linux-kernel - [PATCH v3 09/10] rtc: mt6397: fix alarm register overwrite

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 3 May 2019 17:31:16 +0800
From:   Hsin-Hsiung Wang <hsin-hsiung.wang@...iatek.com>
To:     Lee Jones <lee.jones@...aro.org>, Rob Herring <robh+dt@...nel.org>,
        Mark Brown <broonie@...nel.org>,
        Matthias Brugger <matthias.bgg@...il.com>
CC:     Liam Girdwood <lgirdwood@...il.com>,
        Mark Rutland <mark.rutland@....com>,
        Eddie Huang <eddie.huang@...iatek.com>,
        Sean Wang <sean.wang@...iatek.com>,
        Alessandro Zummo <a.zummo@...ertech.it>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>,
        Hsin-Hsiung Wang <hsin-hsiung.wang@...iatek.com>,
        <devicetree@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-mediatek@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <linux-rtc@...r.kernel.org>,
        <srv_heupstream@...iatek.com>, Ran Bi <ran.bi@...iatek.com>
Subject: [PATCH v3 09/10] rtc: mt6397: fix alarm register overwrite

From: Ran Bi <ran.bi@...iatek.com>

Alarm registers high byte was reserved for other functions.
This add mask in alarm registers operation functions.
This also fix error condition in interrupt handler.

Fixes: fc2979118f3f ("rtc: mediatek: Add MT6397 RTC driver")

Signed-off-by: Ran Bi <ran.bi@...iatek.com>
---
 drivers/rtc/rtc-mt6397.c | 47 ++++++++++++++++++++++++++++------------
 1 file changed, 33 insertions(+), 14 deletions(-)

diff --git a/drivers/rtc/rtc-mt6397.c b/drivers/rtc/rtc-mt6397.c
index e9a25ec4d434..f85f1fc29e32 100644
--- a/drivers/rtc/rtc-mt6397.c
+++ b/drivers/rtc/rtc-mt6397.c
@@ -55,6 +55,14 @@
 
 #define RTC_AL_SEC		0x0018
 
+#define RTC_AL_SEC_MASK		0x003f
+#define RTC_AL_MIN_MASK		0x003f
+#define RTC_AL_HOU_MASK		0x001f
+#define RTC_AL_DOM_MASK		0x001f
+#define RTC_AL_DOW_MASK		0x0007
+#define RTC_AL_MTH_MASK		0x000f
+#define RTC_AL_YEA_MASK		0x007f
+
 #define RTC_PDN2		0x002e
 #define RTC_PDN2_PWRON_ALARM	BIT(4)
 
@@ -111,7 +119,7 @@ static irqreturn_t mtk_rtc_irq_handler_thread(int irq, void *data)
 		irqen = irqsta & ~RTC_IRQ_EN_AL;
 		mutex_lock(&rtc->lock);
 		if (regmap_write(rtc->regmap, rtc->addr_base + RTC_IRQ_EN,
-				 irqen) < 0)
+				 irqen) == 0)
 			mtk_rtc_write_trigger(rtc);
 		mutex_unlock(&rtc->lock);
 
@@ -233,12 +241,12 @@ static int mtk_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 	alm->pending = !!(pdn2 & RTC_PDN2_PWRON_ALARM);
 	mutex_unlock(&rtc->lock);
 
-	tm->tm_sec = data[RTC_OFFSET_SEC];
-	tm->tm_min = data[RTC_OFFSET_MIN];
-	tm->tm_hour = data[RTC_OFFSET_HOUR];
-	tm->tm_mday = data[RTC_OFFSET_DOM];
-	tm->tm_mon = data[RTC_OFFSET_MTH];
-	tm->tm_year = data[RTC_OFFSET_YEAR];
+	tm->tm_sec = data[RTC_OFFSET_SEC] & RTC_AL_SEC_MASK;
+	tm->tm_min = data[RTC_OFFSET_MIN] & RTC_AL_MIN_MASK;
+	tm->tm_hour = data[RTC_OFFSET_HOUR] & RTC_AL_HOU_MASK;
+	tm->tm_mday = data[RTC_OFFSET_DOM] & RTC_AL_DOM_MASK;
+	tm->tm_mon = data[RTC_OFFSET_MTH] & RTC_AL_MTH_MASK;
+	tm->tm_year = data[RTC_OFFSET_YEAR] & RTC_AL_YEA_MASK;
 
 	tm->tm_year += RTC_MIN_YEAR_OFFSET;
 	tm->tm_mon--;
@@ -259,14 +267,25 @@ static int mtk_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 	tm->tm_year -= RTC_MIN_YEAR_OFFSET;
 	tm->tm_mon++;
 
-	data[RTC_OFFSET_SEC] = tm->tm_sec;
-	data[RTC_OFFSET_MIN] = tm->tm_min;
-	data[RTC_OFFSET_HOUR] = tm->tm_hour;
-	data[RTC_OFFSET_DOM] = tm->tm_mday;
-	data[RTC_OFFSET_MTH] = tm->tm_mon;
-	data[RTC_OFFSET_YEAR] = tm->tm_year;
-
 	mutex_lock(&rtc->lock);
+	ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_AL_SEC,
+			       data, RTC_OFFSET_COUNT);
+	if (ret < 0)
+		goto exit;
+
+	data[RTC_OFFSET_SEC] = ((data[RTC_OFFSET_SEC] & ~(RTC_AL_SEC_MASK)) |
+				(tm->tm_sec & RTC_AL_SEC_MASK));
+	data[RTC_OFFSET_MIN] = ((data[RTC_OFFSET_MIN] & ~(RTC_AL_MIN_MASK)) |
+				(tm->tm_min & RTC_AL_MIN_MASK));
+	data[RTC_OFFSET_HOUR] = ((data[RTC_OFFSET_HOUR] & ~(RTC_AL_HOU_MASK)) |
+				(tm->tm_hour & RTC_AL_HOU_MASK));
+	data[RTC_OFFSET_DOM] = ((data[RTC_OFFSET_DOM] & ~(RTC_AL_DOM_MASK)) |
+				(tm->tm_mday & RTC_AL_DOM_MASK));
+	data[RTC_OFFSET_MTH] = ((data[RTC_OFFSET_MTH] & ~(RTC_AL_MTH_MASK)) |
+				(tm->tm_mon & RTC_AL_MTH_MASK));
+	data[RTC_OFFSET_YEAR] = ((data[RTC_OFFSET_YEAR] & ~(RTC_AL_YEA_MASK)) |
+				(tm->tm_year & RTC_AL_YEA_MASK));
+
 	if (alm->enabled) {
 		ret = regmap_bulk_write(rtc->regmap,
 					rtc->addr_base + RTC_AL_SEC,
-- 
2.18.0