Re: linux-next: Tree for Mar 20 (objtool warnings)

From: Andrey Konovalov
Date: Tue Mar 24 2020 - 19:03:10 EST


On Tue, Mar 24, 2020 at 10:13 PM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> On Tue, Mar 24, 2020 at 10:53:05AM -0700, Randy Dunlap wrote:
> > >> kernel/kcov.o: warning: objtool: __sanitizer_cov_trace_pc()+0x89: call to __ubsan_handle_load_invalid_value() with UACCESS enabled
> > >>
> >
> > config-r1510 is attached.
> > and kcov.o is attached.
>
> I'm thinking this is because of commit:
>
> 0d6958a70483 kcov: collect coverage from interrupts
>
> Which has:
>
> @@ -1230,6 +1230,9 @@ struct task_struct {
>
> + bool kcov_softirq;
>
> @@ -145,9 +157,10 @@ static notrace bool check_kcov_mode(enum kcov_mode needed_mode, struct task_stru
>
> + if (!in_task() && !(in_serving_softirq() && t->kcov_softirq))
>
> And this __ubsan_handle_load_invalid_value() is verifying a bool is 0,1.
>
> Another reason to hate on _Bool I suppose...
>
> Let me see what to do about that... :/

Hm, let's turn it into an unsigned int if bool causes a problem? I can
send a patch.