Subject: [GIT pull] x86/srbds: Special Register Buffer Data Sampling (SRBDS)

Linus,

please pull the x86/srbds branch from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/srbds

up to: 3798cc4d106e ("x86/speculation: Add Ivy Bridge to affected list")

The 9th episode of the dime novel "The performance killer" with the
subtitle "Slow Randomizing Boosts Denial of Service".

SRBDS is an MDS-like speculative side channel that can leak bits from the
random number generator (RNG) across cores and threads. New microcode
serializes the processor access during the execution of RDRAND and
RDSEED. This ensures that the shared buffer is overwritten before it is
released for reuse.

The mitigation support comes with the usual pile of unpleasent
ingredients:

 - command line options
 - sysfs file
 - microcode checks
 - a list of vulnerable CPUs

Thanks,

        tglx
---
P.S. : The virtual tip branch is attached as bundle, based on
       5.7-rc2 and still merges fine into mainline.

P.P.S: The backports will come in a separate mail.