linux/kernel/time, branch v5.6

y2038: remove unused time32 interfaces

2020-02-21T19:22:15Z

No users remain, so kill these off before we grow new ones. Link: http://lkml.kernel.org/r/20200110154232.4104492-3-arnd@arndb.de Signed-off-by: Arnd Bergmann Acked-by: Thomas Gleixner Cc: Deepa Dinamani Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'timers-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-02-09T20:00:12Z

Pull timer fixes from Thomas Gleixner: "Two small fixes for the time(r) subsystem: - Handle a subtle race between the clocksource watchdog and a concurrent clocksource watchdog stop/start sequence correctly to prevent a timer double add bug. - Fix the file path for the core time namespace file" * tag 'timers-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clocksource: Prevent double add_timer_on() for watchdog_timer MAINTAINERS: Correct path to time namespace source file

clocksource: Prevent double add_timer_on() for watchdog_timer

2020-02-01T10:07:56Z

Kernel crashes inside QEMU/KVM are observed: kernel BUG at kernel/time/timer.c:1154! BUG_ON(timer_pending(timer) || !timer->function) in add_timer_on(). At the same time another cpu got: general protection fault: 0000 [#1] SMP PTI of poinson pointer 0xdead000000000200 in: __hlist_del at include/linux/list.h:681 (inlined by) detach_timer at kernel/time/timer.c:818 (inlined by) expire_timers at kernel/time/timer.c:1355 (inlined by) __run_timers at kernel/time/timer.c:1686 (inlined by) run_timer_softirq at kernel/time/timer.c:1699 Unfortunately kernel logs are badly scrambled, stacktraces are lost. Printing the timer->function before the BUG_ON() pointed to clocksource_watchdog(). The execution of clocksource_watchdog() can race with a sequence of clocksource_stop_watchdog() .. clocksource_start_watchdog(): expire_timers() detach_timer(timer, true); timer->entry.pprev = NULL; raw_spin_unlock_irq(&base->lock); call_timer_fn clocksource_watchdog() clocksource_watchdog_kthread() or clocksource_unbind() spin_lock_irqsave(&watchdog_lock, flags); clocksource_stop_watchdog(); del_timer(&watchdog_timer); watchdog_running = 0; spin_unlock_irqrestore(&watchdog_lock, flags); spin_lock_irqsave(&watchdog_lock, flags); clocksource_start_watchdog(); add_timer_on(&watchdog_timer, ...); watchdog_running = 1; spin_unlock_irqrestore(&watchdog_lock, flags); spin_lock(&watchdog_lock); add_timer_on(&watchdog_timer, ...); BUG_ON(timer_pending(timer) || !timer->function); timer_pending() -> true BUG() I.e. inside clocksource_watchdog() watchdog_timer could be already armed. Check timer_pending() before calling add_timer_on(). This is sufficient as all operations are synchronized by watchdog_lock. Fixes: 75c5158f70c0 ("timekeeping: Update clocksource with stop_machine") Signed-off-by: Konstantin Khlebnikov Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/158048693917.4378.13823603769948933793.stgit@buzz

Merge tag 'y2038-drivers-for-v5.6-signed' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

2020-01-29T22:55:47Z

Pull y2038 updates from Arnd Bergmann: "Core, driver and file system changes These are updates to device drivers and file systems that for some reason or another were not included in the kernel in the previous y2038 series. I've gone through all users of time_t again to make sure the kernel is in a long-term maintainable state, replacing all remaining references to time_t with safe alternatives. Some related parts of the series were picked up into the nfsd, xfs, alsa and v4l2 trees. A final set of patches in linux-mm removes the now unused time_t/timeval/timespec types and helper functions after all five branches are merged for linux-5.6, ensuring that no new users get merged. As a result, linux-5.6, or my backport of the patches to 5.4 [1], should be the first release that can serve as a base for a 32-bit system designed to run beyond year 2038, with a few remaining caveats: - All user space must be compiled with a 64-bit time_t, which will be supported in the coming musl-1.2 and glibc-2.32 releases, along with installed kernel headers from linux-5.6 or higher. - Applications that use the system call interfaces directly need to be ported to use the time64 syscalls added in linux-5.1 in place of the existing system calls. This impacts most users of futex() and seccomp() as well as programming languages that have their own runtime environment not based on libc. - Applications that use a private copy of kernel uapi header files or their contents may need to update to the linux-5.6 version, in particular for sound/asound.h, xfs/xfs_fs.h, linux/input.h, linux/elfcore.h, linux/sockios.h, linux/timex.h and linux/can/bcm.h. - A few remaining interfaces cannot be changed to pass a 64-bit time_t in a compatible way, so they must be configured to use CLOCK_MONOTONIC times or (with a y2106 problem) unsigned 32-bit timestamps. Most importantly this impacts all users of 'struct input_event'. - All y2038 problems that are present on 64-bit machines also apply to 32-bit machines. In particular this affects file systems with on-disk timestamps using signed 32-bit seconds: ext4 with ext3-style small inodes, ext2, xfs (to be fixed soon) and ufs" [1] https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/log/?h=y2038-endgame * tag 'y2038-drivers-for-v5.6-signed' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (21 commits) Revert "drm/etnaviv: reject timeouts with tv_nsec >= NSEC_PER_SEC" y2038: sh: remove timeval/timespec usage from headers y2038: sparc: remove use of struct timex y2038: rename itimerval to __kernel_old_itimerval y2038: remove obsolete jiffies conversion functions nfs: fscache: use timespec64 in inode auxdata nfs: fix timstamp debug prints nfs: use time64_t internally sunrpc: convert to time64_t for expiry drm/etnaviv: avoid deprecated timespec drm/etnaviv: reject timeouts with tv_nsec >= NSEC_PER_SEC drm/msm: avoid using 'timespec' hfs/hfsplus: use 64-bit inode timestamps hostfs: pass 64-bit timestamps to/from user space packet: clarify timestamp overflow tsacct: add 64-bit btime field acct: stop using get_seconds() um: ubd: use 64-bit time_t where possible xtensa: ISS: avoid struct timeval dlm: use SO_SNDTIMEO_NEW instead of SO_SNDTIMEO_OLD ...

Merge tag 'timers-core-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-01-28T00:47:05Z

Pull timer updates from Thomas Gleixner: "The timekeeping and timers departement provides: - Time namespace support: If a container migrates from one host to another then it expects that clocks based on MONOTONIC and BOOTTIME are not subject to disruption. Due to different boot time and non-suspended runtime these clocks can differ significantly on two hosts, in the worst case time goes backwards which is a violation of the POSIX requirements. The time namespace addresses this problem. It allows to set offsets for clock MONOTONIC and BOOTTIME once after creation and before tasks are associated with the namespace. These offsets are taken into account by timers and timekeeping including the VDSO. Offsets for wall clock based clocks (REALTIME/TAI) are not provided by this mechanism. While in theory possible, the overhead and code complexity would be immense and not justified by the esoteric potential use cases which were discussed at Plumbers '18. The overhead for tasks in the root namespace (ie where host time offsets = 0) is in the noise and great effort was made to ensure that especially in the VDSO. If time namespace is disabled in the kernel configuration the code is compiled out. Kudos to Andrei Vagin and Dmitry Sofanov who implemented this feature and kept on for more than a year addressing review comments, finding better solutions. A pleasant experience. - Overhaul of the alarmtimer device dependency handling to ensure that the init/suspend/resume ordering is correct. - A new clocksource/event driver for Microchip PIT64 - Suspend/resume support for the Hyper-V clocksource - The usual pile of fixes, updates and improvements mostly in the driver code" * tag 'timers-core-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits) alarmtimer: Make alarmtimer_get_rtcdev() a stub when CONFIG_RTC_CLASS=n alarmtimer: Use wakeup source from alarmtimer platform device alarmtimer: Make alarmtimer platform device child of RTC device alarmtimer: Update alarmtimer_get_rtcdev() docs to reflect reality hrtimer: Add missing sparse annotation for __run_timer() lib/vdso: Only read hrtimer_res when needed in __cvdso_clock_getres() MIPS: vdso: Define BUILD_VDSO32 when building a 32bit kernel clocksource/drivers/hyper-v: Set TSC clocksource as default w/ InvariantTSC clocksource/drivers/hyper-v: Untangle stimers and timesync from clocksources clocksource/drivers/timer-microchip-pit64b: Fix sparse warning clocksource/drivers/exynos_mct: Rename Exynos to lowercase clocksource/drivers/timer-ti-dm: Fix uninitialized pointer access clocksource/drivers/timer-ti-dm: Switch to platform_get_irq clocksource/drivers/timer-ti-dm: Convert to devm_platform_ioremap_resource clocksource/drivers/em_sti: Fix variable declaration in em_sti_probe clocksource/drivers/em_sti: Convert to devm_platform_ioremap_resource clocksource/drivers/bcm2835_timer: Fix memory leak of timer clocksource/drivers/cadence-ttc: Use ttc driver as platform driver clocksource/drivers/timer-microchip-pit64b: Add Microchip PIT64B support clocksource/drivers/hyper-v: Reserve PAGE_SIZE space for tsc page ...

alarmtimer: Make alarmtimer_get_rtcdev() a stub when CONFIG_RTC_CLASS=n

2020-01-24T20:03:53Z

The stubbed version of alarmtimer_get_rtcdev() is not exported. so this won't work if this function is used in a module when CONFIG_RTC_CLASS=n. Move the stub function to the header file and make it inline so that callers don't have to worry about linking against this symbol. rtcdev isn't used outside of this ifdef so it's not required to be redefined to NULL. Drop that while touching this area. Signed-off-by: Stephen Boyd Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20200124055849.154411-4-swboyd@chromium.org

alarmtimer: Use wakeup source from alarmtimer platform device

2020-01-24T20:00:21Z

Use the wakeup source that can be associated with the 'alarmtimer' platform device instead of registering another one by hand. Signed-off-by: Stephen Boyd Signed-off-by: Thomas Gleixner Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/20200124055849.154411-3-swboyd@chromium.org

alarmtimer: Make alarmtimer platform device child of RTC device

2020-01-24T20:00:20Z

The alarmtimer_suspend() function will fail if an RTC device is on a bus such as SPI or i2c and that RTC device registers and probes after alarmtimer_init() registers and probes the 'alarmtimer' platform device. This is because system wide suspend suspends devices in the reverse order of their probe. When alarmtimer_suspend() attempts to program the RTC for a wakeup it will try to program an RTC device on a bus that has already been suspended. Move the alarmtimer device registration to happen when the RTC which is used for wakeup is registered. Register the 'alarmtimer' platform device as a child of the RTC device too, so that it can be guaranteed that the RTC device won't be suspended when alarmtimer_suspend() is called. Reported-by: Douglas Anderson Signed-off-by: Stephen Boyd Signed-off-by: Thomas Gleixner Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/20200124055849.154411-2-swboyd@chromium.org

alarmtimer: Update alarmtimer_get_rtcdev() docs to reflect reality

2020-01-24T20:00:20Z

This function doesn't do anything like this comment says when an RTC device hasn't been chosen. It looks like we used to do something like that before commit 8bc0dafb5cf3 ("alarmtimers: Rework RTC device selection using class interface") but that's long gone now. Remove this sentence to avoid confusing the reader. Signed-off-by: Stephen Boyd Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20200124055849.154411-5-swboyd@chromium.org

hrtimer: Add missing sparse annotation for __run_timer()

2020-01-22T14:50:11Z

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 Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20200120224347.51843-1-jbi.octave@gmail.com