From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31A2DC46461 for ; Mon, 30 Jul 2018 08:01:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD04220892 for ; Mon, 30 Jul 2018 08:01:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DD04220892 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bitron.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726755AbeG3Je4 (ORCPT ); Mon, 30 Jul 2018 05:34:56 -0400 Received: from nov-007-i652.relay.mailchannels.net ([46.232.183.206]:31306 "EHLO nov-007-i652.relay.mailchannels.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726469AbeG3Je4 (ORCPT ); Mon, 30 Jul 2018 05:34:56 -0400 X-Greylist: delayed 360 seconds by postgrey-1.27 at vger.kernel.org; Mon, 30 Jul 2018 05:34:53 EDT X-Sender-Id: novatrend|x-authuser|juerg@bitron.ch Received: from relay.mailchannels.net (localhost [127.0.0.1]) by relay.mailchannels.net (Postfix) with ESMTP id 255861B60459; Mon, 30 Jul 2018 07:55:07 +0000 (UTC) Received: from srv17.tophost.ch (swiss-ingress-2.mailchannels.ch [46.232.183.6]) by relay.mailchannels.net (Postfix) with ESMTPA id C1A5C1B6044E; Mon, 30 Jul 2018 07:55:04 +0000 (UTC) X-Sender-Id: novatrend|x-authuser|juerg@bitron.ch Received: from srv17.tophost.ch (srv17.tophost.ch [193.33.128.141]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384) by 0.0.0.0:2500 (trex/5.15.2); Mon, 30 Jul 2018 07:55:07 +0000 X-MC-Relay: Neutral X-MailChannels-SenderId: novatrend|x-authuser|juerg@bitron.ch X-MailChannels-Auth-Id: novatrend X-Descriptive-Ruddy: 08a7824915c98f29_1532937306862_2834289741 X-MC-Loop-Signature: 1532937306861:3079363934 X-MC-Ingress-Time: 1532937306861 Received: from [80.219.231.201] (port=56880 helo=jzen.bitron.ch) by srv17.tophost.ch with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-SHA256:128) (Exim 4.91) (envelope-from ) id 1fk31A-005VQR-9T; Mon, 30 Jul 2018 09:55:00 +0200 From: =?UTF-8?q?J=C3=BCrg=20Billeter?= To: Andrew Morton Cc: Oleg Nesterov , Eric Biederman , linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, =?UTF-8?q?J=C3=BCrg=20Billeter?= Subject: [PATCH] prctl: add PR_[GS]ET_KILLABLE Date: Mon, 30 Jul 2018 09:52:41 +0200 Message-Id: <20180730075241.24002-1-j@bitron.ch> X-Mailer: git-send-email 2.18.0 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AuthUser: juerg@bitron.ch Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org PR_SET_KILLABLE clears the SIGNAL_UNKILLABLE flag. This allows CLONE_NEWPID tasks to restore normal signal behavior, opting out of the special signal protection for init processes. This is required for job control in a shell that uses CLONE_NEWPID for child processes. This prctl does not allow setting the SIGNAL_UNKILLABLE flag, only clearing. Signed-off-by: Jürg Billeter --- include/uapi/linux/prctl.h | 4 ++++ kernel/sys.c | 11 +++++++++++ 2 files changed, 15 insertions(+) diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h index c0d7ea0bf5b6..92afb63da727 100644 --- a/include/uapi/linux/prctl.h +++ b/include/uapi/linux/prctl.h @@ -219,4 +219,8 @@ struct prctl_mm_map { # define PR_SPEC_DISABLE (1UL << 2) # define PR_SPEC_FORCE_DISABLE (1UL << 3) +/* Control SIGNAL_UNKILLABLE */ +#define PR_GET_KILLABLE 54 +#define PR_SET_KILLABLE 55 + #endif /* _LINUX_PRCTL_H */ diff --git a/kernel/sys.c b/kernel/sys.c index 38509dc1f77b..264de630d548 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -2484,6 +2484,17 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, return -EINVAL; error = arch_prctl_spec_ctrl_set(me, arg2, arg3); break; + case PR_GET_KILLABLE: + if (arg3 || arg4 || arg5) + return -EINVAL; + error = put_user(!(me->signal->flags & SIGNAL_UNKILLABLE), + (int __user *)arg2); + break; + case PR_SET_KILLABLE: + if (arg2 != 1 || arg3 || arg4 || arg5) + return -EINVAL; + me->signal->flags &= ~SIGNAL_UNKILLABLE; + break; default: error = -EINVAL; break; -- 2.18.0