Bug 229215 - hw.spec_store_bypass_disable_active=0 when hw.spec_store_bypass_disable=1 on AMD CPU
Summary: hw.spec_store_bypass_disable_active=0 when hw.spec_store_bypass_disable=1 on ...
Status: New
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: 12.1-RELEASE
Hardware: Any Any
: --- Affects Only Me
Assignee: freebsd-bugs (Nobody)
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2018-06-21 18:01 UTC by Piotr Kubaj
Modified: 2019-10-26 20:09 UTC (History)
6 users (show)

See Also:

Attachments
Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description Piotr Kubaj freebsd_committer freebsd_triage 2018-06-21 18:01:01 UTC 
I have two boxes with AMD Opteron 6262HE and 6386SE.

Both are reportedly vulnerable to Spectre v4, but it's reported that they don't need new microcode, only kernel patches.

I'm running 11-STABLE and have hw.spec_store_bypass_disable=1.

Even then I can see that hw.spec_store_bypass_disable_active is 0.

On another PC, with new Intel microcode from platomav repo, hw.spec_store_bypass_disable_active is 1, which suggests that something is wrong with SSBD for AMD.
Comment 1 Konstantin Belousov freebsd_committer freebsd_triage 2019-04-16 12:36:06 UTC 
SSBD on amd is not implemented.
Comment 2 Piotr Kubaj freebsd_committer freebsd_triage 2019-04-16 12:57:41 UTC 
(In reply to Konstantin Belousov from comment #1)
Then there should be some info to users that they are still vulnerable to variant 4 (at least in console when they switch hw.spec_store_bypass_disable).