arm64: Unmap the kernel whilst running in userspace (KAISER)

From: Will Deacon <will.deacon-AT-arm.com> To: linux-arm-kernel-AT-lists.infradead.org Subject: [PATCH v2 00/18] arm64: Unmap the kernel whilst running in userspace (KAISER) Date: Thu, 30 Nov 2017 16:39:28 +0000 Message-ID: <1512059986-21325-1-git-send-email-will.deacon@arm.com> Cc: linux-kernel-AT-vger.kernel.org, catalin.marinas-AT-arm.com, mark.rutland-AT-arm.com, ard.biesheuvel-AT-linaro.org, sboyd-AT-codeaurora.org, dave.hansen-AT-linux.intel.com, keescook-AT-chromium.org, msalter-AT-redhat.com, labbott-AT-redhat.com, tglx-AT-linutronix.de, Will Deacon <will.deacon-AT-arm.com>

Hi again, This is version two of the patches previously posted here: http://lists.infradead.org/pipermail/linux-arm-kernel/201... 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. 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(-) -- 2.1.4