From patchwork Thu Sep 21 18:29:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 13394282 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 BD22AE7D0A6 for ; Thu, 21 Sep 2023 18:37:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230347AbjIUSho (ORCPT ); Thu, 21 Sep 2023 14:37:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35374 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230300AbjIUShR (ORCPT ); Thu, 21 Sep 2023 14:37:17 -0400 Received: from mail-io1-xd2b.google.com (mail-io1-xd2b.google.com [IPv6:2607:f8b0:4864:20::d2b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CD9EED7DBA for ; Thu, 21 Sep 2023 11:29:18 -0700 (PDT) Received: by mail-io1-xd2b.google.com with SMTP id ca18e2360f4ac-79f96830e4dso3975739f.1 for ; Thu, 21 Sep 2023 11:29:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1695320957; x=1695925757; darn=vger.kernel.org; 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=aeITMYfcld3mteb+NSEcBXXoBeyRBDS9X8Wlurs1dfY=; b=elkX0bbQnyNGl1I50jhGbi+pWcQeuY5xLC5VLpCo+FVlOp7UwN6P0Qjig8a5k6gTkQ IL7gyU0LgEPpo9Y/PpIaiUVN0MVHLzLecVmUCsHkN14IwxkjxIkhNo9w2VQxBKO2Gpyr T3n2Z7dN+Z75R5u4IwI8PyaftN/9UYXl9GqRtbYkA4PM7NrFR1UmBTFreO0O11jsr1a4 DbXsv1worfom++ih99/XxocYLChcdRN0DHTxZPIdcbChypfX1OaaNmOSAeXQr2AkEGZZ H8ULrGx+Y3Ie51DabPn9XxVnN6c6uFlFfjOXjZgyG9q3PPDHxGudBcFECoeA6MCZe4Eq jFCg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695320957; x=1695925757; 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=aeITMYfcld3mteb+NSEcBXXoBeyRBDS9X8Wlurs1dfY=; b=ag37ZVE7GxFR1PqwOZ5zrzE5YLJrQzE0WMp08Zlcy1QsW98y1K6bfFy7NAhK2yVD8b xTPAs2rRQDaaWLUAdMsUkoSikISWtWHQPG/owWdW7oMzIjz9cfk8+4OJCzHXJY7EJahy kUXxNNn3gI1j0VLuQqC6KK6zVVMT8Qg5CUnb1F8QSXEDNbEWaYDLje75Os+mahnaDYy8 KWpSD7fPt0d+rgW+UqOEwZ7UeN+Xl/oKQKNnG6HF4jm98Gq3ulJIPcfOyvIXmrReYprp pFb/zBO8Nux3KK4/It37vSU7AQFz7gGL3bpJw85QhK4Dt+A1CvrgCwhGnweQ3UAcfEOd MwuQ== X-Gm-Message-State: AOJu0YxPtnAcsW40OdP5NvpenFhFD9L+XERvgf3BiZf3+VWvYTmjoxnN nsSMtbUjEEWN2BQdJvEzy2fiQeUIXfLpptuSJ8uWZg== X-Google-Smtp-Source: AGHT+IEMeR7eiw0nzdlaXpVdshFLf4QAnYLaYjf6wZVS+llAK8oxoAXqFB8JQnoxkaPkNldByScrSw== X-Received: by 2002:a92:d903:0:b0:350:f353:4017 with SMTP id s3-20020a92d903000000b00350f3534017mr6601502iln.0.1695320957710; Thu, 21 Sep 2023 11:29:17 -0700 (PDT) Received: from localhost.localdomain ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id o25-20020a02c6b9000000b0042b227eb1ddsm500441jan.55.2023.09.21.11.29.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 21 Sep 2023 11:29:16 -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 3/8] futex: abstract out a __futex_wake_mark() helper Date: Thu, 21 Sep 2023 12:29:03 -0600 Message-Id: <20230921182908.160080-4-axboe@kernel.dk> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230921182908.160080-1-axboe@kernel.dk> References: <20230921182908.160080-1-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 547f509b2c87..33835b81e0c3 100644 --- a/kernel/futex/futex.h +++ b/kernel/futex/futex.h @@ -219,6 +219,7 @@ 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 35c6a637a4bb..6fcf5f723719 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.