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  1. 11 10月, 2021 3 次提交
  3. 30 9月, 2020 1 次提交
  5. 08 5月, 2020 1 次提交
  7. 07 3月, 2020 1 次提交
    • I
      arm64: trap to EL1 accesses to AMU counters from EL0 · 87a1f063
      由 Ionela Voinescu 提交于 
      The activity monitors extension is an optional extension introduced
by the ARMv8.4 CPU architecture. In order to access the activity
monitors counters safely, if desired, the kernel should detect the
presence of the extension through the feature register, and mediate
the access.

Therefore, disable direct accesses to activity monitors counters
from EL0 (userspace) and trap them to EL1 (kernel).

To be noted that the ARM64_AMU_EXTN kernel config does not have an
effect on this code. Given that the amuserenr_el0 resets to an
UNKNOWN value, setting the trap of EL0 accesses to EL1 is always
attempted for safety and security considerations. Therefore firmware
should still ensure accesses to AMU registers are not trapped in
EL2/EL3 as this code cannot be bypassed if the CPU implements the
Activity Monitors Unit.
Signed-off-by: NIonela Voinescu <ionela.voinescu@arm.com>
Reviewed-by: NJames Morse <james.morse@arm.com>
Reviewed-by: NValentin Schneider <valentin.schneider@arm.com>
Reviewed-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
      87a1f063
  9. 27 2月, 2020 1 次提交
    • M
      arm64: mm: convert cpu_do_switch_mm() to C · 25b92693
      由 Mark Rutland 提交于 
      There's no reason that cpu_do_switch_mm() needs to be written as an
assembly function, and having it as a C function would make it easier to
maintain.

This patch converts cpu_do_switch_mm() to C, removing code that this
change makes redundant (e.g. the mmid macro). Since the header comment
was stale and the prototype now implies all the necessary information,
this comment is removed. The 'pgd_phys' argument is made a phys_addr_t
to match the return type of virt_to_phys().

At the same time, post_ttbr_update_workaround() is updated to use
IS_ENABLED(), which allows the compiler to figure out it can elide calls
for !CONFIG_CAVIUM_ERRATUM_27456 builds.

There should be no functional change as a result of this patch.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
[catalin.marinas@arm.com: change comments from asm-style to C-style]
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
      25b92693
  11. 17 1月, 2020 2 次提交
  13. 09 1月, 2020 1 次提交
  15. 08 1月, 2020 1 次提交
    • M
      arm64: asm: Add new-style position independent function annotations · 35e61c77
      由 Mark Brown 提交于 
      As part of an effort to make the annotations in assembly code clearer and
more consistent new macros have been introduced, including replacements
for ENTRY() and ENDPROC().

On arm64 we have ENDPIPROC(), a custom version of ENDPROC() which is
used for code that will need to run in position independent environments
like EFI, it creates an alias for the function with the prefix __pi_ and
then emits the standard ENDPROC. Add new-style macros to replace this
which expand to the standard SYM_FUNC_*() and SYM_FUNC_ALIAS_*(),
resulting in the same object code. These are added in linkage.h for
consistency with where the generic assembler code has its macros.
Signed-off-by: NMark Brown <broonie@kernel.org>
[will: Rename 'WEAK' macro, use ';' instead of ASM_NL, deprecate ENDPIPROC]
Signed-off-by: NWill Deacon <will@kernel.org>
      35e61c77
  17. 08 12月, 2019 1 次提交
  19. 09 8月, 2019 2 次提交
    • S
      arm64: mm: Introduce 52-bit Kernel VAs · b6d00d47
      由 Steve Capper 提交于 
      Most of the machinery is now in place to enable 52-bit kernel VAs that
are detectable at boot time.

This patch adds a Kconfig option for 52-bit user and kernel addresses
and plumbs in the requisite CONFIG_ macros as well as sets TCR.T1SZ,
physvirt_offset and vmemmap at early boot.

To simplify things this patch also removes the 52-bit user/48-bit kernel
kconfig option.
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>
      b6d00d47
    • S
      arm64: mm: Logic to make offset_ttbr1 conditional · c812026c
      由 Steve Capper 提交于 
      When running with a 52-bit userspace VA and a 48-bit kernel VA we offset
ttbr1_el1 to allow the kernel pagetables with a 52-bit PTRS_PER_PGD to
be used for both userspace and kernel.

Moving on to a 52-bit kernel VA we no longer require this offset to
ttbr1_el1 should we be running on a system with HW support for 52-bit
VAs.

This patch introduces conditional logic to offset_ttbr1 to query
SYS_ID_AA64MMFR2_EL1 whenever 52-bit VAs are selected. If there is HW
support for 52-bit VAs then the ttbr1 offset is skipped.

We choose to read a system register rather than vabits_actual because
offset_ttbr1 can be called in places where the kernel data is not
actually mapped.

Calls to offset_ttbr1 appear to be made from rarely called code paths so
this extra logic is not expected to adversely affect performance.
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>
      c812026c
  21. 05 8月, 2019 1 次提交
  23. 05 7月, 2019 1 次提交
    • J
      arm64: assembler: Switch ESB-instruction with a vanilla nop if !ARM64_HAS_RAS · 2b68a2a9
      由 James Morse 提交于 
      The ESB-instruction is a nop on CPUs that don't implement the RAS
extensions. This lets us use it in places like the vectors without
having to use alternatives.

If someone disables CONFIG_ARM64_RAS_EXTN, this instruction still has
its RAS extensions behaviour, but we no longer read DISR_EL1 as this
register does depend on alternatives.

This could go wrong if we want to synchronize an SError from a KVM
guest. On a CPU that has the RAS extensions, but the KConfig option
was disabled, we consume the pending SError with no chance of ever
reading it.

Hide the ESB-instruction behind the CONFIG_ARM64_RAS_EXTN option,
outputting a regular nop if the feature has been disabled.
Reported-by: NJulien Thierry <julien.thierry@arm.com>
Signed-off-by: NJames Morse <james.morse@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
      2b68a2a9
  25. 19 6月, 2019 1 次提交
  27. 14 5月, 2019 1 次提交
  29. 16 4月, 2019 1 次提交
  31. 05 4月, 2019 1 次提交
  33. 01 3月, 2019 1 次提交
    • Z
      arm64: Add workaround for Fujitsu A64FX erratum 010001 · 3e32131a
      由 Zhang Lei 提交于 
      On the Fujitsu-A64FX cores ver(1.0, 1.1), memory access may cause
an undefined fault (Data abort, DFSC=0b111111). This fault occurs under
a specific hardware condition when a load/store instruction performs an
address translation. Any load/store instruction, except non-fault access
including Armv8 and SVE might cause this undefined fault.

The TCR_ELx.NFD1 bit is used by the kernel when CONFIG_RANDOMIZE_BASE
is enabled to mitigate timing attacks against KASLR where the kernel
address space could be probed using the FFR and suppressed fault on
SVE loads.

Since this erratum causes spurious exceptions, which may corrupt
the exception registers, we clear the TCR_ELx.NFDx=1 bits when
booting on an affected CPU.
Signed-off-by: NZhang Lei <zhang.lei@jp.fujitsu.com>
[Generated MIDR value/mask for __cpu_setup(), removed spurious-fault handler
 and always disabled the NFDx bits on affected CPUs]
Signed-off-by: NJames Morse <james.morse@arm.com>
Tested-by: Nzhang.lei <zhang.lei@jp.fujitsu.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
      3e32131a
  35. 27 2月, 2019 1 次提交
  37. 06 2月, 2019 1 次提交
  39. 12 12月, 2018 1 次提交
    • W
      arm64: preempt: Fix big-endian when checking preempt count in assembly · 7faa313f
      由 Will Deacon 提交于 
      Commit 39624469 ("arm64: preempt: Provide our own implementation of
asm/preempt.h") extended the preempt count field in struct thread_info
to 64 bits, so that it consists of a 32-bit count plus a 32-bit flag
indicating whether or not the current task needs rescheduling.

Whilst the asm-offsets definition of TSK_TI_PREEMPT was updated to point
to this new field, the assembly usage was left untouched meaning that a
32-bit load from TSK_TI_PREEMPT on a big-endian machine actually returns
the reschedule flag instead of the count.

Whilst we could fix this by pointing TSK_TI_PREEMPT at the count field,
we're actually better off reworking the two assembly users so that they
operate on the whole 64-bit value in favour of inspecting the thread
flags separately in order to determine whether a reschedule is needed.
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Reported-by: N"kernelci.org bot" <bot@kernelci.org>
Tested-by: NKevin Hilman <khilman@baylibre.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      7faa313f
  41. 11 12月, 2018 3 次提交
    • W
      arm64: Kconfig: Re-jig CONFIG options for 52-bit VA · 68d23da4
      由 Will Deacon 提交于 
      Enabling 52-bit VAs for userspace is pretty confusing, since it requires
you to select "48-bit" virtual addressing in the Kconfig.

Rework the logic so that 52-bit user virtual addressing is advertised in
the "Virtual address space size" choice, along with some help text to
describe its interaction with Pointer Authentication. The EXPERT-only
option to force all user mappings to the 52-bit range is then made
available immediately below the VA size selection.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      68d23da4
    • S
      arm64: mm: introduce 52-bit userspace support · 67e7fdfc
      由 Steve Capper 提交于 
      On arm64 there is optional support for a 52-bit virtual address space.
To exploit this one has to be running with a 64KB page size and be
running on hardware that supports this.

For an arm64 kernel supporting a 48 bit VA with a 64KB page size,
some changes are needed to support a 52-bit userspace:
 * TCR_EL1.T0SZ needs to be 12 instead of 16,
 * TASK_SIZE needs to reflect the new size.

This patch implements the above when the support for 52-bit VAs is
detected at early boot time.

On arm64 userspace addresses translation is controlled by TTBR0_EL1. As
well as userspace, TTBR0_EL1 controls:
 * The identity mapping,
 * EFI runtime code.

It is possible to run a kernel with an identity mapping that has a
larger VA size than userspace (and for this case __cpu_set_tcr_t0sz()
would set TCR_EL1.T0SZ as appropriate). However, when the conditions for
52-bit userspace are met; it is possible to keep TCR_EL1.T0SZ fixed at
12. Thus in this patch, the TCR_EL1.T0SZ size changing logic is
disabled.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      67e7fdfc
    • S
      arm64: mm: Offset TTBR1 to allow 52-bit PTRS_PER_PGD · e842dfb5
      由 Steve Capper 提交于 
      Enabling 52-bit VAs on arm64 requires that the PGD table expands from 64
entries (for the 48-bit case) to 1024 entries. This quantity,
PTRS_PER_PGD is used as follows to compute which PGD entry corresponds
to a given virtual address, addr:

pgd_index(addr) -> (addr >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)

Userspace addresses are prefixed by 0's, so for a 48-bit userspace
address, uva, the following is true:
(uva >> PGDIR_SHIFT) & (1024 - 1) == (uva >> PGDIR_SHIFT) & (64 - 1)

In other words, a 48-bit userspace address will have the same pgd_index
when using PTRS_PER_PGD = 64 and 1024.

Kernel addresses are prefixed by 1's so, given a 48-bit kernel address,
kva, we have the following inequality:
(kva >> PGDIR_SHIFT) & (1024 - 1) != (kva >> PGDIR_SHIFT) & (64 - 1)

In other words a 48-bit kernel virtual address will have a different
pgd_index when using PTRS_PER_PGD = 64 and 1024.

If, however, we note that:
kva = 0xFFFF << 48 + lower (where lower[63:48] == 0b)
and, PGDIR_SHIFT = 42 (as we are dealing with 64KB PAGE_SIZE)

We can consider:
(kva >> PGDIR_SHIFT) & (1024 - 1) - (kva >> PGDIR_SHIFT) & (64 - 1)
 = (0xFFFF << 6) & 0x3FF - (0xFFFF << 6) & 0x3F	// "lower" cancels out
 = 0x3C0

In other words, one can switch PTRS_PER_PGD to the 52-bit value globally
provided that they increment ttbr1_el1 by 0x3C0 * 8 = 0x1E00 bytes when
running with 48-bit kernel VAs (TCR_EL1.T1SZ = 16).

For kernel configuration where 52-bit userspace VAs are possible, this
patch offsets ttbr1_el1 and sets PTRS_PER_PGD corresponding to the
52-bit value.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Suggested-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NSteve Capper <steve.capper@arm.com>
[will: added comment to TTBR1_BADDR_4852_OFFSET calculation]
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      e842dfb5
  43. 10 12月, 2018 2 次提交
    • W
      arm64: Fix minor issues with the dcache_by_line_op macro · 33309ecd
      由 Will Deacon 提交于 
      The dcache_by_line_op macro suffers from a couple of small problems:

First, the GAS directives that are currently being used rely on
assembler behavior that is not documented, and probably not guaranteed
to produce the correct behavior going forward. As a result, we end up
with some undefined symbols in cache.o:

$ nm arch/arm64/mm/cache.o
         ...
         U civac
         ...
         U cvac
         U cvap
         U cvau

This is due to the fact that the comparisons used to select the
operation type in the dcache_by_line_op macro are comparing symbols
not strings, and even though it seems that GAS is doing the right
thing here (undefined symbols by the same name are equal to each
other), it seems unwise to rely on this.

Second, when patching in a DC CVAP instruction on CPUs that support it,
the fallback path consists of a DC CVAU instruction which may be
affected by CPU errata that require ARM64_WORKAROUND_CLEAN_CACHE.

Solve these issues by unrolling the various maintenance routines and
using the conditional directives that are documented as operating on
strings. To avoid the complexity of nested alternatives, we move the
DC CVAP patching to __clean_dcache_area_pop, falling back to a branch
to __clean_dcache_area_poc if DCPOP is not supported by the CPU.
Reported-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Suggested-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      33309ecd
    • M
      arm64: add EXPORT_SYMBOL_NOKASAN() · 386b3c7b
      由 Mark Rutland 提交于 
      So that we can export symbols directly from assembly files, let's make
use of the generic <asm/export.h>. We have a few symbols that we'll want
to conditionally export for !KASAN kernel builds, so we add a helper for
that in <asm/assembler.h>.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      386b3c7b
  45. 07 12月, 2018 1 次提交
  47. 20 9月, 2018 1 次提交
  49. 12 4月, 2018 2 次提交
  51. 20 3月, 2018 1 次提交
  53. 07 2月, 2018 6 次提交