diff options
Diffstat (limited to 'kernel/futex/futex.h')
| -rw-r--r-- | kernel/futex/futex.h | 140 |
1 files changed, 129 insertions, 11 deletions
diff --git a/kernel/futex/futex.h b/kernel/futex/futex.h index 8b195d06f4e8..fcd1617212ee 100644 --- a/kernel/futex/futex.h +++ b/kernel/futex/futex.h @@ -6,6 +6,8 @@ #include <linux/rtmutex.h> #include <linux/sched/wake_q.h> #include <linux/compat.h> +#include <linux/uaccess.h> +#include <linux/cleanup.h> #ifdef CONFIG_PREEMPT_RT #include <linux/rcuwait.h> @@ -37,6 +39,7 @@ #define FLAGS_HAS_TIMEOUT 0x0040 #define FLAGS_NUMA 0x0080 #define FLAGS_STRICT 0x0100 +#define FLAGS_MPOL 0x0200 /* FUTEX_ to FLAGS_ */ static inline unsigned int futex_to_flags(unsigned int op) @@ -52,7 +55,7 @@ static inline unsigned int futex_to_flags(unsigned int op) return flags; } -#define FUTEX2_VALID_MASK (FUTEX2_SIZE_MASK | FUTEX2_PRIVATE) +#define FUTEX2_VALID_MASK (FUTEX2_SIZE_MASK | FUTEX2_NUMA | FUTEX2_MPOL | FUTEX2_PRIVATE) /* FUTEX2_ to FLAGS_ */ static inline unsigned int futex2_to_flags(unsigned int flags2) @@ -65,6 +68,9 @@ static inline unsigned int futex2_to_flags(unsigned int flags2) if (flags2 & FUTEX2_NUMA) flags |= FLAGS_NUMA; + if (flags2 & FUTEX2_MPOL) + flags |= FLAGS_MPOL; + return flags; } @@ -85,6 +91,19 @@ static inline bool futex_flags_valid(unsigned int flags) if ((flags & FLAGS_SIZE_MASK) != FLAGS_SIZE_32) return false; + /* + * Must be able to represent both FUTEX_NO_NODE and every valid nodeid + * in a futex word. + */ + if (flags & FLAGS_NUMA) { + int bits = 8 * futex_size(flags); + u64 max = ~0ULL; + + max >>= 64 - bits; + if (nr_node_ids >= max) + return false; + } + return true; } @@ -116,6 +135,7 @@ struct futex_hash_bucket { atomic_t waiters; spinlock_t lock; struct plist_head chain; + struct futex_private_hash *priv; } ____cacheline_aligned_in_smp; /* @@ -155,6 +175,7 @@ typedef void (futex_wake_fn)(struct wake_q_head *wake_q, struct futex_q *q); * @requeue_pi_key: the requeue_pi target futex key * @bitset: bitset for the optional bitmasked wakeup * @requeue_state: State field for futex_requeue_pi() + * @drop_hb_ref: Waiter should drop the extra hash bucket reference if true * @requeue_wait: RCU wait for futex_requeue_pi() (RT only) * * We use this hashed waitqueue, instead of a normal wait_queue_entry_t, so @@ -181,6 +202,7 @@ struct futex_q { union futex_key *requeue_pi_key; u32 bitset; atomic_t requeue_state; + bool drop_hb_ref; #ifdef CONFIG_PREEMPT_RT struct rcuwait requeue_wait; #endif @@ -195,12 +217,35 @@ enum futex_access { extern int get_futex_key(u32 __user *uaddr, unsigned int flags, union futex_key *key, enum futex_access rw); - +extern void futex_q_lockptr_lock(struct futex_q *q); extern struct hrtimer_sleeper * futex_setup_timer(ktime_t *time, struct hrtimer_sleeper *timeout, int flags, u64 range_ns); extern struct futex_hash_bucket *futex_hash(union futex_key *key); +#ifdef CONFIG_FUTEX_PRIVATE_HASH +extern void futex_hash_get(struct futex_hash_bucket *hb); +extern void futex_hash_put(struct futex_hash_bucket *hb); + +extern struct futex_private_hash *futex_private_hash(void); +extern bool futex_private_hash_get(struct futex_private_hash *fph); +extern void futex_private_hash_put(struct futex_private_hash *fph); + +#else /* !CONFIG_FUTEX_PRIVATE_HASH */ +static inline void futex_hash_get(struct futex_hash_bucket *hb) { } +static inline void futex_hash_put(struct futex_hash_bucket *hb) { } +static inline struct futex_private_hash *futex_private_hash(void) { return NULL; } +static inline bool futex_private_hash_get(void) { return false; } +static inline void futex_private_hash_put(struct futex_private_hash *fph) { } +#endif + +DEFINE_CLASS(hb, struct futex_hash_bucket *, + if (_T) futex_hash_put(_T), + futex_hash(key), union futex_key *key); + +DEFINE_CLASS(private_hash, struct futex_private_hash *, + if (_T) futex_private_hash_put(_T), + futex_private_hash(), void); /** * futex_match - Check whether two futex keys are equal @@ -218,25 +263,95 @@ static inline int futex_match(union futex_key *key1, union futex_key *key2) } 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); + struct futex_q *q, union futex_key *key2, + struct task_struct *task); +extern void futex_do_wait(struct futex_q *q, struct hrtimer_sleeper *timeout); extern bool __futex_wake_mark(struct futex_q *q); extern void futex_wake_mark(struct wake_q_head *wake_q, struct futex_q *q); extern int fault_in_user_writeable(u32 __user *uaddr); -extern int futex_cmpxchg_value_locked(u32 *curval, u32 __user *uaddr, u32 uval, u32 newval); -extern int futex_get_value_locked(u32 *dest, u32 __user *from); extern struct futex_q *futex_top_waiter(struct futex_hash_bucket *hb, union futex_key *key); +static inline int futex_cmpxchg_value_locked(u32 *curval, u32 __user *uaddr, u32 uval, u32 newval) +{ + int ret; + + pagefault_disable(); + ret = futex_atomic_cmpxchg_inatomic(curval, uaddr, uval, newval); + pagefault_enable(); + + return ret; +} + +/* + * This does a plain atomic user space read, and the user pointer has + * already been verified earlier by get_futex_key() to be both aligned + * and actually in user space, just like futex_atomic_cmpxchg_inatomic(). + * + * We still want to avoid any speculation, and while __get_user() is + * the traditional model for this, it's actually slower than doing + * this manually these days. + * + * We could just have a per-architecture special function for it, + * the same way we do futex_atomic_cmpxchg_inatomic(), but rather + * than force everybody to do that, write it out long-hand using + * the low-level user-access infrastructure. + * + * This looks a bit overkill, but generally just results in a couple + * of instructions. + */ +static __always_inline int futex_get_value(u32 *dest, u32 __user *from) +{ + u32 val; + + if (can_do_masked_user_access()) + from = masked_user_access_begin(from); + else if (!user_read_access_begin(from, sizeof(*from))) + return -EFAULT; + unsafe_get_user(val, from, Efault); + user_read_access_end(); + *dest = val; + return 0; +Efault: + user_read_access_end(); + return -EFAULT; +} + +static __always_inline int futex_put_value(u32 val, u32 __user *to) +{ + if (can_do_masked_user_access()) + to = masked_user_access_begin(to); + else if (!user_read_access_begin(to, sizeof(*to))) + return -EFAULT; + unsafe_put_user(val, to, Efault); + user_read_access_end(); + return 0; +Efault: + user_read_access_end(); + return -EFAULT; +} + +static inline int futex_get_value_locked(u32 *dest, u32 __user *from) +{ + int ret; + + pagefault_disable(); + ret = futex_get_value(dest, from); + pagefault_enable(); + + return ret; +} + extern void __futex_unqueue(struct futex_q *q); -extern void __futex_queue(struct futex_q *q, struct futex_hash_bucket *hb); +extern void __futex_queue(struct futex_q *q, struct futex_hash_bucket *hb, + struct task_struct *task); extern int futex_unqueue(struct futex_q *q); /** * futex_queue() - Enqueue the futex_q on the futex_hash_bucket * @q: The futex_q to enqueue * @hb: The destination hash bucket + * @task: Task queueing this futex * * The hb->lock must be held by the caller, and is released here. A call to * futex_queue() is typically paired with exactly one call to futex_unqueue(). The @@ -244,11 +359,14 @@ extern int futex_unqueue(struct futex_q *q); * or nothing if the unqueue is done as part of the wake process and the unqueue * state is implicit in the state of woken task (see futex_wait_requeue_pi() for * an example). + * + * Note that @task may be NULL, for async usage of futexes. */ -static inline void futex_queue(struct futex_q *q, struct futex_hash_bucket *hb) +static inline void futex_queue(struct futex_q *q, struct futex_hash_bucket *hb, + struct task_struct *task) __releases(&hb->lock) { - __futex_queue(q, hb); + __futex_queue(q, hb, task); spin_unlock(&hb->lock); } @@ -294,7 +412,7 @@ static inline int futex_hb_waiters_pending(struct futex_hash_bucket *hb) #endif } -extern struct futex_hash_bucket *futex_q_lock(struct futex_q *q); +extern void futex_q_lock(struct futex_q *q, struct futex_hash_bucket *hb); extern void futex_q_unlock(struct futex_hash_bucket *hb); |