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From:   weizhenliang <weizhenliang@huawei.com>
To:     Oleg Nesterov <oleg@redhat.com>
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Subject: RE: [PATCH] signal: trace_signal_deliver when signal_group_exit
Thread-Topic: [PATCH] signal: trace_signal_deliver when signal_group_exit
Thread-Index: AdT4sMRJz5sKA+ApROaRV0FeV6WCvA==
Date:   Mon, 22 Apr 2019 02:37:21 +0000
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On 04/20, Oleg Nesterov wrote:
>On 04/20, Zhenliang Wei wrote:
>>
>> --- a/kernel/signal.c
>> +++ b/kernel/signal.c
>> @@ -2441,6 +2441,8 @@ bool get_signal(struct ksignal *ksig)
>>  	if (signal_group_exit(signal)) {
>>  		ksig->info.si_signo = signr = SIGKILL;
>>  		sigdelset(&current->pending.signal, SIGKILL);
>> +		trace_signal_deliver(signr, &ksig->info,
>> +				&sighand->action[signr - 1]);
>
>Well, in this case ksig->info is not fully initialized for TP_STORE_SIGINFO() which reads si_errno/si_code...
>
>How about
>
>		trace_signal_deliver(SIGKILL, SEND_SIG_NOINFO, SIG_DFL)
>
>?
>
>We know that action[SIGKILL] must be SIG_DFL.
>
>And SEND_SIG_NOINFO matches the fact that SIGKILL doesn't have any info,
>collect_signal() sets SI_USER and clears si_errno in this case.
>
>Oleg.

Thank you for your review, I agree with your suggestion, and I will recommit the patch later.

Zhenliang Wei.