[PATCH 0/5] Spectre big.Little updates
From: linux@armlinux.org.uk (Russell King - ARM Linux)
Date: 2018-09-19 09:48:02
This series of patches allows Spectre to be worked around on big.Little systems, and as far as I'm aware, completes the Spectre workarounds as were known at the beginning of the year for 32-bit ARM. In order to solve Spectre for such systems, we need to introduce per-CPU indirection of the "processor" vtable, but we are unable to use the kernel's per-CPU infrastructure as this is not initialised early enough. To work around that, we fall back to using a static array of processor vtables indexed by the logical CPU number. This should not be a problem as 32-bit ARM systems are limited to 8 logical CPUs. arch/arm/include/asm/cputype.h | 2 ++ arch/arm/include/asm/proc-fns.h | 49 ++++++++++++++++++++++++++++++++--------- arch/arm/kernel/bugs.c | 4 ++-- arch/arm/kernel/head-common.S | 6 ++--- arch/arm/kernel/setup.c | 40 ++++++++++++++++++++------------- arch/arm/kernel/smp.c | 31 ++++++++++++++++++++++++++ arch/arm/mm/proc-v7-bugs.c | 17 ++------------ 7 files changed, 103 insertions(+), 46 deletions(-) -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 13.8Mbps down 630kbps up According to speedtest.net: 13Mbps down 490kbps up