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Subject[PATCH AUTOSEL 4.19 007/191] net: socionext: Fix two sleep-in-atomic-context bugs in ave_rxfifo_reset()
Date
From: Jia-Ju Bai <baijiaju1990@gmail.com>

[ Upstream commit 0020f5c807ef67954d9210eea0ba17a6134cdf7d ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/socionext/sni_ave.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/socionext/sni_ave.c b/drivers/net/ethernet/socionext/sni_ave.c
index f27d67a4d3045..09d25b87cf7c0 100644
--- a/drivers/net/ethernet/socionext/sni_ave.c
+++ b/drivers/net/ethernet/socionext/sni_ave.c
@@ -906,11 +906,11 @@ 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);
--
2.20.1
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