Re: [PATCH] [RFC] x86: avoid -mtune=atom for objtool warnings

From: Josh Poimboeuf
Date: Wed Mar 01 2017 - 09:47:26 EST


On Wed, Mar 01, 2017 at 10:45:03AM +0100, Arnd Bergmann wrote:
> On Wed, Mar 1, 2017 at 10:34 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> > On Tue, Oct 11, 2016 at 10:38 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> >> On Tuesday, October 11, 2016 10:51:46 AM CEST Josh Poimboeuf wrote:
> >>>
> >>> 3) 0xFC244C03-config:
> >>> drivers/scsi/fnic/fnic_main.o: warning: objtool: fnic_log_q_error() falls through to next function fnic_handle_link_event()
> >>> drivers/scsi/snic/snic_res.o: warning: objtool: .text: unexpected end of section
> >>>
> >>> These look like another bad gcc bug which is truncating functions:
> >>
> >> Same bug for both of them?
> >
> > I ran into this one again today, after updating to the latest gcc-7.0.1:
> >
> > drivers/infiniband/sw/rxe/rxe_resp.o: warning: objtool:
> > rxe_responder()+0xfe: sibling call from callable instruction with
> > changed frame pointer
> >
> > Josh, did you get around to updating objtool the last time I reported it, or
> > is it still the same problem? If this is a new variation, I can provide more
> > details about the failure, otherwise I'll just ignore it for now.
>
> Actually, something must have changed in gcc since last month, I also
> just got a report in another file:
>
> drivers/i2c/busses/i2c-img-scb.o: warning: objtool: img_i2c_probe()
> falls through to next function img_i2c_read_fifo()

This one looks like it could be related to some recent objtool changes
which affect how it interprets 'ud2'. Which commit were you testing
with? Can you provide the .config file, and the object file if it's not
too big?

--
Josh