linux-stable.git/drivers/rtc/interface.c, branch v3.18.136

rtc: ensure rtc_set_alarm fails when alarms are not supported

2018-08-09T10:20:25+00:00

[ Upstream commit abfdff44bc38e9e2ef7929f633fb8462632299d4 ]

When using RTC_ALM_SET or RTC_WKALM_SET with rtc_wkalrm.enabled not set,
rtc_timer_enqueue() is not called and rtc_set_alarm() may succeed but the
subsequent RTC_AIE_ON ioctl will fail. RTC_ALM_READ would also fail in that
case.

Ensure rtc_set_alarm() fails when alarms are not supported to avoid letting
programs think the alarms are working for a particular RTC when they are
not.

Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

rtc: interface: Validate alarm-time before handling rollover

2018-04-13T17:52:16+00:00

[ Upstream commit da96aea0ed177105cb13ee83b328f6c61e061d3f ]

In function __rtc_read_alarm() its possible for an alarm time-stamp to
be invalid even after replacing missing components with current
time-stamp. The condition 'alarm->time.tm_year < 70' will trigger this
case and will cause the call to 'rtc_tm_to_time64(&alarm->time)'
return a negative value for variable t_alm.

While handling alarm rollover this negative t_alm (assumed to seconds
offset from '1970-01-01 00:00:00') is converted back to rtc_time via
rtc_time64_to_tm() which results in this error log with seemingly
garbage values:

"rtc rtc0: invalid alarm value: -2-1--1041528741
2005511117:71582844:32"

This error was generated when the rtc driver (rtc-opal in this case)
returned an alarm time-stamp of '00-00-00 00:00:00' to indicate that
the alarm is disabled. Though I have submitted a separate fix for the
rtc-opal driver, this issue may potentially impact other
existing/future rtc drivers.

To fix this issue the patch validates the alarm time-stamp just after
filling up the missing datetime components and if rtc_valid_tm() still
reports it to be invalid then bails out of the function without
handling the rollover.

Reported-by: Steve Best 
Signed-off-by: Vaibhav Jain 
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

drivers/rtc/interface.c: check the error after __rtc_read_time()

2014-08-08T22:57:19+00:00

In __rtc_set_alarm(), 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 
Acked-by: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

drivers/rtc/interface.c: fix infinite loop in initializing the alarm

2014-06-06T23:08:06+00:00

In __rtc_read_alarm(), if the alarm time retrieved by
rtc_read_alarm_internal() from the device contains invalid values (e.g.
month=2,mday=31) and the year not set (=-1), the initialization will
loop infinitely because the year-fixing loop expects the time being
invalid due to leap year.

Fix reduces the loop to the leap years and adds final validity check.

Signed-off-by: Ales Novak 
Acked-by: Alessandro Zummo 
Reported-by: Jiri Bohac 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rtc: verify a critical argument to rtc_update_irq() before using it

2014-04-03T23:21:22+00:00

This small addition to the core simplifies code in the drivers and makes
them more robust when handling shared IRQs.

Signed-off-by: Alessandro Zummo 
Cc: Alexander Shiyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rtc: Keep system awake until all expired RTC timers are handled

2013-07-22T16:38:25+00:00

Current implementation of RTC interface allows for system suspend to
occur in the following cases:
(a) if a timer is set in the past and rtc_timer_do_work() is scheduled
to handle it, and
(b) if rtc_timer_do_work() is called to handle expired timers whose
handlers implement a preemption point.

A pending suspend request may be honoured in the above cases causing
timer handling to be delayed until after the next resume. This is
undesirable since timer handlers may have time-critical code to execute.

This patch makes sure that the system stays awake until all expired
timers are handled.

Note that all calls to pm_stay_awake() are eventually paired with
the single pm_relax() call in rtc_timer_do_work(), which is launched
using schedule_work().

Cc: Alessandro Zummo 
Cc: John Stultz 
Cc: Arve Hjonnevag 
Cc: Todd Poynor 
Signed-off-by: Zoran Markovic 
Signed-off-by: John Stultz

drivers/rtc/interface.c: return -EBUSY, not -EACCES when device is busy

2013-07-03T23:08:00+00:00

If rtc->irq_task is non-NULL and task is NULL, they always
rtc_irq_set_freq(), whenever err is set to -EBUSY it will then immediately
be set to -EACCES, misleading the caller as to the underlying problem.

Signed-off-by: Chris Brand 
Acked-by: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

drivers/rtc/interface.c: fix checkpatch errors

2013-07-03T23:07:46+00:00

Fixes the following types of errors:
  ERROR: "foo* bar" should be "foo *bar"
  ERROR: else should follow close brace '}'
  WARNING: braces {} are not necessary for single statement blocks

Signed-off-by: Sachin Kamat 
Cc: Jingoo Han 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

driver-core: constify data for class_find_device()

2013-02-06T20:18:56+00:00

All in-kernel users of class_find_device() don't really need mutable
data for match callback.

In two places (kernel/power/suspend_test.c, drivers/scsi/osd/osd_uld.c)
this patch changes match callbacks to use const search data.

The const is propagated to rtc_class_open() and power_supply_get_by_name()
parameters.

Note that there's a dev reference leak in suspend_test.c that's not
touched in this patch.

Signed-off-by: Michał Mirosław 
Acked-by: Grant Likely 
Signed-off-by: Greg Kroah-Hartman

RTC: Avoid races between RTC alarm wakeup and suspend.

2012-08-08T18:49:16+00:00

If an RTC alarm fires just as suspend is happening, it is possible for
suspend to complete and the alarm to be missed.

To avoid the race, we must register the event with the PM core.

As the event is made visible to userspace through a thread which is
only scheduled by the interrupt, we need a pm_stay_awake/pm_relax
pair preventing suspend from the interrupt until the thread completes
its work.

This makes the pm_wakeup_event() call in cmos_interrupt unnecessary as
it provides suspend protection for all RTCs that use rtc_update_irq.

Signed-off-by: NeilBrown 
Signed-off-by: Rafael J. Wysocki