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 4AAAAC001DE for ; Mon, 31 Jul 2023 17:42:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230008AbjGaRmP (ORCPT ); Mon, 31 Jul 2023 13:42:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229464AbjGaRmP (ORCPT ); Mon, 31 Jul 2023 13:42:15 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 85CD91AD; Mon, 31 Jul 2023 10:42:13 -0700 (PDT) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1690825331; 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=6uM5FAWSraTF9ANkM/RUmC/VT5LAIL5f6xuNyR6CtXc=; b=wLX5xXa3KKs4oWRl7RM9tDekVld4fxYHH+Z0whYiiVmHaDEsEllfAXbyWJphyeg5+HPds/ nLQlnCCzdLLgEJqjARagiUXRSTyiVtq43iwdHHIvFLhXPkHkGK1+E7zmXcmyRxFZtm35DA k6MoXYwE5oRD1yqXJ+zuIBW+mP8s7fNs6piPVn5A6UQml3ALhY8TkBCnuqvxCadSYBHG4g Z2E3jdv431oHpf1zA0809fJPbLq3bBOX66prnGyv3XsHoKzdBtwx9eGM1huKHt+/VmvkpN 7aekZoy8gyMuQKkiAV2XteDD9zY6sac92NBwkWG5DuntmNE/E0h4eEXZALMfAQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1690825331; 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=6uM5FAWSraTF9ANkM/RUmC/VT5LAIL5f6xuNyR6CtXc=; b=0qUHJK4AU408x6a0y+G2L9DA0OvkZEV/pL8k3VSHNHWY2v93IvUv/Q51lk2G4v2dDi11w2 //lPmALRQigWJ0Dw== To: Peter Zijlstra , axboe@kernel.dk Cc: linux-kernel@vger.kernel.org, peterz@infradead.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 In-Reply-To: <87edkonjrk.ffs@tglx> References: <20230721102237.268073801@infradead.org> <20230721105743.819362688@infradead.org> <87edkonjrk.ffs@tglx> Date: Mon, 31 Jul 2023 19:42:11 +0200 Message-ID: <87mszcm0zw.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Mon, Jul 31 2023 at 18:11, 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. Aargh. This is really nasty to make FUTEX2_64 0x3 and abuse it to test the flags for validity. Intuitive and obvious is something else.