From: "Jason A. Donenfeld" <Jason@zx2c4.com>
To: Germano Massullo <germano.massullo@gmail.com>
Cc: WireGuard mailing list <wireguard@lists.zx2c4.com>
Subject: Re: AMD RDRAND
Date: Tue, 12 Jan 2021 00:20:40 +0100 [thread overview]
Message-ID: <CAHmME9qzEYxA6uES=Mq8zUrUCogsrP_BmSasVH++_T=2VvennA@mail.gmail.com> (raw)
In-Reply-To: <78d6a7df-fa89-7d75-480b-aea3c52f72ee@gmail.com>
Hi Germano,
On Mon, Jan 11, 2021 at 10:54 PM Germano Massullo
<germano.massullo@gmail.com> wrote:
>
> I would like to inform Wireguard developers about the following.
> it seems that this [1] old AMD RDRAND problem is still present:
> RDRAND on AMD Ryzen 9 5900X is flakey -
> https://github.com/systemd/systemd/issues/18184
>
> I own 2x Ryzen 3600, feel free to write me in case you would like to run
> some tests
>
> [1]:
> https://arstechnica.com/gadgets/2019/10/how-a-months-old-amd-microcode-bug-destroyed-my-weekend/
I fixed this already, by removing the use of RDRAND from
get_random_{u32,u64,int,long} entirely:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=69efea712f5b0489e67d07565aad5c94e09a3e52
This happened almost a year ago back in February, and was backported
to the stable kernels too, which means you should have no issues
finding a working kernel for your brand new Ryzen.
Is this actually a problem you're experiencing or is your report
mostly just speculation based on that systemd issue you linked to?
Jason
next prev parent reply other threads:[~2021-01-11 23:21 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-11 21:52 Germano Massullo
2021-01-11 23:20 ` Jason A. Donenfeld [this message]
2021-01-12 12:07 ` Germano Massullo
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