kernel.git/arch/arm64/kernel/vdso.c, branch linux-4.10.y

arm/arm64: arch_timer: Use archdata to indicate vdso suitability

2016-09-23T16:19:25Z

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 Acked-by: Russell King Acked-by: Marc Zyngier Signed-off-by: Scott Wood Signed-off-by: Will Deacon

arm64: apply __ro_after_init to some objects

2016-08-22T11:32:29Z

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 Signed-off-by: Jisheng Zhang Signed-off-by: Will Deacon

arm64: vdso: constify vm_special_mapping used for aarch32 vectors page

2016-08-22T11:32:22Z

The vm_special_mapping spec which is used for aarch32 vectors page is never modified, so mark it as const. Acked-by: Mark Rutland Signed-off-by: Jisheng Zhang Signed-off-by: Will Deacon

arm64: vdso: add __init section marker to alloc_vectors_page

2016-08-22T11:32:01Z

It is not needed after booting, this patch moves the alloc_vectors_page function to the __init section. Acked-by: Mark Rutland Signed-off-by: Jisheng Zhang Signed-off-by: Will Deacon

arm64: Add support for CLOCK_MONOTONIC_RAW in clock_gettime() vDSO

2016-07-12T15:06:32Z

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 Signed-off-by: Kevin Brodsky Reviewed-by: Dave Martin Acked-by: Will Deacon Signed-off-by: Catalin Marinas

vdso: make arch_setup_additional_pages wait for mmap_sem for write killable

2016-05-24T00:04:14Z

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 Acked-by: Andy Lutomirski [x86 vdso] Acked-by: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

arm64: vdso: avoid virt_to_page() translations on kernel symbols

2016-04-14T15:31:49Z

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 Signed-off-by: Will Deacon

arm64: VDSO: fix coarse clock monotonicity regression

2015-08-10T14:37:45Z

Since 906c55579a63 ("timekeeping: Copy the shadow-timekeeper over the real timekeeper last") it has become possible on arm64 to: - Obtain a CLOCK_MONOTONIC_COARSE or CLOCK_REALTIME_COARSE timestamp via syscall. - Subsequently obtain a timestamp for the same clock ID via VDSO which predates the first timestamp (by one jiffy). This is because arm64's update_vsyscall is deriving the coarse time using the __current_kernel_time interface, when it should really be using the timekeeper object provided to it by the timekeeping core. It happened to work before only because __current_kernel_time would access the same timekeeper object which had been passed to update_vsyscall. This is no longer the case. Signed-off-by: Nathan Lynch Acked-by: Will Deacon Signed-off-by: Catalin Marinas

time: Rename timekeeper::tkr to timekeeper::tkr_mono

2015-03-27T08:45:06Z

In preparation of adding another tkr field, rename this one to tkr_mono. Also rename tk_read_base::base_mono to tk_read_base::base, since the structure is not specific to CLOCK_MONOTONIC and the mono name got added to the tk_read_base instance. Lots of trivial churn. Signed-off-by: Peter Zijlstra (Intel) Acked-by: John Stultz Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20150319093400.344679419@infradead.org Signed-off-by: Ingo Molnar

arm64,ia64,ppc,s390,sh,tile,um,x86,mm: remove default gate area

2014-08-08T22:57:27Z

The core mm code will provide a default gate area based on FIXADDR_USER_START and FIXADDR_USER_END if !defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR). This default is only useful for ia64. arm64, ppc, s390, sh, tile, 64-bit UML, and x86_32 have their own code just to disable it. arm, 32-bit UML, and x86_64 have gate areas, but they have their own implementations. This gets rid of the default and moves the code into ia64. This should save some code on architectures without a gate area: it's now possible to inline the gate_area functions in the default case. Signed-off-by: Andy Lutomirski Acked-by: Nathan Lynch Acked-by: H. Peter Anvin Acked-by: Benjamin Herrenschmidt [in principle] Acked-by: Richard Weinberger [for um] Acked-by: Will Deacon [for arm64] Cc: Catalin Marinas Cc: Will Deacon Cc: Tony Luck Cc: Fenghua Yu Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Chris Metcalf Cc: Jeff Dike Cc: Richard Weinberger Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Nathan Lynch Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds