Gentoo Archives: gentoo-user

From: Adam Carter <adamcarter3@×××××.com>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] AMD microcode updates - where are they?!
Date: Mon, 15 Jul 2019 00:42:35
Message-Id: CAC=wYCGNj=B9tSqiep3=i9H5Xi0ekX7uQXi+rd+Y+BoN=p-1FA@mail.gmail.com
In Reply to: Re: [gentoo-user] AMD microcode updates - where are they?! by Mick
1 > Then I came across this old message regarding Piledriver CPUs:
2 >
3 > https://lists.debian.org/debian-security/2016/03/msg00084.html
4 >
5 > The post refers to model 2 of cpu family 21. Not all models in the same
6 > family, only model 2. So I am thinking although patch files are named per
7 > CPU
8 > family, whether they are applicable and applied as an update to the CPU is
9 > probably determined by the particular CPU *model*. Logically, errata in
10 > previous CPU revisions may have been fixed in later models of the same
11 > family
12 > and therefore such microcode updates would not be needed. When offered by
13 > the
14 > OS the CPU won't select to have them applied.
15 >
16 > This explains why my AMD models, which are later revisions of the same 15h
17 > family do not apply any microcode updates - they don't need them.
18 >
19 > Please share if you know differently and thank you all for your responses.
20
21
22 Sounds reasonable, but the 15h code was updated mid 2018, so unless the cpu
23 or BIOS update is from after then, i would be concerned.
24
25 If your APUs return similar to this then then there's nothing to worry about
26
27 # grep . /sys/devices/system/cpu/vulnerabilities/*
28 /sys/devices/system/cpu/vulnerabilities/l1tf:Not affected
29 /sys/devices/system/cpu/vulnerabilities/mds:Not affected
30 /sys/devices/system/cpu/vulnerabilities/meltdown:Not affected
31 /sys/devices/system/cpu/vulnerabilities/spec_store_bypass:Mitigation:
32 Speculative Store Bypass disabled via prctl and seccomp
33 /sys/devices/system/cpu/vulnerabilities/spectre_v1:Mitigation: __user
34 pointer sanitization
35 /sys/devices/system/cpu/vulnerabilities/spectre_v2:Mitigation: Full AMD
36 retpoline, IBPB: conditional, STIBP: disabled, RSB filling