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Date:   Sun, 02 Sep 2018 16:05:38 -0700 (PDT)
Message-Id: <20180902.160538.1996490624543458172.davem@davemloft.net>
To:     baijiaju1990@gmail.com
Cc:     nicolas.ferre@microchip.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: cadence: Fix a sleep-in-atomic-context bug in
 macb_halt_tx()
From:   David Miller <davem@davemloft.net>
In-Reply-To: <20180901121105.436-1-baijiaju1990@gmail.com>
References: <20180901121105.436-1-baijiaju1990@gmail.com>
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From: Jia-Ju Bai <baijiaju1990@gmail.com>
Date: Sat,  1 Sep 2018 20:11:05 +0800

> The kernel module may sleep with holding a spinlock.
> 
> The function call paths (from bottom to top) in Linux-4.16 are:
> 
> [FUNC] usleep_range
> drivers/net/ethernet/cadence/macb_main.c, 648: 
> 	usleep_range in macb_halt_tx
> drivers/net/ethernet/cadence/macb_main.c, 730: 
> 	macb_halt_tx in macb_tx_error_task
> drivers/net/ethernet/cadence/macb_main.c, 721: 
> 	_raw_spin_lock_irqsave in macb_tx_error_task
> 
> To fix this bug, usleep_range() is replaced with udelay().
> 
> This bug is found by my static analysis tool DSAC.
> 
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>

Applied, thanks.