Re: [PATCH 2/3] tools/objtool: add kasan_check_* to uaccess whitelist

[Peter Zijlstra]

On Wed, May 29, 2019 at 11:46:10AM +0200, Marco Elver wrote:
> On Wed, 29 May 2019 at 10:55, Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
> >
> > On Tue, May 28, 2019 at 7:19 PM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> > >
> > > On Tue, May 28, 2019 at 06:32:57PM +0200, Marco Elver wrote:
> > > > This is a pre-requisite for enabling bitops instrumentation. Some bitops
> > > > may safely be used with instrumentation in uaccess regions.
> > > >
> > > > For example, on x86, `test_bit` is used to test a CPU-feature in a
> > > > uaccess region:   arch/x86/ia32/ia32_signal.c:361
> > >
> > > That one can easily be moved out of the uaccess region. Any else?
> >
> > Marco, try to update config with "make allyesconfig" and then build
> > the kernel without this change.
> >
> 
> Done. The only instance of the uaccess warning is still in
> arch/x86/ia32/ia32_signal.c.
> 
> Change the patch to move this access instead? Let me know what you prefer.

Yes, I think that might be best. The whitelist should be minimal.