linux-stable.git/kernel/time/time.c, branch v4.12.2

time: delete current_fs_time()

2017-05-12T22:57:15+00:00

All uses of the current_fs_time() function have been replaced by other
time interfaces.

And, its use cases can be fulfilled by current_time() or ktime_get_*
variants.

Link: http://lkml.kernel.org/r/1491613030-11599-13-git-send-email-deepa.kernel@gmail.com
Signed-off-by: Deepa Dinamani 
Reviewed-by: Arnd Bergmann 
Cc: John Stultz 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

time: Delete do_sys_setimeofday()

2017-04-14T19:49:54+00:00

struct timespec is not y2038 safe on 32 bit machines and needs to be
replaced with struct timespec64.

do_sys_timeofday() is just a wrapper function.  Replace all calls to this
function with direct calls to do_sys_timeofday64() instead and delete
do_sys_timeofday().

Signed-off-by: Deepa Dinamani 
Cc: y2038@lists.linaro.org
Cc: john.stultz@linaro.org
Cc: arnd@arndb.de
Cc: linux-alpha@vger.kernel.org
Link: http://lkml.kernel.org/r/1490555058-4603-2-git-send-email-deepa.kernel@gmail.com
Signed-off-by: Thomas Gleixner

time: Introduce jiffies64_to_nsecs()

2017-02-01T08:13:45+00:00

This will be needed for the cputime_t to nsec conversion.

Signed-off-by: Frederic Weisbecker 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Michael Ellerman 
Cc: Heiko Carstens 
Cc: Martin Schwidefsky 
Cc: Tony Luck 
Cc: Fenghua Yu 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Cc: Stanislaw Gruszka 
Cc: Wanpeng Li 
Link: http://lkml.kernel.org/r/1485832191-26889-2-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar

Replace with globally

2016-12-24T19:46:01+00:00

This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*'
  sed -i -e "s!$PATT!#include !" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro 
Signed-off-by: Linus Torvalds

time: Avoid undefined behaviour in timespec64_add_safe()

2016-08-31T21:43:35+00:00

I ran into this:

    ================================================================================
    UBSAN: Undefined behaviour in kernel/time/time.c:783:2
    signed integer overflow:
    5273 + 9223372036854771711 cannot be represented in type 'long int'
    CPU: 0 PID: 17363 Comm: trinity-c0 Not tainted 4.8.0-rc1+ #88
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org
    04/01/2014
     0000000000000000 ffff88011457f8f0 ffffffff82344f50 0000000041b58ab3
     ffffffff84f98080 ffffffff82344ea4 ffff88011457f918 ffff88011457f8c8
     ffff88011457f8e0 7fffffffffffefff ffff88011457f6d8 dffffc0000000000
    Call Trace:
     [] dump_stack+0xac/0xfc
     [] ? _atomic_dec_and_lock+0xc4/0xc4
     [] ubsan_epilogue+0xd/0x8a
     [] handle_overflow+0x202/0x23d
     [] ? val_to_string.constprop.6+0x11e/0x11e
     [] ? debug_smp_processor_id+0x17/0x20
     [] ? __sigqueue_free.part.13+0x51/0x70
     [] ? rcu_is_watching+0x110/0x110
     [] __ubsan_handle_add_overflow+0xe/0x10
     [] timespec64_add_safe+0x298/0x340
     [] ? timespec_add_safe+0x330/0x330
     [] ? wait_noreap_copyout+0x1d0/0x1d0
     [] poll_select_set_timeout+0xf8/0x170
     [] ? poll_schedule_timeout+0x2b0/0x2b0
     [] ? __might_sleep+0x5b/0x260
     [] __sys_recvmmsg+0x107/0x790
     [] ? SyS_recvmsg+0x20/0x20
     [] ? hrtimer_start_range_ns+0x3b8/0x1380
     [] ? _raw_spin_unlock_irqrestore+0x3b/0x60
     [] ? do_setitimer+0x39a/0x8e0
     [] ? __might_sleep+0x5b/0x260
     [] ? __sys_recvmmsg+0x790/0x790
     [] SyS_recvmmsg+0xd9/0x160
     [] ? __sys_recvmmsg+0x790/0x790
     [] ? __this_cpu_preempt_check+0x13/0x20
     [] ? __context_tracking_exit.part.3+0x30/0x1b0
     [] ? __sys_recvmmsg+0x790/0x790
     [] do_syscall_64+0x1b3/0x4b0
     [] entry_SYSCALL64_slow_path+0x25/0x25
    ================================================================================

Line 783 is this:

783         set_normalized_timespec64(&res, lhs.tv_sec + rhs.tv_sec,
784                         lhs.tv_nsec + rhs.tv_nsec);

In other words, since lhs.tv_sec and rhs.tv_sec are both time64_t, this
is a signed addition which will cause undefined behaviour on overflow.

Note that this is not currently a huge concern since the kernel should be
built with -fno-strict-overflow by default, but could be a problem in the
future, a problem with older compilers, or other compilers than gcc.

The easiest way to avoid the overflow is to cast one of the arguments to
unsigned (so the addition will be done using unsigned arithmetic).

Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Richard Cochran 
Cc: Prarit Bhargava 
Signed-off-by: Vegard Nossum 
Signed-off-by: John Stultz

time: remove timespec_add_safe()

2016-05-20T02:12:14+00:00

All references to timespec_add_safe() now use timespec64_add_safe().

The plan is to replace struct timespec references with struct timespec64
throughout the kernel as timespec is not y2038 safe.

Drop timespec_add_safe() and use timespec64_add_safe() for all
architectures.

Link: http://lkml.kernel.org/r/1461947989-21926-4-git-send-email-deepa.kernel@gmail.com
Signed-off-by: Deepa Dinamani 
Acked-by: John Stultz 
Cc: Thomas Gleixner 
Cc: Arnd Bergmann 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

time: add missing implementation for timespec64_add_safe()

2016-05-20T02:12:14+00:00

timespec64_add_safe() has been defined in time64.h for 64 bit systems.
But, 32 bit systems only have an extern function prototype defined.
Provide a definition for the above function.

The function will be necessary as part of y2038 changes.  struct
timespec is not y2038 safe.  All references to timespec will be replaced
by struct timespec64.  The function is meant to be a replacement for
timespec_add_safe().

The implementation is similar to timespec_add_safe().

Link: http://lkml.kernel.org/r/1461947989-21926-2-git-send-email-deepa.kernel@gmail.com
Signed-off-by: Deepa Dinamani 
Acked-by: John Stultz 
Cc: Thomas Gleixner 
Cc: Arnd Bergmann 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

time: Introduce do_sys_settimeofday64()

2016-04-22T18:49:04+00:00

The do_sys_settimeofday() function uses a timespec, which is not year
2038 safe on 32bit systems.

Thus this patch introduces do_sys_settimeofday64(), which allows us to
transition users of do_sys_settimeofday() to using 64bit time types.

Cc: Prarit Bhargava 
Cc: Richard Cochran 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Signed-off-by: Baolin Wang 
[jstultz: Include errno-base.h to avoid build issue on some arches]
Signed-off-by: John Stultz

Handle ISO 8601 leap seconds and encodings of midnight in mktime64()

2016-02-29T14:29:40+00:00

Handle the following ISO 8601 features in mktime64():

 (1) Leap seconds.

     Leap seconds are indicated by the seconds parameter being the value
     60.  Handle this by treating it the same as 00 of the following
     minute.

     It has been pointed out that a minute may contain two leap seconds.
     However, pending discussion of what that looks like and how to handle
     it, I'm not going to concern myself with it.

 (2) Alternate encodings of midnight.

     Two different encodings of midnight are permitted - 00:00:00 and
     24:00:00 - the first is midnight today and the second is midnight
     tomorrow and is exactly equivalent to the first with tomorrow's date.

As it happens, we don't actually need to change mktime64() to handle either
of these - just comment them as valid parameters.

These facility will be used by the X.509 parser.  Doing it in mktime64()
makes the policy common to the whole kernel and easier to find.

Signed-off-by: David Howells 
Acked-by: Arnd Bergmann 
cc: John Stultz 
cc: Rudolf Polzer 
cc: One Thousand Gnomes

Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-09-01T21:04:50+00:00

Pull timer updates from Thomas Gleixner:
 "Rather large, but nothing exiting:

   - new range check for settimeofday() to prevent that boot time
     becomes negative.
   - fix for file time rounding
   - a few simplifications of the hrtimer code
   - fix for the proc/timerlist code so the output of clock realtime
     timers is accurate
   - more y2038 work
   - tree wide conversion of clockevent drivers to the new callbacks"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (88 commits)
  hrtimer: Handle failure of tick_init_highres() gracefully
  hrtimer: Unconfuse switch_hrtimer_base() a bit
  hrtimer: Simplify get_target_base() by returning current base
  hrtimer: Drop return code of hrtimer_switch_to_hres()
  time: Introduce timespec64_to_jiffies()/jiffies_to_timespec64()
  time: Introduce current_kernel_time64()
  time: Introduce struct itimerspec64
  time: Add the common weak version of update_persistent_clock()
  time: Always make sure wall_to_monotonic isn't positive
  time: Fix nanosecond file time rounding in timespec_trunc()
  timer_list: Add the base offset so remaining nsecs are accurate for non monotonic timers
  cris/time: Migrate to new 'set-state' interface
  kernel: broadcast-hrtimer: Migrate to new 'set-state' interface
  xtensa/time: Migrate to new 'set-state' interface
  unicore/time: Migrate to new 'set-state' interface
  um/time: Migrate to new 'set-state' interface
  sparc/time: Migrate to new 'set-state' interface
  sh/localtimer: Migrate to new 'set-state' interface
  score/time: Migrate to new 'set-state' interface
  s390/time: Migrate to new 'set-state' interface
  ...