Re: Curious about Copy Fail Linux bug and any relation to FreeBSD

On Sat, 2026-05-02 at 17:23 +0200, Dag-Erling Smørgrav wrote:
> Ralf Mardorf <[email protected]> writes:
> > It was once claimed that FreeBSD was not affected by Meltdown and
> > Spectre due to its architecture.
> 
> No, nobody ever made any such claim.  Spectre and Meltdown are CPU-
> level bugs [snip]

You don't need to explain this to me, since I know this.

I'm currently suffering from cervical spine syndrome and can't spend
much time sifting through all the nonsensical claims, but I've already
come across the following in a quick search. At first, there were all
sorts of unbelievable explanations as to why it supposedly only affects
Intel CPUs and why it supposedly doesn't affect FreeBSD, all of them
unqualified claims. Users usually assume the best, while I’ve always
assumed the worst, and so far, I’ve always been right.

-------- Forwarded Message --------
From: Baho Utot <[email protected]>
To: Aryeh Friedman <[email protected]>
Cc: FreeBSD Mailing List <[email protected]>
Subject: Re: Meltdown – Spectre
Date: 01/08/2018 01:53:44 PM
Mailer: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101
Thunderbird/52.5.2



On 1/8/2018 7:37 AM, Aryeh Friedman wrote:


On Mon, Jan 8, 2018 at 7:28 AM, Baho Utot <[email protected] 
<mailto:[email protected]>> wrote:



    On 1/8/2018 4:15 AM, Aryeh Friedman wrote:

        On Mon, Jan 8, 2018 at 3:57 AM, Matthias Apitz
<[email protected]
        <mailto:[email protected]>> wrote:



    This is not operating system specific,  read the papers on theses
    two. it attacks the cpu, usally through a JIT


Please learn a little OS design theory before making insane claims.   
Specifically it *ONLY* effects OS's that rely on the specific CPU 
architecture (vs. a generic one).  Namely if you strictly partition
the page table between userland and kernel space (which xxxBSD has
always done and Linux has not) and don't use any CPU specific
instructions to do so (except for protected vs. unprotected mode in
the original 386 design FreeBSD does not do this while yet again
microslut and linux do).

For more info go read the more technical thread then here in -hackers@
and -current@.

[snip]