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Date:   Wed, 17 May 2023 12:16:03 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Fangrui Song <maskray@google.com>
Cc:     ndesaulniers@google.com, masahiroy@kernel.org,
        linux-kbuild@vger.kernel.org, nathan@kernel.org,
        linux-hardening@vger.kernel.org, jpoimboe@kernel.org,
        llvm@lists.linux.dev, mbenes@suse.cz, linux-kernel@vger.kernel.org,
        trix@redhat.com, peterz@infradead.org
Subject: Re: [PATCH] ubsan: remove cc-option test for UBSAN_TRAP
Message-ID: <202305171215.7C58897@keescook>
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On Wed, May 17, 2023 at 12:09:35PM -0700, Fangrui Song wrote:
> On Wed, May 17, 2023 at 12:08 PM Fangrui Song <maskray@google.com> wrote:
> >
> > On Wed, May 17, 2023 at 12:02 PM Kees Cook <keescook@chromium.org> wrote:
> > >
> > > On Fri, 7 Apr 2023 14:54:06 -0700, Nick Desaulniers wrote:
> > > > -fsanitize-undefined-trap-on-error has been supported since GCC 5.1 and
> > > > Clang 3.2.  The minimum supported version of these according to
> > > > Documentation/process/changes.rst is 5.1 and 11.0.0 respectively. Drop
> > > > this cc-option check.
> > > >
> > > >
> > >
> > > Applied to for-next/hardening, thanks!
> > >
> > > [1/1] ubsan: remove cc-option test for UBSAN_TRAP
> > >       https://git.kernel.org/kees/c/08e4044243a6
> > >
> > > --
> > > Kees Cook
> > >
> > >
> >
> > For this -fsanitize-undefined-trap-on-error, I think we need a v2 patch that
> > tries -fsanitize-trap=all as well.
> 
> Correction: -fsanitize-trap=undefined
> 
> > -fsanitize-undefined-trap-on-error has been deprecated in Clang for 8
> > years, and at some point we will remove the option.
> >
> > GCC implements -fsanitize-trap=all later, but
> > -fsanitize-undefined-trap-on-error is documented as deprecated as
> > well.

Right now all the compilers support the old way, and I'd rather remove a
cc-option call than add two. :)

-- 
Kees Cook