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  1. 12 8月, 2016 1 次提交
  3. 04 8月, 2016 1 次提交
    • S
      arm64: Fix copy-on-write referencing in HugeTLB · 747a70e6
      由 Steve Capper 提交于 
      set_pte_at(.) will set or unset the PTE_RDONLY hardware bit before
writing the entry to the table.

This can cause problems with the copy-on-write logic in hugetlb_cow:
 *) hugetlb_cow(.) called to handle a write fault on read only pte,
 *) Before the copy-on-write updates the new page table a call is
    made to pte_same(huge_ptep_get(ptep), pte)), to check for a race,
 *) Because set_pte_at(.) changed the pte, *ptep != pte, and the
    hugetlb_cow(.) code erroneously assumes that it lost the race,
 *) The new page is subsequently freed without being used.

On arm64 this problem only becomes apparent when we apply:
67961f9d mm/hugetlb: fix huge page reserve accounting for private
mappings

When one runs the libhugetlbfs test suite, there are allocation errors
and hugetlbfs pages become erroneously locked in memory as reserved.
(There is a high HugePages_Rsvd: count).

In this patch we introduce pte_same which ignores the PTE_RDONLY bit,
allowing for the libhugetlbfs test suite to pass as expected and
without leaking any reserved HugeTLB pages.
Reported-by: NHuang Shijie <shijie.huang@arm.com>
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      747a70e6
  5. 29 7月, 2016 1 次提交
    • J
      arm64: Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFO · 3146bc64
      由 James Hogan 提交于 
      AT_VECTOR_SIZE_ARCH should be defined with the maximum number of
NEW_AUX_ENT entries that ARCH_DLINFO can contain, but it wasn't defined
for arm64 at all even though ARCH_DLINFO will contain one NEW_AUX_ENT
for the VDSO address.

This shouldn't be a problem as AT_VECTOR_SIZE_BASE includes space for
AT_BASE_PLATFORM which arm64 doesn't use, but lets define it now and add
the comment above ARCH_DLINFO as found in several other architectures to
remind future modifiers of ARCH_DLINFO to keep AT_VECTOR_SIZE_ARCH up to
date.

Fixes: f668cd16 ("arm64: ELF definitions")
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      3146bc64
  7. 27 7月, 2016 2 次提交
  9. 19 7月, 2016 9 次提交
  11. 12 7月, 2016 2 次提交
    • S
      arm64: cpuinfo: Expose MIDR_EL1 and REVIDR_EL1 to sysfs · f8d9f924
      由 Steve Capper 提交于 
      It can be useful for JIT software to be aware of MIDR_EL1 and
REVIDR_EL1 to ascertain the presence of any core errata that could
affect code generation.

This patch exposes these registers through sysfs:

/sys/devices/system/cpu/cpu$ID/regs/identification/midr_el1
/sys/devices/system/cpu/cpu$ID/regs/identification/revidr_el1

where $ID is the cpu number. For big.LITTLE systems, one can have a
mixture of cores (e.g. Cortex A53 and Cortex A57), thus all CPUs need
to be enumerated.

If the kernel does not have valid information to populate these entries
with, an empty string is returned to userspace.

Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NSteve Capper <steve.capper@linaro.org>
[suzuki.poulose@arm.com: ABI documentation updates, hotplug notifiers, kobject changes]
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
      f8d9f924
    • K
      arm64: Add support for CLOCK_MONOTONIC_RAW in clock_gettime() vDSO · 49eea433
      由 Kevin Brodsky 提交于 
      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: NKevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: NDave Martin <dave.martin@arm.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
      49eea433
  13. 08 7月, 2016 1 次提交
  15. 07 7月, 2016 2 次提交
  17. 06 7月, 2016 1 次提交
  19. 04 7月, 2016 13 次提交
  21. 01 7月, 2016 7 次提交