linux-kernel - Re: [PATCH v2] x86: bring back rep movsq for user access on CPUs without ERMS

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAHk-=wiohUShtCtCxee5-SGvMetd6vgnWgboLNHq2m4cpyNUJQ@mail.gmail.com>
Date:   Sun, 3 Sep 2023 14:08:58 -0700
From:   Linus Torvalds <torvalds@...ux-foundation.org>
To:     Mateusz Guzik <mjguzik@...il.com>
Cc:     linux-kernel@...r.kernel.org, linux-arch@...r.kernel.org,
        bp@...en8.de
Subject: Re: [PATCH v2] x86: bring back rep movsq for user access on CPUs
 without ERMS

On Sun, 3 Sept 2023 at 14:06, Mateusz Guzik <mjguzik@...il.com> wrote:
>
> I don't think it is *that* bad. I did a quick sanity check on that
> front by rolling with bpftrace on cases which pass AT_EMPTY_PATH *and*
> provide a path.

I guess you are right - nobody sane would use AT_EMPTY_PATH except if
they don't have a path.

Of course, the only reason we're discussing this in the first place is
because people are doing insane things, which makes _that_ particular
argument very weak indeed...

                     Linus