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From:   Andrey Konovalov <andreyknvl@google.com>
Date:   Wed, 25 Mar 2020 00:02:55 +0100
Message-ID: <CAAeHK+xS-EGjoz0467cXW6P5MQW0+s65gAh96tqZThxyZiJZrg@mail.gmail.com>
Subject: Re: linux-next: Tree for Mar 20 (objtool warnings)
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     Randy Dunlap <rdunlap@infradead.org>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Stephen Rothwell <sfr@canb.auug.org.au>,
        Linux Next Mailing List <linux-next@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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On Tue, Mar 24, 2020 at 10:13 PM Peter Zijlstra <peterz@infradead.org> 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.