The current correction for leap years will fail in 3477. 3476-12-31 being
3477-01-00 because this is 366 leap years after 1970 and 3477 isn't a leap
year.
Fix that by looping over until days is positive or zero.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
If we convert one large time values to rtc_time, in the original formula
'days * 86400' can be overflowed in 'unsigned int' type to make the formula
get one incorrect remain seconds value. Thus we can use div_s64_rem()
function to avoid this situation.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
The Kconfig currently controlling compilation of this code is:
drivers/rtc/Kconfig:config RTC_LIB
drivers/rtc/Kconfig: bool
...meaning that it currently is not being built as a module by anyone.
Lets remove the couple traces of modular infrastructure use, so that
when reading the driver there is no doubt it is builtin-only.
We delete the MODULE_LICENSE tag since all that information
is already contained at the top of the file in the comments.
We don't replace module.h with init.h since the file doesn't need that.
However we do add export.h since the file uses EXPORT_SYMBOL.
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: rtc-linux@googlegroups.com
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
As part of addressing "y2038 problem" for in-kernel uses, this patch
adds safe rtc_tm_to_time64()/rtc_time64_to_tm() respectively using
time64_t.
After this patch, rtc_tm_to_time() is deprecated and all its call
sites will be fixed using corresponding safe versions, it can be
removed when having no users. Also change rtc_tm_to_time64() to
return time64_t directly instead of just as a parameter like
rtc_tm_to_time() does.
After this patch, rtc_time_to_tm() is deprecated and all its call
sites will be fixed using corresponding safe versions, it can be
removed when having no users.
In addition, change rtc_tm_to_ktime() and rtc_ktime_to_tm() to use
the safe version in passing.
Signed-off-by: pang.xunlei <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Even though the Linux kernel does not use the tm_isdst field, it is
exposed as part of the ABI. This field can accidentally be left
initialized, which is why we currently memset buffers returned to
userland in rtc_read_time.
There is a case however where the field can return garbage from the
stack though when using the RTC_ALM_READ ioctl on the rtc device. This
ioctl invokes rtc_read_alarm, which is careful to memset the rtc_wkalrm
buffer that is copied to userland, but it then uses a struct copy to
assign to alarm->time given the return value from rtc_ktime_to_tm().
rtc_ktime_to_tm() is implemented by calling rtc_time_to_tm using a
derivative seconds counds from ktime, but rtc_time_to_tm does not assign
a value to ->tm_isdst. This results in garbage from rtc_ktime_to_tm()'s
frame ending up being copied out to userland as part of the returned
rtc_wkalrm.
Fix this by initializing rtc_time->tm_isdst to 0 in rtc_time_to_tm.
Signed-off-by: Mike Waychison <mikew@google.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
This patch reworks a large portion of the generic RTC code
to in-effect virtualize the rtc interrupt code.
The current RTC interface is very much a raw hardware interface.
Via the proc, /dev/, or sysfs interfaces, applciations can set
the hardware to trigger interrupts in one of three modes:
AIE: Alarm interrupt
UIE: Update interrupt (ie: once per second)
PIE: Periodic interrupt (sub-second irqs)
The problem with this interface is that it limits the RTC hardware
so it can only be used by one application at a time.
The purpose of this patch is to extend the RTC code so that we can
multiplex multiple applications event needs onto a single RTC device.
This is done by utilizing the timerqueue infrastructure to manage
a list of events, which cause the RTC hardware to be programmed
to fire an interrupt for the next event in the list.
In order to preserve the functionality of the exsting proc,/dev/ and
sysfs interfaces, we emulate the different interrupt modes as follows:
AIE: We create a rtc_timer dedicated to AIE mode interrupts. There is
only one per device, so we don't change existing interface semantics.
UIE: Again, a dedicated rtc_timer, set for periodic mode, is used
to emulate UIE interrupts. Again, only one per device.
PIE: Since PIE mode interrupts fire faster then the RTC's clock read
granularity, we emulate PIE mode interrupts using a hrtimer. Again,
one per device.
With this patch, the rtctest.c application in Documentation/rtc.txt
passes fine on x86 hardware. However, there may very well still be
bugs, so greatly I'd appreciate any feedback or testing!
Signed-off-by: John Stultz <john.stultz@linaro.org>
LKML Reference: <1290136329-18291-4-git-send-email-john.stultz@linaro.org>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
CC: Alessandro Zummo <a.zummo@towertech.it>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Richard Cochran <richardcochran@gmail.com>
- the LEAP_YEAR macro is buggy - it references its arg multiple times.
Fix this by turning it into a C function.
- give it a more approriate name
- Move it to rtc.h so that other .c files can use it, instead of copying it.
Cc: dann frazier <dannf@hp.com>
Acked-by: Alessandro Zummo <alessandro.zummo@towertech.it>
Cc: stephane eranian <eranian@googlemail.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit 945185a69d ("rtc: rtc_time_to_tm: use
unsigned arithmetic") changed the some types in rtc_time_to_tm() to
unsigned:
void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
{
- register int days, month, year;
+ unsigned int days, month, year;
This doesn't work for all cases, because days is checked for < 0 later
on:
if (days < 0) {
year -= 1;
days += 365 + LEAP_YEAR(year);
}
I think the correct fix would be to keep days signed and do an appropriate
cast later on.
Signed-off-by: Jan Altenberg <jan.altenberg@linutronix.de>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The input argument to rtc_time_to_tm() is unsigned as well as are members of
the output structure. However signed arithmetic is used within for
calculations leading to incorrect results for input values outside the signed
positive range. If this happens the time of day returned is out of range.
Found the problem when fiddling with the RTC and the driver where year was set
to an unexpectedly large value like 2070, e.g.:
rtc0: setting system clock to 2070-01-01 1193046:71582832:26 UTC (3155760954)
while it should be:
rtc0: setting system clock to 2070-01-01 00:15:54 UTC (3155760954)
Changing types to unsigned fixes the problem.
[akpm@linux-foundation.org: remove old-fashioned `register' keyword]
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David says "884b4aaaa242a2db8c8252796f0118164a680ab5 should be reverted. It
added an rtc_merge_alarm() call to the 2.6.20 kernel, which hasn't yet been
used by any in-tree driver; this patch obviates the need for that call, and
uses a more robust approach."
Cc: Scott Wood <scottwood@freescale.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add rtc_merge_alarm(), which can be used by rtc drivers to turn a partially
specified alarm expiry (i.e. most significant fields set to -1, as with the
RTC_ALM_SET ioctl()) into a fully specified expiry.
If the most significant specified field is earlier than the current time, the
least significant unspecified field is incremented.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The rtc_is_valid_tm() routine needs to treat some of the fields it checks as
unsigned, to prevent wrongly accepting invalid rtc_time structs; this is the
same approach used elsewhere in the RTC code for such tests.
Conversely, rtc_proc_show() is missing one invalid-day-of-month test that
rtc_is_valid_tm() makes: there is no day zero.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
RTC: Add exported function rtc_year_days() to calculate the tm_yday value.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
