From: Chengwen Feng <fengchengwen@huawei.com>
To: <dev@dpdk.org>
Cc: <thomas@monjalon.net>, <kevin.laatz@intel.com>,
<bruce.richardson@intel.com>
Subject: [PATCH 3/4] dma/hisilicon: enhance robustness of scan CQ
Date: Fri, 27 May 2022 11:40:54 +0800 [thread overview]
Message-ID: <20220527034055.33271-4-fengchengwen@huawei.com> (raw)
In-Reply-To: <20220527034055.33271-1-fengchengwen@huawei.com>
The CQ (completion queue) descriptors were updated by hardware, and then
scanned by driver to retrieve hardware completion status.
This patch enhances robustness by following:
1. replace while (true) with a finite loop to avoid potential dead loop.
2. check the csq_head field in CQ descriptor to avoid status array
overflows.
Fixes: 2db4f0b82360 ("dma/hisilicon: add data path")
Cc: stable@dpdk.org
Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
---
drivers/dma/hisilicon/hisi_dmadev.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/hisilicon/hisi_dmadev.c b/drivers/dma/hisilicon/hisi_dmadev.c
index f5c3cd914d..fbe09284ed 100644
--- a/drivers/dma/hisilicon/hisi_dmadev.c
+++ b/drivers/dma/hisilicon/hisi_dmadev.c
@@ -634,7 +634,7 @@ hisi_dma_scan_cq(struct hisi_dma_dev *hw)
uint16_t count = 0;
uint64_t misc;
- while (true) {
+ while (count < hw->cq_depth) {
cqe = &hw->cqe[cq_head];
misc = cqe->misc;
misc = rte_le_to_cpu_64(misc);
@@ -642,6 +642,16 @@ hisi_dma_scan_cq(struct hisi_dma_dev *hw)
break;
csq_head = FIELD_GET(CQE_SQ_HEAD_MASK, misc);
+ if (unlikely(csq_head > hw->sq_depth_mask)) {
+ /**
+ * Defensive programming to prevent overflow of the
+ * status array indexed by csq_head. Only error logs
+ * are used for prompting.
+ */
+ HISI_DMA_ERR(hw, "invalid csq_head:%u!\n", csq_head);
+ count = 0;
+ break;
+ }
if (unlikely(misc & CQE_STATUS_MASK))
hw->status[csq_head] = FIELD_GET(CQE_STATUS_MASK,
misc);
--
2.33.0
next prev parent reply other threads:[~2022-05-27 3:47 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-27 3:40 [PATCH 0/4] bugfix and feature for Hisilicon DMA PMD Chengwen Feng
2022-05-27 3:40 ` [PATCH 1/4] dma/hisilicon: fix return last-idx when no DMA completed Chengwen Feng
2022-05-27 3:40 ` [PATCH 2/4] app/test: support test " Chengwen Feng
2022-05-30 11:40 ` Kevin Laatz
2022-05-27 3:40 ` Chengwen Feng [this message]
2022-05-27 3:40 ` [PATCH 4/4] dma/hisilicon: support vchan-status ops Chengwen Feng
2022-06-07 10:44 ` [PATCH 0/4] bugfix and feature for Hisilicon DMA PMD Thomas Monjalon
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