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Date: Tue, 19 Mar 2024 12:17:51 +0100
From: Jiri Pirko <jiri@resnulli.us>
To: Jijie Shao <shaojijie@huawei.com>
Cc: yisen.zhuang@huawei.com, salil.mehta@huawei.com, davem@davemloft.net,
	edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
	michal.kubiak@intel.com, rkannoth@marvell.com,
	shenjian15@huawei.com, wangjie125@huawei.com,
	liuyonglong@huawei.com, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH V3 net 2/3] net: hns3: fix kernel crash when devlink
 reload during pf initialization
Message-ID: <Zfl0Xz3vNNH_3Mfo@nanopsycho>
References: <20240318132948.3624333-1-shaojijie@huawei.com>
 <20240318132948.3624333-3-shaojijie@huawei.com>
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In-Reply-To: <20240318132948.3624333-3-shaojijie@huawei.com>

Mon, Mar 18, 2024 at 02:29:47PM CET, shaojijie@huawei.com wrote:
>From: Yonglong Liu <liuyonglong@huawei.com>
>
>The devlink reload process will access the hardware resources,
>but the register operation is done before the hardware is initialized.
>so, if process the devlink reload during initialization, may lead to kernel
>crash. This patch fixes this by checking whether the NIC is initialized.

Fix your locking, you should take devl_lock during your init. That would
disallow reload to race with it.

pw-bot: cr

>
>Fixes: b741269b2759 ("net: hns3: add support for registering devlink for PF")
>Signed-off-by: Yonglong Liu <liuyonglong@huawei.com>
>Signed-off-by: Jijie Shao <shaojijie@huawei.com>
>---
> drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_devlink.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_devlink.c b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_devlink.c
>index 9a939c0b217f..80db4f7b05f6 100644
>--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_devlink.c
>+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_devlink.c
>@@ -40,8 +40,9 @@ static int hclge_devlink_reload_down(struct devlink *devlink, bool netns_change,
> 	struct pci_dev *pdev = hdev->pdev;
> 	int ret;
> 
>-	if (test_bit(HCLGE_STATE_RST_HANDLING, &hdev->state)) {
>-		dev_err(&pdev->dev, "reset is handling\n");
>+	if (test_bit(HCLGE_STATE_RST_HANDLING, &hdev->state) ||
>+	    !test_bit(HCLGE_STATE_NIC_REGISTERED, &hdev->state)) {
>+		dev_err(&pdev->dev, "reset is handling or driver removed\n");
> 		return -EBUSY;
> 	}
> 
>-- 
>2.30.0
>
>