From: Jason Gunthorpe <jgg@ziepe.ca>
To: Weihang Li <liweihang@hisilicon.com>, dledford@redhat.com
Cc: linux-rdma@vger.kernel.org, linuxarm@huawei.com
Subject: Re: [PATCH for-rc 1/2] RDMA/hns: Fix memory leaks about mr
Date: Mon, 28 Oct 2019 15:24:29 -0300 [thread overview]
Message-ID: <20191028182429.GA14440@ziepe.ca> (raw)
In-Reply-To: <1572072995-11277-2-git-send-email-liweihang@hisilicon.com>
On Sat, Oct 26, 2019 at 02:56:34PM +0800, Weihang Li wrote:
> From: Lijun Ou <oulijun@huawei.com>
>
> In hns_roce_v1_dereg_mr(), 'mr_work' is not freed in some cases, for
> example, try_wait_for_completion() runs fail, which will cause memory
> leaks.
>
> Fixes: bfcc681bd09d ("IB/hns: Fix the bug when free mr")
> Signed-off-by: Lijun Ou <oulijun@huawei.com>
> Signed-off-by: Weihang Li <liweihang@hisilicon.com>
> drivers/infiniband/hw/hns/hns_roce_hw_v1.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v1.c b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
> index 5f74bf5..88c1cd9 100644
> +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
> @@ -1094,7 +1094,6 @@ static void hns_roce_v1_mr_free_work_fn(struct work_struct *work)
> free_work:
> if (mr_work->comp_flag)
> complete(mr_work->comp);
> - kfree(mr_work);
> }
>
> static int hns_roce_v1_dereg_mr(struct hns_roce_dev *hr_dev,
> @@ -1137,18 +1136,21 @@ static int hns_roce_v1_dereg_mr(struct hns_roce_dev *hr_dev,
>
> while (end > 0) {
> if (try_wait_for_completion(&comp))
> - goto free_mr;
> + goto err;
> msleep(HNS_ROCE_V1_FREE_MR_WAIT_VALUE);
> end -= HNS_ROCE_V1_FREE_MR_WAIT_VALUE;
> }
>
> mr_work->comp_flag = 0;
> if (try_wait_for_completion(&comp))
> - goto free_mr;
> + goto err;
>
> dev_warn(dev, "Free mr work 0x%x over 50s and failed!\n", mr->key);
> ret = -ETIMEDOUT;
>
> +err:
> + kfree(mr_work);
This whole thing makes absolutely no sense.
Why is work being pushed onto a WQ and then the same routine turns
around and does wait_for_completion??
Further, trying to make this 'non blocking' by sleep spinning on
'try_wait_for_completion' is utterly insane.
Then going on to uncondionally free memory that we don't even know if
the work is finished with or not is just wrong.
Doug, you took this spin loop stuff, you get to review the fixes for
it! :)
Jason
next prev parent reply other threads:[~2019-10-28 18:24 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-26 6:56 [PATCH for-rc 0/2] RDMA/hns: Fix memory leaks Weihang Li
2019-10-26 6:56 ` [PATCH for-rc 1/2] RDMA/hns: Fix memory leaks about mr Weihang Li
2019-10-28 18:24 ` Jason Gunthorpe [this message]
2019-10-26 6:56 ` [PATCH for-rc 2/2] RDMA/hns: Prevent memory leaks about eq Weihang Li
2019-10-28 18:25 ` Jason Gunthorpe
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