[PATCH] driver/rtc/class.c: check the error after rtc_read_time()

From: Hyogi Gim
Date: Tue Jul 15 2014 - 04:27:26 EST


In rtc_suspend() and rtc_resume(), the error after rtc_read_time() is not
checked. If rtc device fail to read time, we cannot guarantee the following
process.

Add the verification code for returned rtc_read_time() error.

Signed-off-by: Hyogi Gim <hyogi.gim@xxxxxxx>
---
drivers/rtc/class.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c
index 589351e..38e26be 100644
--- a/drivers/rtc/class.c
+++ b/drivers/rtc/class.c
@@ -53,6 +53,7 @@ static int rtc_suspend(struct device *dev)
struct rtc_device *rtc = to_rtc_device(dev);
struct rtc_time tm;
struct timespec delta, delta_delta;
+ int err;

if (has_persistent_clock())
return 0;
@@ -61,7 +62,12 @@ static int rtc_suspend(struct device *dev)
return 0;

/* snapshot the current RTC and system time at suspend*/
- rtc_read_time(rtc, &tm);
+ err = rtc_read_time(rtc, &tm);
+ if (err < 0) {
+ pr_debug("%s: fail to read rtc time\n", dev_name(&rtc->dev));
+ return 0;
+ }
+
getnstimeofday(&old_system);
rtc_tm_to_time(&tm, &old_rtc.tv_sec);

@@ -94,6 +100,7 @@ static int rtc_resume(struct device *dev)
struct rtc_time tm;
struct timespec new_system, new_rtc;
struct timespec sleep_time;
+ int err;

if (has_persistent_clock())
return 0;
@@ -104,7 +111,12 @@ static int rtc_resume(struct device *dev)

/* snapshot the current rtc and system time at resume */
getnstimeofday(&new_system);
- rtc_read_time(rtc, &tm);
+ err = rtc_read_time(rtc, &tm);
+ if (err < 0) {
+ pr_debug("%s: fail to read rtc time\n", dev_name(&rtc->dev));
+ return 0;
+ }
+
if (rtc_valid_tm(&tm) != 0) {
pr_debug("%s: bogus resume time\n", dev_name(&rtc->dev));
return 0;
--
1.8.3.2

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