Re: [PATCH] ubsan: remove cc-option test for UBSAN_TRAP

[Fangrui Song]

On Wed, May 17, 2023 at 12:16 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>
> 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@xxxxxxxxxx> wrote:
> > >
> > > On Wed, May 17, 2023 at 12:02 PM Kees Cook <keescook@xxxxxxxxxxxx> 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

Hmm, this gives Clang developers a disadvantage... Anyone who removes
Clang's -fsanitize-undefined-trap-on-error (or give it a warning
before removal) will probably face complaints from kernel
developers...



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