linux-kernel - Re: [PATCH v2 5/7] ubsan: Enable for all*config builds

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: <CAK8P3a1Br8JFJX2PxyjVxMPMhi-y8mxf+vdEAZQq_Wm2wYP7ZA@mail.gmail.com>
Date:   Thu, 3 Dec 2020 09:51:40 +0100
From:   Arnd Bergmann <arnd@...nel.org>
To:     Kees Cook <keescook@...omium.org>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Ard Biesheuvel <ardb@...nel.org>,
        Arnd Bergmann <arnd@...db.de>,
        Masahiro Yamada <masahiroy@...nel.org>,
        Michal Marek <michal.lkml@...kovi.net>,
        Nathan Chancellor <natechancellor@...il.com>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Marco Elver <elver@...gle.com>,
        Randy Dunlap <rdunlap@...radead.org>,
        Dmitry Vyukov <dvyukov@...gle.com>,
        George Popescu <georgepope@...roid.com>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        Peter Oberparleiter <oberpar@...ux.ibm.com>,
        Andrey Ryabinin <aryabinin@...tuozzo.com>,
        clang-built-linux <clang-built-linux@...glegroups.com>,
        Linux Kbuild mailing list <linux-kbuild@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 5/7] ubsan: Enable for all*config builds

On Thu, Dec 3, 2020 at 1:44 AM Kees Cook <keescook@...omium.org> wrote:
>
> With UBSAN_OBJECT_SIZE disabled for GCC, only UBSAN_ALIGNMENT remained
> a noisy UBSAN option. Disable it for COMPILE_TEST so the rest of UBSAN
> can be used for full all*config builds or other large combinations.
>
> Link: https://lore.kernel.org/lkml/CAHk-=wgXW=YLxGN0QVpp-1w5GDd2pf1W-FqY15poKzoVfik2qA@mail.gmail.com/
> Signed-off-by: Kees Cook <keescook@...omium.org>

Have you checked if this has a notable impact on allmodconfig compile speed
with gcc or clang? I think I've seen significant increases in build times before
with this, but I don't remember the actual magnitude.

Making it 20% slower would probably be ok, but making it twice as slow might
be too much.

       Arnd