Re: linux-next: Tree for Mar 18 (objtool)

From: Josh Poimboeuf
Date: Wed Mar 18 2020 - 12:55:46 EST


On Wed, Mar 18, 2020 at 09:48:01AM -0700, Randy Dunlap wrote:
> On 3/18/20 4:09 AM, Stephen Rothwell wrote:
> > Hi all,
> >
> > Changes since 20200317:
> >
>
> Hi,
>
> For some reason, the attached .config file generates over 350 objtool warnings.
> There are all "unreachable instruction" warnings.
>
> Here is a small sample:
>
> mm/page-writeback.o: warning: objtool: __set_page_dirty_nobuffers()+0x25b: unreachable instruction
> kernel/sched/fair.o: warning: objtool: load_balance()+0x54c: unreachable instruction
> kernel/power/process.o: warning: objtool: freeze_kernel_threads()+0x115: unreachable instruction
> mm/readahead.o: warning: objtool: read_cache_pages_invalidate_page()+0x1b5: unreachable instruction
> kernel/power/suspend.o: warning: objtool: suspend_devices_and_enter()+0x101f: unreachable instruction
> kernel/sched/rt.o: warning: objtool: dequeue_top_rt_rq()+0x67: unreachable instruction

WTH. This looks like the BUG "double ud2" problem we saw the other day.

I wonder what changed.

--
Josh