Subject: Re: mmotm 2019-12-10-19-14 uploaded (objtool: func() falls through)

From: Josh Poimboeuf <[email-masked]>
Date: Thu, 12 Dec 2019 14:58:11 -0600

On Thu, Dec 12, 2019 at 12:21:17PM -0800, Randy Dunlap wrote:
> On 12/12/19 10:48 AM, Josh Poimboeuf wrote:
> > On Wed, Dec 11, 2019 at 08:31:08AM -0800, Randy Dunlap wrote:
> >> On 12/10/19 7:14 PM, Andrew Morton wrote:
> >>> The mm-of-the-moment snapshot 2019-12-10-19-14 has been uploaded to
> >>>
> >>>    http://www.ozlabs.org/~akpm/mmotm/
> >>>
> >>> mmotm-readme.txt says
> >>>
> >>> README for mm-of-the-moment:
> >>>
> >>> http://www.ozlabs.org/~akpm/mmotm/
> >>>
> >>> This is a snapshot of my -mm patch queue.  Uploaded at random hopefully
> >>> more than once a week.
> >>>
> >>> You will need quilt to apply these patches to the latest Linus release (5.x
> >>> or 5.x-rcY).  The series file is in broken-out.tar.gz and is duplicated in
> >>> http://ozlabs.org/~akpm/mmotm/series
> >>>
> >>> The file broken-out.tar.gz contains two datestamp files: .DATE and
> >>> .DATE-yyyy-mm-dd-hh-mm-ss.  Both contain the string yyyy-mm-dd-hh-mm-ss,
> >>> followed by the base kernel version against which this patch series is to
> >>> be applied.
> >>
> >> on x86_64:
> >>
> >> drivers/hwmon/f71882fg.o: warning: objtool: f71882fg_update_device() falls through to next function show_pwm_auto_point_temp_hyst()
> >> drivers/ide/ide-probe.o: warning: objtool: hwif_register_devices() falls through to next function hwif_release_dev()
> >> drivers/ide/ide-probe.o: warning: objtool: ide_host_remove() falls through to next function ide_disable_port()
> > 
> > Randy, can you share the .o files?
> 
> Sure. They are attached.

These look like compiler bugs to me... execution is falling off the edge
of the functions for no apparent reason.  Could potentially be triggered
by the '#define if' trace code.

-- 
Josh