From patchwork Sat Sep 4 23:11:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Andr=C3=A9_Almeida?= X-Patchwork-Id: 44849 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 45E90383F40E for ; Sat, 4 Sep 2021 23:13:17 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 45E90383F40E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1630797197; bh=gyxGd8WQx7i9bmt2v+veAiTfgeyT8etlwUgIc6oqcio=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=rZ6BwjAzKLNBfH5vASXlp3Pg7kw+x2mHkq8h14Y1+Ru+AXd22Jk1WSjeoRykwD/hC re4lpacrjsSmakRImhOorZKMWcUWLOX/fXmqFEHZnKHgAeOYdrI67VFTnLjVU7JI2G MJNdX5RY8c76RVcP+Z2I8CxusisNfhCdUcku1Y5U= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by sourceware.org (Postfix) with ESMTPS id 46DC3383F400 for ; Sat, 4 Sep 2021 23:12:18 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 46DC3383F400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: tonyk) with ESMTPSA id 9AC8E1F41C89 To: Thomas Gleixner , Ingo Molnar , Peter Zijlstra , Darren Hart , linux-kernel@vger.kernel.org, Steven Rostedt , Sebastian Andrzej Siewior Subject: [PATCH v2 1/5] futex: Prepare for futex_wait_multiple() Date: Sat, 4 Sep 2021 20:11:55 -0300 Message-Id: <20210904231159.13292-2-andrealmeid@collabora.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210904231159.13292-1-andrealmeid@collabora.com> References: <20210904231159.13292-1-andrealmeid@collabora.com> MIME-Version: 1.0 X-Spam-Status: No, score=-12.1 required=5.0 tests=BAYES_00, GIT_PATCH_0, KAM_DMARC_STATUS, KAM_MANYTO, SPF_HELO_PASS, SPF_PASS, TXREP, UNPARSEABLE_RELAY autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: =?utf-8?q?Andr=C3=A9_Almeida_via_Libc-alpha?= From: =?utf-8?q?Andr=C3=A9_Almeida?= Reply-To: =?utf-8?q?Andr=C3=A9_Almeida?= Cc: Davidlohr Bueso , libc-alpha@sourceware.org, linux-api@vger.kernel.org, mtk.manpages@gmail.com, =?utf-8?q?Andr=C3=A9_Alm?= =?utf-8?q?eida?= , kernel@collabora.com, krisman@collabora.com Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" Make public functions and defines that will be used for futex_wait_multiple() function in next commit. Signed-off-by: André Almeida --- kernel/futex.c | 134 +--------------------------------------------- kernel/futex.h | 140 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 142 insertions(+), 132 deletions(-) create mode 100644 kernel/futex.h diff --git a/kernel/futex.c b/kernel/futex.c index e7b4c6121da4..58f2dc29c408 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -34,14 +34,11 @@ #include #include #include -#include #include #include #include -#include - -#include +#include "futex.h" #include "locking/rtmutex_common.h" /* @@ -150,22 +147,6 @@ static int __read_mostly futex_cmpxchg_enabled; #endif -/* - * Futex flags used to encode options to functions and preserve them across - * restarts. - */ -#ifdef CONFIG_MMU -# define FLAGS_SHARED 0x01 -#else -/* - * NOMMU does not have per process address space. Let the compiler optimize - * code away. - */ -# define FLAGS_SHARED 0x00 -#endif -#define FLAGS_CLOCKRT 0x02 -#define FLAGS_HAS_TIMEOUT 0x04 - /* * Priority Inheritance state: */ @@ -187,103 +168,6 @@ struct futex_pi_state { union futex_key key; } __randomize_layout; -/** - * struct futex_q - The hashed futex queue entry, one per waiting task - * @list: priority-sorted list of tasks waiting on this futex - * @task: the task waiting on the futex - * @lock_ptr: the hash bucket lock - * @key: the key the futex is hashed on - * @pi_state: optional priority inheritance state - * @rt_waiter: rt_waiter storage for use with requeue_pi - * @requeue_pi_key: the requeue_pi target futex key - * @bitset: bitset for the optional bitmasked wakeup - * @requeue_state: State field for futex_requeue_pi() - * @requeue_wait: RCU wait for futex_requeue_pi() (RT only) - * - * We use this hashed waitqueue, instead of a normal wait_queue_entry_t, so - * we can wake only the relevant ones (hashed queues may be shared). - * - * A futex_q has a woken state, just like tasks have TASK_RUNNING. - * It is considered woken when plist_node_empty(&q->list) || q->lock_ptr == 0. - * The order of wakeup is always to make the first condition true, then - * the second. - * - * PI futexes are typically woken before they are removed from the hash list via - * the rt_mutex code. See unqueue_me_pi(). - */ -struct futex_q { - struct plist_node list; - - struct task_struct *task; - spinlock_t *lock_ptr; - union futex_key key; - struct futex_pi_state *pi_state; - struct rt_mutex_waiter *rt_waiter; - union futex_key *requeue_pi_key; - u32 bitset; - atomic_t requeue_state; -#ifdef CONFIG_PREEMPT_RT - struct rcuwait requeue_wait; -#endif -} __randomize_layout; - -/* - * On PREEMPT_RT, the hash bucket lock is a 'sleeping' spinlock with an - * underlying rtmutex. The task which is about to be requeued could have - * just woken up (timeout, signal). After the wake up the task has to - * acquire hash bucket lock, which is held by the requeue code. As a task - * can only be blocked on _ONE_ rtmutex at a time, the proxy lock blocking - * and the hash bucket lock blocking would collide and corrupt state. - * - * On !PREEMPT_RT this is not a problem and everything could be serialized - * on hash bucket lock, but aside of having the benefit of common code, - * this allows to avoid doing the requeue when the task is already on the - * way out and taking the hash bucket lock of the original uaddr1 when the - * requeue has been completed. - * - * The following state transitions are valid: - * - * On the waiter side: - * Q_REQUEUE_PI_NONE -> Q_REQUEUE_PI_IGNORE - * Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_WAIT - * - * On the requeue side: - * Q_REQUEUE_PI_NONE -> Q_REQUEUE_PI_INPROGRESS - * Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_DONE/LOCKED - * Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_NONE (requeue failed) - * Q_REQUEUE_PI_WAIT -> Q_REQUEUE_PI_DONE/LOCKED - * Q_REQUEUE_PI_WAIT -> Q_REQUEUE_PI_IGNORE (requeue failed) - * - * The requeue side ignores a waiter with state Q_REQUEUE_PI_IGNORE as this - * signals that the waiter is already on the way out. It also means that - * the waiter is still on the 'wait' futex, i.e. uaddr1. - * - * The waiter side signals early wakeup to the requeue side either through - * setting state to Q_REQUEUE_PI_IGNORE or to Q_REQUEUE_PI_WAIT depending - * on the current state. In case of Q_REQUEUE_PI_IGNORE it can immediately - * proceed to take the hash bucket lock of uaddr1. If it set state to WAIT, - * which means the wakeup is interleaving with a requeue in progress it has - * to wait for the requeue side to change the state. Either to DONE/LOCKED - * or to IGNORE. DONE/LOCKED means the waiter q is now on the uaddr2 futex - * and either blocked (DONE) or has acquired it (LOCKED). IGNORE is set by - * the requeue side when the requeue attempt failed via deadlock detection - * and therefore the waiter q is still on the uaddr1 futex. - */ -enum { - Q_REQUEUE_PI_NONE = 0, - Q_REQUEUE_PI_IGNORE, - Q_REQUEUE_PI_IN_PROGRESS, - Q_REQUEUE_PI_WAIT, - Q_REQUEUE_PI_DONE, - Q_REQUEUE_PI_LOCKED, -}; - -static const struct futex_q futex_q_init = { - /* list gets initialized in queue_me()*/ - .key = FUTEX_KEY_INIT, - .bitset = FUTEX_BITSET_MATCH_ANY, - .requeue_state = ATOMIC_INIT(Q_REQUEUE_PI_NONE), -}; /* * Hash buckets are shared by all the futex_keys that hash to the same @@ -453,7 +337,7 @@ enum futex_access { * Return: Initialized hrtimer_sleeper structure or NULL if no timeout * value given */ -static inline struct hrtimer_sleeper * +inline struct hrtimer_sleeper * futex_setup_timer(ktime_t *time, struct hrtimer_sleeper *timeout, int flags, u64 range_ns) { @@ -3973,20 +3857,6 @@ static __always_inline bool futex_cmd_has_timeout(u32 cmd) return false; } -static __always_inline int -futex_init_timeout(u32 cmd, u32 op, struct timespec64 *ts, ktime_t *t) -{ - if (!timespec64_valid(ts)) - return -EINVAL; - - *t = timespec64_to_ktime(*ts); - if (cmd == FUTEX_WAIT) - *t = ktime_add_safe(ktime_get(), *t); - else if (cmd != FUTEX_LOCK_PI && !(op & FUTEX_CLOCK_REALTIME)) - *t = timens_ktime_to_host(CLOCK_MONOTONIC, *t); - return 0; -} - SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val, const struct __kernel_timespec __user *, utime, u32 __user *, uaddr2, u32, val3) diff --git a/kernel/futex.h b/kernel/futex.h new file mode 100644 index 000000000000..c914e0080cf1 --- /dev/null +++ b/kernel/futex.h @@ -0,0 +1,140 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _FUTEX_H +#define _FUTEX_H + +#include + +#include +#include + +/* + * Futex flags used to encode options to functions and preserve them across + * restarts. + */ +#ifdef CONFIG_MMU +# define FLAGS_SHARED 0x01 +#else +/* + * NOMMU does not have per process address space. Let the compiler optimize + * code away. + */ +# define FLAGS_SHARED 0x00 +#endif +#define FLAGS_CLOCKRT 0x02 +#define FLAGS_HAS_TIMEOUT 0x04 + +/** + * struct futex_q - The hashed futex queue entry, one per waiting task + * @list: priority-sorted list of tasks waiting on this futex + * @task: the task waiting on the futex + * @lock_ptr: the hash bucket lock + * @key: the key the futex is hashed on + * @pi_state: optional priority inheritance state + * @rt_waiter: rt_waiter storage for use with requeue_pi + * @requeue_pi_key: the requeue_pi target futex key + * @bitset: bitset for the optional bitmasked wakeup + * + * We use this hashed waitqueue, instead of a normal wait_queue_entry_t, so + * we can wake only the relevant ones (hashed queues may be shared). + * + * A futex_q has a woken state, just like tasks have TASK_RUNNING. + * It is considered woken when plist_node_empty(&q->list) || q->lock_ptr == 0. + * The order of wakeup is always to make the first condition true, then + * the second. + * + * PI futexes are typically woken before they are removed from the hash list via + * the rt_mutex code. See unqueue_me_pi(). + */ +struct futex_q { + struct plist_node list; + + struct task_struct *task; + spinlock_t *lock_ptr; + union futex_key key; + struct futex_pi_state *pi_state; + struct rt_mutex_waiter *rt_waiter; + union futex_key *requeue_pi_key; + u32 bitset; + atomic_t requeue_state; +#ifdef CONFIG_PREEMPT_RT + struct rcuwait requeue_wait; +#endif +} __randomize_layout; + +/* + * On PREEMPT_RT, the hash bucket lock is a 'sleeping' spinlock with an + * underlying rtmutex. The task which is about to be requeued could have + * just woken up (timeout, signal). After the wake up the task has to + * acquire hash bucket lock, which is held by the requeue code. As a task + * can only be blocked on _ONE_ rtmutex at a time, the proxy lock blocking + * and the hash bucket lock blocking would collide and corrupt state. + * + * On !PREEMPT_RT this is not a problem and everything could be serialized + * on hash bucket lock, but aside of having the benefit of common code, + * this allows to avoid doing the requeue when the task is already on the + * way out and taking the hash bucket lock of the original uaddr1 when the + * requeue has been completed. + * + * The following state transitions are valid: + * + * On the waiter side: + * Q_REQUEUE_PI_NONE -> Q_REQUEUE_PI_IGNORE + * Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_WAIT + * + * On the requeue side: + * Q_REQUEUE_PI_NONE -> Q_REQUEUE_PI_INPROGRESS + * Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_DONE/LOCKED + * Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_NONE (requeue failed) + * Q_REQUEUE_PI_WAIT -> Q_REQUEUE_PI_DONE/LOCKED + * Q_REQUEUE_PI_WAIT -> Q_REQUEUE_PI_IGNORE (requeue failed) + * + * The requeue side ignores a waiter with state Q_REQUEUE_PI_IGNORE as this + * signals that the waiter is already on the way out. It also means that + * the waiter is still on the 'wait' futex, i.e. uaddr1. + * + * The waiter side signals early wakeup to the requeue side either through + * setting state to Q_REQUEUE_PI_IGNORE or to Q_REQUEUE_PI_WAIT depending + * on the current state. In case of Q_REQUEUE_PI_IGNORE it can immediately + * proceed to take the hash bucket lock of uaddr1. If it set state to WAIT, + * which means the wakeup is interleaving with a requeue in progress it has + * to wait for the requeue side to change the state. Either to DONE/LOCKED + * or to IGNORE. DONE/LOCKED means the waiter q is now on the uaddr2 futex + * and either blocked (DONE) or has acquired it (LOCKED). IGNORE is set by + * the requeue side when the requeue attempt failed via deadlock detection + * and therefore the waiter q is still on the uaddr1 futex. + */ +enum { + Q_REQUEUE_PI_NONE = 0, + Q_REQUEUE_PI_IGNORE, + Q_REQUEUE_PI_IN_PROGRESS, + Q_REQUEUE_PI_WAIT, + Q_REQUEUE_PI_DONE, + Q_REQUEUE_PI_LOCKED, +}; + +static const struct futex_q futex_q_init = { + /* list gets initialized in queue_me()*/ + .key = FUTEX_KEY_INIT, + .bitset = FUTEX_BITSET_MATCH_ANY, + .requeue_state = ATOMIC_INIT(Q_REQUEUE_PI_NONE), +}; + +inline struct hrtimer_sleeper * +futex_setup_timer(ktime_t *time, struct hrtimer_sleeper *timeout, + int flags, u64 range_ns); + +static __always_inline int +futex_init_timeout(u32 cmd, u32 op, struct timespec64 *ts, ktime_t *t) +{ + if (!timespec64_valid(ts)) + return -EINVAL; + + *t = timespec64_to_ktime(*ts); + if (cmd == FUTEX_WAIT) + *t = ktime_add_safe(ktime_get(), *t); + else if (cmd != FUTEX_LOCK_PI && !(op & FUTEX_CLOCK_REALTIME)) + *t = timens_ktime_to_host(CLOCK_MONOTONIC, *t); + return 0; +} + +#endif From patchwork Sat Sep 4 23:11:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Andr=C3=A9_Almeida?= X-Patchwork-Id: 44850 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id C27EC383F409 for ; Sat, 4 Sep 2021 23:13:59 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org C27EC383F409 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1630797239; bh=6v88YLpy2vA6HSWlYYbb3hUF1xrDvr5bhTnPF3TqAEg=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=VcWvY1tEpL0ENRRjlMHHXXa3yxPN1uRUz6X5oNXwhcbBa7mqd2OFY/aVLfyo8n/Pu B1GnRebiXvDPBFJn2QFCUSsnM6phKfKyBLbXskUSY7iyiVIlMy3OHfHWWIgmlSc0eX VDzEyrZrtGJKLtWfuLvPC0Jwb3jJgmm0tju850GE= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by sourceware.org (Postfix) with ESMTPS id 953E8383F412 for ; Sat, 4 Sep 2021 23:12:22 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 953E8383F412 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: tonyk) with ESMTPSA id CCC681F41D9B To: Thomas Gleixner , Ingo Molnar , Peter Zijlstra , Darren Hart , linux-kernel@vger.kernel.org, Steven Rostedt , Sebastian Andrzej Siewior Subject: [PATCH v2 2/5] futex2: Implement vectorized wait Date: Sat, 4 Sep 2021 20:11:56 -0300 Message-Id: <20210904231159.13292-3-andrealmeid@collabora.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210904231159.13292-1-andrealmeid@collabora.com> References: <20210904231159.13292-1-andrealmeid@collabora.com> MIME-Version: 1.0 X-Spam-Status: No, score=-12.1 required=5.0 tests=BAYES_00, GIT_PATCH_0, KAM_DMARC_STATUS, KAM_MANYTO, SPF_HELO_PASS, SPF_PASS, TXREP, UNPARSEABLE_RELAY autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: =?utf-8?q?Andr=C3=A9_Almeida_via_Libc-alpha?= From: =?utf-8?q?Andr=C3=A9_Almeida?= Reply-To: =?utf-8?q?Andr=C3=A9_Almeida?= Cc: Davidlohr Bueso , libc-alpha@sourceware.org, linux-api@vger.kernel.org, mtk.manpages@gmail.com, =?utf-8?q?Andr=C3=A9_Alm?= =?utf-8?q?eida?= , kernel@collabora.com, krisman@collabora.com Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" Add support to wait on multiple futexes. This is the interface implemented by this syscall: futex_waitv(struct futex_waitv *waiters, unsigned int nr_futexes, unsigned int flags, struct timespec *timo) struct futex_waitv { __u64 val; __u64 uaddr; __u32 flags; __u32 __reserved; }; Given an array of struct futex_waitv, wait on each uaddr. The thread wakes if a futex_wake() is performed at any uaddr. The syscall returns immediately if any waiter has *uaddr != val. *timo is an optional absolute timeout value for the operation. This syscall supports only 64bit sized timeout structs. The flags argument of the syscall should be used solely for specifying the timeout clock as realtime, if needed. Flags for shared futexes, sizes, etc. should be used on the individual flags of each waiter. __reserved is used for explicit padding and should be 0, but it might be used for future extensions. If the userspace uses 32-bit pointers, it should make sure to explicitly cast it when assigning to waitv::uaddr. Returns the array index of one of the awakened futexes. There’s no given information of how many were awakened, or any particular attribute of it (if it’s the first awakened, if it is of the smaller index...). Signed-off-by: André Almeida --- MAINTAINERS | 3 +- include/linux/compat.h | 3 + include/uapi/asm-generic/unistd.h | 5 +- include/uapi/linux/futex.h | 25 ++++ init/Kconfig | 7 ++ kernel/Makefile | 1 + kernel/futex.c | 201 ++++++++++++++++++++++++++++++ kernel/futex.h | 15 +++ kernel/futex2.c | 131 +++++++++++++++++++ kernel/sys_ni.c | 4 + 10 files changed, 393 insertions(+), 2 deletions(-) create mode 100644 kernel/futex2.c diff --git a/MAINTAINERS b/MAINTAINERS index e4bdea045e85..69b1de05a12a 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -7701,6 +7701,7 @@ M: Ingo Molnar R: Peter Zijlstra R: Darren Hart R: Davidlohr Bueso +R: André Almeida L: linux-kernel@vger.kernel.org S: Maintained T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking/core @@ -7708,7 +7709,7 @@ F: Documentation/locking/*futex* F: include/asm-generic/futex.h F: include/linux/futex.h F: include/uapi/linux/futex.h -F: kernel/futex.c +F: kernel/futex* F: tools/perf/bench/futex* F: tools/testing/selftests/futex/ diff --git a/include/linux/compat.h b/include/linux/compat.h index 8e0598c7d1d1..f833587e93db 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -688,6 +688,9 @@ asmlinkage long compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr, compat_size_t __user *len_ptr); +asmlinkage long sys_futex_waitv(struct futex_waitv *waiters, + compat_uint_t nr_futexes, compat_uint_t flags, + struct __kernel_timespec __user *timo); /* kernel/itimer.c */ asmlinkage long compat_sys_getitimer(int which, struct old_itimerval32 __user *it); diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index 14c8fe863c6d..90748493c582 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -880,8 +880,11 @@ __SYSCALL(__NR_memfd_secret, sys_memfd_secret) #define __NR_process_mrelease 448 __SYSCALL(__NR_process_mrelease, sys_process_mrelease) +#define __NR_futex_waitv 449 +__SC_COMP(__NR_futex_waitv, sys_futex_waitv, compat_sys_futex_waitv) + #undef __NR_syscalls -#define __NR_syscalls 449 +#define __NR_syscalls 450 /* * 32 bit systems traditionally used different diff --git a/include/uapi/linux/futex.h b/include/uapi/linux/futex.h index 235e5b2facaa..71a5df8d2689 100644 --- a/include/uapi/linux/futex.h +++ b/include/uapi/linux/futex.h @@ -43,6 +43,31 @@ #define FUTEX_CMP_REQUEUE_PI_PRIVATE (FUTEX_CMP_REQUEUE_PI | \ FUTEX_PRIVATE_FLAG) +/* + * Flags to specify the bit length of the futex word for futex2 syscalls. + * Currently, only 32 is supported. + */ +#define FUTEX_32 2 + +/* + * Max numbers of elements in a futex_waitv array + */ +#define FUTEX_WAITV_MAX 128 + +/** + * struct futex_waitv - A waiter for vectorized wait + * @val: Expected value at uaddr + * @uaddr: User address to wait on + * @flags: Flags for this waiter + * @__reserved: Reserved member to preserve data alignment. Should be 0. + */ +struct futex_waitv { + __u64 val; + __u64 uaddr; + __u32 flags; + __u32 __reserved; +}; + /* * Support for robust futexes: the kernel cleans up held futexes at * thread exit time. diff --git a/init/Kconfig b/init/Kconfig index e708180e9a59..802f5f7be905 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1567,6 +1567,13 @@ config FUTEX support for "fast userspace mutexes". The resulting kernel may not run glibc-based applications correctly. +config FUTEX2 + bool "Enable futex2 support" if EXPERT + depends on FUTEX + default y + help + Support for futex2 interface. + config FUTEX_PI bool depends on FUTEX && RT_MUTEXES diff --git a/kernel/Makefile b/kernel/Makefile index 4df609be42d0..1eaf2af50283 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -60,6 +60,7 @@ obj-$(CONFIG_PROFILING) += profile.o obj-$(CONFIG_STACKTRACE) += stacktrace.o obj-y += time/ obj-$(CONFIG_FUTEX) += futex.o +obj-$(CONFIG_FUTEX2) += futex2.o obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o obj-$(CONFIG_SMP) += smp.o ifneq ($(CONFIG_SMP),y) diff --git a/kernel/futex.c b/kernel/futex.c index 58f2dc29c408..ab3d513fceb1 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -2707,6 +2707,207 @@ static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q, __set_current_state(TASK_RUNNING); } +/** + * unqueue_multiple - Remove various futexes from their hash bucket + * @v: The list of futexes to unqueue + * @count: Number of futexes in the list + * + * Helper to unqueue a list of futexes. This can't fail. + * + * Return: + * - >=0 - Index of the last futex that was awoken; + * - -1 - No futex was awoken + */ +static int unqueue_multiple(struct futex_vector *v, int count) +{ + int ret = -1, i; + + for (i = 0; i < count; i++) { + if (!unqueue_me(&v[i].q)) + ret = i; + } + + return ret; +} + +/** + * futex_wait_multiple_setup - Prepare to wait and enqueue multiple futexes + * @vs: The futex list to wait on + * @count: The size of the list + * @awaken: Index of the last awoken futex, if any. Used to notify the + * caller that it can return this index to userspace (return parameter) + * + * Prepare multiple futexes in a single step and enqueue them. This may fail if + * the futex list is invalid or if any futex was already awoken. On success the + * task is ready to interruptible sleep. + * + * Return: + * - 1 - One of the futexes was awaken by another thread + * - 0 - Success + * - <0 - -EFAULT, -EWOULDBLOCK or -EINVAL + */ +static int futex_wait_multiple_setup(struct futex_vector *vs, int count, int *awaken) +{ + struct futex_hash_bucket *hb; + bool retry = false; + int ret, i; + u32 uval; + + /* + * Enqueuing multiple futexes is tricky, because we need to enqueue + * each futex in the list before dealing with the next one to avoid + * deadlocking on the hash bucket. But, before enqueuing, we need to + * make sure that current->state is TASK_INTERRUPTIBLE, so we don't + * absorb any awake events, which cannot be done before the + * get_futex_key of the next key, because it calls get_user_pages, + * which can sleep. Thus, we fetch the list of futexes keys in two + * steps, by first pinning all the memory keys in the futex key, and + * only then we read each key and queue the corresponding futex. + * + * Private futexes doesn't need to recalculate hash in retry, so skip + * get_futex_key() when retrying. + */ +retry: + for (i = 0; i < count; i++) { + if ((vs[i].w.flags & FUTEX_PRIVATE_FLAG) && retry) + continue; + + ret = get_futex_key(u64_to_user_ptr(vs[i].w.uaddr), + !(vs[i].w.flags & FUTEX_PRIVATE_FLAG), + &vs[i].q.key, FUTEX_READ); + + if (unlikely(ret)) + return ret; + } + + set_current_state(TASK_INTERRUPTIBLE); + + for (i = 0; i < count; i++) { + u32 __user *uaddr = (u32 __user *)vs[i].w.uaddr; + struct futex_q *q = &vs[i].q; + u32 val = (u32)vs[i].w.val; + + hb = queue_lock(q); + ret = get_futex_value_locked(&uval, uaddr); + + if (!ret && uval == val) { + /* + * The bucket lock can't be held while dealing with the + * next futex. Queue each futex at this moment so hb can + * be unlocked. + */ + queue_me(q, hb); + continue; + } + + queue_unlock(hb); + __set_current_state(TASK_RUNNING); + + /* + * Even if something went wrong, if we find out that a futex + * was awaken, we don't return error and return this index to + * userspace + */ + *awaken = unqueue_multiple(vs, i); + if (*awaken >= 0) + return 1; + + if (uval != val) + return -EWOULDBLOCK; + + if (ret) { + /* + * If we need to handle a page fault, we need to do so + * without any lock and any enqueued futex (otherwise + * we could lose some wakeup). So we do it here, after + * undoing all the work done so far. In success, we + * retry all the work. + */ + if (get_user(uval, uaddr)) + return -EFAULT; + + retry = true; + goto retry; + } + } + + return 0; +} + +/** + * futex_sleep_multiple - Check sleeping conditions and sleep + * @vs: List of futexes to wait for + * @count: Length of vs + * @to: Timeout + * + * Sleep if and only if the timeout hasn't expired and no futex on the list has + * been awaken. + */ +static void futex_sleep_multiple(struct futex_vector *vs, unsigned int count, + struct hrtimer_sleeper *to) +{ + if (to && !to->task) + return; + + for (; count; count--, vs++) { + if (!READ_ONCE(vs->q.lock_ptr)) + return; + } + + freezable_schedule(); +} + +/** + * futex_wait_multiple - Prepare to wait on and enqueue several futexes + * @vs: The list of futexes to wait on + * @count: The number of objects + * @to: Timeout before giving up and returning to userspace + * + * Entry point for the FUTEX_WAIT_MULTIPLE futex operation, this function + * sleeps on a group of futexes and returns on the first futex that is + * wake, or after the timeout has elapsed. + * + * Return: + * - >=0 - Hint to the futex that was awoken + * - <0 - On error + */ +int futex_wait_multiple(struct futex_vector *vs, unsigned int count, + struct hrtimer_sleeper *to) +{ + int ret, hint = 0; + + if (to) + hrtimer_sleeper_start_expires(to, HRTIMER_MODE_ABS); + + while (1) { + ret = futex_wait_multiple_setup(vs, count, &hint); + if (ret) { + if (ret > 0) { + /* A futex was awaken during setup */ + ret = hint; + } + return ret; + } + + futex_sleep_multiple(vs, count, to); + + __set_current_state(TASK_RUNNING); + + ret = unqueue_multiple(vs, count); + if (ret >= 0) + return ret; + + if (to && !to->task) + return -ETIMEDOUT; + else if (signal_pending(current)) + return -ERESTARTSYS; + /* + * The final case is a spurious wakeup, for + * which just retry. + */ + } +} + /** * futex_wait_setup() - Prepare to wait on a futex * @uaddr: the futex userspace address diff --git a/kernel/futex.h b/kernel/futex.h index c914e0080cf1..bcd0142c3f6e 100644 --- a/kernel/futex.h +++ b/kernel/futex.h @@ -137,4 +137,19 @@ futex_init_timeout(u32 cmd, u32 op, struct timespec64 *ts, ktime_t *t) return 0; } +/** + * struct futex_vector - Auxiliary struct for futex_waitv() + * @w: Userspace provided data + * @q: Kernel side data + * + * Struct used to build an array with all data need for futex_waitv() + */ +struct futex_vector { + struct futex_waitv w; + struct futex_q q; +}; + +int futex_wait_multiple(struct futex_vector *vs, unsigned int count, + struct hrtimer_sleeper *to); + #endif diff --git a/kernel/futex2.c b/kernel/futex2.c new file mode 100644 index 000000000000..34e4b1b85387 --- /dev/null +++ b/kernel/futex2.c @@ -0,0 +1,131 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * futex2 interface system calls + * + * futex_waitv by André Almeida + * + * Copyright 2021 Collabora Ltd. + */ + +#include "futex.h" + +/* Mask of available flags for each futex in futex_waitv list */ +#define FUTEXV_WAITER_MASK (FUTEX_32 | FUTEX_PRIVATE_FLAG) + +/* Mask of available flags for sys_futex_waitv flag */ +#define FUTEXV_MASK (FUTEX_CLOCK_REALTIME) + +/** + * futex_parse_waitv - Parse a waitv array from userspace + * @futexv: Kernel side list of waiters to be filled + * @uwaitv: Userspace list to be parsed + * @nr_futexes: Length of futexv + * + * 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) +{ + struct futex_waitv aux; + unsigned int i; + + for (i = 0; i < nr_futexes; i++) { + if (copy_from_user(&aux, &uwaitv[i], sizeof(aux))) + return -EFAULT; + + if ((aux.flags & ~FUTEXV_WAITER_MASK) || aux.__reserved) + return -EINVAL; + + futexv[i].w.flags = aux.flags; + futexv[i].w.val = aux.val; + futexv[i].w.uaddr = aux.uaddr; + futexv[i].q = futex_q_init; + } + + return 0; +} + +/** + * futex_waitv - Wait on a list of futexes + * @waiters: List of futexes to wait on + * @nr_futexes: Length of futexv + * @flags: Flag for timeout (monotonic/realtime) + * @timo: Optional absolute timeout. + * + * Given an array of `struct futex_waitv`, wait on each uaddr. The thread wakes + * if a futex_wake() is performed at any uaddr. The syscall returns immediately + * if any waiter has *uaddr != val. *timo is an optional timeout value for the + * operation. Each waiter has individual flags. The `flags` argument for the + * syscall should be used solely for specifying the timeout as realtime, if + * needed. Flags for shared futexes, sizes, etc. should be used on the + * individual flags of each waiter. + * + * Returns the array index of one of the awaken futexes. There's no given + * information of how many were awakened, or any particular attribute of it (if + * it's the first awakened, if it is of the smaller index...). + */ +static long futex_waitv(struct futex_waitv __user *waiters, unsigned int nr_futexes, + unsigned int flags, struct __kernel_timespec __user *timo) +{ + struct hrtimer_sleeper to; + struct futex_vector *futexv; + struct timespec64 ts; + ktime_t time; + int ret; + + if (flags & ~FUTEXV_MASK) + return -EINVAL; + + if (!nr_futexes || nr_futexes > FUTEX_WAITV_MAX || !waiters) + return -EINVAL; + + if (timo) { + int flag_clkid = (flags & FUTEX_CLOCK_REALTIME) ? FLAGS_CLOCKRT : 0; + + if (get_timespec64(&ts, timo)) + return -EFAULT; + + /* + * Since there's no opcode for futex_waitv, use + * FUTEX_WAIT_BITSET that uses absolute timeout as well + */ + ret = futex_init_timeout(FUTEX_WAIT_BITSET, flags, &ts, &time); + if (ret) + return ret; + + futex_setup_timer(&time, &to, flag_clkid, 0); + } + + futexv = kcalloc(nr_futexes, sizeof(*futexv), GFP_KERNEL); + if (!futexv) + return -ENOMEM; + + ret = futex_parse_waitv(futexv, waiters, nr_futexes); + if (!ret) + ret = futex_wait_multiple(futexv, nr_futexes, timo ? &to : NULL); + + if (timo) { + hrtimer_cancel(&to.timer); + destroy_hrtimer_on_stack(&to.timer); + } + + kfree(futexv); + return ret; +} + +#ifdef CONFIG_COMPAT +COMPAT_SYSCALL_DEFINE4(futex_waitv, struct futex_waitv __user *, waiters, + unsigned int, nr_futexes, unsigned int, flags, + struct __kernel_timespec __user *, timo) +{ + return futex_waitv(waiters, nr_futexes, flags, timo); +} +#endif + +SYSCALL_DEFINE4(futex_waitv, struct futex_waitv __user *, waiters, + unsigned int, nr_futexes, unsigned int, flags, + struct __kernel_timespec __user *, timo) +{ + return futex_waitv(waiters, nr_futexes, flags, timo); +} diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 64578adfe115..55f07c8feaf6 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -151,6 +151,10 @@ COND_SYSCALL_COMPAT(set_robust_list); COND_SYSCALL(get_robust_list); COND_SYSCALL_COMPAT(get_robust_list); +/* kernel/futex2.c */ +COND_SYSCALL(futex_waitv); +COND_SYSCALL_COMPAT(futex_waitv); + /* kernel/hrtimer.c */ /* kernel/itimer.c */ From patchwork Sat Sep 4 23:11:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Andr=C3=A9_Almeida?= X-Patchwork-Id: 44851 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id BF06B383F40B for ; Sat, 4 Sep 2021 23:14:50 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org BF06B383F40B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1630797290; bh=BE+CtnRe6/nn7XpKV/l/qkcLEYOs1Y+5jmNtINaVay4=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=s3Sgflz0jkyGcEj0HWXAs6Co4sakctx7qPAtPoywJR7fnQ2UVIGPXwE+hDzVRUw9i QWI+3iq2q4JLrMocHqDbKn0BSGlkxdz3Ov/abdbocFKLJZSRARc6gT9EBRGe/1lmCs +Dq2mlbSWiOeM7ilX9pcyu7wJaBPbayRoeAHk1wA= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by sourceware.org (Postfix) with ESMTPS id 09D38383F40C for ; Sat, 4 Sep 2021 23:12:27 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 09D38383F40C Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: tonyk) with ESMTPSA id 1F18A1F41F44 To: Thomas Gleixner , Ingo Molnar , Peter Zijlstra , Darren Hart , linux-kernel@vger.kernel.org, Steven Rostedt , Sebastian Andrzej Siewior Subject: [PATCH v2 3/5] futex2: wire up syscall for x86 Date: Sat, 4 Sep 2021 20:11:57 -0300 Message-Id: <20210904231159.13292-4-andrealmeid@collabora.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210904231159.13292-1-andrealmeid@collabora.com> References: <20210904231159.13292-1-andrealmeid@collabora.com> MIME-Version: 1.0 X-Spam-Status: No, score=-11.9 required=5.0 tests=BAYES_00, GIT_PATCH_0, KAM_DMARC_STATUS, KAM_MANYTO, KAM_NUMSUBJECT, SPF_HELO_PASS, SPF_PASS, TXREP, UNPARSEABLE_RELAY autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: =?utf-8?q?Andr=C3=A9_Almeida_via_Libc-alpha?= From: =?utf-8?q?Andr=C3=A9_Almeida?= Reply-To: =?utf-8?q?Andr=C3=A9_Almeida?= Cc: Davidlohr Bueso , libc-alpha@sourceware.org, linux-api@vger.kernel.org, mtk.manpages@gmail.com, =?utf-8?q?Andr=C3=A9_Alm?= =?utf-8?q?eida?= , kernel@collabora.com, krisman@collabora.com Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" Wire up syscall entry point for x86 arch, for both i386 and x86_64. Signed-off-by: André Almeida --- arch/x86/entry/syscalls/syscall_32.tbl | 1 + arch/x86/entry/syscalls/syscall_64.tbl | 1 + 2 files changed, 2 insertions(+) diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index 61f18b72552b..d5b2ed3802c7 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -453,3 +453,4 @@ 446 i386 landlock_restrict_self sys_landlock_restrict_self 447 i386 memfd_secret sys_memfd_secret 448 i386 process_mrelease sys_process_mrelease +449 i386 futex_waitv sys_futex_waitv compat_sys_futex_waitv diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index 807b6a1de8e8..b4cd3923399a 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -370,6 +370,7 @@ 446 common landlock_restrict_self sys_landlock_restrict_self 447 common memfd_secret sys_memfd_secret 448 common process_mrelease sys_process_mrelease +449 common futex_waitv sys_futex_waitv # # Due to a historical design error, certain syscalls are numbered differently From patchwork Sat Sep 4 23:11:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Andr=C3=A9_Almeida?= X-Patchwork-Id: 44852 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 12D3C3840C0D for ; Sat, 4 Sep 2021 23:15:33 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 12D3C3840C0D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1630797333; bh=X702utzC/Jz5tYVNNsk6XSXgQwncmG5+qNFNFp9SZ6Q=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=p6AN/sVc46EXT29LQdckZiWOKc5w0j7S85ruEtDbTsyHG3RvGa6UQS110wVWuY7ri 81LMISMnbkHvlErek5GmfIbCN8G9i3M0xvuddNEnVYeTGT6txJzClmI2VaIcfXMx7o WLXvTMs8tUVTj1vVb1dx0On+Hmv5cCIcaMSxqa2k= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by sourceware.org (Postfix) with ESMTPS id B088A383F408 for ; Sat, 4 Sep 2021 23:12:30 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org B088A383F408 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: tonyk) with ESMTPSA id 348F31F4208E To: Thomas Gleixner , Ingo Molnar , Peter Zijlstra , Darren Hart , linux-kernel@vger.kernel.org, Steven Rostedt , Sebastian Andrzej Siewior Subject: [PATCH v2 4/5] selftests: futex2: Add waitv test Date: Sat, 4 Sep 2021 20:11:58 -0300 Message-Id: <20210904231159.13292-5-andrealmeid@collabora.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210904231159.13292-1-andrealmeid@collabora.com> References: <20210904231159.13292-1-andrealmeid@collabora.com> MIME-Version: 1.0 X-Spam-Status: No, score=-12.2 required=5.0 tests=BAYES_00, GIT_PATCH_0, KAM_DMARC_STATUS, KAM_MANYTO, SPF_HELO_PASS, SPF_PASS, TXREP, UNPARSEABLE_RELAY autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: =?utf-8?q?Andr=C3=A9_Almeida_via_Libc-alpha?= From: =?utf-8?q?Andr=C3=A9_Almeida?= Reply-To: =?utf-8?q?Andr=C3=A9_Almeida?= Cc: Davidlohr Bueso , libc-alpha@sourceware.org, linux-api@vger.kernel.org, mtk.manpages@gmail.com, =?utf-8?q?Andr=C3=A9_Alm?= =?utf-8?q?eida?= , kernel@collabora.com, krisman@collabora.com Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" Create a new file to test the waitv mechanism. Test both private and shared futexes. Wake the last futex in the array, and check if the return value from futex_waitv() is the right index. Signed-off-by: André Almeida --- .../selftests/futex/functional/.gitignore | 1 + .../selftests/futex/functional/Makefile | 3 +- .../selftests/futex/functional/futex_waitv.c | 158 ++++++++++++++++++ .../testing/selftests/futex/functional/run.sh | 3 + .../selftests/futex/include/futex2test.h | 31 ++++ 5 files changed, 195 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/futex/functional/futex_waitv.c create mode 100644 tools/testing/selftests/futex/include/futex2test.h diff --git a/tools/testing/selftests/futex/functional/.gitignore b/tools/testing/selftests/futex/functional/.gitignore index 0e78b49d0f2f..fbcbdb6963b3 100644 --- a/tools/testing/selftests/futex/functional/.gitignore +++ b/tools/testing/selftests/futex/functional/.gitignore @@ -8,3 +8,4 @@ futex_wait_uninitialized_heap futex_wait_wouldblock futex_wait futex_requeue +futex_waitv diff --git a/tools/testing/selftests/futex/functional/Makefile b/tools/testing/selftests/futex/functional/Makefile index bd1fec59e010..5cc38de9d8ea 100644 --- a/tools/testing/selftests/futex/functional/Makefile +++ b/tools/testing/selftests/futex/functional/Makefile @@ -17,7 +17,8 @@ TEST_GEN_FILES := \ futex_wait_uninitialized_heap \ futex_wait_private_mapped_file \ futex_wait \ - futex_requeue + futex_requeue \ + futex_waitv TEST_PROGS := run.sh diff --git a/tools/testing/selftests/futex/functional/futex_waitv.c b/tools/testing/selftests/futex/functional/futex_waitv.c new file mode 100644 index 000000000000..567667dfa7cf --- /dev/null +++ b/tools/testing/selftests/futex/functional/futex_waitv.c @@ -0,0 +1,158 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/****************************************************************************** + * + * Copyright Collabora Ltd., 2021 + * + * DESCRIPTION + * Test waitv/wake mechanism of futex2, using 32bit sized futexes. + * + * AUTHOR + * André Almeida + * + * HISTORY + * 2021-Feb-5: Initial version by André + * + *****************************************************************************/ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "futextest.h" +#include "futex2test.h" +#include "logging.h" + +#define TEST_NAME "futex-wait" +#define WAKE_WAIT_US 10000 +#define NR_FUTEXES 30 +static struct futex_waitv waitv[NR_FUTEXES]; +u_int32_t futexes[NR_FUTEXES] = {0}; + +void usage(char *prog) +{ + printf("Usage: %s\n", prog); + printf(" -c Use color\n"); + printf(" -h Display this help message\n"); + printf(" -v L Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n", + VQUIET, VCRITICAL, VINFO); +} + +void *waiterfn(void *arg) +{ + struct timespec to; + int res; + + /* setting absolute timeout for futex2 */ + if (clock_gettime(CLOCK_MONOTONIC, &to)) + error("gettime64 failed\n", errno); + + to.tv_sec++; + + res = futex_waitv(waitv, NR_FUTEXES, 0, &to); + if (res < 0) { + ksft_test_result_fail("futex_waitv returned: %d %s\n", + errno, strerror(errno)); + } else if (res != NR_FUTEXES - 1) { + ksft_test_result_fail("futex_waitv returned: %d, expecting %d\n", + res, NR_FUTEXES - 1); + } + + return NULL; +} + +int main(int argc, char *argv[]) +{ + pthread_t waiter; + int res, ret = RET_PASS; + int c, i; + + while ((c = getopt(argc, argv, "cht:v:")) != -1) { + switch (c) { + case 'c': + log_color(1); + break; + case 'h': + usage(basename(argv[0])); + exit(0); + case 'v': + log_verbosity(atoi(optarg)); + break; + default: + usage(basename(argv[0])); + exit(1); + } + } + + ksft_print_header(); + ksft_set_plan(2); + ksft_print_msg("%s: Test FUTEX_WAITV\n", + basename(argv[0])); + + for (i = 0; i < NR_FUTEXES; i++) { + waitv[i].uaddr = (uintptr_t)&futexes[i]; + waitv[i].flags = FUTEX_32 | FUTEX_PRIVATE_FLAG; + waitv[i].val = 0; + waitv[i].__reserved = 0; + } + + /* Private waitv */ + if (pthread_create(&waiter, NULL, waiterfn, NULL)) + error("pthread_create failed\n", errno); + + usleep(WAKE_WAIT_US); + + res = futex_wake(u64_to_ptr(waitv[NR_FUTEXES - 1].uaddr), 1, FUTEX_PRIVATE_FLAG); + if (res != 1) { + ksft_test_result_fail("futex_wake private returned: %d %s\n", + res ? errno : res, + res ? strerror(errno) : ""); + ret = RET_FAIL; + } else { + ksft_test_result_pass("futex_waitv private\n"); + } + + /* Shared waitv */ + for (i = 0; i < NR_FUTEXES; i++) { + int shm_id = shmget(IPC_PRIVATE, 4096, IPC_CREAT | 0666); + + if (shm_id < 0) { + perror("shmget"); + exit(1); + } + + unsigned int *shared_data = shmat(shm_id, NULL, 0); + + *shared_data = 0; + waitv[i].uaddr = (uintptr_t)shared_data; + waitv[i].flags = FUTEX_32; + waitv[i].val = 0; + waitv[i].__reserved = 0; + } + + if (pthread_create(&waiter, NULL, waiterfn, NULL)) + error("pthread_create failed\n", errno); + + usleep(WAKE_WAIT_US); + + res = futex_wake(u64_to_ptr(waitv[NR_FUTEXES - 1].uaddr), 1, 0); + if (res != 1) { + ksft_test_result_fail("futex_wake shared returned: %d %s\n", + res ? errno : res, + res ? strerror(errno) : ""); + ret = RET_FAIL; + } else { + ksft_test_result_pass("futex_waitv shared\n"); + } + + for (i = 0; i < NR_FUTEXES; i++) + shmdt(u64_to_ptr(waitv[i].uaddr)); + + ksft_print_cnts(); + return ret; +} diff --git a/tools/testing/selftests/futex/functional/run.sh b/tools/testing/selftests/futex/functional/run.sh index 11a9d62290f5..5ccd599da6c3 100755 --- a/tools/testing/selftests/futex/functional/run.sh +++ b/tools/testing/selftests/futex/functional/run.sh @@ -79,3 +79,6 @@ echo echo ./futex_requeue $COLOR + +echo +./futex_waitv $COLOR diff --git a/tools/testing/selftests/futex/include/futex2test.h b/tools/testing/selftests/futex/include/futex2test.h new file mode 100644 index 000000000000..51a3b9356c9b --- /dev/null +++ b/tools/testing/selftests/futex/include/futex2test.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/****************************************************************************** + * + * Copyright Collabora Ltd., 2021 + * + * DESCRIPTION + * Futex2 library addons for futex tests + * + * AUTHOR + * André Almeida + * + * HISTORY + * 2021-Feb-5: Initial version by André + * + *****************************************************************************/ +#include + +#define u64_to_ptr(x) ((void *)(uintptr_t)(x)) + +/** + * futex_waitv - Wait at multiple futexes, wake on any + * @waiters: Array of waiters + * @nr_waiters: Length of waiters array + * @flags: Operation flags + * @timo: Optional timeout for operation + */ +static inline int futex_waitv(volatile struct futex_waitv *waiters, unsigned long nr_waiters, + unsigned long flags, struct timespec *timo) +{ + return syscall(__NR_futex_waitv, waiters, nr_waiters, flags, timo); +} From patchwork Sat Sep 4 23:11:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Andr=C3=A9_Almeida?= X-Patchwork-Id: 44853 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 1B6EE383F410 for ; Sat, 4 Sep 2021 23:16:15 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 1B6EE383F410 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1630797375; bh=YbEz7hbR0vUTJcANoy2TUU8aIBHuxfll14EJQRAOdbQ=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=lj0LxiLPokCYBbWCMMfPJfie4SmCDsuMmcsT5rHpcfRNnUqqLGphECWIDXNYSqPWG kCidUuGgkZwKDM6jfDTrodfbn0qpNj8lrq8ghsJsKXv5FwDWk+JE+T7Lqv316/PsyW +5IP0jjHq3HdXh8wsgyNpnHYdIO8ga6ZG/x6i75g= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by sourceware.org (Postfix) with ESMTPS id B8B52383F41A for ; Sat, 4 Sep 2021 23:12:34 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org B8B52383F41A Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: tonyk) with ESMTPSA id 3F1DE1F4210F To: Thomas Gleixner , Ingo Molnar , Peter Zijlstra , Darren Hart , linux-kernel@vger.kernel.org, Steven Rostedt , Sebastian Andrzej Siewior Subject: [PATCH v2 5/5] selftests: futex2: Test futex_waitv timeout Date: Sat, 4 Sep 2021 20:11:59 -0300 Message-Id: <20210904231159.13292-6-andrealmeid@collabora.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210904231159.13292-1-andrealmeid@collabora.com> References: <20210904231159.13292-1-andrealmeid@collabora.com> MIME-Version: 1.0 X-Spam-Status: No, score=-12.2 required=5.0 tests=BAYES_00, GIT_PATCH_0, KAM_DMARC_STATUS, KAM_MANYTO, SPF_HELO_PASS, SPF_PASS, TXREP, UNPARSEABLE_RELAY autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: =?utf-8?q?Andr=C3=A9_Almeida_via_Libc-alpha?= From: =?utf-8?q?Andr=C3=A9_Almeida?= Reply-To: =?utf-8?q?Andr=C3=A9_Almeida?= Cc: Davidlohr Bueso , libc-alpha@sourceware.org, linux-api@vger.kernel.org, mtk.manpages@gmail.com, =?utf-8?q?Andr=C3=A9_Alm?= =?utf-8?q?eida?= , kernel@collabora.com, krisman@collabora.com Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" Test if the futex_waitv timeout is working as expected, using the supported clockid options. Signed-off-by: André Almeida --- .../futex/functional/futex_wait_timeout.c | 21 ++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/futex/functional/futex_wait_timeout.c b/tools/testing/selftests/futex/functional/futex_wait_timeout.c index 1f8f6daaf1e7..4cdada0fcb81 100644 --- a/tools/testing/selftests/futex/functional/futex_wait_timeout.c +++ b/tools/testing/selftests/futex/functional/futex_wait_timeout.c @@ -17,6 +17,7 @@ #include #include "futextest.h" +#include "futex2test.h" #include "logging.h" #define TEST_NAME "futex-wait-timeout" @@ -96,6 +97,12 @@ int main(int argc, char *argv[]) struct timespec to; pthread_t thread; int c; + struct futex_waitv waitv = { + .uaddr = (uintptr_t)&f1, + .val = f1, + .flags = FUTEX_32, + .__reserved = 0 + }; while ((c = getopt(argc, argv, "cht:v:")) != -1) { switch (c) { @@ -118,7 +125,7 @@ int main(int argc, char *argv[]) } ksft_print_header(); - ksft_set_plan(7); + ksft_set_plan(9); ksft_print_msg("%s: Block on a futex and wait for timeout\n", basename(argv[0])); ksft_print_msg("\tArguments: timeout=%ldns\n", timeout_ns); @@ -175,6 +182,18 @@ int main(int argc, char *argv[]) res = futex_lock_pi(&futex_pi, NULL, 0, FUTEX_CLOCK_REALTIME); test_timeout(res, &ret, "futex_lock_pi invalid timeout flag", ENOSYS); + /* futex_waitv with CLOCK_MONOTONIC */ + if (futex_get_abs_timeout(CLOCK_MONOTONIC, &to, timeout_ns)) + return RET_FAIL; + res = futex_waitv(&waitv, 1, 0, &to); + test_timeout(res, &ret, "futex_waitv monotonic", ETIMEDOUT); + + /* futex_waitv with CLOCK_REALTIME */ + if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns)) + return RET_FAIL; + res = futex_waitv(&waitv, 1, FUTEX_CLOCK_REALTIME, &to); + test_timeout(res, &ret, "futex_waitv realtime", ETIMEDOUT); + ksft_print_cnts(); return ret; }