Commit 0020f5c8 authored Sep 15, 2018 by Jia-Ju Bai Committed by David S. Miller Sep 17, 2018

net: socionext: Fix two sleep-in-atomic-context bugs in ave_rxfifo_reset()



The driver may sleep with holding a spinlock.
The function call paths (from bottom to top) in Linux-4.17 are:

[FUNC] usleep_range
drivers/net/ethernet/socionext/sni_ave.c, 892:
	usleep_range in ave_rxfifo_reset
drivers/net/ethernet/socionext/sni_ave.c, 932:
	ave_rxfifo_reset in ave_irq_handler

[FUNC] usleep_range
drivers/net/ethernet/socionext/sni_ave.c, 888:
	usleep_range in ave_rxfifo_reset
drivers/net/ethernet/socionext/sni_ave.c, 932:
	ave_rxfifo_reset in ave_irq_handler

To fix these bugs, usleep_range() is replaced with udelay().

These bugs are found by my static analysis tool DSAC.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 5d288b88

drivers/net/ethernet/socionext/sni_ave.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -895,11 +895,11 @@ static void ave_rxfifo_reset(struct net_device *ndev)

		/* assert reset */
		writel(AVE_GRR_RXFFR, priv->base + AVE_GRR);
		usleep_range(40, 50);
		udelay(50);

		/* negate reset */
		writel(0, priv->base + AVE_GRR);
		usleep_range(10, 20);
		udelay(20);

		/* negate interrupt status */
		writel(AVE_GI_RXOVF, priv->base + AVE_GISR);

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