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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Tue, 22 Mar 2022 09:21:20 -0700
Message-ID: <CAHk-=wjH7rNyP_S7ut3EUPfa_dOYAP1T6yOxS6hdVi3zPV9SzA@mail.gmail.com>
Subject: Re: [PATCH v1] random: block in /dev/urandom
To:     Guenter Roeck <linux@roeck-us.net>
Cc:     "Jason A. Donenfeld" <Jason@zx2c4.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
        linux-arch <linux-arch@vger.kernel.org>,
        Dinh Nguyen <dinguyen@kernel.org>,
        Nick Hu <nickhu@andestech.com>,
        Max Filippov <jcmvbkbc@gmail.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        "David S . Miller" <davem@davemloft.net>,
        Yoshinori Sato <ysato@users.sourceforge.jp>,
        Michal Simek <monstr@monstr.eu>,
        Borislav Petkov <bp@alien8.de>, Guo Ren <guoren@kernel.org>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Joshua Kinard <kumba@gentoo.org>,
        David Laight <David.Laight@aculab.com>,
        Dominik Brodowski <linux@dominikbrodowski.net>,
        Eric Biggers <ebiggers@google.com>,
        Ard Biesheuvel <ardb@kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        Andy Lutomirski <luto@kernel.org>,
        Kees Cook <keescook@chromium.org>,
        Lennart Poettering <mzxreary@0pointer.de>,
        Konstantin Ryabitsev <konstantin@linuxfoundation.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Theodore Ts'o" <tytso@mit.edu>
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On Tue, Mar 22, 2022 at 8:58 AM Guenter Roeck <linux@roeck-us.net> wrote:
>
> This patch (or a later version of it) made it into mainline and causes a
> large number of qemu boot test failures for various architectures (arm,
> m68k, microblaze, sparc32, xtensa are the ones I observed). Common
> denominator is that boot hangs at "Saving random seed:". A sample bisect
> log is attached. Reverting this patch fixes the problem.

Ok, it was worth trying, but yeah, it clearly causes problems for
various platforms that can't do jitter entropy and have nothing else
happening either.

Will revert.

Thanks.

               Linus