From d14a8e605afcf6e04f484e99b851b0823d8fb564 Mon Sep 17 00:00:00 2001 From: Hugo Villeneuve Date: Wed, 17 Aug 2022 10:58:11 +0800 Subject: [PATCH] rtc: pcf2127: fix bug when reading alarm registers stable inclusion from stable-v5.10.118 commit c39b91fcd5e35b62da3dc649ad4d239ae50389cb category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5L686 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c39b91fcd5e35b62da3dc649ad4d239ae50389cb -------------------------------- [ Upstream commit 73ce05302007eece23a6acb7dc124c92a2209087 ] The first bug is that reading the 5 alarm registers results in a read operation of 20 bytes. The reason is because the destination buffer is defined as an array of "unsigned int", and we use the sizeof() operator on this array to define the bulk read count. The second bug is that the read value is invalid, because we are indexing the destination buffer as integers (4 bytes), instead of indexing it as u8. Changing the destination buffer type to u8 fixes both problems. Signed-off-by: Hugo Villeneuve Signed-off-by: Alexandre Belloni Link: https://lore.kernel.org/r/20220208162908.3182581-1-hugo@hugovil.com Signed-off-by: Sasha Levin Signed-off-by: Zheng Zengkai Acked-by: Xie XiuQi --- drivers/rtc/rtc-pcf2127.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c index f0a6861ff3ae..715513311ece 100644 --- a/drivers/rtc/rtc-pcf2127.c +++ b/drivers/rtc/rtc-pcf2127.c @@ -366,7 +366,8 @@ static int pcf2127_watchdog_init(struct device *dev, struct pcf2127 *pcf2127) static int pcf2127_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct pcf2127 *pcf2127 = dev_get_drvdata(dev); - unsigned int buf[5], ctrl2; + u8 buf[5]; + unsigned int ctrl2; int ret; ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL2, &ctrl2); -- GitLab