Commit 861bc949 authored by Jean-Philippe Brucker's avatar Jean-Philippe Brucker Committed by Zheng Zengkai
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iommu/arm-smmu-v3: Ratelimit event dump 

maillist inclusion
category: feature
bugzilla: 51855
CVE: NA

Reference: https://jpbrucker.net/git/linux/commit/?h=sva/2021-03-01&id=b61d8bac171c221b3d14c03eba78338bfbbb8825



---------------------------------------------

When a device or driver misbehaves, it is possible to receive events
much faster than we can print them out. Ratelimit the printing of
events.

Signed-off-by: default avatarJean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: default avatarLijun Fang <fanglijun3@huawei.com>
Reviewed-by: default avatarWeilong Chen <chenweilong@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 24092300

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c

+3 −1
Original line number Diff line number Diff line
@@ -1546,6 +1546,8 @@ static irqreturn_t arm_smmu_evtq_thread(int irq, void *dev) 
	struct arm_smmu_device *smmu = dev;

	struct arm_smmu_queue *q = &smmu->evtq.q;

	struct arm_smmu_ll_queue *llq = &q->llq;

	static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,

				      DEFAULT_RATELIMIT_BURST);

	u64 evt[EVTQ_ENT_DWORDS];



	do {
@@ -1553,7 +1555,7 @@ static irqreturn_t arm_smmu_evtq_thread(int irq, void *dev) 
			u8 id = FIELD_GET(EVTQ_0_ID, evt[0]);



			ret = arm_smmu_handle_evt(smmu, evt);

			if (!ret)

			if (!ret || !__ratelimit(&rs))

				continue;



			dev_info(smmu->dev, "event 0x%02x received:\n", id);