user/sven/linux.git/kernel/time/hrtimer.c, branch v4.1.15

ktime: Fix ktime_divns to do signed division

2015-05-13T08:19:35Z

It was noted that the 32bit implementation of ktime_divns() was doing unsigned division and didn't properly handle negative values. And when a ktime helper was changed to utilize ktime_divns, it caused a regression on some IR blasters. See the following bugzilla for details: https://bugzilla.redhat.com/show_bug.cgi?id=1200353 This patch fixes the problem in ktime_divns by checking and preserving the sign bit, and then reapplying it if appropriate after the division, it also changes the return type to a s64 to make it more obvious this is expected. Nicolas also pointed out that negative dividers would cause infinite loops on 32bit systems, negative dividers is unlikely for users of this function, but out of caution this patch adds checks for negative dividers for both 32-bit (BUG_ON) and 64-bit(WARN_ON) versions to make sure no such use cases creep in. [ tglx: Hand an u64 to do_div() to avoid the compiler warning ] Fixes: 166afb64511e 'ktime: Sanitize ktime_to_us/ms conversion' Reported-and-tested-by: Trevor Cordes Signed-off-by: John Stultz Acked-by: Nicolas Pitre Cc: Ingo Molnar Cc: Josh Boyer Cc: One Thousand Gnomes Cc: Link: http://lkml.kernel.org/r/1431118043-23452-1-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner

clockevents: Cleanup dead cpu explicitely

2015-04-03T06:44:37Z

clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the cleanup function for a dead cpu and invoke it directly from the cpu down code. Make it conditional on CPU_HOTPLUG as well. Temporary change, will be refined in the future. Signed-off-by: Thomas Gleixner [ Rebased, added clockevents_notify() removal ] Signed-off-by: Rafael J. Wysocki Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1735025.raBZdQHM3m@vostro.rjw.lan Signed-off-by: Ingo Molnar

clockevents: Make tick handover explicit

2015-04-03T06:44:36Z

clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the tick_handover call and invoke it explicitely from the hotplug code. Temporary solution will be cleaned up in later patches. Signed-off-by: Thomas Gleixner [ Rebase ] Signed-off-by: Rafael J. Wysocki Cc: Peter Zijlstra Cc: John Stultz Cc: Linus Torvalds Cc: Andrew Morton Link: http://lkml.kernel.org/r/1658173.RkEEILFiQZ@vostro.rjw.lan Signed-off-by: Ingo Molnar

tick: Move core only declarations and functions to core

2015-04-01T12:22:58Z

No point to expose everything to the world. People just believe such functions can be abused for whatever purposes. Sigh. Signed-off-by: Thomas Gleixner [ Rebased on top of 4.0-rc5 ] Signed-off-by: Rafael J. Wysocki Cc: Nicolas Pitre Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/28017337.VbCUc39Gme@vostro.rjw.lan [ Merged to latest timers/core ] Signed-off-by: Ingo Molnar

all arches, signal: move restart_block to struct task_struct

2015-02-13T02:54:12Z

If an attacker can cause a controlled kernel stack overflow, overwriting the restart block is a very juicy exploit target. This is because the restart_block is held in the same memory allocation as the kernel stack. Moving the restart block to struct task_struct prevents this exploit by making the restart_block harder to locate. Note that there are other fields in thread_info that are also easy targets, at least on some architectures. It's also a decent simplification, since the restart code is more or less identical on all architectures. [james.hogan@imgtec.com: metag: align thread_info::supervisor_stack] Signed-off-by: Andy Lutomirski Cc: Thomas Gleixner Cc: Al Viro Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Kees Cook Cc: David Miller Acked-by: Richard Weinberger Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Vineet Gupta Cc: Russell King Cc: Catalin Marinas Cc: Will Deacon Cc: Haavard Skinnemoen Cc: Hans-Christian Egtvedt Cc: Steven Miao Cc: Mark Salter Cc: Aurelien Jacquiot Cc: Mikael Starvik Cc: Jesper Nilsson Cc: David Howells Cc: Richard Kuo Cc: "Luck, Tony" Cc: Geert Uytterhoeven Cc: Michal Simek Cc: Ralf Baechle Cc: Jonas Bonn Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Acked-by: Michael Ellerman (powerpc) Tested-by: Michael Ellerman (powerpc) Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Chen Liqin Cc: Lennox Wu Cc: Chris Metcalf Cc: Guan Xuetao Cc: Chris Zankel Cc: Max Filippov Cc: Oleg Nesterov Cc: Guenter Roeck Signed-off-by: James Hogan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

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

2015-02-10T00:33:07Z

Pull timer updates from Ingo Molnar: "The main changes in this cycle were: - rework hrtimer expiry calculation in hrtimer_interrupt(): the previous code had a subtle bug where expiry caching would miss an expiry, resulting in occasional bogus (late) expiry of hrtimers. - continuing Y2038 fixes - ktime division optimization - misc smaller fixes and cleanups" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: hrtimer: Make __hrtimer_get_next_event() static rtc: Convert rtc_set_ntp_time() to use timespec64 rtc: Remove redundant rtc_valid_tm() from rtc_hctosys() rtc: Modify rtc_hctosys() to address y2038 issues rtc: Update rtc-dev to use y2038-safe time interfaces rtc: Update interface.c to use y2038-safe time interfaces time: Expose get_monotonic_boottime64 for in-kernel use time: Expose getboottime64 for in-kernel uses ktime: Optimize ktime_divns for constant divisors hrtimer: Prevent stale expiry time in hrtimer_interrupt() ktime.h: Introduce ktime_ms_delta

hrtimer: Fix incorrect tai offset calculation for non high-res timer systems

2015-02-05T07:39:37Z

I noticed some CLOCK_TAI timer test failures on one of my less-frequently used configurations. And after digging in I found in 76f4108892d9 (Cleanup hrtimer accessors to the timekepeing state), the hrtimer_get_softirq_time tai offset calucation was incorrectly rewritten, as the tai offset we return shold be from CLOCK_MONOTONIC, and not CLOCK_REALTIME. This results in CLOCK_TAI timers expiring early on non-highres capable machines. This patch fixes the issue, calculating the tai time properly from the monotonic base. Signed-off-by: John Stultz Cc: Thomas Gleixner Cc: stable # 3.17+ Link: http://lkml.kernel.org/r/1423097126-10236-1-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar

hrtimer: Make __hrtimer_get_next_event() static

2015-01-24T09:53:36Z

kernel/time/hrtimer.c:444:9: sparse: symbol '__hrtimer_get_next_event' was not declared. Should it be static? Fixes: 9bc7491906b4 hrtimer: Prevent stale expiry time in hrtimer_interrupt() Signed-off-by: Fengguang Wu Cc: kbuild-all@01.org Link: http://lkml.kernel.org/r/20150123121206.GA4766@snb Signed-off-by: Thomas Gleixner

Merge tag 'fortglx-3.20-time' of https://git.linaro.org/people/john.stultz/linux into timers/core

2015-01-24T09:11:12Z

Pull time updates from John Stultz for 3.20: * ktime division optimization * Expose a few more y2038-safe timekeeping interfaces * RTC core changes to address y2038

ktime: Optimize ktime_divns for constant divisors

2015-01-24T01:21:31Z

At least on ARM, do_div() is optimized to turn constant divisors into an inline multiplication by the reciprocal value at compile time. However this optimization is missed entirely whenever ktime_divns() is used and the slow out-of-line division code is used all the time. Let ktime_divns() use do_div() inline whenever the divisor is constant and small enough. This will make things like ktime_to_us() and ktime_to_ms() much faster. Cc: Arnd Bergmann Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Nicolas Pitre Acked-by: Arnd Bergmann Signed-off-by: Nicolas Pitre Signed-off-by: John Stultz