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Message-Id: <1513173350-18385-1-git-send-email-baijiaju1990@gmail.com>
Date: Wed, 13 Dec 2017 21:55:50 +0800
From: Jia-Ju Bai <baijiaju1990@...il.com>
To: akinobu.mita@...il.com, a.zummo@...ertech.it,
alexandre.belloni@...e-electrons.com
Cc: linux-rtc@...r.kernel.org, linux-kernel@...r.kernel.org,
Jia-Ju Bai <baijiaju1990@...il.com>
Subject: [PATCH 1/2] rtc-r7301: Fix a possible sleep-in-atomic bug in rtc7301_read_time
The driver may sleep under a spinlock.
The function call path is:
rtc7301_read_time (acquire the spinlock)
rtc7301_wait_while_busy
usleep_range --> may sleep
To fix it, usleep_range is replaced with udelay.
This bug is found by my static analysis tool(DSAC) and checked by my code review.
Signed-off-by: Jia-Ju Bai <baijiaju1990@...il.com>
---
drivers/rtc/rtc-r7301.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/rtc/rtc-r7301.c b/drivers/rtc/rtc-r7301.c
index 28d5408..d846e97 100644
--- a/drivers/rtc/rtc-r7301.c
+++ b/drivers/rtc/rtc-r7301.c
@@ -95,7 +95,7 @@ static int rtc7301_wait_while_busy(struct rtc7301_priv *priv)
if (!(val & RTC7301_CONTROL_BUSY))
return 0;
- usleep_range(200, 300);
+ udelay(300);
}
return -ETIMEDOUT;
--
1.7.9.5
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