From: Victor Ding <victording@google.com>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Victor Ding <victording@google.com>,
Alessandro Zummo <a.zummo@towertech.it>,
Alexandre Belloni <alexandre.belloni@bootlin.com>,
linux-rtc@vger.kernel.org
Subject: [PATCH] rtc: cmos: initialize rtc time when reading alarm
Date: Thu, 13 Aug 2020 15:41:34 +1000 [thread overview]
Message-ID: <20200813154020.1.Iaf7638a2f2a87ff68d85fcb8dec615e41340c97f@changeid> (raw)
cmos_read_alarm() may leave certain fields of a struct rtc_time
untouched; therefore, these fields contain garbage if not properly
initialized, leading to inconsistent values when converting into
time64_t.
This patch to set all fields of a struct rtc_time to -1 before calling
cmos_read_alarm().
Signed-off-by: Victor Ding <victording@google.com>
---
drivers/rtc/rtc-cmos.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index bcc96ab7793f..c99af567780d 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -1006,6 +1006,7 @@ static int cmos_suspend(struct device *dev)
enable_irq_wake(cmos->irq);
}
+ memset(&cmos->saved_wkalrm.time, -1, sizeof(struct rtc_time));
cmos_read_alarm(dev, &cmos->saved_wkalrm);
dev_dbg(dev, "suspend%s, ctrl %02x\n",
@@ -1054,6 +1055,7 @@ static void cmos_check_wkalrm(struct device *dev)
return;
}
+ memset(¤t_alarm.time, -1, sizeof(struct rtc_time));
cmos_read_alarm(dev, ¤t_alarm);
t_current_expires = rtc_tm_to_time64(¤t_alarm.time);
t_saved_expires = rtc_tm_to_time64(&cmos->saved_wkalrm.time);
--
2.28.0.236.gb10cc79966-goog
next reply other threads:[~2020-08-13 5:42 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-13 5:41 Victor Ding [this message]
2020-08-13 7:33 ` [PATCH] rtc: cmos: initialize rtc time when reading alarm Alexandre Belloni
2020-08-14 6:10 ` Victor Ding
2020-08-14 8:15 ` Alexandre Belloni
2020-08-14 8:56 ` Victor Ding
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