Messages in this thread |  | | Subject | Re: [RFC 09/10] x86/enter: Create macros to restrict/unrestrict Indirect Branch Speculation | From | Mason <> | Date | Mon, 29 Jan 2018 12:59:46 +0100 |
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[ Dropping large CC list ]
On 25/01/2018 18:16, Greg Kroah-Hartman wrote:
> On Thu, Jan 25, 2018 at 05:19:04PM +0100, Mason wrote: > >> On 23/01/2018 10:30, David Woodhouse wrote: >> >>> Skylake takes predictions from the generic branch target buffer when >>> the RSB underflows. >> >> Adding LAKML. >> >> AFAIU, some ARM Cortex cores have the same optimization. >> (A9 maybe, A17 probably, some recent 64-bit cores) >> >> Are there software work-arounds for Spectre planned for arm32 and arm64? > > Yes, I think they are currently buried in one of the arm64 trees, and > they have been posted to the mailing list a few times in the past.
Found the burial ground, thanks Greg.
https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/log/?h=kpti
Via https://developer.arm.com/support/security-update
"For Cortex-R8, Cortex-A8, Cortex-A9, and Cortex-A17, invalidate the branch predictor using a BPIALL instruction."
The latest arm32 patch series was submitted recently:
https://www.spinics.net/lists/arm-kernel/msg630892.html
Regards.
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