From patchwork Fri Jul 28 16:42:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 127809 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:918b:0:b0:3e4:2afc:c1 with SMTP id s11csp610823vqg; Fri, 28 Jul 2023 11:13:49 -0700 (PDT) X-Google-Smtp-Source: APBJJlEWS0KanCxeCpXSBG9SAwmVJC1HJ/UwSAzHe13EazWshKa7gqY9NZdzHrSWws/iW/3/JRSb X-Received: by 2002:a05:6a00:1989:b0:67e:6269:6ea8 with SMTP id d9-20020a056a00198900b0067e62696ea8mr3560932pfl.22.1690568029423; Fri, 28 Jul 2023 11:13:49 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1690568029; cv=none; d=google.com; s=arc-20160816; b=yvJBZ3sPoClw32RMCXEIHeBon1Rkq3W4rzw/710hmJrzroAVD4pd7vavN/02G/6XUe mZo4kTM7p+7SO0eQ/jcZyo+Ls51j9FyGG1wNL0KNUBlYBCfvzYJpF/V6HJOPMYQlBeay wAEX3O9mkFQb7vMY4rcH0ZSTAp2Jyn5u07zE5egEJOPS+J2lj1bd6U1ZBBdewYD+70xA k+kaRAFtWazN51uZ5f0xkrcfJGvytu8nADDnS8QE+kQCZrKZxqnPosvkTbTmgsT3eu/H OPHnGpyPwyKTx98j/YucXrUy5GBI+whuAjAXhxwAhuwf7B3duyNc8YI4Xm+ef8ntMD0b hy1Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=qfXIoWZOPMTUuZ51sHKPtDeshXixERaT1oNJnhO0ex0=; fh=DnWmIIJo3B+rGTNXkDMzawWuDVsJB9JjWDIPE9Mz7eQ=; b=lfyHbIK3mEIoN3Aln0iFDSp+mDVmT/9qzmSzBWlFpHJ+aoXb1J2h31/BkQkAM9v+p7 wwf3xnpEX2UTdpO5gkMZo7KzfcEbUYkW+X0OshJp/HUO9qqznSFNsjEPrI/aA5XIPTSr XdKmCsG8lZspbtZMKCiZ5oGRZmwcuMvybri4WUiglFcYirVjRTza0G/gsh+I04c2LTQi 9rGPcdgH7fvZfsJmd1C4CKHcXJcLJxobzGLqPM7oCzZcIXYj6IvEQQjNfCMDdnmmlcVA qNMT/2CQsMYzWvFXiLhf5FUKiPQxEbl5+sl6PLxrVgCf4Cz522KoR6EJLlFhx2ydKOx7 kbSg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel-dk.20221208.gappssmtp.com header.s=20221208 header.b=It3a8uIR; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id 34-20020a631862000000b0053b928deb7asi3322762pgy.344.2023.07.28.11.13.36; Fri, 28 Jul 2023 11:13:49 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel-dk.20221208.gappssmtp.com header.s=20221208 header.b=It3a8uIR; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233128AbjG1Qms (ORCPT + 99 others); Fri, 28 Jul 2023 12:42:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45702 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229564AbjG1Qmm (ORCPT ); Fri, 28 Jul 2023 12:42:42 -0400 Received: from mail-io1-xd2d.google.com (mail-io1-xd2d.google.com [IPv6:2607:f8b0:4864:20::d2d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E952219A4 for ; Fri, 28 Jul 2023 09:42:40 -0700 (PDT) Received: by mail-io1-xd2d.google.com with SMTP id ca18e2360f4ac-78706966220so22787239f.1 for ; Fri, 28 Jul 2023 09:42:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20221208.gappssmtp.com; s=20221208; t=1690562560; x=1691167360; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=qfXIoWZOPMTUuZ51sHKPtDeshXixERaT1oNJnhO0ex0=; b=It3a8uIRBWBxtFna+HZJERO/3/0f2r4nyuR/E+sjXiG9TQGNLD0TfIGecOO32rhhu/ nQ0XUBk8WmxIZY4qJQaI/VevgEsW/CwC4nLk8hoIU8YxvQl3AwGLhkgFzwIi4tKY+8su Oyl/hwKdVV/FUPnGD472zaZePQjaJGgeRkhyHLD/8mRuCDBX3cOvi9Y040oyMhHLRBrG RlhjY65j/7wF/feBfAD43VQKB3zPIAz3pDn5QXxTz+Cy61LdylA3/pmWHZ7uMGveK7ci pMkLlV0TBFxQdPM9H7ZjTdWt8u9Brkuy2GgG3dCpn0Vy2XHOmVX/Rz+RtnHNAt8sddmh 1lJA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690562560; x=1691167360; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=qfXIoWZOPMTUuZ51sHKPtDeshXixERaT1oNJnhO0ex0=; b=FiJcTD0YOS1G6jiYe9vwx1DdoMjemrU1Cb3eui4nSsVb5WaLDk6dcsWc9uXxEl2RzZ YaQTB+31mqQ36xBpnJxLAm9XdwIg18hRiTOBmFw6jk8JB6SzP9xCg5pOGA+X36MrELYW hMOTApe/qtelCXfKJEeVcoITugyuFje/DHKzXbJ1qyXax7v+Oc0AnrCozmRcMaYiwcTj E/jitCB8C0WjOYtDvOMsfa7xYz7DJ7aJJQYdR0qAdfbIsD7KRYxLoVHNJ620AlnyYA2I xVtA/axfo6LWYzkcCZQSeSN2nXIOjtnNtvW7gAkK5km0/0U2LKpEfvuSJA1i09c0IhGk Vm9Q== X-Gm-Message-State: ABy/qLaCmazsyTw5GYgOfP8XInk0LSNTpOq0shqYWAekrRKCI6AbLiJO UVhLY9aORmLMqI9NimOUSGmAiA== X-Received: by 2002:a05:6602:14ce:b0:787:16ec:2699 with SMTP id b14-20020a05660214ce00b0078716ec2699mr113690iow.2.1690562560150; Fri, 28 Jul 2023 09:42:40 -0700 (PDT) Received: from localhost.localdomain ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id b2-20020a029a02000000b0042b37dda71asm1158808jal.136.2023.07.28.09.42.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Jul 2023 09:42:39 -0700 (PDT) From: Jens Axboe To: io-uring@vger.kernel.org, linux-kernel@vger.kernel.org Cc: peterz@infradead.org, andres@anarazel.de, tglx@linutronix.de, Jens Axboe Subject: [PATCH 01/12] futex: Clarify FUTEX2 flags Date: Fri, 28 Jul 2023 10:42:24 -0600 Message-Id: <20230728164235.1318118-2-axboe@kernel.dk> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230728164235.1318118-1-axboe@kernel.dk> References: <20230728164235.1318118-1-axboe@kernel.dk> MIME-Version: 1.0 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1772689061880538732 X-GMAIL-MSGID: 1772689061880538732 From: Peter Zijlstra sys_futex_waitv() is part of the futex2 series (the first and only so far) of syscalls and has a flags field per futex (as opposed to flags being encoded in the futex op). This new flags field has a new namespace, which unfortunately isn't super explicit. Notably it currently takes FUTEX_32 and FUTEX_PRIVATE_FLAG. Introduce the FUTEX2 namespace to clarify this Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Jens Axboe --- include/uapi/linux/futex.h | 16 +++++++++++++--- kernel/futex/syscalls.c | 7 +++---- 2 files changed, 16 insertions(+), 7 deletions(-) diff --git a/include/uapi/linux/futex.h b/include/uapi/linux/futex.h index 71a5df8d2689..0c5abb6aa8f8 100644 --- a/include/uapi/linux/futex.h +++ b/include/uapi/linux/futex.h @@ -44,10 +44,20 @@ FUTEX_PRIVATE_FLAG) /* - * Flags to specify the bit length of the futex word for futex2 syscalls. - * Currently, only 32 is supported. + * Flags for futex2 syscalls. */ -#define FUTEX_32 2 + /* 0x00 */ + /* 0x01 */ +#define FUTEX2_32 0x02 + /* 0x04 */ + /* 0x08 */ + /* 0x10 */ + /* 0x20 */ + /* 0x40 */ +#define FUTEX2_PRIVATE FUTEX_PRIVATE_FLAG + +/* do not use */ +#define FUTEX_32 FUTEX2_32 /* historical accident :-( */ /* * Max numbers of elements in a futex_waitv array diff --git a/kernel/futex/syscalls.c b/kernel/futex/syscalls.c index a8074079b09e..42b6c2fac7db 100644 --- a/kernel/futex/syscalls.c +++ b/kernel/futex/syscalls.c @@ -183,8 +183,7 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val, return do_futex(uaddr, op, val, tp, uaddr2, (unsigned long)utime, val3); } -/* Mask of available flags for each futex in futex_waitv list */ -#define FUTEXV_WAITER_MASK (FUTEX_32 | FUTEX_PRIVATE_FLAG) +#define FUTEX2_MASK (FUTEX2_32 | FUTEX2_PRIVATE) /** * futex_parse_waitv - Parse a waitv array from userspace @@ -205,10 +204,10 @@ static int futex_parse_waitv(struct futex_vector *futexv, if (copy_from_user(&aux, &uwaitv[i], sizeof(aux))) return -EFAULT; - if ((aux.flags & ~FUTEXV_WAITER_MASK) || aux.__reserved) + if ((aux.flags & ~FUTEX2_MASK) || aux.__reserved) return -EINVAL; - if (!(aux.flags & FUTEX_32)) + if (!(aux.flags & FUTEX2_32)) return -EINVAL; futexv[i].w.flags = aux.flags;