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Date:   Mon, 30 Jul 2018 12:17:00 +0200
From:   Oleg Nesterov <oleg@redhat.com>
To:     =?iso-8859-1?Q?J=FCrg?= Billeter <j@bitron.ch>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Eric Biederman <ebiederm@xmission.com>,
        linux-api@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] prctl: add PR_[GS]ET_KILLABLE
Message-ID: <20180730101659.GA24781@redhat.com>
References: <20180730075241.24002-1-j@bitron.ch>
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On 07/30, J?rg Billeter wrote:
>
> This is required for job control in a shell that uses CLONE_NEWPID for
> child processes.

Could you explain in more details?

> +	case PR_SET_KILLABLE:
> +		if (arg2 != 1 || arg3 || arg4 || arg5)
> +			return -EINVAL;
> +		me->signal->flags &= ~SIGNAL_UNKILLABLE;

this needs spin_lock_irq(me->sighand->siglock).

Oleg.