This is a backport to v4.4 of the Spectre v1 and v2 mitigations for 32-bit ARM that have already been backported to v4.9.
Patches #17 and up were cherry-picked from the v4.9 tree, and applied cleanly. The first 16 patches are prerequisites that were introduced between v4.4 and v4.9, and some needed minor massaging to apply. Some notable issues: - the 32-bit KVM host parts were omitted, given the lack of demand and the fact that those pieces saw significantly more churn during the v4.4-v4.9 timeframe due to the fact that the code is shared with arm64 - some other changes are shared between ARM and arm64 (notably, the ARM SMCCCC changes), so the backport affects both architectures.
Patches can be found at [0]. They were build and boot tested using a variety of ARM and arm64 configs and platforms, both locally and on KernelCI.
An RFC of this series was sent out to the linux-arm-kernel mailing list and cc'ed to the maintainer, and no objections were raised. (The only difference between the RFC and this submission is that I have dropped a couple of mostly unrelated patches that were only there to make patch #8 match its context more closely in the file include/linux/arm-smccc.h)
Cc: Russell King rmk+kernel@armlinux.org.uk Cc: Linus Walleij linus.walleij@linaro.org
[0] https://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git/log/?h=arm32-... [1] https://lore.kernel.org/linux-arm-kernel/20191105205846.1394-1-ardb@kernel.o...
Andrey Ryabinin (1): ARM: 8051/1: put_user: fix possible data corruption in put_user
Jens Wiklander (4): ARM: 8478/2: arm/arm64: add arm-smccc ARM: 8479/2: add implementation for arm-smccc ARM: 8480/2: arm64: add implementation for arm-smccc ARM: 8481/2: drivers: psci: replace psci firmware calls
Julien Thierry (8): ARM: 8789/1: signal: copy registers using __copy_to_user() ARM: 8791/1: vfp: use __copy_to_user() when saving VFP state ARM: 8792/1: oabi-compat: copy oabi events using __copy_to_user() ARM: 8793/1: signal: replace __put_user_error with __put_user ARM: 8794/1: uaccess: Prevent speculative use of the current addr_limit ARM: 8795/1: spectre-v1.1: use put_user() for __put_user() ARM: 8796/1: spectre-v1,v1.1: provide helpers for address sanitization ARM: 8810/1: vfp: Fix wrong assignement to ufp_exc
Marc Zyngier (3): arm/arm64: smccc: Add SMCCC-specific return codes arm/arm64: smccc-1.1: Make return values unsigned long arm/arm64: smccc-1.1: Handle function result as parameters
Mark Rutland (6): arm/arm64: KVM: Advertise SMCCC v1.1 arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening support firmware/psci: Expose PSCI conduit firmware/psci: Expose SMCCC version through psci_ops arm/arm64: smccc: Make function identifiers an unsigned quantity arm/arm64: smccc: Implement SMCCC v1.1 inline primitive
Russell King (27): ARM: uaccess: remove put_user() code duplication ARM: add more CPU part numbers for Cortex and Brahma B15 CPUs ARM: bugs: prepare processor bug infrastructure ARM: bugs: hook processor bug checking into SMP and suspend paths ARM: bugs: add support for per-processor bug checking ARM: spectre: add Kconfig symbol for CPUs vulnerable to Spectre ARM: spectre-v2: harden branch predictor on context switches ARM: spectre-v2: add Cortex A8 and A15 validation of the IBE bit ARM: spectre-v2: harden user aborts in kernel space ARM: spectre-v2: add firmware based hardening ARM: spectre-v2: warn about incorrect context switching functions ARM: spectre-v1: add speculation barrier (csdb) macros ARM: spectre-v1: add array_index_mask_nospec() implementation ARM: spectre-v1: fix syscall entry ARM: signal: copy registers using __copy_from_user() ARM: vfp: use __copy_from_user() when restoring VFP state ARM: oabi-compat: copy semops using __copy_from_user() ARM: use __inttype() in get_user() ARM: spectre-v1: use get_user() for __get_user() ARM: spectre-v1: mitigate user accesses ARM: make lookup_processor_type() non-__init ARM: split out processor lookup ARM: clean up per-processor check_bugs method call ARM: add PROC_VTABLE and PROC_TABLE macros ARM: spectre-v2: per-CPU vtables to work around big.Little systems ARM: ensure that processor vtables is not lost after boot ARM: fix the cockup in the previous patch
Vladimir Murzin (1): ARM: Move system register accessors to asm/cp15.h
arch/arm/Kconfig | 3 +- arch/arm/include/asm/arch_gicv3.h | 27 +- arch/arm/include/asm/assembler.h | 23 ++ arch/arm/include/asm/barrier.h | 34 +++ arch/arm/include/asm/bugs.h | 6 +- arch/arm/include/asm/cp15.h | 18 ++ arch/arm/include/asm/cputype.h | 9 + arch/arm/include/asm/proc-fns.h | 65 ++++- arch/arm/include/asm/system_misc.h | 15 ++ arch/arm/include/asm/thread_info.h | 8 +- arch/arm/include/asm/uaccess.h | 177 +++++++----- arch/arm/kernel/Makefile | 4 +- arch/arm/kernel/armksyms.c | 6 + arch/arm/kernel/bugs.c | 18 ++ arch/arm/kernel/entry-common.S | 18 +- arch/arm/kernel/entry-header.S | 25 ++ arch/arm/kernel/head-common.S | 6 +- arch/arm/kernel/psci-call.S | 31 --- arch/arm/kernel/setup.c | 40 +-- arch/arm/kernel/signal.c | 125 +++++---- arch/arm/kernel/smccc-call.S | 62 +++++ arch/arm/kernel/smp.c | 36 +++ arch/arm/kernel/suspend.c | 2 + arch/arm/kernel/sys_oabi-compat.c | 16 +- arch/arm/lib/copy_from_user.S | 5 + arch/arm/mm/Kconfig | 23 ++ arch/arm/mm/Makefile | 2 +- arch/arm/mm/fault.c | 3 + arch/arm/mm/proc-macros.S | 13 +- arch/arm/mm/proc-v7-2level.S | 6 - arch/arm/mm/proc-v7-bugs.c | 161 +++++++++++ arch/arm/mm/proc-v7.S | 154 ++++++++--- arch/arm/vfp/vfpmodule.c | 37 ++- arch/arm64/Kconfig | 1 + arch/arm64/kernel/Makefile | 4 +- arch/arm64/kernel/arm64ksyms.c | 5 + arch/arm64/kernel/asm-offsets.c | 3 + arch/arm64/kernel/psci-call.S | 28 -- arch/arm64/kernel/smccc-call.S | 43 +++ drivers/firmware/Kconfig | 3 + drivers/firmware/psci.c | 78 +++++- include/linux/arm-smccc.h | 283 ++++++++++++++++++++ include/linux/psci.h | 13 + 43 files changed, 1313 insertions(+), 326 deletions(-) create mode 100644 arch/arm/kernel/bugs.c delete mode 100644 arch/arm/kernel/psci-call.S create mode 100644 arch/arm/kernel/smccc-call.S create mode 100644 arch/arm/mm/proc-v7-bugs.c delete mode 100644 arch/arm64/kernel/psci-call.S create mode 100644 arch/arm64/kernel/smccc-call.S create mode 100644 include/linux/arm-smccc.h