summaryrefslogtreecommitdiffstats
path: root/kernel/time
AgeCommit message (Collapse)AuthorFilesLines
2020-01-29Merge tag 'y2038-drivers-for-v5.6-signed' of ↵Linus Torvalds2-62/+14
git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground 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 ...
2020-01-27Merge tag 'timers-core-2020-01-27' of ↵Linus Torvalds11-107/+656
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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 ...
2020-01-24alarmtimer: Make alarmtimer_get_rtcdev() a stub when CONFIG_RTC_CLASS=nStephen Boyd1-5/+0
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 <swboyd@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20200124055849.154411-4-swboyd@chromium.org
2020-01-24alarmtimer: Use wakeup source from alarmtimer platform deviceStephen Boyd1-10/+5
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 <swboyd@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20200124055849.154411-3-swboyd@chromium.org
2020-01-24alarmtimer: Make alarmtimer platform device child of RTC deviceStephen Boyd1-11/+9
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 <dianders@chromium.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20200124055849.154411-2-swboyd@chromium.org
2020-01-24alarmtimer: Update alarmtimer_get_rtcdev() docs to reflect realityStephen Boyd1-2/+0
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 <swboyd@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20200124055849.154411-5-swboyd@chromium.org
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
2020-01-17lib/vdso: Update coarse timekeeper unconditionallyThomas Gleixner1-20/+17
The low resolution parts of the VDSO, i.e.: clock_gettime(CLOCK_*_COARSE), clock_getres(), time() can be used even if there is no VDSO capable clocksource. But if an architecture opts out of the VDSO data update then this information becomes stale. This affects ARM when there is no architected timer available. The lack of update causes userspace to use stale data forever. Make the update of the low resolution parts unconditional and only skip the update of the high resolution parts if the architecture requests it. Fixes: 44f57d788e7d ("timekeeping: Provide a generic update_vsyscall() implementation") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20200114185946.765577901@linutronix.de
2020-01-17lib/vdso: Make __arch_update_vdso_data() logic understandableThomas Gleixner1-1/+1
The function name suggests that this is a boolean checking whether the architecture asks for an update of the VDSO data, but it works the other way round. To spare further confusion invert the logic. Fixes: 44f57d788e7d ("timekeeping: Provide a generic update_vsyscall() implementation") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20200114185946.656652824@linutronix.de
2020-01-15tick/common: Touch watchdog in tick_unfreeze() on all CPUsChunyan Zhang1-0/+2
Suspend to IDLE invokes tick_unfreeze() on resume. tick_unfreeze() on the first resuming CPU resumes timekeeping, which also has the side effect of resetting the softlockup watchdog on this CPU. But on the secondary CPUs the watchdog is not reset in the resume / unfreeze() path, which can result in false softlockup warnings on those CPUs depending on the time spent in suspend. Prevent this by clearing the softlock watchdog in the unfreeze path also on the secondary resuming CPUs. [ tglx: Massaged changelog ] Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20200110083902.27276-1-chunyan.zhang@unisoc.com
2020-01-15alarmtimer: Unregister wakeup source when module get failsStephen Boyd1-3/+5
The alarmtimer_rtc_add_device() function creates a wakeup source and then tries to grab a module reference. If that fails the function returns early with an error code, but fails to remove the wakeup source. Cleanup this exit path so there is no dangling wakeup source, which is named 'alarmtime' left allocated which will conflict with another RTC device that may be registered later. Fixes: 51218298a25e ("alarmtimer: Ensure RTC module is not unloaded") Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Douglas Anderson <dianders@chromium.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200109155910.907-2-swboyd@chromium.org
2020-01-15tick/sched: Annotate lockless access to last_jiffies_updateEric Dumazet1-5/+9
syzbot (KCSAN) reported a data-race in tick_do_update_jiffies64(): BUG: KCSAN: data-race in tick_do_update_jiffies64 / tick_do_update_jiffies64 write to 0xffffffff8603d008 of 8 bytes by interrupt on cpu 1: tick_do_update_jiffies64+0x100/0x250 kernel/time/tick-sched.c:73 tick_sched_do_timer+0xd4/0xe0 kernel/time/tick-sched.c:138 tick_sched_timer+0x43/0xe0 kernel/time/tick-sched.c:1292 __run_hrtimer kernel/time/hrtimer.c:1514 [inline] __hrtimer_run_queues+0x274/0x5f0 kernel/time/hrtimer.c:1576 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1638 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0xdc/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 arch_local_irq_restore arch/x86/include/asm/paravirt.h:756 [inline] kcsan_setup_watchpoint+0x1d4/0x460 kernel/kcsan/core.c:436 check_access kernel/kcsan/core.c:466 [inline] __tsan_read1 kernel/kcsan/core.c:593 [inline] __tsan_read1+0xc2/0x100 kernel/kcsan/core.c:593 kallsyms_expand_symbol.constprop.0+0x70/0x160 kernel/kallsyms.c:79 kallsyms_lookup_name+0x7f/0x120 kernel/kallsyms.c:170 insert_report_filterlist kernel/kcsan/debugfs.c:155 [inline] debugfs_write+0x14b/0x2d0 kernel/kcsan/debugfs.c:256 full_proxy_write+0xbd/0x100 fs/debugfs/file.c:225 __vfs_write+0x67/0xc0 fs/read_write.c:494 vfs_write fs/read_write.c:558 [inline] vfs_write+0x18a/0x390 fs/read_write.c:542 ksys_write+0xd5/0x1b0 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x4c/0x60 fs/read_write.c:620 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffffffff8603d008 of 8 bytes by task 0 on cpu 0: tick_do_update_jiffies64+0x2b/0x250 kernel/time/tick-sched.c:62 tick_nohz_update_jiffies kernel/time/tick-sched.c:505 [inline] tick_nohz_irq_enter kernel/time/tick-sched.c:1257 [inline] tick_irq_enter+0x139/0x1c0 kernel/time/tick-sched.c:1274 irq_enter+0x4f/0x60 kernel/softirq.c:354 entering_irq arch/x86/include/asm/apic.h:517 [inline] entering_ack_irq arch/x86/include/asm/apic.h:523 [inline] smp_apic_timer_interrupt+0x55/0x280 arch/x86/kernel/apic/apic.c:1133 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:571 default_idle_call+0x1e/0x40 kernel/sched/idle.c:94 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x1af/0x280 kernel/sched/idle.c:263 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:355 rest_init+0xec/0xf6 init/main.c:452 arch_call_rest_init+0x17/0x37 start_kernel+0x838/0x85e init/main.c:786 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:490 x86_64_start_kernel+0x72/0x76 arch/x86/kernel/head64.c:471 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Use READ_ONCE() and WRITE_ONCE() to annotate this expected race. Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191205045619.204946-1-edumazet@google.com
2020-01-14fs/proc: Introduce /proc/pid/timens_offsetsAndrei Vagin1-0/+101
API to set time namespace offsets for children processes, i.e.: echo "$clockid $offset_sec $offset_nsec" > /proc/self/timens_offsets Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-28-dima@arista.com
2020-01-14x86/vdso: Zap vvar pages when switching to a time namespaceDmitry Safonov1-0/+10
The VVAR page layout depends on whether a task belongs to the root or non-root time namespace. Whenever a task changes its namespace, the VVAR page tables are cleared and then they will be re-faulted with a corresponding layout. Co-developed-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-27-dima@arista.com
2020-01-14time: Allocate per-timens vvar pageDmitry Safonov1-1/+103
VDSO support for Time namespace needs to set up a page with the same layout as VVAR. That timens page will be placed on position of VVAR page inside namespace. That page contains time namespace clock offsets and it has vdso_data->seq set to 1 to enforce the slow path and vdso_data->clock_mode set to VCLOCK_TIMENS to enforce the time namespace handling path. Allocate the timens page during namespace creation. Setup the offsets when the first task enters the ns and freeze them to guarantee the pace of monotonic/boottime clocks and to avoid breakage of applications. The design decision is to have a global offset_lock which is used during namespace offsets setup and to freeze offsets when the first task joins the new time namespace. That is better in terms of memory usage compared to having a per namespace mutex that's used only during the setup period. Suggested-by: Andy Lutomirski <luto@kernel.org> Based-on-work-by: Thomas Gleixner <tglx@linutronix.de> Co-developed-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-24-dima@arista.com
2020-01-14posix-timers: Make clock_nanosleep() time namespace awareAndrei Vagin2-4/+25
clock_nanosleep() accepts absolute values of expiration time, if the TIMER_ABSTIME flag is set. This value is in the tasks time namespace, which has to be converted to the host time namespace. 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/20191112012724.250792-18-dima@arista.com
2020-01-14hrtimers: Prepare hrtimer_nanosleep() for time namespacesAndrei Vagin3-8/+12
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
2020-01-14alarmtimer: Make nanosleep() time namespace awareAndrei Vagin1-0/+2
clock_nanosleep() accepts absolute values of expiration time when the 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. 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/20191112012724.250792-16-dima@arista.com
2020-01-14posix-timers: Make timer_settime() time namespace awareAndrei Vagin1-0/+2
Wire timer_settime() syscall into time namespace virtualization. sys_timer_settime() calls the ktime->timer_set() callback. Right now, common_timer_set() is the only implementation for the callback. The user-supplied expiry value is converted from timespec64 to ktime and then timens_ktime_to_host() can be used to convert namespace's time to the host time. Inside a time namespace kernel's time differs by a fixed offset from a user-supplied time, but only absolute values (TIMER_ABSTIME) must be converted. 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/20191112012724.250792-15-dima@arista.com
2020-01-14time: Add do_timens_ktime_to_host() helperAndrei Vagin1-0/+36
The helper subtracts namespace's clock offset from the given time and ensures that the result is within [0, KTIME_MAX]. Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-13-dima@arista.com
2020-01-14posix-clocks: Wire up clock_gettime() with timens offsetsAndrei Vagin3-1/+16
Adjust monotonic and boottime clocks with per-timens offsets. As the result a process inside time namespace will see timers and clocks corrected to offsets that were set when the namespace was created Note that applications usually go through vDSO to get time, which is not yet adjusted. Further changes will complete time namespace virtualisation with vDSO support. Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-12-dima@arista.com
2020-01-14posix-timers: Use clock_get_ktime() in common_timer_get()Andrei Vagin1-7/+1
Now, when the clock_get_ktime() callback exists, the suboptimal timespec64-based conversion can be removed from common_timer_get(). Suggested-by: Thomas Gleixner <tglx@linutronix.de> Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-11-dima@arista.com
2020-01-14posix-clocks: Introduce clock_get_ktime() callbackAndrei Vagin3-2/+46
The callsite in common_timer_get() has already a comment: /* * The timespec64 based conversion is suboptimal, but it's not * worth to implement yet another callback. */ kc->clock_get(timr->it_clock, &ts64); now = timespec64_to_ktime(ts64); The upcoming support for time namespaces requires to have access to: - The time in a task's time namespace for sys_clock_gettime() - The time in the root name space for common_timer_get() That adds a valid reason to finally implement a separate callback which returns the time in ktime_t format. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-10-dima@arista.com
2020-01-14alarmtimer: Provide get_timespec() callbackAndrei Vagin1-1/+6
The upcoming support for time namespaces requires to have access to: - The time in a task's time namespace for sys_clock_gettime() - The time in the root name space for common_timer_get() Wire up alarm bases with get_timespec(). Suggested-by: Thomas Gleixner <tglx@linutronix.de> Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-9-dima@arista.com
2020-01-14alarmtimer: Rename gettime() callback to get_ktime()Andrei Vagin1-17/+17
The upcoming support for time namespaces requires to have access to: - The time in a tasks time namespace for sys_clock_gettime() - The time in the root name space for common_timer_get() struct alarm_base needs to follow the same naming convention, so rename .gettime() callback into get_ktime() as a preparation for introducing get_timespec(). Suggested-by: Thomas Gleixner <tglx@linutronix.de> Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-8-dima@arista.com
2020-01-14posix-clocks: Rename .clock_get_timespec() callbacks accordinglyAndrei Vagin2-11/+11
The upcoming support for time namespaces requires to have access to: - The time in a task's time namespace for sys_clock_gettime() - The time in the root name space for common_timer_get() That adds a valid reason to finally implement a separate callback which returns the time in ktime_t format in (struct k_clock). As a preparation ground for introducing clock_get_ktime(), the original callback clock_get() was renamed into clock_get_timespec(). Reflect the renaming into the callback implementations. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-7-dima@arista.com
2020-01-14posix-clocks: Rename the clock_get() callback to clock_get_timespec()Andrei Vagin5-35/+35
The upcoming support for time namespaces requires to have access to: - The time in a task's time namespace for sys_clock_gettime() - The time in the root name space for common_timer_get() That adds a valid reason to finally implement a separate callback which returns the time in ktime_t format, rather than in (struct timespec). Rename the clock_get() callback to clock_get_timespec() as a preparation for introducing clock_get_ktime(). Suggested-by: Thomas Gleixner <tglx@linutronix.de> Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-6-dima@arista.com
2020-01-14time: Add timens_offsets to be used for tasks in time namespaceAndrei Vagin1-0/+2
Introduce offsets for time namespace. They will contain an adjustment needed to convert clocks to/from host's. A new namespace is created with the same offsets as the time namespace of the current process. 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/20191112012724.250792-5-dima@arista.com
2020-01-14ns: Introduce Time NamespaceAndrei Vagin2-0/+218
Time Namespace isolates clock values. The kernel provides access to several clocks CLOCK_REALTIME, CLOCK_MONOTONIC, CLOCK_BOOTTIME, etc. CLOCK_REALTIME System-wide clock that measures real (i.e., wall-clock) time. CLOCK_MONOTONIC Clock that cannot be set and represents monotonic time since some unspecified starting point. CLOCK_BOOTTIME Identical to CLOCK_MONOTONIC, except it also includes any time that the system is suspended. For many users, the time namespace means the ability to changes date and time in a container (CLOCK_REALTIME). Providing per namespace notions of CLOCK_REALTIME would be complex with a massive overhead, but has a dubious value. But in the context of checkpoint/restore functionality, monotonic and boottime clocks become interesting. Both clocks are monotonic with unspecified starting points. These clocks are widely used to measure time slices and set timers. After restoring or migrating processes, it has to be guaranteed that they never go backward. In an ideal case, the behavior of these clocks should be the same as for a case when a whole system is suspended. All this means that it is required to set CLOCK_MONOTONIC and CLOCK_BOOTTIME clocks, which can be achieved by adding per-namespace offsets for clocks. A time namespace is similar to a pid namespace in the way how it is created: unshare(CLONE_NEWTIME) system call creates a new time namespace, but doesn't set it to the current process. Then all children of the process will be born in the new time namespace, or a process can use the setns() system call to join a namespace. This scheme allows setting clock offsets for a namespace, before any processes appear in it. All available clone flags have been used, so CLONE_NEWTIME uses the highest bit of CSIGNAL. It means that it can be used only with the unshare() and the clone3() system calls. [ tglx: Adjusted paragraph about clone3() to reality and massaged the changelog a bit. ] Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://criu.org/Time_namespace Link: https://lists.openvz.org/pipermail/criu/2018-June/041504.html Link: https://lore.kernel.org/r/20191112012724.250792-4-dima@arista.com
2020-01-10Merge branch 'timers/urgent' into timers/coreThomas Gleixner1-0/+3
Pick up upstream VDSO fix before adding more VDSO changes.
2020-01-09time/sched_clock: Disable interrupts in sched_clock_register()Paul Cercueil1-2/+5
Instead of issueing a warning if sched_clock_register() is called from a context where IRQs are enabled, the code now ensures that IRQs are indeed disabled. Signed-off-by: Paul Cercueil <paul@crapouillou.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20200107010630.954648-1-paul@crapouillou.net
2020-01-09time/posix-stubs: Provide compat itimer supoprt for alphaArnd Bergmann1-0/+3
Using compat_sys_getitimer and compat_sys_setitimer on alpha causes a link failure in the Alpha tinyconfig and other configurations that turn off CONFIG_POSIX_TIMERS. Use the same #ifdef check for the stub version as well. Fixes: 4c22ea2b9120 ("y2038: use compat_{get,set}_itimer on alpha") Reported-by: Guenter Roeck <linux@roeck-us.net> Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20191207191043.656328-1-arnd@arndb.de
2019-12-30ptp: fix the race between the release of ptp_clock and cdevVladis Dronov1-18/+13
In a case when a ptp chardev (like /dev/ptp0) is open but an underlying device is removed, closing this file leads to a race. This reproduces easily in a kvm virtual machine: ts# cat openptp0.c int main() { ... fp = fopen("/dev/ptp0", "r"); ... sleep(10); } ts# uname -r 5.5.0-rc3-46cf053e ts# cat /proc/cmdline ... slub_debug=FZP ts# modprobe ptp_kvm ts# ./openptp0 & [1] 670 opened /dev/ptp0, sleeping 10s... ts# rmmod ptp_kvm ts# ls /dev/ptp* ls: cannot access '/dev/ptp*': No such file or directory ts# ...woken up [ 48.010809] general protection fault: 0000 [#1] SMP [ 48.012502] CPU: 6 PID: 658 Comm: openptp0 Not tainted 5.5.0-rc3-46cf053e #25 [ 48.014624] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), ... [ 48.016270] RIP: 0010:module_put.part.0+0x7/0x80 [ 48.017939] RSP: 0018:ffffb3850073be00 EFLAGS: 00010202 [ 48.018339] RAX: 000000006b6b6b6b RBX: 6b6b6b6b6b6b6b6b RCX: ffff89a476c00ad0 [ 48.018936] RDX: fffff65a08d3ea08 RSI: 0000000000000247 RDI: 6b6b6b6b6b6b6b6b [ 48.019470] ... ^^^ a slub poison [ 48.023854] Call Trace: [ 48.024050] __fput+0x21f/0x240 [ 48.024288] task_work_run+0x79/0x90 [ 48.024555] do_exit+0x2af/0xab0 [ 48.024799] ? vfs_write+0x16a/0x190 [ 48.025082] do_group_exit+0x35/0x90 [ 48.025387] __x64_sys_exit_group+0xf/0x10 [ 48.025737] do_syscall_64+0x3d/0x130 [ 48.026056] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.026479] RIP: 0033:0x7f53b12082f6 [ 48.026792] ... [ 48.030945] Modules linked in: ptp i6300esb watchdog [last unloaded: ptp_kvm] [ 48.045001] Fixing recursive fault but reboot is needed! This happens in: static void __fput(struct file *file) { ... if (file->f_op->release) file->f_op->release(inode, file); <<< cdev is kfree'd here if (unlikely(S_ISCHR(inode->i_mode) && inode->i_cdev != NULL && !(mode & FMODE_PATH))) { cdev_put(inode->i_cdev); <<< cdev fields are accessed here Namely: __fput() posix_clock_release() kref_put(&clk->kref, delete_clock) <<< the last reference delete_clock() delete_ptp_clock() kfree(ptp) <<< cdev is embedded in ptp cdev_put module_put(p->owner) <<< *p is kfree'd, bang! Here cdev is embedded in posix_clock which is embedded in ptp_clock. The race happens because ptp_clock's lifetime is controlled by two refcounts: kref and cdev.kobj in posix_clock. This is wrong. Make ptp_clock's sysfs device a parent of cdev with cdev_device_add() created especially for such cases. This way the parent device with its ptp_clock is not released until all references to the cdev are released. This adds a requirement that an initialized but not exposed struct device should be provided to posix_clock_register() by a caller instead of a simple dev_t. This approach was adopted from the commit 72139dfa2464 ("watchdog: Fix the race between the release of watchdog_core_data and cdev"). See details of the implementation in the commit 233ed09d7fda ("chardev: add helper function to register char devs with a struct device"). Link: https://lore.kernel.org/linux-fsdevel/20191125125342.6189-1-vdronov@redhat.com/T/#u Analyzed-by: Stephen Johnston <sjohnsto@redhat.com> Analyzed-by: Vern Lovejoy <vlovejoy@redhat.com> Signed-off-by: Vladis Dronov <vdronov@redhat.com> Acked-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-18y2038: rename itimerval to __kernel_old_itimervalArnd Bergmann1-9/+9
Take the renaming of timeval and timespec one level further, also renaming itimerval to __kernel_old_itimerval, to avoid namespace conflicts with the user-space structure that may use 64-bit time_t members. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-12-18y2038: remove obsolete jiffies conversion functionsArnd Bergmann1-53/+5
Now that the last user of timespec_to_jiffies() is gone, these can just be removed, everything else is using ktime_t or timespec64 already. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-12-03Merge branch 'timers-core-for-linus' of ↵Linus Torvalds2-15/+22
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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
2019-12-01Merge tag 'y2038-cleanups-5.5' of ↵Linus Torvalds3-76/+147
git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground Pull y2038 cleanups from Arnd Bergmann: "y2038 syscall implementation cleanups This is a series of cleanups for the y2038 work, mostly intended for namespace cleaning: the kernel defines the traditional time_t, timeval and timespec types that often lead to y2038-unsafe code. Even though the unsafe usage is mostly gone from the kernel, having the types and associated functions around means that we can still grow new users, and that we may be missing conversions to safe types that actually matter. There are still a number of driver specific patches needed to get the last users of these types removed, those have been submitted to the respective maintainers" Link: https://lore.kernel.org/lkml/20191108210236.1296047-1-arnd@arndb.de/ * tag 'y2038-cleanups-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (26 commits) y2038: alarm: fix half-second cut-off y2038: ipc: fix x32 ABI breakage y2038: fix typo in powerpc vdso "LOPART" y2038: allow disabling time32 system calls y2038: itimer: change implementation to timespec64 y2038: move itimer reset into itimer.c y2038: use compat_{get,set}_itimer on alpha y2038: itimer: compat handling to itimer.c y2038: time: avoid timespec usage in settimeofday() y2038: timerfd: Use timespec64 internally y2038: elfcore: Use __kernel_old_timeval for process times y2038: make ns_to_compat_timeval use __kernel_old_timeval y2038: socket: use __kernel_old_timespec instead of timespec y2038: socket: remove timespec reference in timestamping y2038: syscalls: change remaining timeval to __kernel_old_timeval y2038: rusage: use __kernel_old_timeval y2038: uapi: change __kernel_time_t to __kernel_old_time_t y2038: stat: avoid 'time_t' in 'struct stat' y2038: ipc: remove __kernel_time_t reference from headers y2038: vdso: powerpc: avoid timespec references ...
2019-11-26Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds1-0/+11
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "The main changes in this cycle were: - Dynamic tick (nohz) updates, perhaps most notably changes to force the tick on when needed due to lengthy in-kernel execution on CPUs on which RCU is waiting. - Linux-kernel memory consistency model updates. - Replace rcu_swap_protected() with rcu_prepace_pointer(). - Torture-test updates. - Documentation updates. - Miscellaneous fixes" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits) security/safesetid: Replace rcu_swap_protected() with rcu_replace_pointer() net/sched: Replace rcu_swap_protected() with rcu_replace_pointer() net/netfilter: Replace rcu_swap_protected() with rcu_replace_pointer() net/core: Replace rcu_swap_protected() with rcu_replace_pointer() bpf/cgroup: Replace rcu_swap_protected() with rcu_replace_pointer() fs/afs: Replace rcu_swap_protected() with rcu_replace_pointer() drivers/scsi: Replace rcu_swap_protected() with rcu_replace_pointer() drm/i915: Replace rcu_swap_protected() with rcu_replace_pointer() x86/kvm/pmu: Replace rcu_swap_protected() with rcu_replace_pointer() rcu: Upgrade rcu_swap_protected() to rcu_replace_pointer() rcu: Suppress levelspread uninitialized messages rcu: Fix uninitialized variable in nocb_gp_wait() rcu: Update descriptions for rcu_future_grace_period tracepoint rcu: Update descriptions for rcu_nocb_wake tracepoint rcu: Remove obsolete descriptions for rcu_barrier tracepoint rcu: Ensure that ->rcu_urgent_qs is set before resched IPI workqueue: Convert for_each_wq to use built-in list check rcu: Several rcu_segcblist functions can be static rcu: Remove unused function hlist_bl_del_init_rcu() Documentation: Rename rcu_node_context_switch() to rcu_note_context_switch() ...
2019-11-25y2038: alarm: fix half-second cut-offArnd Bergmann1-1/+1
Changing alarm_itimer accidentally broke the logic for arithmetic rounding of half seconds in the return code. Change it to a constant based on NSEC_PER_SEC, as suggested by Ben Hutchings. Fixes: bd40a175769d ("y2038: itimer: change implementation to timespec64") Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-11-25Merge branch 'timers/urgent' into timers/core, to pick up fixIngo Molnar3-8/+6
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-21time: Zero the upper 32-bits in __kernel_timespec on 32-bitDmitry Safonov1-1/+2
On compat interfaces, the high order bits of nanoseconds should be zeroed out. This is because the application code or the libc do not guarantee zeroing of these. If used without zeroing, kernel might be at risk of using timespec values incorrectly. Originally it was handled correctly, but lost during is_compat_syscall() cleanup. Revert the condition back to check CONFIG_64BIT. Fixes: 98f76206b335 ("compat: Cleanup in_compat_syscall() callers") Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20191121000303.126523-1-dima@arista.com
2019-11-18Merge tag 'v5.4-rc8' into sched/core, to pick up fixes and dependenciesIngo Molnar1-1/+1
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-15y2038: itimer: change implementation to timespec64Arnd Bergmann1-62/+96
There is no 64-bit version of getitimer/setitimer since that is not actually needed. However, the implementation is built around the deprecated 'struct timeval' type. Change the code to use timespec64 internally to reduce the dependencies on timeval and associated helper functions. Minor adjustments in the code are needed to make the native and compat version work the same way, and to keep the range check working after the conversion. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-11-15y2038: move itimer reset into itimer.cArnd Bergmann1-2/+13
Preparing for a change to the itimer internals, stop using the do_setitimer() symbol and instead use a new higher-level interface. The do_getitimer()/do_setitimer functions can now be made static, allowing the compiler to potentially produce better object code. Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-11-15y2038: use compat_{get,set}_itimer on alphaArnd Bergmann1-2/+2
The itimer handling for the old alpha osf_setitimer/osf_getitimer system calls is identical to the compat version of getitimer/setitimer, so just use those directly. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-11-15y2038: itimer: compat handling to itimer.cArnd Bergmann1-7/+35
The structure is only used in one place, moving it there simplifies the interface and helps with later changes to this code. Rename it to match the other time32 structures in the process. Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-11-15y2038: time: avoid timespec usage in settimeofday()Arnd Bergmann1-11/+9
The compat_get_timeval() and timeval_valid() interfaces are deprecated and getting removed along with the definition of struct timeval itself. Change the two implementations of the settimeofday() system call to open-code these helpers and completely avoid references to timeval. The timeval_valid() call is not needed any more here, only a check to avoid overflowing tv_nsec during the multiplication, as there is another range check in do_sys_settimeofday64(). Tested-by: syzbot+dccce9b26ba09ca49966@syzkaller.appspotmail.com Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-11-15y2038: syscalls: change remaining timeval to __kernel_old_timevalArnd Bergmann1-1/+1
All of the remaining syscalls that pass a timeval (gettimeofday, utime, futimesat) can trivially be changed to pass a __kernel_old_timeval instead, which has a compatible layout, but avoids ambiguity with the timeval type in user space. Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-11-15y2038: uapi: change __kernel_time_t to __kernel_old_time_tArnd Bergmann1-3/+3
This is mainly a patch for clarification, and to let us remove the time_t definition from the kernel to prevent new users from creeping in that might not be y2038-safe. All remaining uses of 'time_t' or '__kernel_time_t' are part of the user API that cannot be changed by that either have a replacement or that do not suffer from the y2038 overflow. Acked-by: Deepa Dinamani <deepa.kernel@gmail.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-11-15y2038: remove CONFIG_64BIT_TIMEArnd Bergmann2-3/+3
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>