struct ib_smp *in_mad;
> +    struct ib_smp *out_mad;
>    int err;
>    int have_ib_ports;
>    struct mlx4_uverbs_ex_query_device cmd;
> @@ -458,10 +458,14 @@ static int mlx4_ib_query_device(struct ib_device *ibdev,
>    resp.response_length = offsetof(typeof(resp), response_length) +
>        sizeof(resp.response_length);
>    in_mad  = kzalloc(sizeof(*in_mad), GFP_KERNEL);
> +    if (!in_mad)
> +        return -ENOMEM;
> +
>    out_mad = kmalloc(sizeof(*out_mad), GFP_KERNEL);
> -    err = -ENOMEM;
> -    if (!in_mad || !out_mad)
> -        goto out;
> +    if (!out_mad) {
> +        err = -ENOMEM;
> +        goto free_in_mad;
> +    }
> 
>    init_query_mad(in_mad);
>    in_mad->attr_id = IB_SMP_ATTR_NODE_INFO;
> @@ -570,9 +574,9 @@ static int mlx4_ib_query_device(struct ib_device *ibdev,
>            goto out;
>    }
> out:
> -    kfree(in_mad);
>    kfree(out_mad);
> -
> +free_in_mad:
> +    kfree(in_mad);
>    return err;
> }
> 
> @@ -588,16 +592,21 @@ mlx4_ib_port_link_layer(struct ib_device *device, u8 port_num)
> static int ib_link_query_port(struct ib_device *ibdev, u8 port,
>                  struct ib_port_attr *props, int netw_view)
> {
> -    struct ib_smp *in_mad  = NULL;
> -    struct ib_smp *out_mad = NULL;
> +    struct ib_smp *in_mad;
> +    struct ib_smp *out_mad;
>    int ext_active_speed;
>    int mad_ifc_flags = MLX4_MAD_IFC_IGNORE_KEYS;
> -    int err = -ENOMEM;
> +    int err;
> 
>    in_mad  = kzalloc(sizeof(*in_mad), GFP_KERNEL);
> +    if (!in_mad)
> +        return -ENOMEM;
> +
>    out_mad = kmalloc(sizeof(*out_mad), GFP_KERNEL);
> -    if (!in_mad || !out_mad)
> -        goto out;
> +    if (!out_mad) {
> +        err = -ENOMEM;
> +        goto free_in_mad;
> +    }
> 
>    init_query_mad(in_mad);
>    in_mad->attr_id  = IB_SMP_ATTR_PORT_INFO;
> @@ -670,8 +679,9 @@ static int ib_link_query_port(struct ib_device *ibdev, u8 port,
>         props->active_speed = IB_SPEED_SDR;
> 
> out:
> -    kfree(in_mad);
>    kfree(out_mad);
> +free_in_mad:
> +    kfree(in_mad);
>    return err;
> }
> 
> @@ -763,17 +773,22 @@ static int mlx4_ib_query_port(struct ib_device *ibdev, u8 port,
> int __mlx4_ib_query_gid(struct ib_device *ibdev, u8 port, int index,
>            union ib_gid *gid, int netw_view)
> {
> -    struct ib_smp *in_mad  = NULL;
> -    struct ib_smp *out_mad = NULL;
> -    int err = -ENOMEM;
> +    struct ib_smp *in_mad;
> +    struct ib_smp *out_mad;
> +    int err;
>    struct mlx4_ib_dev *dev = to_mdev(ibdev);
>    int clear = 0;
>    int mad_ifc_flags = MLX4_MAD_IFC_IGNORE_KEYS;
> 
>    in_mad  = kzalloc(sizeof(*in_mad), GFP_KERNEL);
> +    if (!in_mad)
> +        return -ENOMEM;
> +
>    out_mad = kmalloc(sizeof(*out_mad), GFP_KERNEL);
> -    if (!in_mad || !out_mad)
> -        goto out;
> +    if (!out_mad) {
> +        err = -ENOMEM;
> +        goto free_in_mad;
> +    }
> 
>    init_query_mad(in_mad);
>    in_mad->attr_id  = IB_SMP_ATTR_PORT_INFO;
> @@ -811,8 +826,9 @@ int __mlx4_ib_query_gid(struct ib_device *ibdev, u8 port, int index,
> out:
>    if (clear)
>        memset(gid->raw + 8, 0, 8);
> -    kfree(in_mad);
>    kfree(out_mad);
> +free_in_mad:
> +    kfree(in_mad);
>    return err;
> }
> 
> @@ -902,15 +918,20 @@ static void mlx4_init_sl2vl_tbl(struct mlx4_ib_dev *mdev)
> int __mlx4_ib_query_pkey(struct ib_device *ibdev, u8 port, u16 index,
>             u16 *pkey, int netw_view)
> {
> -    struct ib_smp *in_mad  = NULL;
> -    struct ib_smp *out_mad = NULL;
> +    struct ib_smp *in_mad;
> +    struct ib_smp *out_mad;
>    int mad_ifc_flags = MLX4_MAD_IFC_IGNORE_KEYS;
> -    int err = -ENOMEM;
> +    int err;
> 
>    in_mad  = kzalloc(sizeof(*in_mad), GFP_KERNEL);
> +    if (!in_mad)
> +        return -ENOMEM;
> +
>    out_mad = kmalloc(sizeof(*out_mad), GFP_KERNEL);
> -    if (!in_mad || !out_mad)
> -        goto out;
> +    if (!out_mad) {
> +        err = -ENOMEM;
> +        goto free_in_mad;
> +    }
> 
>    init_query_mad(in_mad);
>    in_mad->attr_id  = IB_SMP_ATTR_PKEY_TABLE;
> @@ -927,8 +948,9 @@ int __mlx4_ib_query_pkey(struct ib_device *ibdev, u8 port, u16 index,
>    *pkey = be16_to_cpu(((__be16 *) out_mad->data)[index % 32]);
> 
> out:
> -    kfree(in_mad);
>    kfree(out_mad);
> +free_in_mad:
> +    kfree(in_mad);
>    return err;
> }
> 
> @@ -2083,15 +2105,20 @@ static int mlx4_ib_mcg_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
> 
> static int init_node_data(struct mlx4_ib_dev *dev)
> {
> -    struct ib_smp *in_mad  = NULL;
> -    struct ib_smp *out_mad = NULL;
> +    struct ib_smp *in_mad;
> +    struct ib_smp *out_mad;
>    int mad_ifc_flags = MLX4_MAD_IFC_IGNORE_KEYS;
> -    int err = -ENOMEM;
> +    int err;
> 
>    in_mad  = kzalloc(sizeof(*in_mad), GFP_KERNEL);
> +    if (!in_mad)
> +        return -ENOMEM;
> +
>    out_mad = kmalloc(sizeof(*out_mad), GFP_KERNEL);
> -    if (!in_mad || !out_mad)
> -        goto out;
> +    if (!out_mad) {
> +        err = -ENOMEM;
> +        goto free_in_mad;
> +    }
> 
>    init_query_mad(in_mad);
>    in_mad->attr_id = IB_SMP_ATTR_NODE_DESC;
> @@ -2114,8 +2141,9 @@ static int init_node_data(struct mlx4_ib_dev *dev)
>    memcpy(&dev->ib_dev.node_guid, out_mad->data + 12, 8);
> 
> out:
> -    kfree(in_mad);
>    kfree(out_mad);
> +free_in_mad:
> +    kfree(in_mad);
>    return err;
> }
> 
> -- 
> 2.11.1
> 
> --
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Thanks,
Reviewed-by: Majd Dibbiny
<majd@xxxxxxxxxxxx>