From patchwork Thu Jul 20 22:18:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 13321130 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 4AC40EB64DA for ; Thu, 20 Jul 2023 22:19:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230046AbjGTWTV (ORCPT ); Thu, 20 Jul 2023 18:19:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46596 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229941AbjGTWTP (ORCPT ); Thu, 20 Jul 2023 18:19:15 -0400 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6F8310D2 for ; Thu, 20 Jul 2023 15:19:14 -0700 (PDT) Received: by mail-pf1-x435.google.com with SMTP id d2e1a72fcca58-6748a616e17so275285b3a.1 for ; Thu, 20 Jul 2023 15:19:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20221208.gappssmtp.com; s=20221208; t=1689891554; x=1690496354; 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=KrNmrUoR5Wi6oW3AUbferDPa1uD6ufTJlswF9U4gsFE=; b=ddu84UJQmmPrzwNUcMBCwOXE8nxk76dm9ZNv+KenQmgPS/A2gMlOgyY+Farr4xlL3a vH3qrJVNJ3buiSZ7e1gKr1P+PyneefhudGCAaYdWP9zyTpSkYr1fGkLUFPYlWFASKpqA D9SvYXELPN5C23V1tretsjXsm4Oc7hkO03jhQoLTn7VVF3cFHja9E/ghYnglMCmWTws/ qEjcfVm+Wt7YCOaJeij65kYRQTT0vyZ9Hrjwc6bt9lw3EZGEKkQ8sF4zW28+wHp13JDI FnYz5D2zzNftTyeqt94Bz/WVgXmiRf5KTqHNw7yMp4fnSBUl/5+9Gp484Bx/FLlE5LBE igsg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689891554; x=1690496354; 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=KrNmrUoR5Wi6oW3AUbferDPa1uD6ufTJlswF9U4gsFE=; b=KqvvRffaKb8zKypxsoFIqDGUVxlf+Dicn8TspahBE3kmlS14pXurZT1lY0QvhyxOho Larp1brNmN68sCcrv530lyaaUSrkejkYfW3SS+l/MroO/HHuiJQAAxwy+XS+Ofl/7Q4L NzX+z73RjwZMnGopWBFQ9jg2p9K6HtEqBElqi4rHybzeAZORiq725aMLT2kuNUmHGgQX OJ6BX1Got1842raO20K0XtWIjJsB6qFWv9njB0Y0rI9GsHupmA62LSzu+/s7Jdf5aagM jn7EscVgJeV4R/MDi+Ag/DD6i4QP1ag73dQJW5S2k/VlfS0SV9bSSDC0MM9Rw6jSq7R4 n/xQ== X-Gm-Message-State: ABy/qLZ9zYlVIDCbEboyxeyH0XXjOB8JCb/4ii+lT1AujOAryJLGT7Nk 2BV5r9ulb8SIqvPG1TFaQ2iAZ79d14hSzY/ZI5Y= X-Google-Smtp-Source: APBJJlHYTB4DmiBIVBJNyqqY2MhI1jA/DzDhyOjug8qQ3b7qOuDyfxIftzu5V4LUeEr7Tg44/woCgA== X-Received: by 2002:a05:6a00:4186:b0:679:a1f1:a5f8 with SMTP id ca6-20020a056a00418600b00679a1f1a5f8mr121447pfb.3.1689891553713; Thu, 20 Jul 2023 15:19:13 -0700 (PDT) Received: from localhost.localdomain ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id q1-20020a63bc01000000b0055b3af821d5sm1762454pge.25.2023.07.20.15.19.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Jul 2023 15:19:12 -0700 (PDT) From: Jens Axboe To: io-uring@vger.kernel.org, linux-kernel@vger.kernel.org Cc: peterz@infradead.org, andres@anarazel.de, Jens Axboe Subject: [PATCH 05/10] futex: abstract out a __futex_wake_mark() helper Date: Thu, 20 Jul 2023 16:18:53 -0600 Message-Id: <20230720221858.135240-6-axboe@kernel.dk> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230720221858.135240-1-axboe@kernel.dk> References: <20230720221858.135240-1-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 2b18eb889cce..98d43e9efe65 100644 --- a/kernel/futex/futex.h +++ b/kernel/futex/futex.h @@ -190,6 +190,7 @@ 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.