linux/kernel/time, branch v5.3

timekeeping/vsyscall: Prevent math overflow in BOOTTIME update

2019-08-23T00:12:11Z

The VDSO update for CLOCK_BOOTTIME has a overflow issue as it shifts the nanoseconds based boot time offset left by the clocksource shift. That overflows once the boot time offset becomes large enough. As a consequence CLOCK_BOOTTIME in the VDSO becomes a random number causing applications to misbehave. Fix it by storing a timespec64 representation of the offset when boot time is adjusted and add that to the MONOTONIC base time value in the vdso data page. Using the timespec64 representation avoids a 64bit division in the update code. Fixes: 44f57d788e7d ("timekeeping: Provide a generic update_vsyscall() implementation") Reported-by: Chris Clayton Signed-off-by: Thomas Gleixner Tested-by: Chris Clayton Tested-by: Vincenzo Frascino Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908221257580.1983@nanos.tec.linutronix.de

timekeeping/vsyscall: Use __iter_div_u64_rem()

2019-07-10T18:37:49Z

On 32-bit x86 when building with clang-9, the 'division' loop gets turned back into an inefficient division that causes a link error: kernel/time/vsyscall.o: In function `update_vsyscall': vsyscall.c:(.text+0xe3): undefined reference to `__udivdi3' Use the existing __iter_div_u64_rem() function which is used to address the same issue in other places. Fixes: 44f57d788e7d ("timekeeping: Provide a generic update_vsyscall() implementation") Signed-off-by: Arnd Bergmann Signed-off-by: Thomas Gleixner Reviewed-by: Nathan Chancellor Tested-by: Nathan Chancellor Link: https://lkml.kernel.org/r/20190710130206.1670830-1-arnd@arndb.de

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

2019-07-08T23:39:53Z

Pull scheduler updates from Ingo Molnar: - Remove the unused per rq load array and all its infrastructure, by Dietmar Eggemann. - Add utilization clamping support by Patrick Bellasi. This is a refinement of the energy aware scheduling framework with support for boosting of interactive and capping of background workloads: to make sure critical GUI threads get maximum frequency ASAP, and to make sure background processing doesn't unnecessarily move to cpufreq governor to higher frequencies and less energy efficient CPU modes. - Add the bare minimum of tracepoints required for LISA EAS regression testing, by Qais Yousef - which allows automated testing of various power management features, including energy aware scheduling. - Restructure the former tsk_nr_cpus_allowed() facility that the -rt kernel used to modify the scheduler's CPU affinity logic such as migrate_disable() - introduce the task->cpus_ptr value instead of taking the address of &task->cpus_allowed directly - by Sebastian Andrzej Siewior. - Misc optimizations, fixes, cleanups and small enhancements - see the Git log for details. * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits) sched/uclamp: Add uclamp support to energy_compute() sched/uclamp: Add uclamp_util_with() sched/cpufreq, sched/uclamp: Add clamps for FAIR and RT tasks sched/uclamp: Set default clamps for RT tasks sched/uclamp: Reset uclamp values on RESET_ON_FORK sched/uclamp: Extend sched_setattr() to support utilization clamping sched/core: Allow sched_setattr() to use the current policy sched/uclamp: Add system default clamps sched/uclamp: Enforce last task's UCLAMP_MAX sched/uclamp: Add bucket local max tracking sched/uclamp: Add CPU's clamp buckets refcounting sched/fair: Rename weighted_cpuload() to cpu_runnable_load() sched/debug: Export the newly added tracepoints sched/debug: Add sched_overutilized tracepoint sched/debug: Add new tracepoint to track PELT at se level sched/debug: Add new tracepoints to track PELT at rq level sched/debug: Add a new sched_trace_*() helper functions sched/autogroup: Make autogroup_path() always available sched/wait: Deduplicate code with do-while sched/topology: Remove unused 'sd' parameter from arch_scale_cpu_capacity() ...

time: Validate user input in compat_settimeofday()

2019-07-07T10:05:40Z

The user value is validated after converting the timeval to a timespec, but for a wide range of negative tv_usec values the multiplication overflow turns them in positive numbers. So the 'validated later' is not catching the invalid input. Signed-off-by: zhengbin Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/1562460701-113301-1-git-send-email-zhengbin13@huawei.com

Merge branch 'timers/vdso' into timers/core

2019-07-03T08:50:21Z

so the hyper-v clocksource update can be applied.

hrtimer: Use a bullet for the returns bullet list

2019-06-27T21:30:04Z

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 Signed-off-by: Thomas Gleixner Cc: Linux Doc Mailing List Cc: Mauro Carvalho Chehab Cc: Jonathan Corbet Link: https://lkml.kernel.org/r/74ddad7dac331b4e5ce4a90e15c8a49e3a16d2ac.1561372382.git.mchehab+samsung@kernel.org

timer_list: Guard procfs specific code

2019-06-22T22:08:52Z

With CONFIG_PROC_FS=n the following warning is emitted: kernel/time/timer_list.c:361:36: warning: unused variable 'timer_list_sops' [-Wunused-const-variable] static const struct seq_operations timer_list_sops = { Add #ifdef guard around procfs specific code. Signed-off-by: Nathan Huckleberry Signed-off-by: Thomas Gleixner Reviewed-by: Nick Desaulniers Cc: john.stultz@linaro.org Cc: sboyd@kernel.org Cc: clang-built-linux@googlegroups.com Link: https://github.com/ClangBuiltLinux/linux/issues/534 Link: https://lkml.kernel.org/r/20190614181604.112297-1-nhuck@google.com

timekeeping: Provide a generic update_vsyscall() implementation

2019-06-22T19:21:06Z

The new generic VDSO library allows to unify the update_vsyscall[_tz]() implementations. Provide a generic implementation based on the x86 code and the bindings which need to be implemented in architecture specific code. [ tglx: Moved it into kernel/time where it belongs. Removed the pointless line breaks in the stub functions. Massaged changelog ] Signed-off-by: Vincenzo Frascino Signed-off-by: Thomas Gleixner Tested-by: Shijith Thotton Tested-by: Andre Przywara Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: Catalin Marinas Cc: Will Deacon Cc: Arnd Bergmann Cc: Russell King Cc: Ralf Baechle Cc: Paul Burton Cc: Daniel Lezcano Cc: Mark Salyzyn Cc: Peter Collingbourne Cc: Shuah Khan Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Rasmus Villemoes Cc: Huw Davies Link: https://lkml.kernel.org/r/20190621095252.32307-4-vincenzo.frascino@arm.com

posix-timers: Use spin_lock_irq() in itimer_delete()

2019-06-22T10:14:22Z

itimer_delete() uses spin_lock_irqsave() to obtain a `flags' variable which can then be passed to unlock_timer(). It uses already spin_lock locking for the structure instead of lock_timer() because it has a timer which can not be removed by others at this point. The cleanup is always performed with enabled interrupts. Use spin_lock_irq() / spin_unlock_irq() so the `flags' variable can be removed. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20190621143643.25649-3-bigeasy@linutronix.de

posix-timers: Remove "it_signal = NULL" assignment in itimer_delete()

2019-06-22T10:14:22Z

itimer_delete() is invoked during do_exit(). At this point it is the last thread in the group dying and doing the clean up. Since it is the last thread in the group, there can not be any other task attempting to lock the itimer which means the NULL assignment (which avoids lookups in __lock_timer()) is not required. The assignment and comment was copied in commit 0e568881178ff ("[PATCH] fix posix-timers to have proper per-process scope") from sys_timer_delete() which was/is the syscall interface and requires the assignment. Remove the superfluous ->it_signal = NULL assignment. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20190621143643.25649-2-bigeasy@linutronix.de