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2022-08-02wireguard: ratelimiter: use hrtimer in selftestJason A. Donenfeld1-0/+1
Using msleep() is problematic because it's compared against ratelimiter.c's ktime_get_coarse_boottime_ns(), which means on systems with slow jiffies (such as UML's forced HZ=100), the result is inaccurate. So switch to using schedule_hrtimeout(). However, hrtimer gives us access only to the traditional posix timers, and none of the _COARSE variants. So now, rather than being too imprecise like jiffies, it's too precise. One solution would be to give it a large "range" value, but this will still fire early on a loaded system. A better solution is to align the timeout to the actual coarse timer, and then round up to the nearest tick, plus change. So add the timeout to the current coarse time, and then schedule_hrtimer() until the absolute computed time. This should hopefully reduce flakes in CI as well. Note that we keep the retry loop in case the entire function is running behind, because the test could still be scheduled out, by either the kernel or by the hypervisor's kernel, in which case restarting the test and hoping to not be scheduled out still helps. Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-12hrtimer: Unbreak hrtimer_force_reprogram()Thomas Gleixner1-20/+20
Since the recent consoliation of reprogramming functions, hrtimer_force_reprogram() is affected by a check whether the new expiry time is past the current expiry time. This breaks the NOHZ logic as that relies on the fact that the tick hrtimer is moved into the future. That means cpu_base->expires_next becomes stale and subsequent reprogramming attempts fail as well until the situation is cleaned up by an hrtimer interrupts. For some yet unknown reason this leads to a complete stall, so for now partially revert the offending commit to a known working state. The root cause for the stall is still investigated and will be fixed in a subsequent commit. Fixes: b14bca97c9f5 ("hrtimer: Consolidate reprogramming code") Reported-by: Mike Galbraith <efault@gmx.de> Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Mike Galbraith <efault@gmx.de> Link: https://lore.kernel.org/r/8735recskh.ffs@tglx
2021-08-12hrtimer: Use raw_cpu_ptr() in clock_was_set()Thomas Gleixner1-2/+3
clock_was_set() can be invoked from preemptible context. Use raw_cpu_ptr() to check whether high resolution mode is active or not. It does not matter whether the task migrates after acquiring the pointer. Fixes: e71a4153b7c2 ("hrtimer: Force clock_was_set() handling for the HIGHRES=n, NOHZ=y case") Reported-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/875ywacsmb.ffs@tglx
2021-08-10hrtimer: Avoid more SMP function calls in clock_was_set()Thomas Gleixner1-9/+65
By unconditionally updating the offsets there are more indicators whether the SMP function calls on clock_was_set() can be avoided: - When the offset update already happened on the remote CPU then the remote update attempt will yield the same seqeuence number and no IPI is required. - When the remote CPU is currently handling hrtimer_interrupt(). In that case the remote CPU will reevaluate the timer bases before reprogramming anyway, so nothing to do. - After updating it can be checked whether the first expiring timer in the affected clock bases moves before the first expiring (softirq) timer of the CPU. If that's not the case then sending the IPI is not required. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210713135158.887322464@linutronix.de
2021-08-10hrtimer: Avoid unnecessary SMP function calls in clock_was_set()Marcelo Tosatti1-2/+33
Setting of clocks triggers an unconditional SMP function call on all online CPUs to reprogram the clock event device. However, only some clocks have their offsets updated and therefore potentially require a reprogram. That's CLOCK_REALTIME and CLOCK_TAI and in the case of resume (delayed sleep time injection) also CLOCK_BOOTTIME. Instead of sending an IPI unconditionally, check each per CPU hrtimer base whether it has active timers in the affected clock bases which are indicated by the caller in the @bases argument of clock_was_set(). If that's not the case, skip the IPI and update the offsets remotely which ensures that any subsequently armed timers on the affected clocks are evaluated with the correct offsets. [ tglx: Adopted to the new bases argument, removed the softirq_active check, added comment, fixed up stale comment ] Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210713135158.787536542@linutronix.de
2021-08-10hrtimer: Add bases argument to clock_was_set()Thomas Gleixner1-2/+2
clock_was_set() unconditionaly invokes retrigger_next_event() on all online CPUs. This was necessary because that mechanism was also used for resume from suspend to idle which is not longer the case. The bases arguments allows the callers of clock_was_set() to hand in a mask which tells clock_was_set() which of the hrtimer clock bases are affected by the clock setting. This mask will be used in the next step to check whether a CPU base has timers queued on a clock base affected by the event and avoid the SMP function call if there are none. Add a @bases argument, provide defines for the active bases masking and fixup all callsites. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210713135158.691083465@linutronix.de
2021-08-10timekeeping: Distangle resume and clock-was-set eventsThomas Gleixner1-9/+6
Resuming timekeeping is a clock-was-set event and uses the clock-was-set notification mechanism. This is in the way of making the clock-was-set update for hrtimers selective so unnecessary IPIs are avoided when a CPU base does not have timers queued which are affected by the clock setting. Distangle it by invoking hrtimer_resume() on each unfreezing CPU and invoke the new timerfd_resume() function from timekeeping_resume() which is the only place where this is needed. Rename hrtimer_resume() to hrtimer_resume_local() to reflect the change. With this the clock_was_set*() functions are not longer required to IPI all CPUs unconditionally and can get some smarts to avoid them. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210713135158.488853478@linutronix.de
2021-08-10hrtimer: Force clock_was_set() handling for the HIGHRES=n, NOHZ=y caseThomas Gleixner1-28/+59
When CONFIG_HIGH_RES_TIMERS is disabled, but NOHZ is enabled then clock_was_set() is not doing anything. With HIGHRES=n the kernel relies on the periodic tick to update the clock offsets, but when NOHZ is enabled and active then CPUs which are in a deep idle sleep do not have a periodic tick which means the expiry of timers affected by clock_was_set() can be arbitrarily delayed up to the point where the CPUs are brought out of idle again. Make the clock_was_set() logic unconditionaly available so that idle CPUs are kicked out of idle to handle the update. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210713135158.288697903@linutronix.de
2021-08-10hrtimer: Ensure timerfd notification for HIGHRES=nThomas Gleixner1-16/+16
If high resolution timers are disabled the timerfd notification about a clock was set event is not happening for all cases which use clock_was_set_delayed() because that's a NOP for HIGHRES=n, which is wrong. Make clock_was_set_delayed() unconditially available to fix that. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210713135158.196661266@linutronix.de
2021-08-10hrtimer: Consolidate reprogramming codePeter Zijlstra1-43/+29
This code is mostly duplicated. The redudant store in the force reprogram case does no harm and the in hrtimer interrupt condition cannot be true for the force reprogram invocations. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210713135158.054424875@linutronix.de
2021-08-10hrtimer: Avoid double reprogramming in __hrtimer_start_range_ns()Thomas Gleixner1-7/+53
If __hrtimer_start_range_ns() is invoked with an already armed hrtimer then the timer has to be canceled first and then added back. If the timer is the first expiring timer then on removal the clockevent device is reprogrammed to the next expiring timer to avoid that the pending expiry fires needlessly. If the new expiry time ends up to be the first expiry again then the clock event device has to reprogrammed again. Avoid this by checking whether the timer is the first to expire and in that case, keep the timer on the current CPU and delay the reprogramming up to the point where the timer has been enqueued again. Reported-by: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210713135157.873137732@linutronix.de
2021-04-26Merge tag 'timers-core-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-9/+9
Pull timer updates from Thomas Gleixner: "The time and timers updates contain: Core changes: - Allow runtime power management when the clocksource is changed. - A correctness fix for clock_adjtime32() so that the return value on success is not overwritten by the result of the copy to user. - Allow late installment of broadcast clockevent devices which was broken because nothing switched them over to oneshot mode. This went unnoticed so far because clockevent devices used to be built in, but now people started to make them modular. - Debugfs related simplifications - Small cleanups and improvements here and there Driver changes: - The usual set of device tree binding updates for a wide range of drivers/devices. - The usual updates and improvements for drivers all over the place but nothing outstanding. - No new clocksource/event drivers. They'll come back next time" * tag 'timers-core-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) posix-timers: Preserve return value in clock_adjtime32() tick/broadcast: Allow late registered device to enter oneshot mode tick: Use tick_check_replacement() instead of open coding it time/timecounter: Mark 1st argument of timecounter_cyc2time() as const dt-bindings: timer: nuvoton,npcm7xx: Add wpcm450-timer clocksource/drivers/arm_arch_timer: Add __ro_after_init and __init clocksource/drivers/timer-ti-dm: Handle dra7 timer wrap errata i940 clocksource/drivers/timer-ti-dm: Prepare to handle dra7 timer wrap issue clocksource/drivers/dw_apb_timer_of: Add handling for potential memory leak clocksource/drivers/npcm: Add support for WPCM450 clocksource/drivers/sh_cmt: Don't use CMTOUT_IE with R-Car Gen2/3 clocksource/drivers/pistachio: Fix trivial typo clocksource/drivers/ingenic_ost: Fix return value check in ingenic_ost_probe() clocksource/drivers/timer-ti-dm: Add missing set_state_oneshot_stopped clocksource/drivers/timer-ti-dm: Fix posted mode status check order dt-bindings: timer: renesas,cmt: Document R8A77961 dt-bindings: timer: renesas,cmt: Add r8a779a0 CMT support clocksource/drivers/ingenic-ost: Add support for the JZ4760B clocksource/drivers/ingenic: Add support for the JZ4760 dt-bindings: timer: ingenic: Add compatible strings for JZ4760(B) ...
2021-03-22timekeeping, clocksource: Fix various typos in commentsIngo Molnar1-9/+9
Fix ~56 single-word typos in timekeeping & clocksource code comments. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: linux-kernel@vger.kernel.org
2021-03-16kernel, fs: Introduce and use set_restart_fn() and arch_set_restart_data()Oleg Nesterov1-1/+1
Preparation for fixing get_nr_restart_syscall() on X86 for COMPAT. Add a new helper which sets restart_block->fn and calls a dummy arch_set_restart_data() helper. Fixes: 609c19a385c8 ("x86/ptrace: Stop setting TS_COMPAT in ptrace code") Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210201174641.GA17871@redhat.com
2021-03-08hrtimer: Update softirq_expires_next correctly after __hrtimer_get_next_event()Anna-Maria Behnsen1-21/+39
hrtimer_force_reprogram() and hrtimer_interrupt() invokes __hrtimer_get_next_event() to find the earliest expiry time of hrtimer bases. __hrtimer_get_next_event() does not update cpu_base::[softirq_]_expires_next to preserve reprogramming logic. That needs to be done at the callsites. hrtimer_force_reprogram() updates cpu_base::softirq_expires_next only when the first expiring timer is a softirq timer and the soft interrupt is not activated. That's wrong because cpu_base::softirq_expires_next is left stale when the first expiring timer of all bases is a timer which expires in hard interrupt context. hrtimer_interrupt() does never update cpu_base::softirq_expires_next which is wrong too. That becomes a problem when clock_settime() sets CLOCK_REALTIME forward and the first soft expiring timer is in the CLOCK_REALTIME_SOFT base. Setting CLOCK_REALTIME forward moves the clock MONOTONIC based expiry time of that timer before the stale cpu_base::softirq_expires_next. cpu_base::softirq_expires_next is cached to make the check for raising the soft interrupt fast. In the above case the soft interrupt won't be raised until clock monotonic reaches the stale cpu_base::softirq_expires_next value. That's incorrect, but what's worse it that if the softirq timer becomes the first expiring timer of all clock bases after the hard expiry timer has been handled the reprogramming of the clockevent from hrtimer_interrupt() will result in an interrupt storm. That happens because the reprogramming does not use cpu_base::softirq_expires_next, it uses __hrtimer_get_next_event() which returns the actual expiry time. Once clock MONOTONIC reaches cpu_base::softirq_expires_next the soft interrupt is raised and the storm subsides. Change the logic in hrtimer_force_reprogram() to evaluate the soft and hard bases seperately, update softirq_expires_next and handle the case when a soft expiring timer is the first of all bases by comparing the expiry times and updating the required cpu base fields. Split this functionality into a separate function to be able to use it in hrtimer_interrupt() as well without copy paste. Fixes: 5da70160462e ("hrtimer: Implement support for softirq based hrtimers") Reported-by: Mikael Beckius <mikael.beckius@windriver.com> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Mikael Beckius <mikael.beckius@windriver.com> Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20210223160240.27518-1-anna-maria@linutronix.de
2020-12-14Merge tag 'timers-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-1/+1
Pull timers and timekeeping updates from Thomas Gleixner: "Core: - Robustness improvements for the NOHZ tick management - Fixes and consolidation of the NTP/RTC synchronization code - Small fixes and improvements in various places - A set of function documentation udpates and fixes Drivers: - Cleanups and improvements in various clocksoure/event drivers - Removal of the EZChip NPS clocksource driver as the platfrom support was removed from ARC - The usual set of new device tree binding and json conversions - The RTC driver which have been acked by the RTC maintainer: * fix a long standing bug in the MC146818 library code which can cause reading garbage during the RTC internal update. * changes related to the NTP/RTC consolidation work" * tag 'timers-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits) ntp: Fix prototype in the !CONFIG_GENERIC_CMOS_UPDATE case tick/sched: Make jiffies update quick check more robust ntp: Consolidate the RTC update implementation ntp: Make the RTC sync offset less obscure ntp, rtc: Move rtc_set_ntp_time() to ntp code ntp: Make the RTC synchronization more reliable rtc: core: Make the sync offset default more realistic rtc: cmos: Make rtc_cmos sync offset correct rtc: mc146818: Reduce spinlock section in mc146818_set_time() rtc: mc146818: Prevent reading garbage clocksource/drivers/sh_cmt: Fix potential deadlock when calling runtime PM clocksource/drivers/arm_arch_timer: Correct fault programming of CNTKCTL_EL1.EVNTI clocksource/drivers/arm_arch_timer: Use stable count reader in erratum sne clocksource/drivers/dw_apb_timer_of: Add error handling if no clock available clocksource/drivers/riscv: Make RISCV_TIMER depends on RISCV_SBI clocksource/drivers/ingenic: Fix section mismatch clocksource/drivers/cadence_ttc: Fix memory leak in ttc_setup_clockevent() dt-bindings: timer: renesas: tmu: Convert to json-schema dt-bindings: timer: renesas: tmu: Document r8a774e1 bindings clocksource/drivers/orion: Add missing clk_disable_unprepare() on error path ...
2020-11-16hrtimer: Fix kernel-doc markupsMauro Carvalho Chehab1-1/+1
The hrtimer_get_remaining() markup is documenting, instead, __hrtimer_get_remaining(), as it is placed at the C file. In order to properly document it, a kernel-doc markup is needed together with the function prototype. So, add a new one, while preserving the existing one, just fixing the function name. The hrtimer_is_queued prototype has a typo: it is using '=' instead of '-' to split: identifier - description as required by kernel-doc markup. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/9dc87808c2fd07b7e050bafcd033c5ef05808fea.1605521731.git.mchehab+huawei@kernel.org
2020-10-26hrtimer: Remove unused inline function debug_hrtimer_free()YueHaibing1-5/+0
There is no caller in tree, remove it. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20200909134850.21940-1-yuehaibing@huawei.com
2020-09-24treewide: Make all debug_obj_descriptors constStephen Boyd1-2/+2
This should make it harder for the kernel to corrupt the debug object descriptor, used to call functions to fixup state and track debug objects, by moving the structure to read-only memory. Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20200815004027.2046113-3-swboyd@chromium.org
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva1-1/+1
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-07-29hrtimer: Use sequence counter with associated raw spinlockAhmed S. Darwish1-3/+10
A sequence counter write side critical section must be protected by some form of locking to serialize writers. A plain seqcount_t does not contain the information of which lock must be held when entering a write side critical section. Use the new seqcount_raw_spinlock_t data type, which allows to associate a raw spinlock with the sequence counter. This enables lockdep to verify that the raw spinlock used for writer serialization is held when the write side critical section is entered. If lockdep is disabled this lock association is compiled out and has neither storage size nor runtime overhead. Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200720155530.1173732-25-a.darwish@linutronix.de
2020-04-01hrtimer: Don't dereference the hrtimer pointer after the callbackSebastian Andrzej Siewior1-2/+3
A hrtimer can be released in its callback, but lockdep_hrtimer_exit() dereferences the pointer after the callback returns, i.e. a potential use after free. Retrieve the context in which the hrtimer expires before the callback is invoked and use it in lockdep_hrtimer_exit(). Fixes: 40db173965c0 ("lockdep: Add hrtimer context tracing bits") Reported-by: syzbot+62c155c276e580cfb606@syzkaller.appspotmail.com Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200331201849.fkp2siy3vcdqvqlz@linutronix.de
2020-03-30Merge tag 'timers-core-2020-03-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-1/+1
Pull timekeeping and timer updates from Thomas Gleixner: "Core: - Consolidation of the vDSO build infrastructure to address the difficulties of cross-builds for ARM64 compat vDSO libraries by restricting the exposure of header content to the vDSO build. This is achieved by splitting out header content into separate headers. which contain only the minimaly required information which is necessary to build the vDSO. These new headers are included from the kernel headers and the vDSO specific files. - Enhancements to the generic vDSO library allowing more fine grained control over the compiled in code, further reducing architecture specific storage and preparing for adopting the generic library by PPC. - Cleanup and consolidation of the exit related code in posix CPU timers. - Small cleanups and enhancements here and there Drivers: - The obligatory new drivers: Ingenic JZ47xx and X1000 TCU support - Correct the clock rate of PIT64b global clock - setup_irq() cleanup - Preparation for PWM and suspend support for the TI DM timer - Expand the fttmr010 driver to support ast2600 systems - The usual small fixes, enhancements and cleanups all over the place" * tag 'timers-core-2020-03-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (80 commits) Revert "clocksource/drivers/timer-probe: Avoid creating dead devices" vdso: Fix clocksource.h macro detection um: Fix header inclusion arm64: vdso32: Enable Clang Compilation lib/vdso: Enable common headers arm: vdso: Enable arm to use common headers x86/vdso: Enable x86 to use common headers mips: vdso: Enable mips to use common headers arm64: vdso32: Include common headers in the vdso library arm64: vdso: Include common headers in the vdso library arm64: Introduce asm/vdso/processor.h arm64: vdso32: Code clean up linux/elfnote.h: Replace elf.h with UAPI equivalent scripts: Fix the inclusion order in modpost common: Introduce processor.h linux/ktime.h: Extract common header for vDSO linux/jiffies.h: Extract common header for vDSO linux/time64.h: Extract common header for vDSO linux/time32.h: Extract common header for vDSO linux/time.h: Extract common header for vDSO ...
2020-03-21lockdep: Add hrtimer context tracing bitsSebastian Andrzej Siewior1-1/+5
Set current->irq_config = 1 for hrtimers which are not marked to expire in hard interrupt context during hrtimer_init(). These timers will expire in softirq context on PREEMPT_RT. Setting this allows lockdep to differentiate these timers. If a timer is marked to expire in hard interrupt context then the timer callback is not supposed to acquire a regular spinlock instead of a raw_spinlock in the expiry callback. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200321113242.534508206@linutronix.de
2020-03-04hrtimer: Cast explicitely to u32t in __ktime_divns()Wen Yang1-1/+1
do_div() does a 64-by-32 division at least on 32bit platforms, while the divisor 'div' is explicitly casted to unsigned long, thus 64-bit on 64-bit platforms. The code already ensures that the divisor is less than 2^32. Hence the proper cast type is u32. Signed-off-by: Wen Yang <wenyang@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200130130851.29204-1-wenyang@linux.alibaba.com
2020-01-22hrtimer: Add missing sparse annotation for __run_timer()Jules Irenge1-1/+1
Sparse reports a warning at __run_hrtimer() |warning: context imbalance in __run_hrtimer() - unexpected unlock Add the missing must_hold() annotation. Signed-off-by: Jules Irenge <jbi.octave@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20200120224347.51843-1-jbi.octave@gmail.com
2020-01-14hrtimers: Prepare hrtimer_nanosleep() for time namespacesAndrei Vagin1-5/+7
clock_nanosleep() accepts absolute values of expiration time when TIMER_ABSTIME flag is set. This absolute value is inside the task's time namespace, and has to be converted to the host's time. There is timens_ktime_to_host() helper for converting time, but it accepts ktime argument. As a preparation, make hrtimer_nanosleep() accept a clock value in ktime instead of timespec64. Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrei Vagin <avagin@openvz.org> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-17-dima@arista.com
2019-12-03Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-4/+7
Pull timer updates from Ingo Molnar: "The main changes in the timer code in this cycle were: - Clockevent updates: - timer-of framework cleanups. (Geert Uytterhoeven) - Use timer-of for the renesas-ostm and the device name to prevent name collision in case of multiple timers. (Geert Uytterhoeven) - Check if there is an error after calling of_clk_get in asm9260 (Chuhong Yuan) - ABI fix: Zero out high order bits of nanoseconds on compat syscalls. This got broken a year ago, with apparently no side effects so far. Since the kernel would use random data otherwise I don't think we'd have other options but to fix the bug, even if there was a side effect to applications (Dmitry Safonov) - Optimize ns_to_timespec64() on 32-bit systems: move away from div_s64_rem() which can be slow, to div_u64_rem() which is faster (Arnd Bergmann) - Annotate KCSAN-reported false positive data races in hrtimer_is_queued() users by moving timer->state handling over to the READ_ONCE()/WRITE_ONCE() APIs. This documents these accesses (Eric Dumazet) - Misc cleanups and small fixes" [ I undid the "ABI fix" and updated the comments instead. The reason there were apparently no side effects is that the fix was a no-op. The updated comment is to say _why_ it was a no-op. - Linus ] * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: time: Zero the upper 32-bits in __kernel_timespec on 32-bit time: Rename tsk->real_start_time to ->start_boottime hrtimer: Remove the comment about not used HRTIMER_SOFTIRQ time: Fix spelling mistake in comment time: Optimize ns_to_timespec64() hrtimer: Annotate lockless access to timer->state clocksource/drivers/asm9260: Add a check for of_clk_get clocksource/drivers/renesas-ostm: Use unique device name instead of ostm clocksource/drivers/renesas-ostm: Convert to timer_of clocksource/drivers/timer-of: Use unique device name instead of timer clocksource/drivers/timer-of: Convert last full_name to %pOF
2019-11-15y2038: remove CONFIG_64BIT_TIMEArnd Bergmann1-1/+1
The CONFIG_64BIT_TIME option is defined on all architectures, and can be removed for simplicity now. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-11-06hrtimer: Annotate lockless access to timer->stateEric Dumazet1-4/+7
syzbot reported various data-race caused by hrtimer_is_queued() reading timer->state. A READ_ONCE() is required there to silence the warning. Also add the corresponding WRITE_ONCE() when timer->state is set. In remove_hrtimer() the hrtimer_is_queued() helper is open coded to avoid loading timer->state twice. KCSAN reported these cases: BUG: KCSAN: data-race in __remove_hrtimer / tcp_pacing_check write to 0xffff8880b2a7d388 of 1 bytes by interrupt on cpu 0: __remove_hrtimer+0x52/0x130 kernel/time/hrtimer.c:991 __run_hrtimer kernel/time/hrtimer.c:1496 [inline] __hrtimer_run_queues+0x250/0x600 kernel/time/hrtimer.c:1576 hrtimer_run_softirq+0x10e/0x150 kernel/time/hrtimer.c:1593 __do_softirq+0x115/0x33f kernel/softirq.c:292 run_ksoftirqd+0x46/0x60 kernel/softirq.c:603 smpboot_thread_fn+0x37d/0x4a0 kernel/smpboot.c:165 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352 read to 0xffff8880b2a7d388 of 1 bytes by task 24652 on cpu 1: tcp_pacing_check net/ipv4/tcp_output.c:2235 [inline] tcp_pacing_check+0xba/0x130 net/ipv4/tcp_output.c:2225 tcp_xmit_retransmit_queue+0x32c/0x5a0 net/ipv4/tcp_output.c:3044 tcp_xmit_recovery+0x7c/0x120 net/ipv4/tcp_input.c:3558 tcp_ack+0x17b6/0x3170 net/ipv4/tcp_input.c:3717 tcp_rcv_established+0x37e/0xf50 net/ipv4/tcp_input.c:5696 tcp_v4_do_rcv+0x381/0x4e0 net/ipv4/tcp_ipv4.c:1561 sk_backlog_rcv include/net/sock.h:945 [inline] __release_sock+0x135/0x1e0 net/core/sock.c:2435 release_sock+0x61/0x160 net/core/sock.c:2951 sk_stream_wait_memory+0x3d7/0x7c0 net/core/stream.c:145 tcp_sendmsg_locked+0xb47/0x1f30 net/ipv4/tcp.c:1393 tcp_sendmsg+0x39/0x60 net/ipv4/tcp.c:1434 inet_sendmsg+0x6d/0x90 net/ipv4/af_inet.c:807 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg+0x9f/0xc0 net/socket.c:657 BUG: KCSAN: data-race in __remove_hrtimer / __tcp_ack_snd_check write to 0xffff8880a3a65588 of 1 bytes by interrupt on cpu 0: __remove_hrtimer+0x52/0x130 kernel/time/hrtimer.c:991 __run_hrtimer kernel/time/hrtimer.c:1496 [inline] __hrtimer_run_queues+0x250/0x600 kernel/time/hrtimer.c:1576 hrtimer_run_softirq+0x10e/0x150 kernel/time/hrtimer.c:1593 __do_softirq+0x115/0x33f kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0xbb/0xe0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0xe6/0x280 arch/x86/kernel/apic/apic.c:1137 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 read to 0xffff8880a3a65588 of 1 bytes by task 22891 on cpu 1: __tcp_ack_snd_check+0x415/0x4f0 net/ipv4/tcp_input.c:5265 tcp_ack_snd_check net/ipv4/tcp_input.c:5287 [inline] tcp_rcv_established+0x750/0xf50 net/ipv4/tcp_input.c:5708 tcp_v4_do_rcv+0x381/0x4e0 net/ipv4/tcp_ipv4.c:1561 sk_backlog_rcv include/net/sock.h:945 [inline] __release_sock+0x135/0x1e0 net/core/sock.c:2435 release_sock+0x61/0x160 net/core/sock.c:2951 sk_stream_wait_memory+0x3d7/0x7c0 net/core/stream.c:145 tcp_sendmsg_locked+0xb47/0x1f30 net/ipv4/tcp.c:1393 tcp_sendmsg+0x39/0x60 net/ipv4/tcp.c:1434 inet_sendmsg+0x6d/0x90 net/ipv4/af_inet.c:807 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg+0x9f/0xc0 net/socket.c:657 __sys_sendto+0x21f/0x320 net/socket.c:1952 __do_sys_sendto net/socket.c:1964 [inline] __se_sys_sendto net/socket.c:1960 [inline] __x64_sys_sendto+0x89/0xb0 net/socket.c:1960 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 24652 Comm: syz-executor.3 Not tainted 5.4.0-rc3+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ tglx: Added comments ] Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20191106174804.74723-1-edumazet@google.com
2019-10-14hrtimer: Annotate lockless access to timer->baseEric Dumazet1-4/+4
Followup to commit dd2261ed45aa ("hrtimer: Protect lockless access to timer->base") lock_hrtimer_base() fetches timer->base without lock exclusion. Compiler is allowed to read timer->base twice (even if considered dumb) which could end up trying to lock migration_base and return &migration_base. base = timer->base; if (likely(base != &migration_base)) { /* compiler reads timer->base again, and now (base == &migration_base) raw_spin_lock_irqsave(&base->cpu_base->lock, *flags); if (likely(base == timer->base)) return base; /* == &migration_base ! */ Similarly the write sides must use WRITE_ONCE() to avoid store tearing. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20191008173204.180879-1-edumazet@google.com
2019-09-05hrtimer: Add a missing bracket and hide `migration_base' on !SMPSebastian Andrzej Siewior1-1/+11
The recent change to avoid taking the expiry lock when a timer is currently migrated missed to add a bracket at the end of the if statement leading to compile errors. Since that commit the variable `migration_base' is always used but it is only available on SMP configuration thus leading to another compile error. The changelog says "The timer base and base->cpu_base cannot be NULL in the code path", so it is safe to limit this check to SMP configurations only. Add the missing bracket to the if statement and hide `migration_base' behind CONFIG_SMP bars. [ tglx: Mark the functions inline ... ] Fixes: 68b2c8c1e4210 ("hrtimer: Don't take expiry_lock when timer is currently migrated") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190904145527.eah7z56ntwobqm6j@linutronix.de
2019-08-21hrtimer: Don't take expiry_lock when timer is currently migratedJulien Grall1-1/+5
migration_base is used as a placeholder when an hrtimer is migrated to a different CPU. In the case that hrtimer_cancel_wait_running() hits a timer which is currently migrated it would pointlessly acquire the expiry lock of the migration base, which is even not initialized. Surely it could be initialized, but there is absolutely no point in acquiring this lock because the timer is guaranteed not to run it's callback for which the caller waits to finish on that base. So it would just do the inc/lock/dec/unlock dance for nothing. As the base switch is short and non-preemptible, there is no issue when the wait function returns immediately. The timer base and base->cpu_base cannot be NULL in the code path which is invoking that, so just replace those checks with a check whether base is migration base. [ tglx: Updated from RT patch. Massaged changelog. Added comment. ] Signed-off-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190821092409.13225-4-julien.grall@arm.com
2019-08-21hrtimer: Protect lockless access to timer->baseJulien Grall1-1/+2
The update to timer->base is protected by the base->cpu_base->lock(). However, hrtimer_cancel_wait_running() does access it lockless. So the compiler is allowed to refetch timer->base which can cause havoc when the timer base is changed concurrently. Use READ_ONCE() to prevent this. [ tglx: Adapted from a RT patch ] Signed-off-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190821092409.13225-2-julien.grall@arm.com
2019-08-20hrtimer: Improve comments on handling priority inversion against softirq kthreadFrederic Weisbecker1-4/+10
The handling of a priority inversion between timer cancelling and a a not well defined possible preemption of softirq kthread is not very clear. Especially in the posix timers side it's unclear why there is a specific RT wait callback. All the nice explanations can be found in the initial changelog of f61eff83cec9 (hrtimer: Prepare support for PREEMPT_RT"). Extract the detailed informations from there and put it into comments. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190820132656.GC2093@lenoir
2019-08-01hrtimer: Prepare support for PREEMPT_RTAnna-Maria Gleixner1-6/+89
When PREEMPT_RT is enabled, the soft interrupt thread can be preempted. If the soft interrupt thread is preempted in the middle of a timer callback, then calling hrtimer_cancel() can lead to two issues: - If the caller is on a remote CPU then it has to spin wait for the timer handler to complete. This can result in unbound priority inversion. - If the caller originates from the task which preempted the timer handler on the same CPU, then spin waiting for the timer handler to complete is never going to end. To avoid these issues, add a new lock to the timer base which is held around the execution of the timer callbacks. If hrtimer_cancel() detects that the timer callback is currently running, it blocks on the expiry lock. When the callback is finished, the expiry lock is dropped by the softirq thread which wakes up the waiter and the system makes progress. This addresses both the priority inversion and the life lock issues. The same issue can happen in virtual machines when the vCPU which runs a timer callback is scheduled out. If a second vCPU of the same guest calls hrtimer_cancel() it will spin wait for the other vCPU to be scheduled back in. The expiry lock mechanism would avoid that. It'd be trivial to enable this when paravirt spinlocks are enabled in a guest, but it's not clear whether this is an actual problem in the wild, so for now it's an RT only mechanism. [ tglx: Refactored it for mainline ] Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190726185753.737767218@linutronix.de
2019-08-01hrtimer: Determine hard/soft expiry mode for hrtimer sleepers on RTSebastian Andrzej Siewior1-0/+34
On PREEMPT_RT enabled kernels hrtimers which are not explicitely marked for hard interrupt expiry mode are moved into soft interrupt context either for latency reasons or because the hrtimer callback takes regular spinlocks or invokes other functions which are not suitable for hard interrupt context on PREEMPT_RT. The hrtimer_sleeper callback is RT compatible in hard interrupt context, but there is a latency concern: Untrusted userspace can spawn many threads which arm timers for the same expiry time on the same CPU. On expiry that causes a latency spike due to the wakeup of a gazillion threads. OTOH, priviledged real-time user space applications rely on the low latency of hard interrupt wakeups. These syscall related wakeups are all based on hrtimer sleepers. If the current task is in a real-time scheduling class, mark the mode for hard interrupt expiry. [ tglx: Split out of a larger combo patch. Added changelog ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190726185753.645792403@linutronix.de
2019-08-01hrtimer: Move unmarked hrtimers to soft interrupt expiry on RTSebastian Andrzej Siewior1-1/+11
On PREEMPT_RT not all hrtimers can be expired in hard interrupt context even if that is perfectly fine on a PREEMPT_RT=n kernel, e.g. because they take regular spinlocks. Also for latency reasons PREEMPT_RT tries to defer most hrtimers' expiry into softirq context. hrtimers marked with HRTIMER_MODE_HARD must be kept in hard interrupt context expiry mode. Add the required logic. No functional change for PREEMPT_RT=n kernels. [ tglx: Split out of a larger combo patch. Added changelog ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190726185753.551967692@linutronix.de
2019-08-01hrtimer: Make enqueue mode check work on RTThomas Gleixner1-2/+7
hrtimer_start_range_ns() has a WARN_ONCE() which verifies that a timer which is marker for softirq expiry is not queued in the hard interrupt base and vice versa. When PREEMPT_RT is enabled, timers which are not explicitely marked to expire in hard interrupt context are deferrred to the soft interrupt. So the regular check would trigger. Change the check, so when PREEMPT_RT is enabled, it is verified that the timers marked for hard interrupt expiry are not tried to be queued for soft interrupt expiry or any of the unmarked and softirq marked is tried to be expired in hard interrupt context. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2019-08-01hrtimer: Provide hrtimer_sleeper_start_expires()Thomas Gleixner1-2/+17
hrtimer_sleepers will gain a scheduling class dependent treatment on PREEMPT_RT. Create a wrapper around hrtimer_start_expires() to make that possible. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2019-08-01hrtimer: Consolidate hrtimer_init() + hrtimer_init_sleeper() callsSebastian Andrzej Siewior1-11/+32
hrtimer_init_sleeper() calls require prior initialisation of the hrtimer object which is embedded into the hrtimer_sleeper. Combine the initialization and spare a function call. Fixup all call sites. This is also a preparatory change for PREEMPT_RT to do hrtimer sleeper specific initializations of the embedded hrtimer without modifying any of the call sites. No functional change. [ anna-maria: Minor cleanups ] [ tglx: Adopted to the removal of the task argument of hrtimer_init_sleeper() and trivial polishing. Folded a fix from Stephen Rothwell for the vsoc code ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190726185752.887468908@linutronix.de
2019-07-30hrtimer: Remove task argument from hrtimer_init_sleeper()Thomas Gleixner1-4/+4
All callers hand in 'current' and that's the only task pointer which actually makes sense. Remove the task argument and set current in the function. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190726185752.791885290@linutronix.de
2019-06-27hrtimer: Use a bullet for the returns bullet listMauro Carvalho Chehab1-3/+4
That gets rid of this warning: ./kernel/time/hrtimer.c:1119: WARNING: Block quote ends without a blank line; unexpected unindent. and displays nicely both at the source code and at the produced documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linux Doc Mailing List <linux-doc@vger.kernel.org> Cc: Mauro Carvalho Chehab <mchehab@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Link: https://lkml.kernel.org/r/74ddad7dac331b4e5ce4a90e15c8a49e3a16d2ac.1561372382.git.mchehab+samsung@kernel.org
2019-06-12hrtimer: Remove unused header includeYangtao Li1-1/+0
seq_file.h does not need to be included, so remove it. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190607174253.27403-1-tiny.windzz@gmail.com
2019-03-05Merge branch 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-1/+1
Pull year 2038 updates from Thomas Gleixner: "Another round of changes to make the kernel ready for 2038. After lots of preparatory work this is the first set of syscalls which are 2038 safe: 403 clock_gettime64 404 clock_settime64 405 clock_adjtime64 406 clock_getres_time64 407 clock_nanosleep_time64 408 timer_gettime64 409 timer_settime64 410 timerfd_gettime64 411 timerfd_settime64 412 utimensat_time64 413 pselect6_time64 414 ppoll_time64 416 io_pgetevents_time64 417 recvmmsg_time64 418 mq_timedsend_time64 419 mq_timedreceiv_time64 420 semtimedop_time64 421 rt_sigtimedwait_time64 422 futex_time64 423 sched_rr_get_interval_time64 The syscall numbers are identical all over the architectures" * 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) riscv: Use latest system call ABI checksyscalls: fix up mq_timedreceive and stat exceptions unicore32: Fix __ARCH_WANT_STAT64 definition asm-generic: Make time32 syscall numbers optional asm-generic: Drop getrlimit and setrlimit syscalls from default list 32-bit userspace ABI: introduce ARCH_32BIT_OFF_T config option compat ABI: use non-compat openat and open_by_handle_at variants y2038: add 64-bit time_t syscalls to all 32-bit architectures y2038: rename old time and utime syscalls y2038: remove struct definition redirects y2038: use time32 syscall names on 32-bit syscalls: remove obsolete __IGNORE_ macros y2038: syscalls: rename y2038 compat syscalls x86/x32: use time64 versions of sigtimedwait and recvmmsg timex: change syscalls to use struct __kernel_timex timex: use __kernel_timex internally sparc64: add custom adjtimex/clock_adjtime functions time: fix sys_timer_settime prototype time: Add struct __kernel_timex time: make adjtime compat handling available for 32 bit ...
2019-02-07y2038: syscalls: rename y2038 compat syscallsArnd Bergmann1-1/+1
A lot of system calls that pass a time_t somewhere have an implementation using a COMPAT_SYSCALL_DEFINEx() on 64-bit architectures, and have been reworked so that this implementation can now be used on 32-bit architectures as well. The missing step is to redefine them using the regular SYSCALL_DEFINEx() to get them out of the compat namespace and make it possible to build them on 32-bit architectures. Any system call that ends in 'time' gets a '32' suffix on its name for that version, while the others get a '_time32' suffix, to distinguish them from the normal version, which takes a 64-bit time argument in the future. In this step, only 64-bit architectures are changed, doing this rename first lets us avoid touching the 32-bit architectures twice. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-01-29timers: Mark expected switch fall-throughsGustavo A. R. Silva1-1/+1
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where fall through is indeed expected. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Stephen Boyd <sboyd@kernel.org> Link: https://lkml.kernel.org/r/20190123081413.GA3949@embeddedor
2018-11-23hrtimers/tick/clockevents: Remove sloppy license referencesThomas Gleixner1-2/+0
"For licencing details see kernel-base/COPYING" and similar license references have no value over the SPDX identifier. Remove them. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: John Stultz <john.stultz@linaro.org> Acked-by: Corey Minyard <cminyard@mvista.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Peter Anvin <hpa@zytor.com> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Richard Cochran <richardcochran@gmail.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: David Riley <davidriley@chromium.org> Cc: Colin Cross <ccross@android.com> Cc: Mark Brown <broonie@kernel.org> Link: https://lkml.kernel.org/r/20181031182252.963632760@linutronix.de
2018-11-23time: Add SPDX license identifiersThomas Gleixner1-0/+1
Update the time(r) core files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Philippe Ombredanne, Kate Stewart and myself. The data has been created with two independent license scanners and manual inspection. The following files do not contain any direct license information and have been omitted from the big initial SPDX changes: timeconst.bc: The .bc files were not touched time.c, timer.c, timekeeping.c: Licence was deduced from EXPORT_SYMBOL_GPL As those files do not contain direct license references they fall under the project license, i.e. GPL V2 only. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: John Stultz <john.stultz@linaro.org> Acked-by: Corey Minyard <cminyard@mvista.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: David Riley <davidriley@chromium.org> Cc: Colin Cross <ccross@android.com> Cc: Mark Brown <broonie@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: https://lkml.kernel.org/r/20181031182252.879109557@linutronix.de
2018-11-23time: Remove useless filenames in top level commentsThomas Gleixner1-12/+4
Remove the pointless filenames in the top level comments. They have no value at all and just occupy space. While at it tidy up some of the comments and remove a stale one. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: John Stultz <john.stultz@linaro.org> Acked-by: Corey Minyard <cminyard@mvista.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Peter Anvin <hpa@zytor.com> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Richard Cochran <richardcochran@gmail.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: David Riley <davidriley@chromium.org> Cc: Colin Cross <ccross@android.com> Cc: Mark Brown <broonie@kernel.org> Link: https://lkml.kernel.org/r/20181031182252.794898238@linutronix.de