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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6A4F2C04A94 for ; Mon, 14 Aug 2023 14:09:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231542AbjHNOId (ORCPT ); Mon, 14 Aug 2023 10:08:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232099AbjHNOIZ (ORCPT ); Mon, 14 Aug 2023 10:08:25 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 93B2F10F7 for ; Mon, 14 Aug 2023 07:07:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1692022061; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=8Grht1UdEsF4WiLYP8/gvuchTHNIdp67lMPXt4Pailk=; b=YU5WwaanOkhhgGtFsU+8LmxoX5oesR2zVm3DSS4n79XUEsjIOCMguZOl964VLIGspJzmtg 46EhNSloraEi17WYFeRshSgbuQE7Ns6ZLyolM4rqil6Xdw3ss1w+8Iq5ADPNG78yGNjiyK V9e/TFz28S9t1kvX+PG8IbN4HqrOy/o= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-380-yXZucHBoO0eU277vOj6KXA-1; Mon, 14 Aug 2023 10:07:37 -0400 X-MC-Unique: yXZucHBoO0eU277vOj6KXA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 68E238007A4; Mon, 14 Aug 2023 14:07:37 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.225.27]) by smtp.corp.redhat.com (Postfix) with SMTP id A154B2026D68; Mon, 14 Aug 2023 14:07:35 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Mon, 14 Aug 2023 16:06:54 +0200 (CEST) Date: Mon, 14 Aug 2023 16:06:52 +0200 From: Oleg Nesterov To: "Eric W. Biederman" Cc: Petr Skocik , Kees Cook , Thomas Gleixner , Peter Zijlstra , Marco Elver , linux-kernel@vger.kernel.org Subject: Re: [PATCH] signal: Fix the error return of kill -1 Message-ID: <20230814140652.GA30596@redhat.com> References: <20221122161240.137570-1-pskocik@gmail.com> <202211220913.AF86992@keescook> <878rai7u0l.fsf@email.froward.int.ebiederm.org> <336ae9be-c66c-d87f-61fe-b916e9f04ffc@gmail.com> <87pm3t2rvl.fsf@email.froward.int.ebiederm.org> <87jzu12pjh.fsf_-_@email.froward.int.ebiederm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87jzu12pjh.fsf_-_@email.froward.int.ebiederm.org> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Eric, This change LGTM, but ... On 08/11, Eric W. Biederman wrote: > > @@ -1602,7 +1603,8 @@ static int kill_something_info(int sig, struct kernel_siginfo *info, pid_t pid) > ret = __kill_pgrp_info(sig, info, > pid ? find_vpid(-pid) : task_pgrp(current)); > } else { > - int retval = 0, count = 0; > + bool found = false, success = false; > + int retval = 0; > struct task_struct * p; > > for_each_process(p) { > @@ -1610,12 +1612,12 @@ static int kill_something_info(int sig, struct kernel_siginfo *info, pid_t pid) > !same_thread_group(p, current)) { > int err = group_send_sig_info(sig, info, p, > PIDTYPE_MAX); > - ++count; > - if (err != -EPERM) > - retval = err; > + found = true; > + success |= !err; > + retval = err; > } > } > - ret = count ? retval : -ESRCH; > + ret = success ? 0 : (found ? retval : -ESRCH); Why do we need the "bool found" variable ? Afacis } else { bool success = false; int retval = -ESRCH; struct task_struct * p; for_each_process(p) { if (task_pid_vnr(p) > 1 && !same_thread_group(p, current)) { int err = group_send_sig_info(sig, info, p, PIDTYPE_MAX); success |= !err; retval = err; } } ret = success ? 0 : retval; } does the same? Oleg.