From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jia-Ju Bai Subject: [PATCH] net: socionext: Fix two sleep-in-atomic-context bugs in ave_rxfifo_reset() Date: Sat, 15 Sep 2018 12:02:46 +0800 Message-ID: <20180915040246.22703-1-baijiaju1990@gmail.com> Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai To: davem@davemloft.net, hayashi.kunihiko@socionext.com, yamada.masahiro@socionext.com, robh@kernel.org, andrew@lunn.ch Return-path: Received: from mail-pf1-f193.google.com ([209.85.210.193]:38665 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725796AbeIOJY2 (ORCPT ); Sat, 15 Sep 2018 05:24:28 -0400 Sender: netdev-owner@vger.kernel.org List-ID: 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 --- 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 f7ecceeb1e28..3c784a29ce0d 100644 --- a/drivers/net/ethernet/socionext/sni_ave.c +++ b/drivers/net/ethernet/socionext/sni_ave.c @@ -904,11 +904,11 @@ 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); -- 2.17.0