Re: [tip:x86/seves] BUILD SUCCESS WITH WARNING e6eb15c9ba3165698488ae5c34920eea20eaa38e

peterz
2020-09-16T08:30:55Z

On Tue, Sep 15, 2020 at 08:09:16PM +0200, Marco Elver wrote:
> On Tue, 15 Sep 2020 at 19:40, Nick Desaulniers <ndesaulniers@google.com> wrote:
> > On Tue, Sep 15, 2020 at 10:21 AM Borislav Petkov <bp@alien8.de> wrote:

> > > init/calibrate.o: warning: objtool: asan.module_ctor()+0xc: call without frame pointer save/setup
> > > init/calibrate.o: warning: objtool: asan.module_dtor()+0xc: call without frame pointer save/setup
> > > init/version.o: warning: objtool: asan.module_ctor()+0xc: call without frame pointer save/setup
> > > init/version.o: warning: objtool: asan.module_dtor()+0xc: call without frame pointer save/setup
> > > certs/system_keyring.o: warning: objtool: asan.module_ctor()+0xc: call without frame pointer save/setup
> > > certs/system_keyring.o: warning: objtool: asan.module_dtor()+0xc: call without frame pointer save/setup
>
> This one also appears with Clang 11. This is new I think because we
> started emitting ASAN ctors for globals redzone initialization.
>
> I think we really do not care about precise stack frames in these
> compiler-generated functions. So, would it be reasonable to make
> objtool ignore all *san.module_ctor and *san.module_dtor functions (we
> have them for ASAN, TSAN, MSAN)?

The thing is, if objtool cannot follow, it cannot generate ORC data and
our unwinder cannot unwind through the instrumentation, and that is a
fail.

Or am I missing something here?