Commit 811f5559 authored by Mateusz Jończyk's avatar Mateusz Jończyk Committed by Alexandre Belloni
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rtc: mc146818-lib: fix locking in mc146818_set_time 



In mc146818_set_time(), CMOS_READ(RTC_CONTROL) was performed without the
rtc_lock taken, which is required for CMOS accesses. Fix this.

Nothing in kernel modifies RTC_DM_BINARY, so a separate critical section
is allowed here.

Fixes: dcf257e9 ("rtc: mc146818: Reduce spinlock section in mc146818_set_time()")
Signed-off-by: default avatarMateusz Jończyk <mat.jonczyk@o2.pl>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220220090403.153928-1-mat.jonczyk@o2.pl
parent eb74f47b

drivers/rtc/rtc-mc146818-lib.c

+4 −2
Original line number Diff line number Diff line
@@ -232,8 +232,10 @@ int mc146818_set_time(struct rtc_time *time) 
	if (yrs >= 100)

		yrs -= 100;



	if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)

	    || RTC_ALWAYS_BCD) {

	spin_lock_irqsave(&rtc_lock, flags);

	save_control = CMOS_READ(RTC_CONTROL);

	spin_unlock_irqrestore(&rtc_lock, flags);

	if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {

		sec = bin2bcd(sec);

		min = bin2bcd(min);

		hrs = bin2bcd(hrs);