Re: [RFC PATCH v2 04/14] kcov: reject enable on multiple dataflow fds simultaneously

[Alexander Potapenko]

On Thu, Jun 11, 2026 at 6:21 PM Yunseong Kim <yunseong.kim@xxxxxxxx> wrote:
>
> A task could enable tracing on multiple kcov_dataflow file descriptors,
> corrupting the internal tracking state when one is subsequently closed.
>
> Check current->kcov_df_enabled before allowing KCOV_DF_ENABLE and
> return -EBUSY if already active. This matches kcov's check of
> t->kcov != NULL in the KCOV_ENABLE path.
>
> Reported-by: sashiko-bot <sashiko-bot@xxxxxxxxxx>
> Closes: https://sashiko.dev/#/patchset/20260603-kcov-dataflow-next-20260603-v2-0-fee0939de2c4%40est.tech
> Signed-off-by: Yunseong Kim <yunseong.kim@xxxxxxxx>
> ---
>  kernel/kcov_dataflow.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/kcov_dataflow.c b/kernel/kcov_dataflow.c
> index 5248293280d5..27587b8ceeab 100644
> --- a/kernel/kcov_dataflow.c
> +++ b/kernel/kcov_dataflow.c

Please merge this patch into the one introducing kcov_dataflow.c