From: Joerg Roedel <joro@8bytes.org>
To: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Cc: agross@kernel.org, bjorn.andersson@linaro.org, will@kernel.org,
sricharan@codeaurora.org, linux-arm-msm@vger.kernel.org,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
stable@vger.kernel.org
Subject: Re: [PATCH] iommu: fix an incorrect NULL check on list iterator
Date: Thu, 28 Apr 2022 10:11:03 +0200 [thread overview]
Message-ID: <YmpMF3ico9tregcJ@8bytes.org> (raw)
In-Reply-To: <20220327053558.2821-1-xiam0nd.tong@gmail.com>
On Sun, Mar 27, 2022 at 01:35:58PM +0800, Xiaomeng Tong wrote:
> @@ -617,23 +617,17 @@ static int qcom_iommu_of_xlate(struct device *dev,
> {
> struct msm_iommu_dev *iommu;
> unsigned long flags;
> - int ret = 0;
>
> spin_lock_irqsave(&msm_iommu_lock, flags);
> list_for_each_entry(iommu, &qcom_iommu_devices, dev_node)
> - if (iommu->dev->of_node == spec->np)
> - break;
> -
> - if (!iommu || iommu->dev->of_node != spec->np) {
> - ret = -ENODEV;
> - goto fail;
> - }
> -
> - insert_iommu_master(dev, &iommu, spec);
> -fail:
> + if (iommu->dev->of_node == spec->np) {
> + insert_iommu_master(dev, &iommu, spec);
> + spin_unlock_irqrestore(&msm_iommu_lock, flags);
> + return 0;
> + }
> spin_unlock_irqrestore(&msm_iommu_lock, flags);
>
> - return ret;
> + return -ENODEV;
This looks a bit clumsy, a better fix is below:
diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
index 50f57624610f..98d23c52537b 100644
--- a/drivers/iommu/msm_iommu.c
+++ b/drivers/iommu/msm_iommu.c
@@ -610,14 +610,16 @@ static void insert_iommu_master(struct device *dev,
static int qcom_iommu_of_xlate(struct device *dev,
struct of_phandle_args *spec)
{
- struct msm_iommu_dev *iommu;
+ struct msm_iommu_dev *iommu = NULL, *it;
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&msm_iommu_lock, flags);
- list_for_each_entry(iommu, &qcom_iommu_devices, dev_node)
- if (iommu->dev->of_node == spec->np)
+ list_for_each_entry(it, &qcom_iommu_devices, dev_node)
+ if (it->dev->of_node == spec->np) {
+ iommu = it;
break;
+ }
if (!iommu || iommu->dev->of_node != spec->np) {
ret = -ENODEV;
Can you please verify this and re-submit?
Thanks,
Joerg
prev parent reply other threads:[~2022-04-28 8:11 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-27 5:35 [PATCH] iommu: fix an incorrect NULL check on list iterator Xiaomeng Tong
2022-04-28 8:11 ` Joerg Roedel [this message]
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