From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_NEOMUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12129C48BD3 for ; Wed, 26 Jun 2019 16:19:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C1D8D2133F for ; Wed, 26 Jun 2019 16:19:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726497AbfFZQS4 (ORCPT ); Wed, 26 Jun 2019 12:18:56 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:49440 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726341AbfFZQS4 (ORCPT ); Wed, 26 Jun 2019 12:18:56 -0400 Received: from bigeasy by Galois.linutronix.de with local (Exim 4.80) (envelope-from ) id 1hgAd9-0006wZ-Cu; Wed, 26 Jun 2019 18:18:43 +0200 Date: Wed, 26 Jun 2019 18:18:43 +0200 From: Sebastian Andrzej Siewior To: Thomas Gleixner Cc: LKML , linux-rt-users , Steven Rostedt Subject: [ANNOUNCE] v5.0.21-rt14 Message-ID: <20190626161843.2c6r2dxeoxeyxce7@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline User-Agent: NeoMutt/20180716 Sender: linux-rt-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org Dear RT folks! I'm pleased to announce the v5.0.21-rt14 patch set. Changes since v5.0.21-rt13: - Fix a "scheduling while atomic" in zswap. Patch by Luis Claudio R. Goncalves. - Replace a fix for for wait_for_completion() (introduced in v5.0.14-rt9) by an alternative version as suggested by Peter Zijlstra. - Major futex/rtmutex surgery. He Zhe reported that glibc's tst-robustpi8.c triggers a BUG() statement. To address that bug the hash bucket has been made a raw_spinlock_t. - Two x86 FPU patches from upstream to avoid fallout on 32bit and with CRIU. Known issues - rcutorture is currently broken on -RT. Reported by Juri Lelli. The delta patch against v5.0.21-rt13 is appended below and can be found here: https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.0/incr/patch-5.0.21-rt13-rt14.patch.xz You can get this release via the git tree at: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git v5.0.21-rt14 The RT patch against v5.0.21 can be found here: https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.0/older/patch-5.0.21-rt14.patch.xz The split quilt queue is available at: https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.0/older/patches-5.0.21-rt14.tar.xz Sebastian diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index a4715458e972f..c1bb7f276d23b 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -5,6 +5,7 @@ #include #include +#include #include #include @@ -61,6 +62,11 @@ static inline int save_fsave_header(struct task_struct *tsk, void __user *buf) struct user_i387_ia32_struct env; struct _fpstate_32 __user *fp = buf; + fpregs_lock(); + if (!test_thread_flag(TIF_NEED_FPU_LOAD)) + copy_fxregs_to_kernel(&tsk->thread.fpu); + fpregs_unlock(); + convert_from_fxsr(&env, tsk); if (__copy_to_user(buf, &env, sizeof(env)) || @@ -189,15 +195,7 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size) fpregs_unlock(); if (ret) { - int aligned_size; - int nr_pages; - - aligned_size = offset_in_page(buf_fx) + fpu_user_xstate_size; - nr_pages = DIV_ROUND_UP(aligned_size, PAGE_SIZE); - - ret = get_user_pages_unlocked((unsigned long)buf_fx, nr_pages, - NULL, FOLL_WRITE); - if (ret == nr_pages) + if (!fault_in_pages_writeable(buf_fx, fpu_user_xstate_size)) goto retry; return -EFAULT; } diff --git a/include/linux/swait.h b/include/linux/swait.h index 21ae66cd41d30..2ac63a13d26d3 100644 --- a/include/linux/swait.h +++ b/include/linux/swait.h @@ -61,11 +61,13 @@ struct swait_queue_head { struct swait_queue { struct task_struct *task; struct list_head task_list; + unsigned int remove; }; #define __SWAITQUEUE_INITIALIZER(name) { \ .task = current, \ .task_list = LIST_HEAD_INIT((name).task_list), \ + .remove = 1, \ } #define DECLARE_SWAITQUEUE(name) \ diff --git a/kernel/futex.c b/kernel/futex.c index 85c538fcad578..a86955d80f7b9 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -243,7 +243,7 @@ struct futex_q { struct plist_node list; struct task_struct *task; - spinlock_t *lock_ptr; + raw_spinlock_t *lock_ptr; union futex_key key; struct futex_pi_state *pi_state; struct rt_mutex_waiter *rt_waiter; @@ -264,7 +264,7 @@ static const struct futex_q futex_q_init = { */ struct futex_hash_bucket { atomic_t waiters; - spinlock_t lock; + raw_spinlock_t lock; struct plist_head chain; } ____cacheline_aligned_in_smp; @@ -830,13 +830,13 @@ static void get_pi_state(struct futex_pi_state *pi_state) * Drops a reference to the pi_state object and frees or caches it * when the last reference is gone. */ -static void put_pi_state(struct futex_pi_state *pi_state) +static struct futex_pi_state *__put_pi_state(struct futex_pi_state *pi_state) { if (!pi_state) - return; + return NULL; if (!atomic_dec_and_test(&pi_state->refcount)) - return; + return NULL; /* * If pi_state->owner is NULL, the owner is most probably dying @@ -856,9 +856,7 @@ static void put_pi_state(struct futex_pi_state *pi_state) raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock); } - if (current->pi_state_cache) { - kfree(pi_state); - } else { + if (!current->pi_state_cache) { /* * pi_state->list is already empty. * clear pi_state->owner. @@ -867,6 +865,30 @@ static void put_pi_state(struct futex_pi_state *pi_state) pi_state->owner = NULL; atomic_set(&pi_state->refcount, 1); current->pi_state_cache = pi_state; + pi_state = NULL; + } + return pi_state; +} + +static void put_pi_state(struct futex_pi_state *pi_state) +{ + kfree(__put_pi_state(pi_state)); +} + +static void put_pi_state_atomic(struct futex_pi_state *pi_state, + struct list_head *to_free) +{ + if (__put_pi_state(pi_state)) + list_add(&pi_state->list, to_free); +} + +static void free_pi_state_list(struct list_head *to_free) +{ + struct futex_pi_state *p, *next; + + list_for_each_entry_safe(p, next, to_free, list) { + list_del(&p->list); + kfree(p); } } @@ -883,6 +905,7 @@ void exit_pi_state_list(struct task_struct *curr) struct futex_pi_state *pi_state; struct futex_hash_bucket *hb; union futex_key key = FUTEX_KEY_INIT; + LIST_HEAD(to_free); if (!futex_cmpxchg_enabled) return; @@ -916,7 +939,7 @@ void exit_pi_state_list(struct task_struct *curr) } raw_spin_unlock_irq(&curr->pi_lock); - spin_lock(&hb->lock); + raw_spin_lock(&hb->lock); raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock); raw_spin_lock(&curr->pi_lock); /* @@ -926,10 +949,8 @@ void exit_pi_state_list(struct task_struct *curr) if (head->next != next) { /* retain curr->pi_lock for the loop invariant */ raw_spin_unlock(&pi_state->pi_mutex.wait_lock); - raw_spin_unlock_irq(&curr->pi_lock); - spin_unlock(&hb->lock); - raw_spin_lock_irq(&curr->pi_lock); - put_pi_state(pi_state); + raw_spin_unlock(&hb->lock); + put_pi_state_atomic(pi_state, &to_free); continue; } @@ -940,7 +961,7 @@ void exit_pi_state_list(struct task_struct *curr) raw_spin_unlock(&curr->pi_lock); raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock); - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); rt_mutex_futex_unlock(&pi_state->pi_mutex); put_pi_state(pi_state); @@ -948,6 +969,8 @@ void exit_pi_state_list(struct task_struct *curr) raw_spin_lock_irq(&curr->pi_lock); } raw_spin_unlock_irq(&curr->pi_lock); + + free_pi_state_list(&to_free); } #endif @@ -1562,21 +1585,21 @@ static inline void double_lock_hb(struct futex_hash_bucket *hb1, struct futex_hash_bucket *hb2) { if (hb1 <= hb2) { - spin_lock(&hb1->lock); + raw_spin_lock(&hb1->lock); if (hb1 < hb2) - spin_lock_nested(&hb2->lock, SINGLE_DEPTH_NESTING); + raw_spin_lock_nested(&hb2->lock, SINGLE_DEPTH_NESTING); } else { /* hb1 > hb2 */ - spin_lock(&hb2->lock); - spin_lock_nested(&hb1->lock, SINGLE_DEPTH_NESTING); + raw_spin_lock(&hb2->lock); + raw_spin_lock_nested(&hb1->lock, SINGLE_DEPTH_NESTING); } } static inline void double_unlock_hb(struct futex_hash_bucket *hb1, struct futex_hash_bucket *hb2) { - spin_unlock(&hb1->lock); + raw_spin_unlock(&hb1->lock); if (hb1 != hb2) - spin_unlock(&hb2->lock); + raw_spin_unlock(&hb2->lock); } /* @@ -1604,7 +1627,7 @@ futex_wake(u32 __user *uaddr, unsigned int flags, int nr_wake, u32 bitset) if (!hb_waiters_pending(hb)) goto out_put_key; - spin_lock(&hb->lock); + raw_spin_lock(&hb->lock); plist_for_each_entry_safe(this, next, &hb->chain, list) { if (match_futex (&this->key, &key)) { @@ -1623,7 +1646,7 @@ futex_wake(u32 __user *uaddr, unsigned int flags, int nr_wake, u32 bitset) } } - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); wake_up_q(&wake_q); out_put_key: put_futex_key(&key); @@ -1930,6 +1953,7 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, struct futex_hash_bucket *hb1, *hb2; struct futex_q *this, *next; DEFINE_WAKE_Q(wake_q); + LIST_HEAD(to_free); if (nr_wake < 0 || nr_requeue < 0) return -EINVAL; @@ -2157,16 +2181,6 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, requeue_pi_wake_futex(this, &key2, hb2); drop_count++; continue; - } else if (ret == -EAGAIN) { - /* - * Waiter was woken by timeout or - * signal and has set pi_blocked_on to - * PI_WAKEUP_INPROGRESS before we - * tried to enqueue it on the rtmutex. - */ - this->pi_state = NULL; - put_pi_state(pi_state); - continue; } else if (ret) { /* * rt_mutex_start_proxy_lock() detected a @@ -2177,7 +2191,7 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, * object. */ this->pi_state = NULL; - put_pi_state(pi_state); + put_pi_state_atomic(pi_state, &to_free); /* * We stop queueing more waiters and let user * space deal with the mess. @@ -2194,7 +2208,7 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, * in futex_proxy_trylock_atomic() or in lookup_pi_state(). We * need to drop it here again. */ - put_pi_state(pi_state); + put_pi_state_atomic(pi_state, &to_free); out_unlock: double_unlock_hb(hb1, hb2); @@ -2215,6 +2229,7 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, out_put_key1: put_futex_key(&key1); out: + free_pi_state_list(&to_free); return ret ? ret : task_count; } @@ -2238,7 +2253,7 @@ static inline struct futex_hash_bucket *queue_lock(struct futex_q *q) q->lock_ptr = &hb->lock; - spin_lock(&hb->lock); + raw_spin_lock(&hb->lock); return hb; } @@ -2246,7 +2261,7 @@ static inline void queue_unlock(struct futex_hash_bucket *hb) __releases(&hb->lock) { - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); hb_waiters_dec(hb); } @@ -2285,7 +2300,7 @@ static inline void queue_me(struct futex_q *q, struct futex_hash_bucket *hb) __releases(&hb->lock) { __queue_me(q, hb); - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); } /** @@ -2301,41 +2316,41 @@ static inline void queue_me(struct futex_q *q, struct futex_hash_bucket *hb) */ static int unqueue_me(struct futex_q *q) { - spinlock_t *lock_ptr; + raw_spinlock_t *lock_ptr; int ret = 0; /* In the common case we don't take the spinlock, which is nice. */ retry: /* - * q->lock_ptr can change between this read and the following spin_lock. - * Use READ_ONCE to forbid the compiler from reloading q->lock_ptr and - * optimizing lock_ptr out of the logic below. + * q->lock_ptr can change between this read and the following + * raw_spin_lock. Use READ_ONCE to forbid the compiler from reloading + * q->lock_ptr and optimizing lock_ptr out of the logic below. */ lock_ptr = READ_ONCE(q->lock_ptr); if (lock_ptr != NULL) { - spin_lock(lock_ptr); + raw_spin_lock(lock_ptr); /* * q->lock_ptr can change between reading it and - * spin_lock(), causing us to take the wrong lock. This + * raw_spin_lock(), causing us to take the wrong lock. This * corrects the race condition. * * Reasoning goes like this: if we have the wrong lock, * q->lock_ptr must have changed (maybe several times) - * between reading it and the spin_lock(). It can - * change again after the spin_lock() but only if it was - * already changed before the spin_lock(). It cannot, + * between reading it and the raw_spin_lock(). It can + * change again after the raw_spin_lock() but only if it was + * already changed before the raw_spin_lock(). It cannot, * however, change back to the original value. Therefore * we can detect whether we acquired the correct lock. */ if (unlikely(lock_ptr != q->lock_ptr)) { - spin_unlock(lock_ptr); + raw_spin_unlock(lock_ptr); goto retry; } __unqueue_futex(q); BUG_ON(q->pi_state); - spin_unlock(lock_ptr); + raw_spin_unlock(lock_ptr); ret = 1; } @@ -2351,13 +2366,16 @@ static int unqueue_me(struct futex_q *q) static void unqueue_me_pi(struct futex_q *q) __releases(q->lock_ptr) { + struct futex_pi_state *ps; + __unqueue_futex(q); BUG_ON(!q->pi_state); - put_pi_state(q->pi_state); + ps = __put_pi_state(q->pi_state); q->pi_state = NULL; - spin_unlock(q->lock_ptr); + raw_spin_unlock(q->lock_ptr); + kfree(ps); } static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, @@ -2490,7 +2508,7 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, */ handle_err: raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock); - spin_unlock(q->lock_ptr); + raw_spin_unlock(q->lock_ptr); switch (err) { case -EFAULT: @@ -2508,7 +2526,7 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, break; } - spin_lock(q->lock_ptr); + raw_spin_lock(q->lock_ptr); raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock); /* @@ -2604,7 +2622,7 @@ static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q, /* * The task state is guaranteed to be set before another task can * wake it. set_current_state() is implemented using smp_store_mb() and - * queue_me() calls spin_unlock() upon completion, both serializing + * queue_me() calls raw_spin_unlock() upon completion, both serializing * access to the hash list and forcing another memory barrier. */ set_current_state(TASK_INTERRUPTIBLE); @@ -2895,15 +2913,7 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags, * before __rt_mutex_start_proxy_lock() is done. */ raw_spin_lock_irq(&q.pi_state->pi_mutex.wait_lock); - /* - * the migrate_disable() here disables migration in the in_atomic() fast - * path which is enabled again in the following spin_unlock(). We have - * one migrate_disable() pending in the slow-path which is reversed - * after the raw_spin_unlock_irq() where we leave the atomic context. - */ - migrate_disable(); - - spin_unlock(q.lock_ptr); + raw_spin_unlock(q.lock_ptr); /* * __rt_mutex_start_proxy_lock() unconditionally enqueues the @rt_waiter * such that futex_unlock_pi() is guaranteed to observe the waiter when @@ -2911,7 +2921,6 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags, */ ret = __rt_mutex_start_proxy_lock(&q.pi_state->pi_mutex, &rt_waiter, current); raw_spin_unlock_irq(&q.pi_state->pi_mutex.wait_lock); - migrate_enable(); if (ret) { if (ret == 1) @@ -2925,7 +2934,7 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags, ret = rt_mutex_wait_proxy_lock(&q.pi_state->pi_mutex, to, &rt_waiter); cleanup: - spin_lock(q.lock_ptr); + raw_spin_lock(q.lock_ptr); /* * If we failed to acquire the lock (deadlock/signal/timeout), we must * first acquire the hb->lock before removing the lock from the @@ -3026,7 +3035,7 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags) return ret; hb = hash_futex(&key); - spin_lock(&hb->lock); + raw_spin_lock(&hb->lock); /* * Check waiters first. We do not trust user space values at @@ -3060,19 +3069,10 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags) * rt_waiter. Also see the WARN in wake_futex_pi(). */ raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock); - /* - * Magic trickery for now to make the RT migrate disable - * logic happy. The following spin_unlock() happens with - * interrupts disabled so the internal migrate_enable() - * won't undo the migrate_disable() which was issued when - * locking hb->lock. - */ - migrate_disable(); - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); /* drops pi_state->pi_mutex.wait_lock */ ret = wake_futex_pi(uaddr, uval, pi_state); - migrate_enable(); put_pi_state(pi_state); @@ -3108,7 +3108,7 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags) * owner. */ if ((ret = cmpxchg_futex_value_locked(&curval, uaddr, uval, 0))) { - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); switch (ret) { case -EFAULT: goto pi_faulted; @@ -3128,7 +3128,7 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags) ret = (curval == uval) ? 0 : -EAGAIN; out_unlock: - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); out_putkey: put_futex_key(&key); return ret; @@ -3244,7 +3244,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, struct hrtimer_sleeper timeout, *to = NULL; struct futex_pi_state *pi_state = NULL; struct rt_mutex_waiter rt_waiter; - struct futex_hash_bucket *hb, *hb2; + struct futex_hash_bucket *hb; union futex_key key2 = FUTEX_KEY_INIT; struct futex_q q = futex_q_init; int res, ret; @@ -3302,55 +3302,20 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, /* Queue the futex_q, drop the hb lock, wait for wakeup. */ futex_wait_queue_me(hb, &q, to); - /* - * On RT we must avoid races with requeue and trying to block - * on two mutexes (hb->lock and uaddr2's rtmutex) by - * serializing access to pi_blocked_on with pi_lock. - */ - raw_spin_lock_irq(¤t->pi_lock); - if (current->pi_blocked_on) { - /* - * We have been requeued or are in the process of - * being requeued. - */ - raw_spin_unlock_irq(¤t->pi_lock); - } else { - /* - * Setting pi_blocked_on to PI_WAKEUP_INPROGRESS - * prevents a concurrent requeue from moving us to the - * uaddr2 rtmutex. After that we can safely acquire - * (and possibly block on) hb->lock. - */ - current->pi_blocked_on = PI_WAKEUP_INPROGRESS; - raw_spin_unlock_irq(¤t->pi_lock); - - spin_lock(&hb->lock); - - /* - * Clean up pi_blocked_on. We might leak it otherwise - * when we succeeded with the hb->lock in the fast - * path. - */ - raw_spin_lock_irq(¤t->pi_lock); - current->pi_blocked_on = NULL; - raw_spin_unlock_irq(¤t->pi_lock); - - ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to); - spin_unlock(&hb->lock); - if (ret) - goto out_put_keys; - } + raw_spin_lock(&hb->lock); + ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to); + raw_spin_unlock(&hb->lock); + if (ret) + goto out_put_keys; /* - * In order to be here, we have either been requeued, are in - * the process of being requeued, or requeue successfully - * acquired uaddr2 on our behalf. If pi_blocked_on was - * non-null above, we may be racing with a requeue. Do not - * rely on q->lock_ptr to be hb2->lock until after blocking on - * hb->lock or hb2->lock. The futex_requeue dropped our key1 - * reference and incremented our key2 reference count. + * In order for us to be here, we know our q.key == key2, and since + * we took the hb->lock above, we also know that futex_requeue() has + * completed and we no longer have to concern ourselves with a wakeup + * race with the atomic proxy lock acquisition by the requeue code. The + * futex_requeue dropped our key1 reference and incremented our key2 + * reference count. */ - hb2 = hash_futex(&key2); /* Check if the requeue code acquired the second futex for us. */ if (!q.rt_waiter) { @@ -3359,8 +3324,9 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, * did a lock-steal - fix up the PI-state in that case. */ if (q.pi_state && (q.pi_state->owner != current)) { - spin_lock(&hb2->lock); - BUG_ON(&hb2->lock != q.lock_ptr); + struct futex_pi_state *ps_free; + + raw_spin_lock(q.lock_ptr); ret = fixup_pi_state_owner(uaddr2, &q, current); if (ret && rt_mutex_owner(&q.pi_state->pi_mutex) == current) { pi_state = q.pi_state; @@ -3370,8 +3336,9 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, * Drop the reference to the pi state which * the requeue_pi() code acquired for us. */ - put_pi_state(q.pi_state); - spin_unlock(&hb2->lock); + ps_free = __put_pi_state(q.pi_state); + raw_spin_unlock(q.lock_ptr); + kfree(ps_free); } } else { struct rt_mutex *pi_mutex; @@ -3385,8 +3352,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, pi_mutex = &q.pi_state->pi_mutex; ret = rt_mutex_wait_proxy_lock(pi_mutex, to, &rt_waiter); - spin_lock(&hb2->lock); - BUG_ON(&hb2->lock != q.lock_ptr); + raw_spin_lock(q.lock_ptr); if (ret && !rt_mutex_cleanup_proxy_lock(pi_mutex, &rt_waiter)) ret = 0; @@ -4011,7 +3977,7 @@ static int __init futex_init(void) for (i = 0; i < futex_hashsize; i++) { atomic_set(&futex_queues[i].waiters, 0); plist_head_init(&futex_queues[i].chain); - spin_lock_init(&futex_queues[i].lock); + raw_spin_lock_init(&futex_queues[i].lock); } return 0; diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index 9c1ae2f0c1d27..62f14671aeca2 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -142,12 +142,6 @@ static void fixup_rt_mutex_waiters(struct rt_mutex *lock) WRITE_ONCE(*p, owner & ~RT_MUTEX_HAS_WAITERS); } -static int rt_mutex_real_waiter(struct rt_mutex_waiter *waiter) -{ - return waiter && waiter != PI_WAKEUP_INPROGRESS && - waiter != PI_REQUEUE_INPROGRESS; -} - /* * We can speed up the acquire/release, if there's no debugging state to be * set up. @@ -421,8 +415,7 @@ int max_lock_depth = 1024; static inline struct rt_mutex *task_blocked_on_lock(struct task_struct *p) { - return rt_mutex_real_waiter(p->pi_blocked_on) ? - p->pi_blocked_on->lock : NULL; + return p->pi_blocked_on ? p->pi_blocked_on->lock : NULL; } /* @@ -558,7 +551,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, * reached or the state of the chain has changed while we * dropped the locks. */ - if (!rt_mutex_real_waiter(waiter)) + if (!waiter) goto out_unlock_pi; /* @@ -1328,22 +1321,6 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, return -EDEADLK; raw_spin_lock(&task->pi_lock); - /* - * In the case of futex requeue PI, this will be a proxy - * lock. The task will wake unaware that it is enqueueed on - * this lock. Avoid blocking on two locks and corrupting - * pi_blocked_on via the PI_WAKEUP_INPROGRESS - * flag. futex_wait_requeue_pi() sets this when it wakes up - * before requeue (due to a signal or timeout). Do not enqueue - * the task if PI_WAKEUP_INPROGRESS is set. - */ - if (task != current && task->pi_blocked_on == PI_WAKEUP_INPROGRESS) { - raw_spin_unlock(&task->pi_lock); - return -EAGAIN; - } - - BUG_ON(rt_mutex_real_waiter(task->pi_blocked_on)); - waiter->task = task; waiter->lock = lock; waiter->prio = task->prio; @@ -1367,7 +1344,7 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, rt_mutex_enqueue_pi(owner, waiter); rt_mutex_adjust_prio(owner); - if (rt_mutex_real_waiter(owner->pi_blocked_on)) + if (owner->pi_blocked_on) chain_walk = 1; } else if (rt_mutex_cond_detect_deadlock(waiter, chwalk)) { chain_walk = 1; @@ -1467,7 +1444,7 @@ static void remove_waiter(struct rt_mutex *lock, { bool is_top_waiter = (waiter == rt_mutex_top_waiter(lock)); struct task_struct *owner = rt_mutex_owner(lock); - struct rt_mutex *next_lock = NULL; + struct rt_mutex *next_lock; lockdep_assert_held(&lock->wait_lock); @@ -1493,8 +1470,7 @@ static void remove_waiter(struct rt_mutex *lock, rt_mutex_adjust_prio(owner); /* Store the lock on which owner is blocked or NULL */ - if (rt_mutex_real_waiter(owner->pi_blocked_on)) - next_lock = task_blocked_on_lock(owner); + next_lock = task_blocked_on_lock(owner); raw_spin_unlock(&owner->pi_lock); @@ -1530,8 +1506,7 @@ void rt_mutex_adjust_pi(struct task_struct *task) raw_spin_lock_irqsave(&task->pi_lock, flags); waiter = task->pi_blocked_on; - if (!rt_mutex_real_waiter(waiter) || - rt_mutex_waiter_equal(waiter, task_to_waiter(task))) { + if (!waiter || rt_mutex_waiter_equal(waiter, task_to_waiter(task))) { raw_spin_unlock_irqrestore(&task->pi_lock, flags); return; } @@ -2350,34 +2325,6 @@ int __rt_mutex_start_proxy_lock(struct rt_mutex *lock, if (try_to_take_rt_mutex(lock, task, NULL)) return 1; -#ifdef CONFIG_PREEMPT_RT_FULL - /* - * In PREEMPT_RT there's an added race. - * If the task, that we are about to requeue, times out, - * it can set the PI_WAKEUP_INPROGRESS. This tells the requeue - * to skip this task. But right after the task sets - * its pi_blocked_on to PI_WAKEUP_INPROGRESS it can then - * block on the spin_lock(&hb->lock), which in RT is an rtmutex. - * This will replace the PI_WAKEUP_INPROGRESS with the actual - * lock that it blocks on. We *must not* place this task - * on this proxy lock in that case. - * - * To prevent this race, we first take the task's pi_lock - * and check if it has updated its pi_blocked_on. If it has, - * we assume that it woke up and we return -EAGAIN. - * Otherwise, we set the task's pi_blocked_on to - * PI_REQUEUE_INPROGRESS, so that if the task is waking up - * it will know that we are in the process of requeuing it. - */ - raw_spin_lock(&task->pi_lock); - if (task->pi_blocked_on) { - raw_spin_unlock(&task->pi_lock); - return -EAGAIN; - } - task->pi_blocked_on = PI_REQUEUE_INPROGRESS; - raw_spin_unlock(&task->pi_lock); -#endif - /* We enforce deadlock detection for futexes */ ret = task_blocks_on_rt_mutex(lock, waiter, task, RT_MUTEX_FULL_CHAINWALK); diff --git a/kernel/locking/rtmutex_common.h b/kernel/locking/rtmutex_common.h index 546aaf058b9ec..758dc43872e5b 100644 --- a/kernel/locking/rtmutex_common.h +++ b/kernel/locking/rtmutex_common.h @@ -132,9 +132,6 @@ enum rtmutex_chainwalk { /* * PI-futex support (proxy locking functions, etc.): */ -#define PI_WAKEUP_INPROGRESS ((struct rt_mutex_waiter *) 1) -#define PI_REQUEUE_INPROGRESS ((struct rt_mutex_waiter *) 2) - extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock); extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock, struct task_struct *proxy_owner); diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c index 49c14137988ea..755a580849781 100644 --- a/kernel/sched/completion.c +++ b/kernel/sched/completion.c @@ -72,12 +72,12 @@ do_wait_for_common(struct completion *x, if (!x->done) { DECLARE_SWAITQUEUE(wait); + __prepare_to_swait(&x->wait, &wait); do { if (signal_pending_state(state, current)) { timeout = -ERESTARTSYS; break; } - __prepare_to_swait(&x->wait, &wait); __set_current_state(state); raw_spin_unlock_irq(&x->wait.lock); timeout = action(timeout); diff --git a/kernel/sched/swait.c b/kernel/sched/swait.c index c58068d2ee06c..e2c3d2691edf1 100644 --- a/kernel/sched/swait.c +++ b/kernel/sched/swait.c @@ -28,7 +28,8 @@ void swake_up_locked(struct swait_queue_head *q) curr = list_first_entry(&q->task_list, typeof(*curr), task_list); wake_up_process(curr->task); - list_del_init(&curr->task_list); + if (curr->remove) + list_del_init(&curr->task_list); } EXPORT_SYMBOL(swake_up_locked); @@ -77,7 +78,8 @@ void swake_up_all(struct swait_queue_head *q) curr = list_first_entry(&tmp, typeof(*curr), task_list); wake_up_state(curr->task, TASK_NORMAL); - list_del_init(&curr->task_list); + if (curr->remove) + list_del_init(&curr->task_list); if (list_empty(&tmp)) break; diff --git a/localversion-rt b/localversion-rt index 9f7d0bdbffb18..08b3e75841adc 100644 --- a/localversion-rt +++ b/localversion-rt @@ -1 +1 @@ --rt13 +-rt14 diff --git a/mm/zswap.c b/mm/zswap.c index a4e4d36ec0858..fd5d2d5c9ae94 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include #include @@ -990,6 +991,8 @@ static void zswap_fill_page(void *ptr, unsigned long value) memset_l(page, value, PAGE_SIZE / sizeof(unsigned long)); } +/* protect zswap_dstmem from concurrency */ +static DEFINE_LOCAL_IRQ_LOCK(zswap_dstmem_lock); /********************************* * frontswap hooks **********************************/ @@ -1066,12 +1069,11 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, } /* compress */ - dst = get_cpu_var(zswap_dstmem); - tfm = *get_cpu_ptr(entry->pool->tfm); + dst = get_locked_var(zswap_dstmem_lock, zswap_dstmem); + tfm = *this_cpu_ptr(entry->pool->tfm); src = kmap_atomic(page); ret = crypto_comp_compress(tfm, src, PAGE_SIZE, dst, &dlen); kunmap_atomic(src); - put_cpu_ptr(entry->pool->tfm); if (ret) { ret = -EINVAL; goto put_dstmem; @@ -1094,7 +1096,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, memcpy(buf, &zhdr, hlen); memcpy(buf + hlen, dst, dlen); zpool_unmap_handle(entry->pool->zpool, handle); - put_cpu_var(zswap_dstmem); + put_locked_var(zswap_dstmem_lock, zswap_dstmem); /* populate entry */ entry->offset = offset; @@ -1122,7 +1124,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, return 0; put_dstmem: - put_cpu_var(zswap_dstmem); + put_locked_var(zswap_dstmem_lock, zswap_dstmem); zswap_pool_put(entry->pool); freepage: zswap_entry_cache_free(entry);