From patchwork Fri Jul 28 16:42:30 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 13332126 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 CB0DAC001DF for ; Fri, 28 Jul 2023 16:43:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233252AbjG1Qne (ORCPT ); Fri, 28 Jul 2023 12:43:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46120 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233687AbjG1Qmy (ORCPT ); Fri, 28 Jul 2023 12:42:54 -0400 Received: from mail-io1-xd32.google.com (mail-io1-xd32.google.com [IPv6:2607:f8b0:4864:20::d32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C68319A4 for ; Fri, 28 Jul 2023 09:42:46 -0700 (PDT) Received: by mail-io1-xd32.google.com with SMTP id ca18e2360f4ac-78706966220so22790439f.1 for ; Fri, 28 Jul 2023 09:42:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20221208.gappssmtp.com; s=20221208; t=1690562565; x=1691167365; 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=jgmPORLNso3KhGjKAf8ri1EDar6yb/Ua+Lm2vp9NjUk=; b=Ur0yn05vA4g6T1oMAgp5S9eOXhQtpLAoIUiHwtUeZg7WO3bUolj2hC6IlLND4XUMQk 1f6OAMKnGzk4YG7fQyrPaVOicySAWV6S/Uppg1jacyTOFCo0Jg3Ci/zeD2fpcWM+Wacy fQXHgBS5CGBszY2iiZR+K4mhDOLA+caxiY8mRZ9YkvIEC+UdvmAejzvXVylbd5FW88sw YvtNlixuhvlm/8yVwYJfR6N9j4H0qPCMSeouDkwUC91RSldd+8w2qTixfwoIAyYhQ/OZ iHx0excWbAyl4KxIih6EFokslp1PTrvrkYZcLTIMotZrIGaDpyOyTFCWsp9BkQQHkb+u vkog== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690562565; x=1691167365; 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=jgmPORLNso3KhGjKAf8ri1EDar6yb/Ua+Lm2vp9NjUk=; b=hLGWtHgUVD8UbfYSUXdR/4algzyNSgBDhgKoBTBrisxoFmd3Nb77iOdgsJF+52tGxK jfCbXzdEvua8+pOV0WS3Kjps0E/4+6fHG54H5IpfLEK9GShvMoHLUMyVgZdVJD/NT9NC ojtGWTd+svLjp6AwhWlC8FTDRrmMKcqX9HuNIxo8hw9041Ou1nwxRStLmNok28U1MEyS ui4JnY+eVkLhPfxKIMrFk05TStuHFAgPgcNwjBLdIkwGraI+gzP6pORhVetgla3sRGln LISqJPoNs/kdbofoAcgvPTW9ZQVop5v41kZuR7mKwK/sdPia6XkW2Tuj9fT6RTTebZ22 g6XQ== X-Gm-Message-State: ABy/qLYjscY/c4+5W/K3yST/mN4GUgO5SILkAv7x4ZQ8jlneSwNvdY+A 9rTQrIdCa8Ns9FF8eHB2JdKV4JkV5QWYvAP5fE0= X-Google-Smtp-Source: APBJJlECGCC1BnbNTLfhF7JxlO0uEAba+K6k5FLKU0FPSM8izihcvb6OwaDmFe2CUiDnhujBkA9Whg== X-Received: by 2002:a6b:c9d3:0:b0:788:2d78:813c with SMTP id z202-20020a6bc9d3000000b007882d78813cmr110344iof.0.1690562565051; Fri, 28 Jul 2023 09:42:45 -0700 (PDT) Received: from localhost.localdomain ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id b2-20020a029a02000000b0042b37dda71asm1158808jal.136.2023.07.28.09.42.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Jul 2023 09:42:44 -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 07/12] futex: abstract out a __futex_wake_mark() helper Date: Fri, 28 Jul 2023 10:42:30 -0600 Message-Id: <20230728164235.1318118-8-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 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Move the unqueue and lock_ptr clear into a helper that futex_wake_mark() calls. Add it to the public functions as well, in preparation for using it outside the core futex code. Suggested-by: Peter Zijlstra Signed-off-by: Jens Axboe --- kernel/futex/futex.h | 1 + kernel/futex/waitwake.c | 33 ++++++++++++++++++++++----------- 2 files changed, 23 insertions(+), 11 deletions(-) diff --git a/kernel/futex/futex.h b/kernel/futex/futex.h index bfc1e3c260b0..e04c74a34832 100644 --- a/kernel/futex/futex.h +++ b/kernel/futex/futex.h @@ -217,6 +217,7 @@ extern int futex_wait_setup(u32 __user *uaddr, u32 val, unsigned int flags, struct futex_q *q, struct futex_hash_bucket **hb); extern void futex_wait_queue(struct futex_hash_bucket *hb, struct futex_q *q, struct hrtimer_sleeper *timeout); +extern bool __futex_wake_mark(struct futex_q *q); extern void futex_wake_mark(struct wake_q_head *wake_q, struct futex_q *q); extern int fault_in_user_writeable(u32 __user *uaddr); diff --git a/kernel/futex/waitwake.c b/kernel/futex/waitwake.c index 0272b8c3b132..86f67f652b95 100644 --- a/kernel/futex/waitwake.c +++ b/kernel/futex/waitwake.c @@ -106,20 +106,11 @@ * double_lock_hb() and double_unlock_hb(), respectively. */ -/* - * The hash bucket lock must be held when this is called. - * Afterwards, the futex_q must not be accessed. Callers - * must ensure to later call wake_up_q() for the actual - * wakeups to occur. - */ -void futex_wake_mark(struct wake_q_head *wake_q, struct futex_q *q) +bool __futex_wake_mark(struct futex_q *q) { - struct task_struct *p = q->task; - if (WARN(q->pi_state || q->rt_waiter, "refusing to wake PI futex\n")) - return; + return false; - get_task_struct(p); __futex_unqueue(q); /* * The waiting task can free the futex_q as soon as q->lock_ptr = NULL @@ -130,6 +121,26 @@ void futex_wake_mark(struct wake_q_head *wake_q, struct futex_q *q) */ smp_store_release(&q->lock_ptr, NULL); + return true; +} + +/* + * The hash bucket lock must be held when this is called. + * Afterwards, the futex_q must not be accessed. Callers + * must ensure to later call wake_up_q() for the actual + * wakeups to occur. + */ +void futex_wake_mark(struct wake_q_head *wake_q, struct futex_q *q) +{ + struct task_struct *p = q->task; + + get_task_struct(p); + + if (!__futex_wake_mark(q)) { + put_task_struct(p); + return; + } + /* * Queue the task for later wakeup for after we've released * the hb->lock.