linux-kernel - Re: x86/random: Speculation to the rescue

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-=whgfz2+OgBTVrHLoHK57emYb4gN6TtJ_s-607U=jBQ+ig@mail.gmail.com>
Date:   Sun, 6 Oct 2019 11:06:38 -0700
From:   Linus Torvalds <torvalds@...ux-foundation.org>
To:     Pavel Machek <pavel@....cz>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        "Ahmed S. Darwish" <darwish.07@...il.com>,
        LKML <linux-kernel@...r.kernel.org>,
        "Theodore Ts'o" <tytso@....edu>,
        Nicholas Mc Guire <hofrat@...ntech.at>,
        "the arch/x86 maintainers" <x86@...nel.org>,
        Andy Lutomirski <luto@...nel.org>,
        Kees Cook <keescook@...omium.org>
Subject: Re: x86/random: Speculation to the rescue

On Sun, Oct 6, 2019 at 10:35 AM Pavel Machek <pavel@....cz> wrote:
>
> It will not: boot is now halted because systemd wants some
> entropy. Everything is idle and very little interrupts are
> happening. We have spinning rust, but it is idle, and thus not
> generating any interrupts.

Yes, but we have that problem now solved.

Except on embedded platforms that have garbage CPU's without even a
cycle counter.

But those won't have spinning rust anyway.

Yes, bad SSD's and MMC disks (that they do have) will generate timing
noise too, but in the absense of a cycle counter, that noise won't be
much use.

                 Linus