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From:   Kees Cook <keescook@chromium.org>
Date:   Fri, 6 Apr 2018 09:47:22 -0700
Message-ID: <CAGXu5jKTtU3fvqP-ygV51WcOAmTkm=y5fysKNv+k0crhJACtVg@mail.gmail.com>
Subject: Re: [bisected] 3c8ba0d61d04ced9f8d9ff93977995a9e4e96e91 oopses on s390
To:     Sebastian Ott <sebott@linux.vnet.ibm.com>,
        Linus Torvalds <torvalds@linux-foundation.org>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Heiko Carstens <heiko.carstens@de.ibm.com>,
        Martin Uecker <Martin.Uecker@med.uni-goettingen.de>,
        Ingo Molnar <mingo@kernel.org>,
        Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
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On Fri, Apr 6, 2018 at 2:47 AM, Sebastian Ott <sebott@linux.vnet.ibm.com> wrote:
> Today's kernel oopsed on s390. Bisect points to:
> 3c8ba0d61d04 ("kernel.h: Retain constant expression output for max()/min()")
>
> [    1.898277] dasd-eckd 0.0.3304: DASD with 4 KB/block, 21636720 KB total size, 48 KB/track, compatible disk layout
> [    1.898308] ------------[ cut here ]------------
> [    1.898310] kernel BUG at block/bio.c:1798!

Well that's extremely bad. :(

> Bisect log and config attached. I'll look at min/max users in the affected
> areas later today.

Seems like a comparison of objdump output with/without the patch may
be needed. And why is this s390 only? Ugh.

-Kees

-- 
Kees Cook
Pixel Security