Spectre big.Little updates
Get series with b4
b4 am [email protected]Versions newest first · linked by author and title
- v2 Latest0 of 5 patches 0 repliesNew
- v14 of 5 patches 0 repliesSuperseded
Changes in v2 from the cover letter
We use CPU0's vtable for some of the function methods to avoid using the CPU number in pre-emptable code, and validate that these methods are identical across all CPUs in the system.
Patches in v2 No applies recorded yet
None of the 5 patches the cover letter announces are in this archive.
Reviews trailers per patch
| Patch | Julien Thierry | Krzysztof Kozlowski |
|---|---|---|
| Series | R-b R-b R-b R-b R-b | T-b |
Trailers given in replies are filled; those carried in the patches from earlier versions are outlined with dashes.
Cover letter [PATCH v2 0/5] Spectre big.Little updates
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.
Changes in v2:
We use CPU0's vtable for some of the function methods to avoid using the CPU number in pre-emptable code, and validate that these methods are identical across all CPUs in the system.
arch/arm/include/asm/cputype.h | 1 + arch/arm/include/asm/proc-fns.h | 58 ++++++++++++++++++++++++++++++++--------- 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, 110 insertions(+), 47 deletions(-)
Signature · 3 lines
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up