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From:   Chao Wang <D202280639@hust.edu.cn>
To:     Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Heiko Stuebner <heiko@sntech.de>,
        Marc Zyngier <maz@kernel.org>, Olof Johansson <olof@lixom.net>
Cc:     hust-os-kernel-patches@googlegroups.com,
        Chao Wang <D202280639@hust.edu.cn>,
        Dongliang Mu <dzm91@hust.edu.cn>, iommu@lists.linux.dev,
        linux-arm-kernel@lists.infradead.org,
        linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH] iommu: Fix unwind goto issue
Date:   Mon, 17 Apr 2023 03:04:21 +0000
Message-Id: <20230417030421.2777-1-D202280639@hust.edu.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Smatch complains that
drivers/iommu/rockchip-iommu.c:1306 rk_iommu_probe() warn: missing unwind goto?

The rk_iommu_probe function, after obtaining the irq value through
platform_get_irq, directly returns an error if the returned value
is negative, without releasing any resources.

Fix this by adding a new error handling label "err_pm_disable" and
use a goto statement to redirect to the error handling process. In
order to preserve the original semantics, set err to the value of irq.

Fixes: 1aa55ca9b14a ("iommu/rockchip: Move irq request past pm_runtime_enable")
Signed-off-by: Chao Wang <D202280639@hust.edu.cn>
Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn>
---
This issue is found by static analysis and remains untested.
---
 drivers/iommu/rockchip-iommu.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index f30db22ea5d7..31cd1e2929e9 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -1302,20 +1302,22 @@ static int rk_iommu_probe(struct platform_device *pdev)
 	for (i = 0; i < iommu->num_irq; i++) {
 		int irq = platform_get_irq(pdev, i);
 
-		if (irq < 0)
-			return irq;
+		if (irq < 0) {
+			err = irq;
+			goto err_pm_disable;
+		}
 
 		err = devm_request_irq(iommu->dev, irq, rk_iommu_irq,
 				       IRQF_SHARED, dev_name(dev), iommu);
-		if (err) {
-			pm_runtime_disable(dev);
-			goto err_remove_sysfs;
-		}
+		if (err)
+			goto err_pm_disable;
 	}
 
 	dma_set_mask_and_coherent(dev, rk_ops->dma_bit_mask);
 
 	return 0;
+err_pm_disable:
+	pm_runtime_disable(dev);
 err_remove_sysfs:
 	iommu_device_sysfs_remove(&iommu->iommu);
 err_put_group:
-- 
2.34.1