Re: [PATCH v3] mm/kfence: print disabling or re-enabling message

[Jackie Liu <liu.yun@linux.dev>]

在 2022/5/18 下午3:24, Marco Elver 写道:
> On Wed, 18 May 2022 at 03:03, Jackie Liu <liu.yun@linux.dev> wrote:
>>
>> From: Jackie Liu <liuyun01@kylinos.cn>
>>
>> By printing information, we can friendly prompt the status change
>> information of kfence by dmesg and record by syslog.
>>
>> Co-developed-by: Marco Elver <elver@google.com>
>> Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
>> ---
>>   v1->v2:
>>     fixup by Marco Elver <elver@google.com>
>>   v2->v3:
>>     write kfence_enabled=false only true before
>>
>>   mm/kfence/core.c | 10 ++++++++--
>>   1 file changed, 8 insertions(+), 2 deletions(-)
>>
>> diff --git a/mm/kfence/core.c b/mm/kfence/core.c
>> index 11a954763be9..41840b8d9cb3 100644
>> --- a/mm/kfence/core.c
>> +++ b/mm/kfence/core.c
>> @@ -67,8 +67,13 @@ 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. */
>> -               WRITE_ONCE(kfence_enabled, false);
>> +       /* Using 0 to indicate KFENCE is disabled. */
>> +       if (!num) {
>> +               if (READ_ONCE(kfence_enabled)) {
> 
> Now you could just write
> 
>    if (!num && READ_ONCE(kfence_enabled)) {

Sure.

>      ....
> 
>> +                       pr_info("disabled\n");
>> +                       WRITE_ONCE(kfence_enabled, false);
>> +               }
>> +       }
>>
>>          *((unsigned long *)kp->arg) = num;
>>
>> @@ -874,6 +879,7 @@ 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
>>