Messages in this thread | | | From | Marco Elver <> | Date | Tue, 2 Jun 2020 21:01:51 +0200 | Subject | Re: [PATCH -tip 1/2] Kconfig: Bump required compiler version of KASAN and UBSAN |
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On Tue, 2 Jun 2020 at 20:57, Nick Desaulniers <ndesaulniers@google.com> wrote: > > On Tue, Jun 2, 2020 at 11:44 AM 'Marco Elver' via Clang Built Linux > <clang-built-linux@googlegroups.com> wrote: > > > > Adds config variable CC_HAS_WORKING_NOSANITIZE, which will be true if we > > have a compiler that does not fail builds due to no_sanitize functions. > > This does not yet mean they work as intended, but for automated > > build-tests, this is the minimum requirement. > > > > For example, we require that __always_inline functions used from > > no_sanitize functions do not generate instrumentation. On GCC <= 7 this > > fails to build entirely, therefore we make the minimum version GCC 8. > > > > For KCSAN this is a non-functional change, however, we should add it in > > case this variable changes in future. > > > > Link: https://lkml.kernel.org/r/20200602175859.GC2604@hirez.programming.kicks-ass.net > > Suggested-by: Peter Zijlstra <peterz@infradead.org> > > Signed-off-by: Marco Elver <elver@google.com> > > Is this a problem only for x86? If so, that's quite a jump in minimal > compiler versions for a feature that I don't think is currently > problematic for other architectures? (Based on > https://lore.kernel.org/lkml/20200529171104.GD706518@hirez.programming.kicks-ass.net/ > )
__always_inline void foo(void) {} __no_sanitize_address void bar(void) { foo(); }
where __no_sanitize_address is implied by 'noinstr' now, and 'noinstr' is no longer just x86.
Therefore, it's broken on *all* architectures. The compiler will just break the build with an error. I don't think we can fix that.
Thanks, -- Marco
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