Re: [PATCH 04/38] IB/ehca: fix handling idr_alloc result

From: Doug Ledford
Date: Tue Sep 29 2015 - 14:23:50 EST


On 09/21/2015 09:33 AM, Andrzej Hajda wrote:
> The function can return negative value.
>
> The problem has been detected using proposed semantic patch
> scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci [1].
>
> [1]: http://permalink.gmane.org/gmane.linux.kernel/2038576
>
> Signed-off-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>

Patch looks fine to me.

Acked-by: Doug Ledford <dledford@xxxxxxxxxx>

> ---
> drivers/staging/rdma/ehca/ehca_cq.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/staging/rdma/ehca/ehca_cq.c b/drivers/staging/rdma/ehca/ehca_cq.c
> index 9b68b17..ea1b5c1 100644
> --- a/drivers/staging/rdma/ehca/ehca_cq.c
> +++ b/drivers/staging/rdma/ehca/ehca_cq.c
> @@ -130,7 +130,7 @@ struct ib_cq *ehca_create_cq(struct ib_device *device,
> void *vpage;
> u32 counter;
> u64 rpage, cqx_fec, h_ret;
> - int ipz_rc, i;
> + int rc, i;
> unsigned long flags;
>
> if (attr->flags)
> @@ -170,16 +170,17 @@ struct ib_cq *ehca_create_cq(struct ib_device *device,
>
> idr_preload(GFP_KERNEL);
> write_lock_irqsave(&ehca_cq_idr_lock, flags);
> - my_cq->token = idr_alloc(&ehca_cq_idr, my_cq, 0, 0x2000000, GFP_NOWAIT);
> + rc = idr_alloc(&ehca_cq_idr, my_cq, 0, 0x2000000, GFP_NOWAIT);
> write_unlock_irqrestore(&ehca_cq_idr_lock, flags);
> idr_preload_end();
>
> - if (my_cq->token < 0) {
> + if (rc < 0) {
> cq = ERR_PTR(-ENOMEM);
> ehca_err(device, "Can't allocate new idr entry. device=%p",
> device);
> goto create_cq_exit1;
> }
> + my_cq->token = rc;
>
> /*
> * CQs maximum depth is 4GB-64, but we need additional 20 as buffer
> @@ -195,11 +196,11 @@ struct ib_cq *ehca_create_cq(struct ib_device *device,
> goto create_cq_exit2;
> }
>
> - ipz_rc = ipz_queue_ctor(NULL, &my_cq->ipz_queue, param.act_pages,
> + rc = ipz_queue_ctor(NULL, &my_cq->ipz_queue, param.act_pages,
> EHCA_PAGESIZE, sizeof(struct ehca_cqe), 0, 0);
> - if (!ipz_rc) {
> + if (!rc) {
> ehca_err(device, "ipz_queue_ctor() failed ipz_rc=%i device=%p",
> - ipz_rc, device);
> + rc, device);
> cq = ERR_PTR(-EINVAL);
> goto create_cq_exit3;
> }
>


--
Doug Ledford <dledford@xxxxxxxxxx>
GPG KeyID: 0E572FDD


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