Post ASyx9RdTUbLvp0hsTQ by taviso@social.sdf.org
 (DIR) More posts by taviso@social.sdf.org
 (DIR) Post #ASyZgIH2vFrRRXLYTg by taviso@social.sdf.org
       2023-02-23T15:57:37Z
       
       0 likes, 2 repeats
       
       I couldn't understand why AVX registers were randomly going back in time on Ryzen, turns out it's a known CPU errata 😬https://lkml.org/lkml/2023/2/22/33
       
 (DIR) Post #ASyw2patuvdq98mkrI by lanodan@queer.hacktivis.me
       2023-02-23T20:14:13.013119Z
       
       0 likes, 0 repeats
       
       @taviso Interestingly it doesn’t seems to reproduce here.$ uname -aLinux NightmareMoon 5.15.80-gentoo #2 SMP Tue Dec 6 00:58:31 2022 x86_64 AMD Ryzen 7 3700X 8-Core Processor AuthenticAMD GNU/Linux
       
 (DIR) Post #ASywSyiOd1o5xnl85o by taviso@social.sdf.org
       2023-02-23T20:17:18Z
       
       0 likes, 0 repeats
       
       @lanodan Sounds like it might be vulnerable, maybe gentoo already has the most recent microcode?
       
 (DIR) Post #ASywSzGQaV1rfLgJ8a by lanodan@queer.hacktivis.me
       2023-02-23T20:18:49.892945Z
       
       0 likes, 0 repeats
       
       @taviso Yeah, I forgot to dig the thread, I'm on 0x8701021 and that's with the stabilized version of linux-firmware.
       
 (DIR) Post #ASywlpStFD0EmEUkim by lanodan@queer.hacktivis.me
       2023-02-23T20:22:20.871610Z
       
       0 likes, 0 repeats
       
       @taviso It does makes me wish for something like a feed from CPU vendors to know about microcode fixes, because I don't think it's in CVEs
       
 (DIR) Post #ASyx9RdTUbLvp0hsTQ by taviso@social.sdf.org
       2023-02-23T20:25:14Z
       
       1 likes, 0 repeats
       
       @lanodan Yeah, although they tend to be very secretive with details, like "under unspecified complex conditions unspecified errors can occur" 😂 It's very rare we actually get to see a repro!
       
 (DIR) Post #ASzmoiJtSf7J6Nz3Sa by amonakov@mastodon.gamedev.place
       2023-02-24T05:59:07Z
       
       0 likes, 0 repeats
       
       @taviso @lanodan Yeah, amazing that you managed to condense the problem to that tiny repro. How many instructions beside ucomiss did you check?By the way, LKML and other lists are much easier to read on lore.kernel.org, e.g. https://lore.kernel.org/lkml/Y%2FW4x7%2FKFqmDmmR7@thinkstation.cmpxchg8b.net/T/#u
       
 (DIR) Post #ASzmojB4GxeRlIrWLI by lanodan@queer.hacktivis.me
       2023-02-24T06:05:32.879367Z
       
       0 likes, 0 repeats
       
       @amonakov @taviso And I guess the nice things about lore on technical side:- Even with all the messages, it's still often much more lightweight- Can be used via NNTP (great to browse in a client but also grab archives), git, …- Download option, including for individual messages, making it great for patches