On 11/30/2017 08:39 AM, Will Deacon wrote:
> Hi again,
>
> This is version two of the patches previously posted here:
>
> http://lists.infradead.org/pipermail/linux-arm-kernel/2017-November/542751.html
>
> Changes since v1 include:
>
> * Based on v4.15-rc1
> * Trampoline moved into FIXMAP area
> * Explicit static key replaced by cpu cap
> * Disable SPE for userspace profiling if kernel unmapped at EL0
> * Changed polarity of cpu feature to match config option
> * Changed command-line option so we can force on in future if necessary
> * Changed Falkor workaround to invalidate different page within 2MB region
> * Reworked alternative sequences in entry.S, since the NOP slides with
> kaiser=off were measurable
>
> I experimented with leaving the vbar set to point at the kaiser vectors,
> but I couldn't measure any performance improvement from that and it made
> the code slightly more complicated, so I've left it as-is.
>
> Patches based on 4.15-rc1 and also pushed here:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git kaiser
>
> Feedback welcome, particularly on a better name for the command-line option.
>
I ran this with one of the LTP mmap tests over the weekend. The mmap
test completed successfully but later the machine was spewing I/O
errors. I think this is because of the hardware and not the patches
so I'm running again for good measure.
> Will
>
> --->8
>
> Will Deacon (18):
> arm64: mm: Use non-global mappings for kernel space
> arm64: mm: Temporarily disable ARM64_SW_TTBR0_PAN
> arm64: mm: Move ASID from TTBR0 to TTBR1
> arm64: mm: Remove pre_ttbr0_update_workaround for Falkor erratum
> #E1003
> arm64: mm: Rename post_ttbr0_update_workaround
> arm64: mm: Fix and re-enable ARM64_SW_TTBR0_PAN
> arm64: mm: Allocate ASIDs in pairs
> arm64: mm: Add arm64_kernel_unmapped_at_el0 helper
> arm64: mm: Invalidate both kernel and user ASIDs when performing TLBI
> arm64: entry: Add exception trampoline page for exceptions from EL0
> arm64: mm: Map entry trampoline into trampoline and kernel page tables
> arm64: entry: Explicitly pass exception level to kernel_ventry macro
> arm64: entry: Hook up entry trampoline to exception vectors
> arm64: erratum: Work around Falkor erratum #E1003 in trampoline code
> arm64: tls: Avoid unconditional zeroing of tpidrro_el0 for native
> tasks
> arm64: entry: Add fake CPU feature for unmapping the kernel at EL0
> arm64: Kconfig: Add CONFIG_UNMAP_KERNEL_AT_EL0
> perf: arm_spe: Disallow userspace profiling when
> arm_kernel_unmapped_at_el0()
>
> arch/arm64/Kconfig | 30 +++--
> arch/arm64/include/asm/asm-uaccess.h | 25 +++--
> arch/arm64/include/asm/assembler.h | 27 +----
> arch/arm64/include/asm/cpucaps.h | 3 +-
> arch/arm64/include/asm/fixmap.h | 4 +
> arch/arm64/include/asm/kernel-pgtable.h | 12 +-
> arch/arm64/include/asm/mmu.h | 10 ++
> arch/arm64/include/asm/mmu_context.h | 9 +-
> arch/arm64/include/asm/pgtable-hwdef.h | 1 +
> arch/arm64/include/asm/pgtable-prot.h | 21 +++-
> arch/arm64/include/asm/pgtable.h | 1 +
> arch/arm64/include/asm/proc-fns.h | 6 -
> arch/arm64/include/asm/tlbflush.h | 16 ++-
> arch/arm64/include/asm/uaccess.h | 21 +++-
> arch/arm64/kernel/asm-offsets.c | 6 +-
> arch/arm64/kernel/cpufeature.c | 41 +++++++
> arch/arm64/kernel/entry.S | 190 +++++++++++++++++++++++++++-----
> arch/arm64/kernel/process.c | 12 +-
> arch/arm64/kernel/vmlinux.lds.S | 17 +++
> arch/arm64/lib/clear_user.S | 2 +-
> arch/arm64/lib/copy_from_user.S | 2 +-
> arch/arm64/lib/copy_in_user.S | 2 +-
> arch/arm64/lib/copy_to_user.S | 2 +-
> arch/arm64/mm/cache.S | 2 +-
> arch/arm64/mm/context.c | 36 +++---
> arch/arm64/mm/mmu.c | 23 ++++
> arch/arm64/mm/proc.S | 12 +-
> arch/arm64/xen/hypercall.S | 2 +-
> drivers/perf/arm_spe_pmu.c | 7 ++
> 29 files changed, 407 insertions(+), 135 deletions(-)
>