On Wed, May 18, 2022 at 03:31PM +0800, Jackie Liu wrote:
> From: Jackie Liu <liuyun01@xxxxxxxxxx>
>
> By printing information, we can friendly prompt the status change
> information of kfence by dmesg and record by syslog.
>
> Also, set kfence_enabled to false only when needed.
>
> Co-developed-by: Marco Elver <elver@xxxxxxxxxx>
Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
> Signed-off-by: Jackie Liu <liuyun01@xxxxxxxxxx>
Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
> ---
> v1->v2:
> fixup by Marco Elver <elver@xxxxxxxxxx>
> v2->v3:
> write kfence_enabled=false only true before
> v3->v4:
> cleanup
>
> mm/kfence/core.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/mm/kfence/core.c b/mm/kfence/core.c
> index 11a954763be9..af0489d4d149 100644
> --- a/mm/kfence/core.c
> +++ b/mm/kfence/core.c
> @@ -67,8 +67,11 @@ static int param_set_sample_interval(const char *val, const struct kernel_param
> if (ret < 0)
> return ret;
>
> - if (!num) /* Using 0 to indicate KFENCE is disabled. */
> + /* Using 0 to indicate KFENCE is disabled. */
> + if (!num && READ_ONCE(kfence_enabled)) {
> + pr_info("disabled\n");
> WRITE_ONCE(kfence_enabled, false);
> + }
>
> *((unsigned long *)kp->arg) = num;
>
> @@ -874,6 +877,7 @@ static int kfence_enable_late(void)
>
> WRITE_ONCE(kfence_enabled, true);
> queue_delayed_work(system_unbound_wq, &kfence_timer, 0);
> + pr_info("re-enabled\n");
> return 0;
> }
>
> --
> 2.25.1
>
