From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1C83A3009E2 for ; Mon, 23 Feb 2026 15:47:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771861635; cv=none; b=SVC7DdX/wYdmzWGHORYGu/6eAfoORVIUz+vwBIcoctlBpEF9gD4xFIHtCCcKKkCeRBuDDUj9UbAZSXIE5t51YZ+gDYfNnc6UWoXAeB1dmKNOqWYHHsp8O67lCKh5QLTQ/Z+ka/QMONH0l0HRub1UGT5iktWgrip9ryx6Lxf7rsM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771861635; c=relaxed/simple; bh=iHyB59AlPRHpgu0nv4iN8OdrqTn2iD57mlJ8qAQE7fQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Fta1feTYGy5mdAiASA3xVWKWcCLNEPvY5Sk4CXIycmfu83StPD5fEMN3Wmd5hp2//a8F9BNT1J9lW+NKO6wfKtJSZ9XvXohHierLMUHl9lAjH1eNbtuqpfA8wBktEwVzZFFyyqIycafISakPpM/ID57aqDXIBM9R8SEGCCedol8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=JjdTFRx0; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="JjdTFRx0" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1771861632; 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=OxCdAMxs1g6kkp2ZQGBboQJcW5rUk38g9689Mz3dIek=; b=JjdTFRx0C8N0Zm0IbQ6JRltTgdAYy/ftQ6eCzQ+Nsx76BHqIs+q7m7vk1/k9ZAdUpWvVEB UQUAO/a1zROO5eWDMli28pTPWDhTb7G8opod5MptIOotbnQvuzY5hAFOlOoDdnONeCMzXv Ukdrr5OlX0/T8aInJ27HUsB0N48LD6w= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-342-KiD2v9cqNZKA2fwgI8Qrgw-1; Mon, 23 Feb 2026 10:47:10 -0500 X-MC-Unique: KiD2v9cqNZKA2fwgI8Qrgw-1 X-Mimecast-MFC-AGG-ID: KiD2v9cqNZKA2fwgI8Qrgw_1771861628 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A0849195608F; Mon, 23 Feb 2026 15:47:07 +0000 (UTC) Received: from fedora (unknown [10.44.32.38]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 3FB291800465; Mon, 23 Feb 2026 15:47:03 +0000 (UTC) Received: by fedora (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Mon, 23 Feb 2026 16:47:07 +0100 (CET) Date: Mon, 23 Feb 2026 16:47:02 +0100 From: Oleg Nesterov To: Christian Brauner Cc: Jann Horn , Linus Torvalds , Ingo Molnar , Peter Zijlstra , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v4 2/4] pidfd: add CLONE_PIDFD_AUTOKILL Message-ID: References: <20260223-work-pidfs-autoreap-v4-0-e393c08c09d1@kernel.org> <20260223-work-pidfs-autoreap-v4-2-e393c08c09d1@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260223-work-pidfs-autoreap-v4-2-e393c08c09d1@kernel.org> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 On 02/23, Christian Brauner wrote: > > @@ -2259,13 +2268,20 @@ __latent_entropy struct task_struct *copy_process( > * if the fd table isn't shared). > */ > if (clone_flags & CLONE_PIDFD) { > - int flags = (clone_flags & CLONE_THREAD) ? PIDFD_THREAD : 0; > + unsigned flags = PIDFD_STALE; > + > + if (clone_flags & CLONE_THREAD) > + flags |= PIDFD_THREAD; > + if (clone_flags & CLONE_PIDFD_AUTOKILL) { > + task_set_no_new_privs(p); > + flags |= PIDFD_AUTOKILL; > + } > > /* > * Note that no task has been attached to @pid yet indicate > * that via CLONE_PIDFD. > */ > - retval = pidfd_prepare(pid, flags | PIDFD_STALE, &pidfile); > + retval = pidfd_prepare(pid, flags, &pidfile); Confused... I think you also need to change pidfs_alloc_file() to restore O_TRUNC after do_dentry_open() clears this flag? Just like it curently does pidfd_file->f_flags |= (flags & PIDFD_THREAD); ? Oleg.