Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
MIME-Version: 1.0
References: <20220523063033.1778974-1-liu3101@purdue.edu>
In-Reply-To: <20220523063033.1778974-1-liu3101@purdue.edu>
From:   Dmitry Vyukov <dvyukov@google.com>
Date:   Mon, 23 May 2022 10:35:57 +0200
Message-ID: <CACT4Y+Zpasug=cr2k-17aD_EBsvMZB8kQnaJ+KPgoPOZAj___Q@mail.gmail.com>
Subject: Re: [PATCH] tracing: disable kcov on trace_preemptirq.c
To:     Congyu Liu <liu3101@purdue.edu>
Cc:     andreyknvl@gmail.com, rostedt@goodmis.org, mingo@redhat.com,
        kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Mon, 23 May 2022 at 08:30, Congyu Liu <liu3101@purdue.edu> wrote:
>
> Functions in trace_preemptirq.c could be invoked from early interrupt
> code that bypasses kcov trace function's in_task() check. Disable kcov
> on this file to reduce random code coverage.
>
> Signed-off-by: Congyu Liu <liu3101@purdue.edu>

Acked-by: Dmitry Vyukov <dvyukov@google.com>

> ---
>  kernel/trace/Makefile | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
> index d77cd8032213..0d261774d6f3 100644
> --- a/kernel/trace/Makefile
> +++ b/kernel/trace/Makefile
> @@ -31,6 +31,10 @@ ifdef CONFIG_GCOV_PROFILE_FTRACE
>  GCOV_PROFILE := y
>  endif
>
> +# Functions in this file could be invoked from early interrupt
> +# code and produce random code coverage.
> +KCOV_INSTRUMENT_trace_preemptirq.o := n
> +
>  CFLAGS_bpf_trace.o := -I$(src)
>
>  CFLAGS_trace_benchmark.o := -I$(src)
> --
> 2.34.1
>