Re: objtool failures with -march=atom

[Arnd Bergmann]

On Wed, Jul 26, 2017 at 3:55 PM, Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:
> On Wed, Jul 26, 2017 at 12:12:04PM +0200, Arnd Bergmann wrote:
>> With the latest objtool failure, I get countless warnings when
>> -march=atom or -mtune=atom is used,
>> at least with gcc-4.9 through gcc-7 (I did not try older versions:
>>
>> kernel/sched/core.o: warning: objtool:
>> trace_raw_output_sched_stat_runtime()+0x9a: return with modified stack
>> frame
>> kernel/sched/core.o: warning: objtool: cpu_cgroup_fork()+0x7c: return
>> with modified stack frame
>> kernel/sched/core.o: warning: objtool: walk_tg_tree_from()+0xd3:
>> return with modified stack frame
>> kernel/sched/core.o: warning: objtool: ttwu_do_wakeup()+0x2a8: return
>> with modified stack frame
>> kernel/sched/core.o: warning: objtool: do_set_cpus_allowed()+0x1fe:
>> return with modified stack frame
>> kernel/sched/core.o: warning: objtool: sched_ttwu_pending()+0xf2:
>> return with modified stack frame
>> kernel/sched/core.o: warning: objtool: sched_exec()+0xd0: return with
>> modified stack frame
>> kernel/sched/core.o: warning: objtool: task_sched_runtime()+0x148:
>> return with modified stack frame
>> kernel/sched/core.o: warning: objtool: sched_move_task()+0x176: return
>> with modified stack frame
>> kernel/sched/core.o: warning: objtool: sched_init()+0x6cb: return with
>> modified stack frame
>>
>> Can you have a look?
>>
>> There are probably other failures as well, I'm trying to reproduce the
>> others now with atom
>> optimizations disabled.
>
> Does this fix them all?

Looks good so far, thanks! I'll let you know if something comes back.

For the others, I'll try to gather a little more information and start
separate email threads for each class. From what I can tell, we
still get about a dozen warnings with gcc-7, same as with older
kernels, but I also see a few new warnings with your latest objtool.

       Arnd