From nobody Mon Sep 8 09:45:21 2025 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 0F833EB64DA for ; Thu, 20 Jul 2023 22:19:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229949AbjGTWTP (ORCPT ); Thu, 20 Jul 2023 18:19:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46516 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229708AbjGTWTK (ORCPT ); Thu, 20 Jul 2023 18:19:10 -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 DC1F6E44 for ; Thu, 20 Jul 2023 15:19:08 -0700 (PDT) Received: by mail-pf1-x435.google.com with SMTP id d2e1a72fcca58-682a5465e9eso264720b3a.1 for ; Thu, 20 Jul 2023 15:19:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20221208.gappssmtp.com; s=20221208; t=1689891548; x=1690496348; 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=WOL067osaUVD2WGIgkXdT50lTOWUWIgvc4AEqkDscXJLFPBMT0ONp5BBak35zLctZZ AMZnsNVfpx8/08fVLo9HjESlx+fL3eg5vh135rKOTWXQyoqVRxwQag9lzCve0IJR+XFl CjPCfU3Bly9kThOZi5HS+8criRD6s8AlmuoTpjK+BT/BgDgU+WFx66UXFOob1Lebb7Gi K75u9i9VpneJ0NC6/5n4gD4z84Kpu0FHcaY+56XRjjmCE2bYfqVG2RuYXd3m9QA47+oj mGBGlTqOKvANBl6jQBINEwv53cFjn14pfgR5YxoEQ0T9KKKTelIe/ggkoaoFs1qS0iD2 inOA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689891548; x=1690496348; 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=YkUIy4J6rN1rPS0nP56YMNtt+/2WHh01Wjdi9ho72AqiDjW/8I7qSlG6vfgqqQpJh+ 0NRVJLWjy6wqE9bT8umla9utTtU9iAJ+OJdoA4o7kCZVCKiOBQlXRj95YrFyUPtN0JCP 9EszrIJnJb+NLvkZIAhzsADXYwG8BhT2BbTcQdufjY+iUEy4t0HHtidszkPj6xH+xAU4 J0rap5eQEBnTdF9S0BLFroHuzTNwneMtsbQ/IowvTces93fywBt+nvsBXqyrGYPQeNY1 N44FzRcACYI7uNXnhtT6tl4XjBggWGhJ5eGF1QSDj1IPrvcYjzypxswXMlVhg0kXOt9C jVJg== X-Gm-Message-State: ABy/qLZUUvP4025Ahs9xG2b5p+Pxhaj7G+NngO2CtoN5Ocg+VcKWaQCG l5WeONuxrayPJFpdEyaTUdsXD/q3PkZg9IajU0k= X-Google-Smtp-Source: APBJJlHNoXWkTaeiFsQJURdZN83WfpPtpj9P4/mBIuHx8U5G8nUY5PwY02lmoCqavwUbnSiNbkA2Lw== X-Received: by 2002:a05:6a20:42a8:b0:123:3ec2:360d with SMTP id o40-20020a056a2042a800b001233ec2360dmr204903pzj.5.1689891548133; Thu, 20 Jul 2023 15:19:08 -0700 (PDT) Received: from localhost.localdomain ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id q1-20020a63bc01000000b0055b3af821d5sm1762454pge.25.2023.07.20.15.19.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Jul 2023 15:19:07 -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 01/10] futex: Clarify FUTEX2 flags Date: Thu, 20 Jul 2023 16:18:49 -0600 Message-Id: <20230720221858.135240-2-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 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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) =20 /* - * 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 :-( */ =20 /* * 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, u3= 2, val, return do_futex(uaddr, op, val, tp, uaddr2, (unsigned long)utime, val3); } =20 -/* 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) =20 /** * futex_parse_waitv - Parse a waitv array from userspace @@ -205,10 +204,10 @@ static int futex_parse_waitv(struct futex_vector *fut= exv, if (copy_from_user(&aux, &uwaitv[i], sizeof(aux))) return -EFAULT; =20 - if ((aux.flags & ~FUTEXV_WAITER_MASK) || aux.__reserved) + if ((aux.flags & ~FUTEX2_MASK) || aux.__reserved) return -EINVAL; =20 - if (!(aux.flags & FUTEX_32)) + if (!(aux.flags & FUTEX2_32)) return -EINVAL; =20 futexv[i].w.flags =3D aux.flags; --=20 2.40.1 From nobody Mon Sep 8 09:45:21 2025 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 E9DFDEB64DD for ; Thu, 20 Jul 2023 22:19:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229668AbjGTWTS (ORCPT ); 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Thu, 20 Jul 2023 15:19:08 -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 02/10] futex: Extend the FUTEX2 flags Date: Thu, 20 Jul 2023 16:18:50 -0600 Message-Id: <20230720221858.135240-3-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 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Peter Zijlstra Add the definition for the missing but always intended extra sizes, and add a NUMA flag for the planned numa extention. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Jens Axboe --- include/uapi/linux/futex.h | 7 ++++--- kernel/futex/syscalls.c | 4 ++-- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/include/uapi/linux/futex.h b/include/uapi/linux/futex.h index 0c5abb6aa8f8..0ed021acc1d9 100644 --- a/include/uapi/linux/futex.h +++ b/include/uapi/linux/futex.h @@ -46,10 +46,11 @@ /* * Flags for futex2 syscalls. */ - /* 0x00 */ - /* 0x01 */ +#define FUTEX2_8 0x00 +#define FUTEX2_16 0x01 #define FUTEX2_32 0x02 - /* 0x04 */ +#define FUTEX2_64 0x03 +#define FUTEX2_NUMA 0x04 /* 0x08 */ /* 0x10 */ /* 0x20 */ diff --git a/kernel/futex/syscalls.c b/kernel/futex/syscalls.c index 42b6c2fac7db..d5bb6dad22fe 100644 --- a/kernel/futex/syscalls.c +++ b/kernel/futex/syscalls.c @@ -183,7 +183,7 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u3= 2, val, return do_futex(uaddr, op, val, tp, uaddr2, (unsigned long)utime, val3); } =20 -#define FUTEX2_MASK (FUTEX2_32 | FUTEX2_PRIVATE) +#define FUTEX2_MASK (FUTEX2_64 | FUTEX2_PRIVATE) =20 /** * futex_parse_waitv - Parse a waitv array from userspace @@ -207,7 +207,7 @@ static int futex_parse_waitv(struct futex_vector *futex= v, if ((aux.flags & ~FUTEX2_MASK) || aux.__reserved) return -EINVAL; =20 - if (!(aux.flags & FUTEX2_32)) + if ((aux.flags & FUTEX2_64) !=3D FUTEX2_32) return -EINVAL; =20 futexv[i].w.flags =3D aux.flags; --=20 2.40.1 From nobody Mon Sep 8 09:45:21 2025 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 748DAC001E0 for ; Thu, 20 Jul 2023 22:19:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230049AbjGTWTV (ORCPT ); Thu, 20 Jul 2023 18:19:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46548 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229801AbjGTWTM (ORCPT ); Thu, 20 Jul 2023 18:19:12 -0400 Received: from mail-pf1-x42a.google.com (mail-pf1-x42a.google.com [IPv6:2607:f8b0:4864:20::42a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78E29E44 for ; Thu, 20 Jul 2023 15:19:11 -0700 (PDT) Received: by mail-pf1-x42a.google.com with SMTP id d2e1a72fcca58-682a5465e9eso264732b3a.1 for ; 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charset="utf-8" From: Peter Zijlstra Futex has 3 sets of flags: - legacy futex op bits - futex2 flags - internal flags Add a few helpers to convert from the API flags into the internal flags. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Jens Axboe --- kernel/futex/futex.h | 48 ++++++++++++++++++++++++++++++++++++++--- kernel/futex/syscalls.c | 21 +++++++++++------- kernel/futex/waitwake.c | 4 ++-- 3 files changed, 60 insertions(+), 13 deletions(-) diff --git a/kernel/futex/futex.h b/kernel/futex/futex.h index b5379c0e6d6d..54f4470b7db8 100644 --- a/kernel/futex/futex.h +++ b/kernel/futex/futex.h @@ -16,8 +16,15 @@ * Futex flags used to encode options to functions and preserve them across * restarts. */ +#define FLAGS_SIZE_8 0x00 +#define FLAGS_SIZE_16 0x01 +#define FLAGS_SIZE_32 0x02 +#define FLAGS_SIZE_64 0x03 + +#define FLAGS_SIZE_MASK 0x03 + #ifdef CONFIG_MMU -# define FLAGS_SHARED 0x01 +# define FLAGS_SHARED 0x10 #else /* * NOMMU does not have per process address space. Let the compiler optimize @@ -25,8 +32,43 @@ */ # define FLAGS_SHARED 0x00 #endif -#define FLAGS_CLOCKRT 0x02 -#define FLAGS_HAS_TIMEOUT 0x04 +#define FLAGS_CLOCKRT 0x20 +#define FLAGS_HAS_TIMEOUT 0x40 +#define FLAGS_NUMA 0x80 + +/* FUTEX_ to FLAGS_ */ +static inline unsigned int futex_to_flags(unsigned int op) +{ + unsigned int flags =3D FLAGS_SIZE_32; + + if (!(op & FUTEX_PRIVATE_FLAG)) + flags |=3D FLAGS_SHARED; + + if (op & FUTEX_CLOCK_REALTIME) + flags |=3D FLAGS_CLOCKRT; + + return flags; +} + +/* FUTEX2_ to FLAGS_ */ +static inline unsigned int futex2_to_flags(unsigned int flags2) +{ + unsigned int flags =3D flags2 & FUTEX2_64; + + if (!(flags2 & FUTEX2_PRIVATE)) + flags |=3D FLAGS_SHARED; + + if (flags2 & FUTEX2_NUMA) + flags |=3D FLAGS_NUMA; + + return flags; +} + +static inline unsigned int futex_size(unsigned int flags) +{ + unsigned int size =3D flags & FLAGS_SIZE_MASK; + return 1 << size; /* {0,1,2,3} -> {1,2,4,8} */ +} =20 #ifdef CONFIG_FAIL_FUTEX extern bool should_fail_futex(bool fshared); diff --git a/kernel/futex/syscalls.c b/kernel/futex/syscalls.c index d5bb6dad22fe..7234538a490d 100644 --- a/kernel/futex/syscalls.c +++ b/kernel/futex/syscalls.c @@ -85,15 +85,12 @@ SYSCALL_DEFINE3(get_robust_list, int, pid, long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout, u32 __user *uaddr2, u32 val2, u32 val3) { + unsigned int flags =3D futex_to_flags(op); int cmd =3D op & FUTEX_CMD_MASK; - unsigned int flags =3D 0; =20 - if (!(op & FUTEX_PRIVATE_FLAG)) - flags |=3D FLAGS_SHARED; - - if (op & FUTEX_CLOCK_REALTIME) { - flags |=3D FLAGS_CLOCKRT; - if (cmd !=3D FUTEX_WAIT_BITSET && cmd !=3D FUTEX_WAIT_REQUEUE_PI && + if (flags & FLAGS_CLOCKRT) { + if (cmd !=3D FUTEX_WAIT_BITSET && + cmd !=3D FUTEX_WAIT_REQUEUE_PI && cmd !=3D FUTEX_LOCK_PI2) return -ENOSYS; } @@ -201,6 +198,8 @@ static int futex_parse_waitv(struct futex_vector *futex= v, unsigned int i; =20 for (i =3D 0; i < nr_futexes; i++) { + unsigned int bits, flags; + if (copy_from_user(&aux, &uwaitv[i], sizeof(aux))) return -EFAULT; =20 @@ -210,7 +209,13 @@ static int futex_parse_waitv(struct futex_vector *fute= xv, if ((aux.flags & FUTEX2_64) !=3D FUTEX2_32) return -EINVAL; =20 - futexv[i].w.flags =3D aux.flags; + flags =3D futex2_to_flags(aux.flags); + bits =3D 8 * futex_size(flags); + + if (bits < 64 && aux.val >> bits) + return -EINVAL; + + futexv[i].w.flags =3D flags; futexv[i].w.val =3D aux.val; futexv[i].w.uaddr =3D aux.uaddr; futexv[i].q =3D futex_q_init; diff --git a/kernel/futex/waitwake.c b/kernel/futex/waitwake.c index ba01b9408203..fa9757766103 100644 --- a/kernel/futex/waitwake.c +++ b/kernel/futex/waitwake.c @@ -419,11 +419,11 @@ static int futex_wait_multiple_setup(struct futex_vec= tor *vs, int count, int *wo */ retry: for (i =3D 0; i < count; i++) { - if ((vs[i].w.flags & FUTEX_PRIVATE_FLAG) && retry) + if (!(vs[i].w.flags & FLAGS_SHARED) && retry) continue; =20 ret =3D get_futex_key(u64_to_user_ptr(vs[i].w.uaddr), - !(vs[i].w.flags & FUTEX_PRIVATE_FLAG), + vs[i].w.flags & FLAGS_SHARED, &vs[i].q.key, FUTEX_READ); 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charset="utf-8" In preparation for having another waker that isn't futex_wake_mark(), add a wake handler in futex_q. No extra data is associated with the handler outside of struct futex_q itself. futex_wake_mark() is defined as the standard wakeup helper, now set through futex_q_init like other defaults. Normal sync futex waiting relies on wake_q holding tasks that should be woken up. This is what futex_wake_mark() does, it'll unqueue the futex and add the associated task to the wake queue. For async usage of futex waiting, rather than having tasks sleeping on the futex, we'll need to deal with a futex wake differently. For the planned io_uring case, that means posting a completion event for the task in question. Having a definable wake handler can help support that use case. Signed-off-by: Jens Axboe --- kernel/futex/futex.h | 4 ++++ kernel/futex/requeue.c | 3 ++- kernel/futex/waitwake.c | 6 +++--- 3 files changed, 9 insertions(+), 4 deletions(-) diff --git a/kernel/futex/futex.h b/kernel/futex/futex.h index 54f4470b7db8..2b18eb889cce 100644 --- a/kernel/futex/futex.h +++ b/kernel/futex/futex.h @@ -111,6 +111,9 @@ struct futex_pi_state { union futex_key key; } __randomize_layout; =20 +struct futex_q; +typedef void (futex_wake_fn)(struct wake_q_head *wake_q, struct futex_q *q= ); + /** * struct futex_q - The hashed futex queue entry, one per waiting task * @list: priority-sorted list of tasks waiting on this futex @@ -140,6 +143,7 @@ struct futex_q { =20 struct task_struct *task; spinlock_t *lock_ptr; + futex_wake_fn *wake; union futex_key key; struct futex_pi_state *pi_state; struct rt_mutex_waiter *rt_waiter; diff --git a/kernel/futex/requeue.c b/kernel/futex/requeue.c index cba8b1a6a4cc..e892bc6c41d8 100644 --- a/kernel/futex/requeue.c +++ b/kernel/futex/requeue.c @@ -58,6 +58,7 @@ enum { =20 const struct futex_q futex_q_init =3D { /* list gets initialized in futex_queue()*/ + .wake =3D futex_wake_mark, .key =3D FUTEX_KEY_INIT, .bitset =3D FUTEX_BITSET_MATCH_ANY, .requeue_state =3D ATOMIC_INIT(Q_REQUEUE_PI_NONE), @@ -591,7 +592,7 @@ int futex_requeue(u32 __user *uaddr1, unsigned int flag= s, u32 __user *uaddr2, /* Plain futexes just wake or requeue and are done */ if (!requeue_pi) { if (++task_count <=3D nr_wake) - futex_wake_mark(&wake_q, this); + this->wake(&wake_q, this); else requeue_futex(this, hb1, hb2, &key2); continue; diff --git a/kernel/futex/waitwake.c b/kernel/futex/waitwake.c index fa9757766103..0272b8c3b132 100644 --- a/kernel/futex/waitwake.c +++ b/kernel/futex/waitwake.c @@ -174,7 +174,7 @@ int futex_wake(u32 __user *uaddr, unsigned int flags, i= nt nr_wake, u32 bitset) if (!(this->bitset & bitset)) continue; =20 - futex_wake_mark(&wake_q, this); + this->wake(&wake_q, this); if (++ret >=3D nr_wake) break; } @@ -289,7 +289,7 @@ int futex_wake_op(u32 __user *uaddr1, unsigned int flag= s, u32 __user *uaddr2, ret =3D -EINVAL; goto out_unlock; } - futex_wake_mark(&wake_q, this); + this->wake(&wake_q, this); if (++ret >=3D nr_wake) break; } @@ -303,7 +303,7 @@ int futex_wake_op(u32 __user *uaddr1, unsigned int flag= s, u32 __user *uaddr2, ret =3D -EINVAL; goto out_unlock; } - futex_wake_mark(&wake_q, this); + this->wake(&wake_q, this); if (++op_ret >=3D nr_wake2) break; } --=20 2.40.1 From nobody Mon Sep 8 09:45:21 2025 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 539D8EB64DA for ; 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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 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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); =20 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. */ =20 -/* - * 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 =3D q->task; - if (WARN(q->pi_state || q->rt_waiter, "refusing to wake PI futex\n")) - return; + return false; =20 - get_task_struct(p); __futex_unqueue(q); /* * The waiting task can free the futex_q as soon as q->lock_ptr =3D NULL @@ -130,6 +121,26 @@ void futex_wake_mark(struct wake_q_head *wake_q, struc= t futex_q *q) */ smp_store_release(&q->lock_ptr, NULL); =20 + 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 =3D 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. --=20 2.40.1 From nobody Mon Sep 8 09:45:21 2025 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 8F9A4C04A6A for ; Thu, 20 Jul 2023 22:19:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230234AbjGTWTf (ORCPT ); Thu, 20 Jul 2023 18:19:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46690 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230029AbjGTWTU (ORCPT ); Thu, 20 Jul 2023 18:19:20 -0400 Received: from mail-pf1-x42f.google.com (mail-pf1-x42f.google.com [IPv6:2607:f8b0:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C56711737 for ; Thu, 20 Jul 2023 15:19:15 -0700 (PDT) Received: by mail-pf1-x42f.google.com with SMTP id d2e1a72fcca58-682eef7d752so276634b3a.0 for ; Thu, 20 Jul 2023 15:19:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20221208.gappssmtp.com; s=20221208; t=1689891555; x=1690496355; 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=FZQglJaJmAQsYR2SqNO2wMBm2Lj6lDOx3rI5Z/PUUq4=; b=yIojbrOfwVwo4JsWOJHABOx2YCoYHGzBGS6/PB+ODN+NMgP8u5TOWCleuWpkvofWPd yJj5V/EWmpexjnUGRLV1wa2tLsIayOOfRHa9cW8Rm0O+3xymxn/7BWh12qpijeVf/zzX sT2n9lkQG06/JXmAAU/AtuoOfhFTtS+u6quuV8dRgiXdIpwYE13Wx6vQZb/H6lkRMpET 1dsqjyFi3FO/xmHDgWryitQSE3MMTJxMqiro/NAM5VUB921FrrU9Uxo7LHUTXQW3mNaZ 2l7YF/sMPLxKtpZLzkhdSiedfb+osocHw0jAZ6DA7ucpHL8gUCmfzztfQ7cLdkFKvJ2o 7ghw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689891555; x=1690496355; 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=FZQglJaJmAQsYR2SqNO2wMBm2Lj6lDOx3rI5Z/PUUq4=; b=bpqixCpQwTIiYkbs5dU/DJ3x+IV2D2jh2K2OZJhDesbDGhRfSsSXxW123vArCVuX4V Dd9LzsEOTukihpBESTlUwuYHoPylLQzZmvKWfjHbF7x/QphluPzX3hXHh6uuGMjQ2Rhk oPu82+U3nGVHJc+kd6dnW9lj92IYTzidI5GWhnPxdVZoTZeljQtFciFdIsFyRjBr0qFN Y9VNtO3CuCNmEshW07lpGSBX+y/IG2uSByFsVJgHNCJPwHpcKDHaM/BTdQRs66RP1KM8 fZa3QSmo31CLNGpPq2P4bxur56cPS+V+daP13Rl855ruEv0oNtHYeQGOZEY1Mh7oUWc6 yFjA== X-Gm-Message-State: ABy/qLbPtcaQcoorzypJsrKDmubWjzch/JnDIoeL6jtmg5mMpFoVEO+r G0luZUvPm2WFkH2Tr6bA4Z4dfA== X-Google-Smtp-Source: APBJJlFGOr8irArN1ihA0ix97dGGKnKf90pZiOQKe+sKix9GTzeDYA4xwzXwb1OQwijImXTEmTD0hg== X-Received: by 2002:a05:6a20:8f16:b0:125:6443:4eb8 with SMTP id b22-20020a056a208f1600b0012564434eb8mr232873pzk.5.1689891555213; Thu, 20 Jul 2023 15:19:15 -0700 (PDT) Received: from localhost.localdomain ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id q1-20020a63bc01000000b0055b3af821d5sm1762454pge.25.2023.07.20.15.19.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Jul 2023 15:19:14 -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 06/10] io_uring: add support for futex wake and wait Date: Thu, 20 Jul 2023 16:18:54 -0600 Message-Id: <20230720221858.135240-7-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 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Add support for FUTEX_WAKE/WAIT primitives. IORING_OP_FUTEX_WAKE is mix of FUTEX_WAKE and FUTEX_WAKE_BITSET, as it does support passing in a bitset. Similary, IORING_OP_FUTEX_WAIT is a mix of FUTEX_WAIT and FUTEX_WAIT_BITSET. FUTEX_WAKE is straight forward, as those can always be done directly from the io_uring submission without needing async handling. For FUTEX_WAIT, things are a bit more complicated. If the futex isn't ready, then we rely on a callback via futex_queue->wake() when someone wakes up the futex. From that calback, we queue up task_work with the original task, which will post a CQE and wake it, if necessary. Cancelations are supported, both from the application point-of-view, but also to be able to cancel pending waits if the ring exits before all events have occurred. This is just the barebones wait/wake support. PI or REQUEUE support is not added at this point, unclear if we might look into that later. Likewise, explicit timeouts are not supported either. It is expected that users that need timeouts would do so via the usual io_uring mechanism to do that using linked timeouts. Signed-off-by: Jens Axboe --- include/linux/io_uring_types.h | 3 + include/uapi/linux/io_uring.h | 3 + io_uring/Makefile | 4 +- io_uring/cancel.c | 5 + io_uring/cancel.h | 4 + io_uring/futex.c | 220 +++++++++++++++++++++++++++++++++ io_uring/futex.h | 34 +++++ io_uring/io_uring.c | 5 + io_uring/opdef.c | 24 +++- 9 files changed, 300 insertions(+), 2 deletions(-) create mode 100644 io_uring/futex.c create mode 100644 io_uring/futex.h diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h index f04ce513fadb..a7f03d8d879f 100644 --- a/include/linux/io_uring_types.h +++ b/include/linux/io_uring_types.h @@ -273,6 +273,9 @@ struct io_ring_ctx { struct io_wq_work_list locked_free_list; unsigned int locked_free_nr; =20 + struct hlist_head futex_list; + struct io_alloc_cache futex_cache; + const struct cred *sq_creds; /* cred used for __io_sq_thread() */ struct io_sq_data *sq_data; /* if using sq thread polling */ =20 diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 36f9c73082de..3bd2d765f593 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -65,6 +65,7 @@ struct io_uring_sqe { __u32 xattr_flags; __u32 msg_ring_flags; __u32 uring_cmd_flags; + __u32 futex_flags; }; __u64 user_data; /* data to be passed back at completion time */ /* pack this to avoid bogus arm OABI complaints */ @@ -235,6 +236,8 @@ enum io_uring_op { IORING_OP_URING_CMD, IORING_OP_SEND_ZC, IORING_OP_SENDMSG_ZC, + IORING_OP_FUTEX_WAIT, + IORING_OP_FUTEX_WAKE, =20 /* this goes last, obviously */ IORING_OP_LAST, diff --git a/io_uring/Makefile b/io_uring/Makefile index 8cc8e5387a75..2e4779bc550c 100644 --- a/io_uring/Makefile +++ b/io_uring/Makefile @@ -7,5 +7,7 @@ obj-$(CONFIG_IO_URING) +=3D io_uring.o xattr.o nop.o fs.o = splice.o \ openclose.o uring_cmd.o epoll.o \ statx.o net.o msg_ring.o timeout.o \ sqpoll.o fdinfo.o tctx.o poll.o \ - cancel.o kbuf.o rsrc.o rw.o opdef.o notif.o + cancel.o kbuf.o rsrc.o rw.o opdef.o \ + notif.o obj-$(CONFIG_IO_WQ) +=3D io-wq.o +obj-$(CONFIG_FUTEX) +=3D futex.o diff --git a/io_uring/cancel.c b/io_uring/cancel.c index 7b23607cf4af..3dba8ccb1cd8 100644 --- a/io_uring/cancel.c +++ b/io_uring/cancel.c @@ -15,6 +15,7 @@ #include "tctx.h" #include "poll.h" #include "timeout.h" +#include "futex.h" #include "cancel.h" =20 struct io_cancel { @@ -119,6 +120,10 @@ int io_try_cancel(struct io_uring_task *tctx, struct i= o_cancel_data *cd, if (ret !=3D -ENOENT) return ret; =20 + ret =3D io_futex_cancel(ctx, cd, issue_flags); + if (ret !=3D -ENOENT) + return ret; + spin_lock(&ctx->completion_lock); if (!(cd->flags & IORING_ASYNC_CANCEL_FD)) ret =3D io_timeout_cancel(ctx, cd); diff --git a/io_uring/cancel.h b/io_uring/cancel.h index fc98622e6166..c0a8e7c520b6 100644 --- a/io_uring/cancel.h +++ b/io_uring/cancel.h @@ -1,4 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 +#ifndef IORING_CANCEL_H +#define IORING_CANCEL_H =20 #include =20 @@ -22,3 +24,5 @@ void init_hash_table(struct io_hash_table *table, unsigne= d size); =20 int io_sync_cancel(struct io_ring_ctx *ctx, void __user *arg); bool io_cancel_req_match(struct io_kiocb *req, struct io_cancel_data *cd); + +#endif diff --git a/io_uring/futex.c b/io_uring/futex.c new file mode 100644 index 000000000000..0114fda797e1 --- /dev/null +++ b/io_uring/futex.c @@ -0,0 +1,220 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include + +#include + +#include "../kernel/futex/futex.h" +#include "io_uring.h" +#include "rsrc.h" +#include "futex.h" + +struct io_futex { + struct file *file; + u32 __user *uaddr; + unsigned int futex_val; + unsigned int futex_flags; + unsigned int futex_mask; +}; + +struct io_futex_data { + union { + struct futex_q q; + struct io_cache_entry cache; + }; + struct io_kiocb *req; +}; + +void io_futex_cache_init(struct io_ring_ctx *ctx) +{ + io_alloc_cache_init(&ctx->futex_cache, IO_NODE_ALLOC_CACHE_MAX, + sizeof(struct io_futex_data)); +} + +static void io_futex_cache_entry_free(struct io_cache_entry *entry) +{ + kfree(container_of(entry, struct io_futex_data, cache)); +} + +void io_futex_cache_free(struct io_ring_ctx *ctx) +{ + io_alloc_cache_free(&ctx->futex_cache, io_futex_cache_entry_free); +} + +static void io_futex_complete(struct io_kiocb *req, struct io_tw_state *ts) +{ + struct io_futex_data *ifd =3D req->async_data; + struct io_ring_ctx *ctx =3D req->ctx; + + io_tw_lock(ctx, ts); + if (!io_alloc_cache_put(&ctx->futex_cache, &ifd->cache)) + kfree(ifd); + req->async_data =3D NULL; + hlist_del_init(&req->hash_node); + io_req_task_complete(req, ts); +} + +static bool __io_futex_cancel(struct io_ring_ctx *ctx, struct io_kiocb *re= q) +{ + struct io_futex_data *ifd =3D req->async_data; + + /* futex wake already done or in progress */ + if (!futex_unqueue(&ifd->q)) + return false; + + hlist_del_init(&req->hash_node); + io_req_set_res(req, -ECANCELED, 0); + req->io_task_work.func =3D io_futex_complete; + io_req_task_work_add(req); + return true; +} + +int io_futex_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd, + unsigned int issue_flags) +{ + struct hlist_node *tmp; + struct io_kiocb *req; + int nr =3D 0; + + if (cd->flags & (IORING_ASYNC_CANCEL_FD|IORING_ASYNC_CANCEL_FD_FIXED)) + return -ENOENT; + + io_ring_submit_lock(ctx, issue_flags); + hlist_for_each_entry_safe(req, tmp, &ctx->futex_list, hash_node) { + if (req->cqe.user_data !=3D cd->data && + !(cd->flags & IORING_ASYNC_CANCEL_ANY)) + continue; + if (__io_futex_cancel(ctx, req)) + nr++; + if (!(cd->flags & IORING_ASYNC_CANCEL_ALL)) + break; + } + io_ring_submit_unlock(ctx, issue_flags); + + if (nr) + return nr; + + return -ENOENT; +} + +bool io_futex_remove_all(struct io_ring_ctx *ctx, struct task_struct *task, + bool cancel_all) +{ + struct hlist_node *tmp; + struct io_kiocb *req; + bool found =3D false; + + lockdep_assert_held(&ctx->uring_lock); + + hlist_for_each_entry_safe(req, tmp, &ctx->futex_list, hash_node) { + if (!io_match_task_safe(req, task, cancel_all)) + continue; + __io_futex_cancel(ctx, req); + found =3D true; + } + + return found; +} + +int io_futex_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_futex *iof =3D io_kiocb_to_cmd(req, struct io_futex); + + if (unlikely(sqe->fd || sqe->addr2 || sqe->buf_index || sqe->addr3)) + return -EINVAL; + + iof->uaddr =3D u64_to_user_ptr(READ_ONCE(sqe->addr)); + iof->futex_val =3D READ_ONCE(sqe->len); + iof->futex_mask =3D READ_ONCE(sqe->file_index); + iof->futex_flags =3D READ_ONCE(sqe->futex_flags); + if (iof->futex_flags & FUTEX_CMD_MASK) + return -EINVAL; + + return 0; +} + +static void io_futex_wake_fn(struct wake_q_head *wake_q, struct futex_q *q) +{ + struct io_futex_data *ifd =3D container_of(q, struct io_futex_data, q); + struct io_kiocb *req =3D ifd->req; + + if (unlikely(!__futex_wake_mark(q))) + return; + + io_req_set_res(req, 0, 0); + req->io_task_work.func =3D io_futex_complete; + io_req_task_work_add(req); +} + +static struct io_futex_data *io_alloc_ifd(struct io_ring_ctx *ctx) +{ + struct io_cache_entry *entry; + + entry =3D io_alloc_cache_get(&ctx->futex_cache); + if (entry) + return container_of(entry, struct io_futex_data, cache); + + return kmalloc(sizeof(struct io_futex_data), GFP_NOWAIT); +} + +int io_futex_wait(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_futex *iof =3D io_kiocb_to_cmd(req, struct io_futex); + struct io_ring_ctx *ctx =3D req->ctx; + struct io_futex_data *ifd =3D NULL; + struct futex_hash_bucket *hb; + int ret; + + if (!iof->futex_mask) { + ret =3D -EINVAL; + goto done; + } + + io_ring_submit_lock(ctx, issue_flags); + ifd =3D io_alloc_ifd(ctx); + if (!ifd) { + ret =3D -ENOMEM; + goto done_unlock; + } + + req->async_data =3D ifd; + ifd->q =3D futex_q_init; + ifd->q.bitset =3D iof->futex_mask; + ifd->q.wake =3D io_futex_wake_fn; + ifd->req =3D req; + + ret =3D futex_wait_setup(iof->uaddr, iof->futex_val, + futex2_to_flags(iof->futex_flags), &ifd->q, &hb); + if (!ret) { + hlist_add_head(&req->hash_node, &ctx->futex_list); + io_ring_submit_unlock(ctx, issue_flags); + + futex_queue(&ifd->q, hb); + return IOU_ISSUE_SKIP_COMPLETE; + } + +done_unlock: + io_ring_submit_unlock(ctx, issue_flags); +done: + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + kfree(ifd); + return IOU_OK; +} + +int io_futex_wake(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_futex *iof =3D io_kiocb_to_cmd(req, struct io_futex); + int ret; + + ret =3D futex_wake(iof->uaddr, futex2_to_flags(iof->futex_flags), + iof->futex_val, iof->futex_mask); + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_OK; +} diff --git a/io_uring/futex.h b/io_uring/futex.h new file mode 100644 index 000000000000..ddc9e0d73c52 --- /dev/null +++ b/io_uring/futex.h @@ -0,0 +1,34 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "cancel.h" + +int io_futex_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_futex_wait(struct io_kiocb *req, unsigned int issue_flags); +int io_futex_wake(struct io_kiocb *req, unsigned int issue_flags); + +#if defined(CONFIG_FUTEX) +int io_futex_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd, + unsigned int issue_flags); +bool io_futex_remove_all(struct io_ring_ctx *ctx, struct task_struct *task, + bool cancel_all); +void io_futex_cache_init(struct io_ring_ctx *ctx); +void io_futex_cache_free(struct io_ring_ctx *ctx); +#else +static inline int io_futex_cancel(struct io_ring_ctx *ctx, + struct io_cancel_data *cd, + unsigned int issue_flags) +{ + return 0; +} +static inline bool io_futex_remove_all(struct io_ring_ctx *ctx, + struct task_struct *task, bool cancel_all) +{ + return false; +} +static inline void io_futex_cache_init(struct io_ring_ctx *ctx) +{ +} +static inline void io_futex_cache_free(struct io_ring_ctx *ctx) +{ +} +#endif diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 135da2fd0eda..e52cbdcb29b8 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -92,6 +92,7 @@ #include "cancel.h" #include "net.h" #include "notif.h" +#include "futex.h" =20 #include "timeout.h" #include "poll.h" @@ -330,6 +331,7 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(str= uct io_uring_params *p) sizeof(struct async_poll)); io_alloc_cache_init(&ctx->netmsg_cache, IO_ALLOC_CACHE_MAX, sizeof(struct io_async_msghdr)); + io_futex_cache_init(ctx); init_completion(&ctx->ref_comp); xa_init_flags(&ctx->personalities, XA_FLAGS_ALLOC1); mutex_init(&ctx->uring_lock); @@ -349,6 +351,7 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(str= uct io_uring_params *p) INIT_LIST_HEAD(&ctx->tctx_list); ctx->submit_state.free_list.next =3D NULL; INIT_WQ_LIST(&ctx->locked_free_list); + INIT_HLIST_HEAD(&ctx->futex_list); INIT_DELAYED_WORK(&ctx->fallback_work, io_fallback_req_func); INIT_WQ_LIST(&ctx->submit_state.compl_reqs); return ctx; @@ -2869,6 +2872,7 @@ static __cold void io_ring_ctx_free(struct io_ring_ct= x *ctx) io_eventfd_unregister(ctx); io_alloc_cache_free(&ctx->apoll_cache, io_apoll_cache_free); io_alloc_cache_free(&ctx->netmsg_cache, io_netmsg_cache_free); + io_futex_cache_free(ctx); io_destroy_buffers(ctx); mutex_unlock(&ctx->uring_lock); if (ctx->sq_creds) @@ -3281,6 +3285,7 @@ static __cold bool io_uring_try_cancel_requests(struc= t io_ring_ctx *ctx, ret |=3D io_cancel_defer_files(ctx, task, cancel_all); mutex_lock(&ctx->uring_lock); ret |=3D io_poll_remove_all(ctx, task, cancel_all); + ret |=3D io_futex_remove_all(ctx, task, cancel_all); mutex_unlock(&ctx->uring_lock); ret |=3D io_kill_timeouts(ctx, task, cancel_all); if (task) diff --git a/io_uring/opdef.c b/io_uring/opdef.c index 3b9c6489b8b6..c9f23c21a031 100644 --- a/io_uring/opdef.c +++ b/io_uring/opdef.c @@ -33,6 +33,7 @@ #include "poll.h" #include "cancel.h" #include "rw.h" +#include "futex.h" =20 static int io_no_issue(struct io_kiocb *req, unsigned int issue_flags) { @@ -426,11 +427,26 @@ const struct io_issue_def io_issue_defs[] =3D { .issue =3D io_sendmsg_zc, #else .prep =3D io_eopnotsupp_prep, +#endif + }, + [IORING_OP_FUTEX_WAIT] =3D { +#if defined(CONFIG_FUTEX) + .prep =3D io_futex_prep, + .issue =3D io_futex_wait, +#else + .prep =3D io_eopnotsupp_prep, +#endif + }, + [IORING_OP_FUTEX_WAKE] =3D { +#if defined(CONFIG_FUTEX) + .prep =3D io_futex_prep, + .issue =3D io_futex_wake, +#else + .prep =3D io_eopnotsupp_prep, #endif }, }; =20 - const struct io_cold_def io_cold_defs[] =3D { [IORING_OP_NOP] =3D { .name =3D "NOP", @@ -648,6 +664,12 @@ const struct io_cold_def io_cold_defs[] =3D { .fail =3D io_sendrecv_fail, #endif }, + [IORING_OP_FUTEX_WAIT] =3D { + .name =3D "FUTEX_WAIT", + }, + [IORING_OP_FUTEX_WAKE] =3D { + .name =3D "FUTEX_WAKE", + }, }; =20 const char *io_uring_get_opcode(u8 opcode) --=20 2.40.1 From nobody Mon Sep 8 09:45:21 2025 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 4CD1EEB64DD for ; Thu, 20 Jul 2023 22:19:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230085AbjGTWTc (ORCPT ); Thu, 20 Jul 2023 18:19:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46692 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230038AbjGTWTU (ORCPT ); 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Thu, 20 Jul 2023 15:19:15 -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 07/10] futex: add wake_data to struct futex_q Date: Thu, 20 Jul 2023 16:18:55 -0600 Message-Id: <20230720221858.135240-8-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 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" With handling multiple futex_q for waitv, we cannot easily go from the futex_q to data related to that request or queue. Add a wake_data argument that belongs to the wake handler assigned. Signed-off-by: Jens Axboe --- kernel/futex/futex.h | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/futex/futex.h b/kernel/futex/futex.h index 98d43e9efe65..292224816814 100644 --- a/kernel/futex/futex.h +++ b/kernel/futex/futex.h @@ -144,6 +144,7 @@ struct futex_q { struct task_struct *task; spinlock_t *lock_ptr; futex_wake_fn *wake; + void *wake_data; union futex_key key; struct futex_pi_state *pi_state; struct rt_mutex_waiter *rt_waiter; --=20 2.40.1 From nobody Mon Sep 8 09:45:21 2025 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 8D916EB64DA for ; Thu, 20 Jul 2023 22:19:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229941AbjGTWTh (ORCPT ); Thu, 20 Jul 2023 18:19:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229927AbjGTWT3 (ORCPT ); Thu, 20 Jul 2023 18:19:29 -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 D105E2D4D for ; Thu, 20 Jul 2023 15:19:18 -0700 (PDT) Received: by mail-io1-xd2d.google.com with SMTP id ca18e2360f4ac-785d3a53ed6so17475539f.1 for ; Thu, 20 Jul 2023 15:19:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20221208.gappssmtp.com; s=20221208; t=1689891558; x=1690496358; 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=GnoTCF2aB/aSqWAJBLGbR4gHlscBgYaA7yXEbb2wyGE=; b=Q0st3/uuG+jmslAaSSiW1B/Bh02MVEa8TbQgCgFVQqY2UOskLaiChfSXbE5u306RwE /1d8d7kO9+BLFVoQ/IsCvuamQmixezGP3fpL+Yqa3RGQE4S/Kr7iJMXWM7bi9xbHPbiB NU10/v4EYu6lYpP7RWP49FgU3SPYyDh0n0tYDQe8b7cLIlCr0pXANH7grAtV6JM4MV6Z HGnyq4VGdfAUyoDQAEq2+pZ6tHwiBHBD7M3Eupp00m46BKov5Ezh+ANgfhYO4Cx+/lxl /OrUNy7KLxAyyN4H0pC1Q3WmysodwCXsAhUZGu/a+k5HT9GfGdDKclTggq6wLbeZRcPB n8NA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689891558; x=1690496358; 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=GnoTCF2aB/aSqWAJBLGbR4gHlscBgYaA7yXEbb2wyGE=; b=iGLZ3KhOEhNJXf9sYBxnf4jKBHwCL3XJU9tfZY59b3y8Qk0P5NB7k3JNS2nJbgw6GZ rmoQIYa2jFNSi+6cEdfbguCm0XfFo3e5SlTObN7fPkjqbSyHsnAGnalJu7BtaZG9WyYj t+PADVhF3K1+L3p37cZiUzQx5FJ0d18P/zaJF/zQi1S7L3bnNP1qzUgCywKC9wPidwm3 0E3oWeFkFrl1jiV5DGc9O7Ph2DQx7X0ZHoKXW3xO5T5TuaJnmCCHcYjgEmX1J5ciybuA Oo0+O2DZNR31FV6fNuyO+Fw298MJFRbBjVonrf4LI9YIWHG0cB/DJnqusX6mDrAzoJrS edmQ== X-Gm-Message-State: ABy/qLbNaZCe7bZtmsQHAFmAzZwmUC7+B8fz7QtEuJ7ltB6PsNlxBeNV 7JI+M1kX1qErwYPGkrBxD//s0wN+/MQSiXJmQaQ= X-Google-Smtp-Source: APBJJlHJ3y0UO1OnuKcbD2vWBLPGzHgJOOKVljSm7EoBfs00AdoLwdBa0iHswzpqam3eIWA8noQUyA== X-Received: by 2002:a05:6602:14d2:b0:783:6ec1:65f6 with SMTP id b18-20020a05660214d200b007836ec165f6mr184768iow.1.1689891558118; Thu, 20 Jul 2023 15:19:18 -0700 (PDT) Received: from localhost.localdomain ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id q1-20020a63bc01000000b0055b3af821d5sm1762454pge.25.2023.07.20.15.19.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Jul 2023 15:19:17 -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 08/10] futex: make futex_parse_waitv() available as a helper Date: Thu, 20 Jul 2023 16:18:56 -0600 Message-Id: <20230720221858.135240-9-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 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" To make it more generically useful, augment it with allowing the caller to pass in the wake handler and wake data. Convert the futex_waitv() syscall, passing in the default handlers. Signed-off-by: Jens Axboe --- kernel/futex/futex.h | 5 +++++ kernel/futex/syscalls.c | 14 ++++++++++---- 2 files changed, 15 insertions(+), 4 deletions(-) diff --git a/kernel/futex/futex.h b/kernel/futex/futex.h index 292224816814..3536d21adff9 100644 --- a/kernel/futex/futex.h +++ b/kernel/futex/futex.h @@ -327,6 +327,11 @@ struct futex_vector { struct futex_q q; }; =20 +extern int futex_parse_waitv(struct futex_vector *futexv, + struct futex_waitv __user *uwaitv, + unsigned int nr_futexes, futex_wake_fn *wake, + void *wake_data); + extern int futex_wait_multiple(struct futex_vector *vs, unsigned int count, struct hrtimer_sleeper *to); =20 diff --git a/kernel/futex/syscalls.c b/kernel/futex/syscalls.c index 7234538a490d..a182ea44ea89 100644 --- a/kernel/futex/syscalls.c +++ b/kernel/futex/syscalls.c @@ -187,12 +187,15 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, = u32, val, * @futexv: Kernel side list of waiters to be filled * @uwaitv: Userspace list to be parsed * @nr_futexes: Length of futexv + * @wake: Wake to call when futex is woken + * @wake_data: Data for the wake handler * * Return: Error code on failure, 0 on success */ -static int futex_parse_waitv(struct futex_vector *futexv, - struct futex_waitv __user *uwaitv, - unsigned int nr_futexes) +int futex_parse_waitv(struct futex_vector *futexv, + struct futex_waitv __user *uwaitv, + unsigned int nr_futexes, futex_wake_fn *wake, + void *wake_data) { struct futex_waitv aux; unsigned int i; @@ -219,6 +222,8 @@ static int futex_parse_waitv(struct futex_vector *futex= v, futexv[i].w.val =3D aux.val; futexv[i].w.uaddr =3D aux.uaddr; futexv[i].q =3D futex_q_init; + futexv[i].q.wake =3D wake; + futexv[i].q.wake_data =3D wake_data; } =20 return 0; @@ -295,7 +300,8 @@ SYSCALL_DEFINE5(futex_waitv, struct futex_waitv __user = *, waiters, goto destroy_timer; } =20 - ret =3D futex_parse_waitv(futexv, waiters, nr_futexes); + ret =3D futex_parse_waitv(futexv, waiters, nr_futexes, futex_wake_mark, + NULL); if (!ret) ret =3D futex_wait_multiple(futexv, nr_futexes, timeout ? &to : NULL); =20 --=20 2.40.1 From nobody Mon Sep 8 09:45:21 2025 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 1B1BBEB64DA for ; Thu, 20 Jul 2023 22:19:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230333AbjGTWTm (ORCPT ); Thu, 20 Jul 2023 18:19:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46964 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230195AbjGTWTa (ORCPT ); Thu, 20 Jul 2023 18:19:30 -0400 Received: from mail-pf1-x430.google.com (mail-pf1-x430.google.com [IPv6:2607:f8b0:4864:20::430]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1DB68196 for ; Thu, 20 Jul 2023 15:19:20 -0700 (PDT) Received: by mail-pf1-x430.google.com with SMTP id d2e1a72fcca58-682b1768a0bso283306b3a.0 for ; Thu, 20 Jul 2023 15:19:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20221208.gappssmtp.com; s=20221208; t=1689891559; x=1690496359; 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=lq7tP5scFTqDKeEjsRY7Tfz3Q9kMITKiPWmV0T5QGyI=; b=Ij/3TH98pX57tuhiixNKQRc8HG3f1pLySWMkiQRMx0ya7gGEJJughG99K6FG+ADm99 k1clK8HPB0W80Nm8zNcMrBX0UepmGEfetXzk+5oX/eztboEINLcNw7kQtngebfFcg0GW uEUqQMxMYYFogtJgl5/EOBLwKGcvxHIc6u7FmSkOIsXrytbzinUkVM/aHYnOecxJ8UD/ Ye1GaP44TIGKKrqu42h3JkB4BwtzpWgh62s072aFBVidVez+nxUYmpjKomhHNPrmiOdd jE7djQNZCMY64RPzI0k6mVYx7K2VDFylXEOhlZtVF6c6zqdGeJmNFEmUeQexuOxtBEtX eCfg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689891559; x=1690496359; 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=lq7tP5scFTqDKeEjsRY7Tfz3Q9kMITKiPWmV0T5QGyI=; b=FJyAFOEakb7qwk3RRfiQXIgeCnmwDQ/kLmM6VhVBP3IFEd12cPhztnEJgL6Gd4t2KT E/Wm/n0PgIph9K7936XLtP13MvFA/EJ/xFXUU+B5l247CYzQC53UfrFlZ8Yr2F/vpbZG XfyIKujkcrqPdjjx5wd3a0rb/9BmFc8wlC5ZZjaXajvYPEN/ijyNTQGn1OJN5f5Pkrh0 gWsjUY+sZ61BMOf/+mSknGwqQ8DLI801UEy3BYE9fYVNZz2ssswVq4kJBo6nj0TaR19r NN4F1paunD7OppOUxJaXl/SJwx/ojW6AblzIgzoNSqw5H2Jkj1Bj4eioDPdVCS125dfa O5lg== X-Gm-Message-State: ABy/qLYjeq5EybwcCr3/Gt0RLk/ZQAt9K2qcHTq4TaZ+iKmw8JG7AHa9 k6o2tJ/OUKY728wLwmVbd69CuQ== X-Google-Smtp-Source: APBJJlGgnq9cFs6XgobATsTjtEsTTzRagoTDGJ0Q2WImkj5xxjljEUzmAOSf6XA/e4Fzuexwafs+vw== X-Received: by 2002:a05:6a20:6a1d:b0:137:4fd0:e2e1 with SMTP id p29-20020a056a206a1d00b001374fd0e2e1mr276021pzk.4.1689891559262; Thu, 20 Jul 2023 15:19:19 -0700 (PDT) Received: from localhost.localdomain ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id q1-20020a63bc01000000b0055b3af821d5sm1762454pge.25.2023.07.20.15.19.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Jul 2023 15:19:18 -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 09/10] futex: make the vectored futex operations available Date: Thu, 20 Jul 2023 16:18:57 -0600 Message-Id: <20230720221858.135240-10-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 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Rename unqueue_multiple() as futex_unqueue_multiple(), and make both that and futex_wait_multiple_setup() available for external users. This is in preparation for wiring up vectored waits in io_uring. Signed-off-by: Jens Axboe --- kernel/futex/futex.h | 5 +++++ kernel/futex/waitwake.c | 10 +++++----- 2 files changed, 10 insertions(+), 5 deletions(-) diff --git a/kernel/futex/futex.h b/kernel/futex/futex.h index 3536d21adff9..faf84915acb2 100644 --- a/kernel/futex/futex.h +++ b/kernel/futex/futex.h @@ -332,6 +332,11 @@ extern int futex_parse_waitv(struct futex_vector *fute= xv, unsigned int nr_futexes, futex_wake_fn *wake, void *wake_data); =20 +extern int futex_wait_multiple_setup(struct futex_vector *vs, int count, + int *woken); + +extern int futex_unqueue_multiple(struct futex_vector *v, int count); + extern int futex_wait_multiple(struct futex_vector *vs, unsigned int count, struct hrtimer_sleeper *to); =20 diff --git a/kernel/futex/waitwake.c b/kernel/futex/waitwake.c index 86f67f652b95..6c8fb7300558 100644 --- a/kernel/futex/waitwake.c +++ b/kernel/futex/waitwake.c @@ -369,7 +369,7 @@ void futex_wait_queue(struct futex_hash_bucket *hb, str= uct futex_q *q, } =20 /** - * unqueue_multiple - Remove various futexes from their hash bucket + * futex_unqueue_multiple - Remove various futexes from their hash bucket * @v: The list of futexes to unqueue * @count: Number of futexes in the list * @@ -379,7 +379,7 @@ void futex_wait_queue(struct futex_hash_bucket *hb, str= uct futex_q *q, * - >=3D0 - Index of the last futex that was awoken; * - -1 - No futex was awoken */ -static int unqueue_multiple(struct futex_vector *v, int count) +int futex_unqueue_multiple(struct futex_vector *v, int count) { int ret =3D -1, i; =20 @@ -407,7 +407,7 @@ static int unqueue_multiple(struct futex_vector *v, int= count) * - 0 - Success * - <0 - -EFAULT, -EWOULDBLOCK or -EINVAL */ -static int futex_wait_multiple_setup(struct futex_vector *vs, int count, i= nt *woken) +int futex_wait_multiple_setup(struct futex_vector *vs, int count, int *wok= en) { struct futex_hash_bucket *hb; bool retry =3D false; @@ -469,7 +469,7 @@ static int futex_wait_multiple_setup(struct futex_vecto= r *vs, int count, int *wo * was woken, we don't return error and return this index to * userspace */ - *woken =3D unqueue_multiple(vs, i); + *woken =3D futex_unqueue_multiple(vs, i); if (*woken >=3D 0) return 1; =20 @@ -554,7 +554,7 @@ int futex_wait_multiple(struct futex_vector *vs, unsign= ed int count, =20 __set_current_state(TASK_RUNNING); =20 - ret =3D unqueue_multiple(vs, count); + ret =3D futex_unqueue_multiple(vs, count); if (ret >=3D 0) return ret; =20 --=20 2.40.1 From nobody Mon Sep 8 09:45:21 2025 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 48C91EB64DA for ; Thu, 20 Jul 2023 22:19:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230211AbjGTWTu (ORCPT ); Thu, 20 Jul 2023 18:19:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230260AbjGTWTb (ORCPT ); Thu, 20 Jul 2023 18:19:31 -0400 Received: from mail-pf1-x42b.google.com (mail-pf1-x42b.google.com [IPv6:2607:f8b0:4864:20::42b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 53FB42D70 for ; Thu, 20 Jul 2023 15:19:21 -0700 (PDT) Received: by mail-pf1-x42b.google.com with SMTP id d2e1a72fcca58-682ae5d4184so279568b3a.1 for ; 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charset="utf-8" This adds support for IORING_OP_FUTEX_WAITV, which allows registering a notification for a number of futexes at once. If one of the futexes are woken, then the request will complete with the index of the futex that got woken as the result. This is identical to what the normal vectored futex waitv operation does. Use like IORING_OP_FUTEX_WAIT, except sqe->addr must now contain the a pointer to a struct futex_waitv array, and sqe->off must now contain the number of elements in that array. Waiting on N futexes could be done with IORING_OP_FUTEX_WAIT as well, but that punts a lot of the work to the application: 1) Application would need to submit N IORING_OP_FUTEX_WAIT requests, rather than just a single IORING_OP_FUTEX_WAITV. 2) When one futex is woken, application would need to cancel the remaining N-1 requests that didn't trigger. While this is of course doable, having a single vectored futex wait makes for much simpler application code. Signed-off-by: Jens Axboe --- include/uapi/linux/io_uring.h | 1 + io_uring/futex.c | 164 +++++++++++++++++++++++++++++++--- io_uring/futex.h | 2 + io_uring/opdef.c | 11 +++ 4 files changed, 168 insertions(+), 10 deletions(-) diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 3bd2d765f593..420f38675769 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -238,6 +238,7 @@ enum io_uring_op { IORING_OP_SENDMSG_ZC, IORING_OP_FUTEX_WAIT, IORING_OP_FUTEX_WAKE, + IORING_OP_FUTEX_WAITV, =20 /* this goes last, obviously */ IORING_OP_LAST, diff --git a/io_uring/futex.c b/io_uring/futex.c index 0114fda797e1..93df54dffaa0 100644 --- a/io_uring/futex.c +++ b/io_uring/futex.c @@ -14,10 +14,15 @@ =20 struct io_futex { struct file *file; - u32 __user *uaddr; + union { + u32 __user *uaddr; + struct futex_waitv __user *uwaitv; + }; unsigned int futex_val; unsigned int futex_flags; unsigned int futex_mask; + unsigned int futex_nr; + unsigned long futexv_owned; }; =20 struct io_futex_data { @@ -44,6 +49,13 @@ void io_futex_cache_free(struct io_ring_ctx *ctx) io_alloc_cache_free(&ctx->futex_cache, io_futex_cache_entry_free); } =20 +static void __io_futex_complete(struct io_kiocb *req, struct io_tw_state *= ts) +{ + req->async_data =3D NULL; + hlist_del_init(&req->hash_node); + io_req_task_complete(req, ts); +} + static void io_futex_complete(struct io_kiocb *req, struct io_tw_state *ts) { struct io_futex_data *ifd =3D req->async_data; @@ -52,22 +64,59 @@ static void io_futex_complete(struct io_kiocb *req, str= uct io_tw_state *ts) io_tw_lock(ctx, ts); if (!io_alloc_cache_put(&ctx->futex_cache, &ifd->cache)) kfree(ifd); - req->async_data =3D NULL; - hlist_del_init(&req->hash_node); - io_req_task_complete(req, ts); + __io_futex_complete(req, ts); } =20 -static bool __io_futex_cancel(struct io_ring_ctx *ctx, struct io_kiocb *re= q) +static void io_futexv_complete(struct io_kiocb *req, struct io_tw_state *t= s) { - struct io_futex_data *ifd =3D req->async_data; + struct io_futex *iof =3D io_kiocb_to_cmd(req, struct io_futex); + struct futex_vector *futexv =3D req->async_data; + struct io_ring_ctx *ctx =3D req->ctx; + int res =3D 0; =20 - /* futex wake already done or in progress */ - if (!futex_unqueue(&ifd->q)) + io_tw_lock(ctx, ts); + + res =3D futex_unqueue_multiple(futexv, iof->futex_nr); + if (res !=3D -1) + io_req_set_res(req, res, 0); + + kfree(req->async_data); + req->flags &=3D ~REQ_F_ASYNC_DATA; + __io_futex_complete(req, ts); +} + +static bool io_futexv_claimed(struct io_futex *iof) +{ + return test_bit(0, &iof->futexv_owned); +} + +static bool io_futexv_claim(struct io_futex *iof) +{ + if (test_bit(0, &iof->futexv_owned) || + test_and_set_bit(0, &iof->futexv_owned)) return false; + return true; +} + +static bool __io_futex_cancel(struct io_ring_ctx *ctx, struct io_kiocb *re= q) +{ + /* futex wake already done or in progress */ + if (req->opcode =3D=3D IORING_OP_FUTEX_WAIT) { + struct io_futex_data *ifd =3D req->async_data; + + if (!futex_unqueue(&ifd->q)) + return false; + req->io_task_work.func =3D io_futex_complete; + } else { + struct io_futex *iof =3D io_kiocb_to_cmd(req, struct io_futex); + + if (!io_futexv_claim(iof)) + return false; + req->io_task_work.func =3D io_futexv_complete; + } =20 hlist_del_init(&req->hash_node); io_req_set_res(req, -ECANCELED, 0); - req->io_task_work.func =3D io_futex_complete; io_req_task_work_add(req); return true; } @@ -123,7 +172,7 @@ int io_futex_prep(struct io_kiocb *req, const struct io= _uring_sqe *sqe) { struct io_futex *iof =3D io_kiocb_to_cmd(req, struct io_futex); =20 - if (unlikely(sqe->fd || sqe->addr2 || sqe->buf_index || sqe->addr3)) + if (unlikely(sqe->fd || sqe->buf_index || sqe->addr3)) return -EINVAL; =20 iof->uaddr =3D u64_to_user_ptr(READ_ONCE(sqe->addr)); @@ -133,6 +182,52 @@ int io_futex_prep(struct io_kiocb *req, const struct i= o_uring_sqe *sqe) if (iof->futex_flags & FUTEX_CMD_MASK) return -EINVAL; =20 + iof->futexv_owned =3D 0; + return 0; +} + +static void io_futex_wakev_fn(struct wake_q_head *wake_q, struct futex_q *= q) +{ + struct io_kiocb *req =3D q->wake_data; + struct io_futex *iof =3D io_kiocb_to_cmd(req, struct io_futex); + + if (!io_futexv_claim(iof)) + return; + if (unlikely(!__futex_wake_mark(q))) + return; + + io_req_set_res(req, 0, 0); + req->io_task_work.func =3D io_futexv_complete; + io_req_task_work_add(req); +} + +int io_futexv_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_futex *iof =3D io_kiocb_to_cmd(req, struct io_futex); + struct futex_vector *futexv; + int ret; + + ret =3D io_futex_prep(req, sqe); + if (ret) + return ret; + + iof->futex_nr =3D READ_ONCE(sqe->off); + if (!iof->futex_nr || iof->futex_nr > FUTEX_WAITV_MAX) + return -EINVAL; + + futexv =3D kcalloc(iof->futex_nr, sizeof(*futexv), GFP_KERNEL); + if (!futexv) + return -ENOMEM; + + ret =3D futex_parse_waitv(futexv, iof->uwaitv, iof->futex_nr, + io_futex_wakev_fn, req); + if (ret) { + kfree(futexv); + return ret; + } + + req->flags |=3D REQ_F_ASYNC_DATA; + req->async_data =3D futexv; return 0; } =20 @@ -160,6 +255,55 @@ static struct io_futex_data *io_alloc_ifd(struct io_ri= ng_ctx *ctx) return kmalloc(sizeof(struct io_futex_data), GFP_NOWAIT); } =20 +int io_futexv_wait(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_futex *iof =3D io_kiocb_to_cmd(req, struct io_futex); + struct futex_vector *futexv =3D req->async_data; + struct io_ring_ctx *ctx =3D req->ctx; + int ret, woken =3D -1; + + io_ring_submit_lock(ctx, issue_flags); + + ret =3D futex_wait_multiple_setup(futexv, iof->futex_nr, &woken); + + /* + * The above call leaves us potentially non-running. This is fine + * for the sync syscall as it'll be blocking unless we already got + * one of the futexes woken, but it obviously won't work for an async + * invocation. Mark is runnable again. + */ + __set_current_state(TASK_RUNNING); + + /* + * We got woken while setting up, let that side do the completion + */ + if (io_futexv_claimed(iof)) { +skip: + io_ring_submit_unlock(ctx, issue_flags); + return IOU_ISSUE_SKIP_COMPLETE; + } + + /* + * 0 return means that we successfully setup the waiters, and that + * nobody triggered a wakeup while we were doing so. < 0 or 1 return + * is either an error or we got a wakeup while setting up. + */ + if (!ret) { + hlist_add_head(&req->hash_node, &ctx->futex_list); + goto skip; + } + + io_ring_submit_unlock(ctx, issue_flags); + if (ret < 0) + req_set_fail(req); + else if (woken !=3D -1) + ret =3D woken; + io_req_set_res(req, ret, 0); + kfree(futexv); + req->flags &=3D ~REQ_F_ASYNC_DATA; + return IOU_OK; +} + int io_futex_wait(struct io_kiocb *req, unsigned int issue_flags) { struct io_futex *iof =3D io_kiocb_to_cmd(req, struct io_futex); diff --git a/io_uring/futex.h b/io_uring/futex.h index ddc9e0d73c52..0847e9e8a127 100644 --- a/io_uring/futex.h +++ b/io_uring/futex.h @@ -3,7 +3,9 @@ #include "cancel.h" =20 int io_futex_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_futexv_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); int io_futex_wait(struct io_kiocb *req, unsigned int issue_flags); +int io_futexv_wait(struct io_kiocb *req, unsigned int issue_flags); int io_futex_wake(struct io_kiocb *req, unsigned int issue_flags); =20 #if defined(CONFIG_FUTEX) diff --git a/io_uring/opdef.c b/io_uring/opdef.c index c9f23c21a031..b9e1e12cac9c 100644 --- a/io_uring/opdef.c +++ b/io_uring/opdef.c @@ -443,6 +443,14 @@ const struct io_issue_def io_issue_defs[] =3D { .issue =3D io_futex_wake, #else .prep =3D io_eopnotsupp_prep, +#endif + }, + [IORING_OP_FUTEX_WAITV] =3D { +#if defined(CONFIG_FUTEX) + .prep =3D io_futexv_prep, + .issue =3D io_futexv_wait, +#else + .prep =3D io_eopnotsupp_prep, #endif }, }; @@ -670,6 +678,9 @@ const struct io_cold_def io_cold_defs[] =3D { [IORING_OP_FUTEX_WAKE] =3D { .name =3D "FUTEX_WAKE", }, + [IORING_OP_FUTEX_WAITV] =3D { + .name =3D "FUTEX_WAITV", + }, }; =20 const char *io_uring_get_opcode(u8 opcode) --=20 2.40.1