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 8bc0dafb5c ("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
- Fix Kconfig indentation (Krzysztof Kozlowski)
- Add SoC specific bindings for RZ/G2N (r8a774b1) (Biju Das)
- Add Microchip PIT64B support (Claudiu Beznea)
- Convert the cadence ttc driver to a platform driver to initialize
later (Rajan Vaja)
- Fix a memory leak when the initialization fails on bcm2835 (Colin
Ian King)
- Use the combo devm_platform_ioremap_resource() function for em-sti,
ti-dm and switch to platform_get_irq (Yangtao Li)
- Fix Exynos naming in the driver (Krzysztof Kozlowski)
- Fix an uninitialized pointer access in ti-dm timer (Tony Lindgren)
- Fix a sparse warning in microchip-pit64b (Claudiu Beznea)
- Code reorg without functional changes for Hyper-V clocksource
(Andrea Parri)
- Decrease the Hyper-V clocksource rating in order to let the stable
TSC to be selected instead (Andrea Parri)
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQRuKdf4M92Gi9vqihve5qtOL396pgUCXiCm6wAKCRDe5qtOL396
pma2AP9SPecUoUxv7Wf0LtnauNPNbDZlUur/F7syq1CELcmBTAD/cl12kl36SMRh
6hRPgzE/7p6H1Aahk/KK3ycVmbuI+gQ=
=DO9a
-----END PGP SIGNATURE-----
Merge tag 'timers-v5.5-rc6' of https://git.linaro.org/people/daniel.lezcano/linux into timers/core
Pull clocksource/events driver updates from Daniel Lezcano
- Add suspend/resume for Hyper-V clocksource (Dexuan Cui)
- Fix Kconfig indentation (Krzysztof Kozlowski)
- Add SoC specific bindings for RZ/G2N (r8a774b1) (Biju Das)
- Add Microchip PIT64B support (Claudiu Beznea)
- Convert the cadence ttc driver to a platform driver to initialize
later (Rajan Vaja)
- Fix a memory leak when the initialization fails on bcm2835 (Colin
Ian King)
- Use the combo devm_platform_ioremap_resource() function for em-sti,
ti-dm and switch to platform_get_irq (Yangtao Li)
- Fix Exynos naming in the driver (Krzysztof Kozlowski)
- Fix an uninitialized pointer access in ti-dm timer (Tony Lindgren)
- Fix a sparse warning in microchip-pit64b (Claudiu Beznea)
- Code reorg without functional changes for Hyper-V clocksource
(Andrea Parri)
- Decrease the Hyper-V clocksource rating in order to let the stable
TSC to be selected instead (Andrea Parri)
The confinement of the 32bit specific VDSO functions missed to define
BUILD_VDSO32 when building a 32bit MIPS kernel:
arch/mips/vdso/vgettimeofday.c: In function __vdso_clock_gettime:
arch/mips/vdso/vgettimeofday.c:17:9: error: implicit declaration of function __cvdso_clock_gettime32
arch/mips/vdso/vgettimeofday.c: In function __vdso_clock_getres:
arch/mips/vdso/vgettimeofday.c:39:9: error: implicit declaration of function __cvdso_clock_getres_time32
Force the define for 32bit builds in the VDSO Makefile.
Fixes: bf279849ad ("lib/vdso: Build 32 bit specific functions in the right context")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul Burton <paulburton@kernel.org>
Link: https://lore.kernel.org/r/87d0bjfaqa.fsf@nanos.tec.linutronix.de
Change the Hyper-V clocksource ratings to 250, below the TSC clocksource
rating of 300. In configurations where Hyper-V offers an InvariantTSC,
the TSC is not marked "unstable", so the TSC clocksource is available
and preferred. With the higher rating, it will be the default. On
older hardware and Hyper-V versions, the TSC is marked "unstable", so no
TSC clocksource is created and the selected Hyper-V clocksource will be
the default.
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200109160650.16150-3-parri.andrea@gmail.com
hyperv_timer.c exports hyperv_cs, which is used by stimers and the
timesync mechanism. However, the clocksource dependency is not
needed: these mechanisms only depend on the partition reference
counter (which can be read via a MSR or via the TSC Reference Page).
Introduce the (function) pointer hv_read_reference_counter, as an
embodiment of the partition reference counter read, and export it
in place of the hyperv_cs pointer. The latter can be removed.
This should clarify that there's no relationship between Hyper-V
stimers & timesync and the Linux clocksource abstractions. No
functional or semantic change.
Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200109160650.16150-2-parri.andrea@gmail.com
Fix up inconsistent usage of upper and lowercase letters in "Exynos"
name.
"EXYNOS" is not an abbreviation but a regular trademarked name.
Therefore it should be written with lowercase letters starting with
capital letter.
The lowercase "Exynos" name is promoted by its manufacturer Samsung
Electronics Co., Ltd., in advertisement materials and on website.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200104152107.11407-12-krzk@kernel.org
Clean-up commit 8c82723414d5 ("clocksource/drivers/timer-ti-dm: Switch to
platform_get_irq") caused a regression where we now try to access
uninitialized data for timer:
drivers/clocksource/timer-ti-dm.c: In function 'omap_dm_timer_probe':
drivers/clocksource/timer-ti-dm.c:798:13: warning: 'timer' may be used
uninitialized in this function [-Wmaybe-uninitialized]
On boot we now get:
Unable to handle kernel NULL pointer dereference at virtual address
00000004
...
(omap_dm_timer_probe) from [<c061ac7c>] (platform_drv_probe+0x48/0x98)
(platform_drv_probe) from [<c0618c04>] (really_probe+0x1dc/0x348)
(really_probe) from [<c0618ef4>] (driver_probe_device+0x5c/0x160)
Let's fix the issue by moving platform_get_irq to happen after timer has
been allocated.
Fixes: bc83caddf1 ("clocksource/drivers/timer-ti-dm: Switch to platform_get_irq")
Cc: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200106203700.21009-1-tony@atomide.com
platform_get_resource(pdev, IORESOURCE_IRQ) is not recommended for
requesting IRQ's resources, as they can be not ready yet. Using
platform_get_irq() instead is preferred for getting IRQ even if it
was not retrieved earlier.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20191221173027.30716-5-tiny.windzz@gmail.com
Use devm_platform_ioremap_resource() to simplify code, which
wraps 'platform_get_resource' and 'devm_ioremap_resource' in a
single helper.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20191221173027.30716-4-tiny.windzz@gmail.com
Use devm_platform_ioremap_resource() to simplify code, which
wraps 'platform_get_resource' and 'devm_ioremap_resource' in a
single helper.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20191221173027.30716-2-tiny.windzz@gmail.com
Currently when setup_irq fails the error exit path will leak the
recently allocated timer structure. Originally the code would
throw a panic but a later commit changed the behaviour to return
via the err_iounmap path and hence we now have a memory leak. Fix
this by adding a err_timer_free error path that kfree's timer.
Addresses-Coverity: ("Resource Leak")
Fixes: 524a7f0898 ("clocksource/drivers/bcm2835_timer: Convert init function to return error")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20191219213246.34437-1-colin.king@canonical.com
Currently TTC driver is TIMER_OF_DECLARE type driver. Because of
that, TTC driver may be initialized before other clock drivers. If
TTC driver is dependent on that clock driver then initialization of
TTC driver will failed.
So use TTC driver as platform driver instead of using
TIMER_OF_DECLARE.
Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1573122988-18399-1-git-send-email-rajan.vaja@xilinx.com
Add driver for Microchip PIT64B timer. Timer could be used in continuous
mode or oneshot mode. The hardware has 2x32 bit registers for period
emulating a 64 bit timer. The LSB_PR and MSB_PR registers are used to
set the period value (compare value). TLSB and TMSB keeps the current
value of the counter. After a compare the TLSB and TMSB register resets.
The driver uses PIT64B timer for clocksource or clockevent. First
requested timer would be registered as clockevent, second one would be
registered as clocksource. Individual PIT64B hardware resources were
used for clocksource and clockevent to be able to support high resolution
timers with this hardware implementation.
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1576235962-30123-3-git-send-email-claudiu.beznea@microchip.com
Currently, the reserved size for a tsc page is 4K, which is enough for
communicating with hypervisor. However, in the case where we want to
export the tsc page to userspace (e.g. for vDSO to read the
clocksource), the tsc page should be at least PAGE_SIZE, otherwise, when
PAGE_SIZE is larger than 4K, extra kernel data will be mapped into
userspace, which means leaking kernel information.
Therefore reserve PAGE_SIZE space for tsc_pg as a preparation for the
vDSO support of ARM64 in the future. Also, while at it, replace all
reference to tsc_pg with hv_get_tsc_page() since it should be the only
interface to access tsc page.
Signed-off-by: Boqun Feng (Microsoft) <boqun.feng@gmail.com>
Cc: linux-hyperv@vger.kernel.org
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20191126021723.4710-1-boqun.feng@gmail.com
Fix lots of typo, spelling, punctuation, and grammar miscues in
drivers/clocksource/Kconfig.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/4deb42a9-82f2-72f9-891f-972a9a399f4f@infradead.org
Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
$ sed -e 's/^ /\t/' -i */Kconfig
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20191120134236.15959-1-krzk@kernel.org
This is needed for hibernation, e.g. when we resume the old kernel, we need
to disable the "current" kernel's TSC page and then resume the old kernel's.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1574233946-48377-1-git-send-email-decui@microsoft.com
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
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: 51218298a2 ("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
Output on success:
1..1
ok 1 exec
# Pass 1 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0
Output on failure:
1..1
not ok 1 36016 16
Bail out!
Output with lack of permissions:
1..1
not ok 1 # SKIP need to run as root
Output without support of time namespaces:
1..1
not ok 1 # SKIP Time namespaces are not supported
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/20191112012724.250792-35-dima@arista.com
Output on success:
1..4
ok 1 host: clock: monotonic cycles: 148323947
ok 2 host: clock: boottime cycles: 148577503
ok 3 ns: clock: monotonic cycles: 137659217
ok 4 ns: clock: boottime cycles: 137959154
# Pass 4 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0
Output with lack of permissions:
1..4
ok 1 host: clock: monotonic cycles: 145671139
ok 2 host: clock: boottime cycles: 146958357
not ok 3 # SKIP need to run as root
Output without support of time namespaces:
1..4
ok 1 host: clock: monotonic cycles: 145671139
ok 2 host: clock: boottime cycles: 146958357
not ok 3 # SKIP Time namespaces are not supported
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/20191112012724.250792-34-dima@arista.com
Check that timer_create() takes into account clock offsets.
Output on success:
1..3
ok 1 clockid=7
ok 2 clockid=1
ok 3 clockid=9
# Pass 3 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0
Output with lack of permissions:
1..3
not ok 1 # SKIP need to run as root
Output without support of time namespaces:
1..3
not ok 1 # SKIP Time namespaces are not supported
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/20191112012724.250792-33-dima@arista.com
Check that /proc/uptime is correct inside a new time namespace.
Output on success:
1..1
ok 1 Passed for /proc/uptime
# Pass 1 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0
Output with lack of permissions:
1..1
not ok 1 # SKIP need to run as root
Output without support of time namespaces:
1..1
not ok 1 # SKIP Time namespaces are not supported
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/20191112012724.250792-32-dima@arista.com
Check that clock_nanosleep() takes into account clock offsets.
Output on success:
1..4
ok 1 clockid: 1 abs:0
ok 2 clockid: 1 abs:1
ok 3 clockid: 9 abs:0
ok 4 clockid: 9 abs:1
Output with lack of permissions:
1..4
not ok 1 # SKIP need to run as root
Output without support of time namespaces:
1..4
not ok 1 # SKIP Time namespaces are not supported
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/20191112012724.250792-31-dima@arista.com
Check that timerfd_create() takes into account clock offsets.
Output on success:
1..3
ok 1 clockid=7
ok 2 clockid=1
ok 3 clockid=9
# Pass 3 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0
Output on failure:
1..3
not ok 1 clockid: 7 elapsed: 0
not ok 2 clockid: 1 elapsed: 0
not ok 3 clockid: 9 elapsed: 0
Bail out!
Output with lack of permissions:
1..3
not ok 1 # SKIP need to run as root
Output without support of time namespaces:
1..3
not ok 1 # SKIP Time namespaces are not supported
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/20191112012724.250792-30-dima@arista.com
A test to check that all supported clocks work on host and inside
a new time namespace. Use both ways to get time: through VDSO and
by entering the kernel with implicit syscall.
Introduce a new timens directory in selftests framework for
the next timens tests.
Output on success:
1..10
ok 1 Passed for CLOCK_BOOTTIME (syscall)
ok 2 Passed for CLOCK_BOOTTIME (vdso)
ok 3 Passed for CLOCK_BOOTTIME_ALARM (syscall)
ok 4 Passed for CLOCK_BOOTTIME_ALARM (vdso)
ok 5 Passed for CLOCK_MONOTONIC (syscall)
ok 6 Passed for CLOCK_MONOTONIC (vdso)
ok 7 Passed for CLOCK_MONOTONIC_COARSE (syscall)
ok 8 Passed for CLOCK_MONOTONIC_COARSE (vdso)
ok 9 Passed for CLOCK_MONOTONIC_RAW (syscall)
ok 10 Passed for CLOCK_MONOTONIC_RAW (vdso)
# Pass 10 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0
Output with lack of permissions:
1..10
not ok 1 # SKIP need to run as root
Output without support of time namespaces:
1..10
not ok 1 # SKIP Time namespaces are not supported
Co-developed-by: Andrei Vagin <avagin@openvz.org>
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/20191112012724.250792-29-dima@arista.com
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
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
As timens page has offsets to data on VVAR page VVAR is going
to be accessed shortly. Set it up with timens in one page fault
as optimization.
Suggested-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/20191112012724.250792-26-dima@arista.com
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.
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/20191112012724.250792-25-dima@arista.com
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
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 <avagin@openvz.org>
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/20191112012724.250792-23-dima@arista.com
VDSO support for time namespaces 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 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.
To prepare the time namespace page the kernel needs to know the vdso_data
offset. Provide arch_get_vdso_data() helper for locating vdso_data on VVAR
page.
Co-developed-by: Andrei Vagin <avagin@openvz.org>
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/20191112012724.250792-22-dima@arista.com
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.
If VDSO time namespace support is disabled the whole magic is compiled out.
Initial testing shows that the disabled case is almost identical to the
host case which does not take the slow timens path. With the special timens
page installed the performance hit is constant time and in the range of
5-7%.
For the vdso functions which are not using the sequence count an
unconditional check for vdso_data->clock_mode is added which switches to
the real vdso when the clock_mode is VCLOCK_TIMENS.
[avagin: Make do_hres_timens() work with raw clocks too: choose vdso_data
pointer by CS_RAW offset.]
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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/20191112012724.250792-21-dima@arista.com
Forbid splitting VVAR VMA resulting in a stricter ABI and reducing the
amount of corner-cases to consider while working further on VDSO time
namespace support.
As the offset from timens to VVAR page is computed compile-time, the pages
in VVAR should stay together and not being partically mremap()'ed.
Co-developed-by: Andrei Vagin <avagin@openvz.org>
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/20191112012724.250792-20-dima@arista.com
Make sure that /proc/uptime is adjusted to the tasks time namespace.
Co-developed-by: Andrei Vagin <avagin@openvz.org>
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/20191112012724.250792-19-dima@arista.com
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
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
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
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
timerfd_settime() accepts an absolute value of the expiration time if
TFD_TIMER_ABSTIME is specified. This value is in the task's time namespace
and has to be converted to the host's time namespace.
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/20191112012724.250792-14-dima@arista.com
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
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
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
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
