Subj : how many kernels must a penguin compile before they call it stable?
To   : Benny Pedersen
From : Maurice Kinal
Date : Fri Jul 28 2023 09:54 pm

Hey Benny!

 BP> why do you ask me ?  :=)

You're the one that brought it up.  Anyhow here is what I've figured out so far as zenbleed relates to the local scene.

----- From https://www.xda-developers.com/zenbleed/
Here's a table that should make it all clear:

┌─────────────────┬────────────────────────────────────┐
│                 │Impacted CPUs                       │
├─────────────────┼────────────────────────────────────┤
│Ryzen 3000 Series│All except APUs (e.g. Ryzen 3 3200G)│
├─────────────────┼────────────────────────────────────┤
│Epyc Rome        │All                                 │
├─────────────────┼────────────────────────────────────┤
│Ryzen 4000 Series│All                                 │
├─────────────────┼────────────────────────────────────┤
│Ryzen 5000 Series│Only the 5300U, 5500U, and 5700U    │
├─────────────────┼────────────────────────────────────┤
│Ryzen 7000 Series│Only 7020 APUs (e.g. Ryzen 3 7320U) │
└─────────────────┴────────────────────────────────────┘
-----

Note that "AMD Ryzen 7 5800U with Radeon Graphics", which is a zen3 appears to be safe from this particular cpu exploit.  Also the "AMD Ryzen Embedded R1505G", which runs EuroPoint, is a zen1 and thus not affected by this particular exploit.  However according to lscpu these are the exploits that do exist on that cpu;

Vulnerabilities:
  Itlb multihit:         Not affected
  L1tf:                  Not affected
  Mds:                   Not affected
  Meltdown:              Not affected
  Mmio stale data:       Not affected
  Retbleed:              Mitigation; untrained return thunk; SMT vulnerable
  Spec store bypass:     Mitigation; Speculative Store Bypass disabled via prctl
  Spectre v1:            Mitigation; usercopy/swapgs barriers and __user pointer sanitization
  Spectre v2:            Mitigation; Retpolines, IBPB conditional, STIBP disabled, RSB filling, PBRSB-eIBRS Not affected
  Srbds:                 Not affected
  Tsx async abort:       Not affected

Currently it appears that none of the deployed AMDs in this neck of the woods suffer from this particular exploit (zenbleed) ... :::knocking on wood:::

Life is good,
Maurice

-o    o-   o-  -o   -o   -o    o-  -o   -o    o-   o-   o-  -o   -o   -o   -o
 (\  /)   /)    (\   (\   (\  /)    (\   (\  /)   /)   /)    (\   (\   (\   (\
 ^^  ^^   ^^    ^^   ^^   ^^  ^^    ^^   ^^  ^^   ^^   ^^    ^^   ^^   ^^   ^^
.... Fidonet 4K - You load sixteen penguins and what do you get?
--- GNU bash, version 5.2.15(1)-release (x86_64-pc-linux-gnu)
 * Origin: One of us @ (1:153/7001.2989)

.