wireguard-linux/arch/x86/include/asm/vdso, branch jd/unified-crypt-queue

x86/vdso: Enable x86 to use common headers

2020-03-21T14:24:02Z

Enable x86 to use only the common headers in the implementation of the vDSO library. Signed-off-by: Vincenzo Frascino Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200320145351.32292-24-vincenzo.frascino@arm.com

x86: Introduce asm/vdso/clocksource.h

2020-03-21T14:23:54Z

The vDSO library should only include the necessary headers required for a userspace library (UAPI and a minimal set of kernel headers). To make this possible it is necessary to isolate from the kernel headers the common parts that are strictly necessary to build the library. Introduce asm/vdso/clocksource.h to contain all the arm64 specific functions that are suitable for vDSO inclusion. This header will be required by a future patch that will generalize vdso/clocksource.h. Signed-off-by: Vincenzo Frascino Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200320145351.32292-5-vincenzo.frascino@arm.com

x86/vdso: Use generic VDSO clock mode storage

2020-02-17T13:40:23Z

Switch to the generic VDSO clock mode storage. Signed-off-by: Thomas Gleixner Reviewed-by: Vincenzo Frascino (VDSO parts) Acked-by: Juergen Gross (Xen parts) Acked-by: Paolo Bonzini (KVM parts) Link: https://lkml.kernel.org/r/20200207124403.152039903@linutronix.de

x86/vdso: Move VDSO clocksource state tracking to callback

2020-02-17T13:40:22Z

All architectures which use the generic VDSO code have their own storage for the VDSO clock mode. That's pointless and just requires duplicate code. X86 abuses the function which retrieves the architecture specific clock mode storage to mark the clocksource as used in the VDSO. That's silly because this is invoked on every tick when the VDSO data is updated. Move this functionality to the clocksource::enable() callback so it gets invoked once when the clocksource is installed. This allows to make the clock mode storage generic. Signed-off-by: Thomas Gleixner Reviewed-by: Michael Kelley (Hyper-V parts) Reviewed-by: Vincenzo Frascino (VDSO parts) Acked-by: Juergen Gross (Xen parts) Link: https://lkml.kernel.org/r/20200207124402.934519777@linutronix.de

x86/vdso: Mark the TSC clocksource path likely

2020-02-17T13:40:19Z

Jumping out of line for the TSC clcoksource read is creating awful code. TSC is likely to be the clocksource at least on bare metal and the PV interfaces are sufficiently more work that the jump over the TSC read is just in the noise. Signed-off-by: Thomas Gleixner Reviewed-by: Vincenzo Frascino Link: https://lkml.kernel.org/r/20200207124402.328922847@linutronix.de

x86/vdso: Add time napespace page

2020-01-14T11:20:58Z

To support time namespaces in the VDSO with a minimal impact on regular non time namespace affected tasks, the namespace handling needs to be hidden in a slow path. The most obvious place is vdso_seq_begin(). If a task belongs to a time namespace then the VVAR page which contains the system wide VDSO data is replaced with a namespace specific page which has the same layout as the VVAR page. That page 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. The extra check in the case that vdso_data->seq is odd, e.g. a concurrent update of the VDSO data is in progress, is not really affecting regular tasks which are not part of a time namespace as the task is spin waiting for the update to finish and vdso_data->seq to become even again. If a time namespace task hits that code path, it invokes the corresponding time getter function which retrieves the real VVAR page, reads host time and then adds the offset for the requested clock which is stored in the special VVAR page. Allocate the time namespace page among VVAR pages and place vdso_data on it. Provide __arch_get_timens_vdso_data() helper for VDSO code to get the code-relative position of VVARs on that special page. Co-developed-by: Andrei Vagin Signed-off-by: Andrei Vagin Signed-off-by: Dmitry Safonov Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20191112012724.250792-23-dima@arista.com

x86/vdso: Remove unused VDSO_HAS_32BIT_FALLBACK

2020-01-14T11:20:46Z

VDSO_HAS_32BIT_FALLBACK has been removed from the core since the architectures that support the generic vDSO library have been converted to support the 32 bit fallbacks. Remove unused VDSO_HAS_32BIT_FALLBACK from x86 vdso. Signed-off-by: Vincenzo Frascino Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20190830135902.20861-9-vincenzo.frascino@arm.com

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

2019-09-17T19:35:15Z

Pull core timer updates from Thomas Gleixner: "Timers and timekeeping updates: - A large overhaul of the posix CPU timer code which is a preparation for moving the CPU timer expiry out into task work so it can be properly accounted on the task/process. An update to the bogus permission checks will come later during the merge window as feedback was not complete before heading of for travel. - Switch the timerqueue code to use cached rbtrees and get rid of the homebrewn caching of the leftmost node. - Consolidate hrtimer_init() + hrtimer_init_sleeper() calls into a single function - Implement the separation of hrtimers to be forced to expire in hard interrupt context even when PREEMPT_RT is enabled and mark the affected timers accordingly. - Implement a mechanism for hrtimers and the timer wheel to protect RT against priority inversion and live lock issues when a (hr)timer which should be canceled is currently executing the callback. Instead of infinitely spinning, the task which tries to cancel the timer blocks on a per cpu base expiry lock which is held and released by the (hr)timer expiry code. - Enable the Hyper-V TSC page based sched_clock for Hyper-V guests resulting in faster access to timekeeping functions. - Updates to various clocksource/clockevent drivers and their device tree bindings. - The usual small improvements all over the place" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits) posix-cpu-timers: Fix permission check regression posix-cpu-timers: Always clear head pointer on dequeue hrtimer: Add a missing bracket and hide `migration_base' on !SMP posix-cpu-timers: Make expiry_active check actually work correctly posix-timers: Unbreak CONFIG_POSIX_TIMERS=n build tick: Mark sched_timer to expire in hard interrupt context hrtimer: Add kernel doc annotation for HRTIMER_MODE_HARD x86/hyperv: Hide pv_ops access for CONFIG_PARAVIRT=n posix-cpu-timers: Utilize timerqueue for storage posix-cpu-timers: Move state tracking to struct posix_cputimers posix-cpu-timers: Deduplicate rlimit handling posix-cpu-timers: Remove pointless comparisons posix-cpu-timers: Get rid of 64bit divisions posix-cpu-timers: Consolidate timer expiry further posix-cpu-timers: Get rid of zero checks rlimit: Rewrite non-sensical RLIMIT_CPU comment posix-cpu-timers: Respect INFINITY for hard RTTIME limit posix-cpu-timers: Switch thread group sampling to array posix-cpu-timers: Restructure expiry array posix-cpu-timers: Remove cputime_expires ...

clocksource/drivers/hyperv: Enable TSC page clocksource on 32bit

2019-08-23T14:59:54Z

There is no particular reason to not enable TSC page clocksource on 32-bit. mul_u64_u64_shr() is available and despite the increased computational complexity (compared to 64bit) TSC page is still a huge win compared to MSR-based clocksource. In-kernel reads: MSR based clocksource: 3361 cycles TSC page clocksource: 49 cycles Reads from userspace (utilizing vDSO in case of TSC page): MSR based clocksource: 5664 cycles TSC page clocksource: 131 cycles Enabling TSC page on 32bits allows to get rid of CONFIG_HYPERV_TSCPAGE as it is now not any different from CONFIG_HYPERV_TIMER. Signed-off-by: Vitaly Kuznetsov Signed-off-by: Thomas Gleixner Reviewed-by: Michael Kelley Link: https://lkml.kernel.org/r/20190822083630.17059-1-vkuznets@redhat.com

x86/vdso/32: Use 32bit syscall fallback

2019-07-30T22:09:10Z

The generic VDSO implementation uses the Y2038 safe clock_gettime64() and clock_getres_time64() syscalls as fallback for 32bit VDSO. This breaks seccomp setups because these syscalls might be not (yet) allowed. Implement the 32bit variants which use the legacy syscalls and select the variant in the core library. The 64bit time variants are not removed because they are required for the time64 based vdso accessors. Fixes: 7ac870747988 ("x86/vdso: Switch to generic vDSO implementation") Reported-by: Sean Christopherson Reported-by: Paul Bolle Suggested-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Reviewed-by: Vincenzo Frascino Reviewed-by: Andy Lutomirski Link: https://lkml.kernel.org/r/20190728131648.879156507@linutronix.de