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 4CDF5C001DE for ; Mon, 31 Jul 2023 16:26:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231133AbjGaQ0d (ORCPT ); Mon, 31 Jul 2023 12:26:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58968 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233368AbjGaQ02 (ORCPT ); Mon, 31 Jul 2023 12:26:28 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 24D2110E4; Mon, 31 Jul 2023 09:26:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=MjS3rbs97pcRqmVTM4Ntvkn5tG97L9HJKbZqV2SijdA=; b=niqvBOYZHOXE+q73f6SrdABTZ4 fZF5s6RZfVGQvPiG3mFm10Bo/YzgdCgZeT9nAsXkmbQlEUpJ81BzQ/C2Rae2mo3y/ax5ubkKzVnPH FxTf+IGC6MO3OJiff45Jr/SBmTsSLXu1TL/RrC+TAU1nmw7Hmo7ihKY//N7dvQsGnFdyxrIT3sKhN XDe41iSWEvv4P2xFIYl1Xj4kZM06WleapB9notMo/ccxEWK4GssPIItQdDhvgd9zfFsYBroTMZzi5 7tRbyMK6qIsNlQST+Qf5fQDGFFUbZ5CrzKSYULOKg04mTpkAaLqozLTjX+2+u+3Ck7xs1ydQM5sC6 UX9EwdMw==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1qQViP-002cvL-7X; Mon, 31 Jul 2023 16:25:49 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 8404C300134; Mon, 31 Jul 2023 18:25:48 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 4D19F203C783E; Mon, 31 Jul 2023 18:25:48 +0200 (CEST) Date: Mon, 31 Jul 2023 18:25:48 +0200 From: Peter Zijlstra To: Thomas Gleixner Cc: axboe@kernel.dk, linux-kernel@vger.kernel.org, mingo@redhat.com, dvhart@infradead.org, dave@stgolabs.net, andrealmeid@igalia.com, Andrew Morton , urezki@gmail.com, hch@infradead.org, lstoakes@gmail.com, Arnd Bergmann , linux-api@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, malteskarupke@web.de Subject: Re: [PATCH v1 02/14] futex: Extend the FUTEX2 flags Message-ID: <20230731162548.GN29590@hirez.programming.kicks-ass.net> References: <20230721102237.268073801@infradead.org> <20230721105743.819362688@infradead.org> <87edkonjrk.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87edkonjrk.ffs@tglx> Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Mon, Jul 31, 2023 at 06:11:27PM +0200, Thomas Gleixner wrote: > On Fri, Jul 21 2023 at 12:22, Peter Zijlstra wrote: > > +#define FUTEX2_8 0x00 > > +#define FUTEX2_16 0x01 > > #define FUTEX2_32 0x02 > > - /* 0x04 */ > > +#define FUTEX2_64 0x03 > > +#define FUTEX2_NUMA 0x04 > > /* 0x08 */ > > /* 0x10 */ > > /* 0x20 */ > > --- a/kernel/futex/syscalls.c > > +++ b/kernel/futex/syscalls.c > > @@ -183,7 +183,7 @@ SYSCALL_DEFINE6(futex, u32 __user *, uad > > return do_futex(uaddr, op, val, tp, uaddr2, (unsigned long)utime, val3); > > } > > > > -#define FUTEX2_MASK (FUTEX2_32 | FUTEX2_PRIVATE) > > +#define FUTEX2_MASK (FUTEX2_64 | FUTEX2_PRIVATE) > > > > /** > > * futex_parse_waitv - Parse a waitv array from userspace > > @@ -207,7 +207,12 @@ static int futex_parse_waitv(struct fute > > if ((aux.flags & ~FUTEX2_MASK) || aux.__reserved) > > return -EINVAL; > > With the above aux.flags with FUTEX2_32 set will result in -EINVAL. I > don't think that's intentional. FUTEX2_8 0 FUTEX2_16 1 FUTEX2_32 2 FUTEX2_64 3 Therefore FUTEX2_64, when used as a mask, includes then all. Arnd suggested adding FUTEX2_SIZE_MASK or something. And I initially had something like that, but pulled it for not wanting to pullute the uabi. Can easily add back.