linux-stable.git/arch/arm64/kernel/vdso.c, branch linux-4.9.y Linux kernel stable tree arm64, vdso: Define vdso_{start,end} as array 2019-07-10T07:55:46+00:00 Kees Cook keescook@chromium.org 2019-07-05T18:47:20+00:00 830d3a71e1ce42f3a06d071d29ebdd838626b76f Commit dbbb08f500d6146398b794fdc68a8e811366b451 upstream. Adjust vdso_{start|end} to be char arrays to avoid compile-time analysis that flags "too large" memcmp() calls with CONFIG_FORTIFY_SOURCE. Cc: Jisheng Zhang <jszhang@marvell.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
Commit dbbb08f500d6146398b794fdc68a8e811366b451 upstream.

Adjust vdso_{start|end} to be char arrays to avoid compile-time analysis
that flags "too large" memcmp() calls with CONFIG_FORTIFY_SOURCE.

Cc: Jisheng Zhang <jszhang@marvell.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
arm64: vdso: Fix clock_getres() for CLOCK_REALTIME 2019-05-31T13:48:23+00:00 Vincenzo Frascino vincenzo.frascino@arm.com 2019-04-16T16:14:30+00:00 9f641ee2b749d57b4672e4c28f4dba9523923ac4 [ Upstream commit 81fb8736dd81da3fe94f28968dac60f392ec6746 ] clock_getres() in the vDSO library has to preserve the same behaviour of posix_get_hrtimer_res(). In particular, posix_get_hrtimer_res() does: sec = 0; ns = hrtimer_resolution; where 'hrtimer_resolution' depends on whether or not high resolution timers are enabled, which is a runtime decision. The vDSO incorrectly returns the constant CLOCK_REALTIME_RES. Fix this by exposing 'hrtimer_resolution' in the vDSO datapage and returning that instead. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> [will: Use WRITE_ONCE(), move adr off COARSE path, renumber labels, use 'w' reg] Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 81fb8736dd81da3fe94f28968dac60f392ec6746 ]

clock_getres() in the vDSO library has to preserve the same behaviour
of posix_get_hrtimer_res().

In particular, posix_get_hrtimer_res() does:

    sec = 0;
    ns = hrtimer_resolution;

where 'hrtimer_resolution' depends on whether or not high resolution
timers are enabled, which is a runtime decision.

The vDSO incorrectly returns the constant CLOCK_REALTIME_RES. Fix this
by exposing 'hrtimer_resolution' in the vDSO datapage and returning that
instead.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
[will: Use WRITE_ONCE(), move adr off COARSE path, renumber labels, use 'w' reg]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
arm64/vdso: Fix nsec handling for CLOCK_MONOTONIC_RAW 2017-06-29T11:00:30+00:00 Will Deacon will.deacon@arm.com 2017-06-08T23:44:22+00:00 99f66b5182a4f3d89563634f2fe156d4629b9c10 commit dbb236c1ceb697a559e0694ac4c9e7b9131d0b16 upstream. Recently vDSO support for CLOCK_MONOTONIC_RAW was added in 49eea433b326 ("arm64: Add support for CLOCK_MONOTONIC_RAW in clock_gettime() vDSO"). Noticing that the core timekeeping code never set tkr_raw.xtime_nsec, the vDSO implementation didn't bother exposing it via the data page and instead took the unshifted tk->raw_time.tv_nsec value which was then immediately shifted left in the vDSO code. Unfortunately, by accellerating the MONOTONIC_RAW clockid, it uncovered potential 1ns time inconsistencies caused by the timekeeping core not handing sub-ns resolution. Now that the core code has been fixed and is actually setting tkr_raw.xtime_nsec, we need to take that into account in the vDSO by adding it to the shifted raw_time value, in order to fix the user-visible inconsistency. Rather than do that at each use (and expand the data page in the process), instead perform the shift/addition operation when populating the data page and remove the shift from the vDSO code entirely. [jstultz: minor whitespace tweak, tried to improve commit message to make it more clear this fixes a regression] Reported-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Tested-by: Daniel Mentz <danielmentz@google.com> Acked-by: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Stephen Boyd <stephen.boyd@linaro.org> Cc: Miroslav Lichvar <mlichvar@redhat.com> Link: http://lkml.kernel.org/r/1496965462-20003-4-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit dbb236c1ceb697a559e0694ac4c9e7b9131d0b16 upstream.

Recently vDSO support for CLOCK_MONOTONIC_RAW was added in
49eea433b326 ("arm64: Add support for CLOCK_MONOTONIC_RAW in
clock_gettime() vDSO"). Noticing that the core timekeeping code
never set tkr_raw.xtime_nsec, the vDSO implementation didn't
bother exposing it via the data page and instead took the
unshifted tk->raw_time.tv_nsec value which was then immediately
shifted left in the vDSO code.

Unfortunately, by accellerating the MONOTONIC_RAW clockid, it
uncovered potential 1ns time inconsistencies caused by the
timekeeping core not handing sub-ns resolution.

Now that the core code has been fixed and is actually setting
tkr_raw.xtime_nsec, we need to take that into account in the
vDSO by adding it to the shifted raw_time value, in order to
fix the user-visible inconsistency. Rather than do that at each
use (and expand the data page in the process), instead perform
the shift/addition operation when populating the data page and
remove the shift from the vDSO code entirely.

[jstultz: minor whitespace tweak, tried to improve commit
 message to make it more clear this fixes a regression]
Reported-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Tested-by: Daniel Mentz <danielmentz@google.com>
Acked-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Link: http://lkml.kernel.org/r/1496965462-20003-4-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arm/arm64: arch_timer: Use archdata to indicate vdso suitability 2016-09-23T16:19:25+00:00 Scott Wood oss@buserror.net 2016-09-22T08:35:18+00:00 1d8f51d41fc7116f3753fe9f9a5dd93e0b550a2c Instead of comparing the name to a magic string, use archdata to explicitly communicate whether the arch timer is suitable for direct vdso access. Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Scott Wood <oss@buserror.net> Signed-off-by: Will Deacon <will.deacon@arm.com> 
Instead of comparing the name to a magic string, use archdata to
explicitly communicate whether the arch timer is suitable for
direct vdso access.

Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>
arm64: apply __ro_after_init to some objects 2016-08-22T11:32:29+00:00 Jisheng Zhang jszhang@marvell.com 2016-08-15T06:45:46+00:00 5a9e3e156ec1ab26ba70b4c44157858c92bbeee0 These objects are set during initialization, thereafter are read only. Previously I only want to mark vdso_pages, vdso_spec, vectors_page and cpu_ops as __read_mostly from performance point of view. Then inspired by Kees's patch[1] to apply more __ro_after_init for arm, I think it's better to mark them as __ro_after_init. What's more, I find some more objects are also read only after init. So apply __ro_after_init to all of them. This patch also removes global vdso_pagelist and tries to clean up vdso_spec[] assignment code. [1] http://www.spinics.net/lists/arm-kernel/msg523188.html Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Signed-off-by: Will Deacon <will.deacon@arm.com> 
These objects are set during initialization, thereafter are read only.

Previously I only want to mark vdso_pages, vdso_spec, vectors_page and
cpu_ops as __read_mostly from performance point of view. Then inspired
by Kees's patch[1] to apply more __ro_after_init for arm, I think it's
better to mark them as __ro_after_init. What's more, I find some more
objects are also read only after init. So apply __ro_after_init to all
of them.

This patch also removes global vdso_pagelist and tries to clean up
vdso_spec[] assignment code.

[1] http://www.spinics.net/lists/arm-kernel/msg523188.html

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
arm64: vdso: constify vm_special_mapping used for aarch32 vectors page 2016-08-22T11:32:22+00:00 Jisheng Zhang jszhang@marvell.com 2016-08-15T06:45:45+00:00 b6d081bddf397026575a437b603b118dff2606ff The vm_special_mapping spec which is used for aarch32 vectors page is never modified, so mark it as const. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Signed-off-by: Will Deacon <will.deacon@arm.com> 
The vm_special_mapping spec which is used for aarch32 vectors page is
never modified, so mark it as const.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
arm64: vdso: add __init section marker to alloc_vectors_page 2016-08-22T11:32:01+00:00 Jisheng Zhang jszhang@marvell.com 2016-08-15T06:45:44+00:00 1aed28f94ce6c1f6c24bcbbd5fcd749b55f65e9e It is not needed after booting, this patch moves the alloc_vectors_page function to the __init section. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Signed-off-by: Will Deacon <will.deacon@arm.com> 
It is not needed after booting, this patch moves the alloc_vectors_page
function to the __init section.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
arm64: Add support for CLOCK_MONOTONIC_RAW in clock_gettime() vDSO 2016-07-12T15:06:32+00:00 Kevin Brodsky kevin.brodsky@arm.com 2016-07-12T10:24:00+00:00 49eea433b326a0ac5c7c941a011b2c65990bd19b So far the arm64 clock_gettime() vDSO implementation only supported the following clocks, falling back to the syscall for the others: - CLOCK_REALTIME{,_COARSE} - CLOCK_MONOTONIC{,_COARSE} This patch adds support for the CLOCK_MONOTONIC_RAW clock, taking advantage of the recent refactoring of the vDSO time functions. Like the non-_COARSE clocks, this only works when the "arch_sys_counter" clocksource is in use (allowing us to read the current time from the virtual counter register), otherwise we also have to fall back to the syscall. Most of the data is shared with CLOCK_MONOTONIC, and the algorithm is similar. The reference implementation in kernel/time/timekeeping.c shows that: - CLOCK_MONOTONIC = tk->wall_to_monotonic + tk->xtime_sec + timekeeping_get_ns(&tk->tkr_mono) - CLOCK_MONOTONIC_RAW = tk->raw_time + timekeeping_get_ns(&tk->tkr_raw) - tkr_mono and tkr_raw are identical (in particular, same clocksource), except these members: * mult (only mono's multiplier is NTP-adjusted) * xtime_nsec (always 0 for raw) Therefore, tk->raw_time and tkr_raw->mult are now also stored in the vDSO data page. Cc: Ali Saidi <ali.saidi@arm.com> Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Reviewed-by: Dave Martin <dave.martin@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
So far the arm64 clock_gettime() vDSO implementation only supported
the following clocks, falling back to the syscall for the others:
- CLOCK_REALTIME{,_COARSE}
- CLOCK_MONOTONIC{,_COARSE}

This patch adds support for the CLOCK_MONOTONIC_RAW clock, taking
advantage of the recent refactoring of the vDSO time functions. Like
the non-_COARSE clocks, this only works when the "arch_sys_counter"
clocksource is in use (allowing us to read the current time from the
virtual counter register), otherwise we also have to fall back to the
syscall.

Most of the data is shared with CLOCK_MONOTONIC, and the algorithm is
similar. The reference implementation in kernel/time/timekeeping.c
shows that:
- CLOCK_MONOTONIC = tk->wall_to_monotonic + tk->xtime_sec +
  timekeeping_get_ns(&tk->tkr_mono)
- CLOCK_MONOTONIC_RAW = tk->raw_time + timekeeping_get_ns(&tk->tkr_raw)
- tkr_mono and tkr_raw are identical (in particular, same
  clocksource), except these members:
  * mult (only mono's multiplier is NTP-adjusted)
  * xtime_nsec (always 0 for raw)

Therefore, tk->raw_time and tkr_raw->mult are now also stored in the
vDSO data page.

Cc: Ali Saidi <ali.saidi@arm.com>
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
vdso: make arch_setup_additional_pages wait for mmap_sem for write killable 2016-05-24T00:04:14+00:00 Michal Hocko mhocko@suse.com 2016-05-23T23:25:54+00:00 69048176078adda4087a648c9b1812ddd800fad1 most architectures are relying on mmap_sem for write in their arch_setup_additional_pages. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Andy Lutomirski <luto@amacapital.net> [x86 vdso] Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
most architectures are relying on mmap_sem for write in their
arch_setup_additional_pages.  If the waiting task gets killed by the oom
killer it would block oom_reaper from asynchronous address space reclaim
and reduce the chances of timely OOM resolving.  Wait for the lock in
the killable mode and return with EINTR if the task got killed while
waiting.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>	[x86 vdso]
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arm64: vdso: avoid virt_to_page() translations on kernel symbols 2016-04-14T15:31:49+00:00 Ard Biesheuvel ard.biesheuvel@linaro.org 2016-03-30T14:45:56+00:00 97bbb54e4f27f4c63645f603bf767183ee0dd549 The translation performed by virt_to_page() is only valid for linear addresses, and kernel symbols are no longer in the linear mapping. So perform the __pa() translation explicitly, which does the right thing in either case, and only then translate to a struct page offset. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> 
The translation performed by virt_to_page() is only valid for linear
addresses, and kernel symbols are no longer in the linear mapping.
So perform the __pa() translation explicitly, which does the right
thing in either case, and only then translate to a struct page offset.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>