#include <linux/sched/rt.h>
#include <linux/hugetlb.h>
#include <linux/freezer.h>
+#include <linux/bootmem.h>
#include <asm/futex.h>
int __read_mostly futex_cmpxchg_enabled;
-#define FUTEX_HASHBITS (CONFIG_BASE_SMALL ? 4 : 8)
-
/*
* Futex flags used to encode options to functions and preserve them across
* restarts.
struct futex_hash_bucket {
spinlock_t lock;
struct plist_head chain;
-};
+} ____cacheline_aligned_in_smp;
-static struct futex_hash_bucket futex_queues[1<<FUTEX_HASHBITS];
+static unsigned long __read_mostly futex_hashsize;
+
+static struct futex_hash_bucket *futex_queues;
/*
* We hash on the keys returned from get_futex_key (see below).
u32 hash = jhash2((u32*)&key->both.word,
(sizeof(key->both.word)+sizeof(key->both.ptr))/4,
key->both.offset);
- return &futex_queues[hash & ((1 << FUTEX_HASHBITS)-1)];
+ return &futex_queues[hash & (futex_hashsize - 1)];
}
/*
return -EINVAL;
address -= key->both.offset;
+ if (unlikely(!access_ok(rw, uaddr, sizeof(u32))))
+ return -EFAULT;
+
/*
* PROCESS_PRIVATE futexes are fast.
* As the mm cannot disappear under us and the 'key' only needs
* but access_ok() should be faster than find_vma()
*/
if (!fshared) {
- if (unlikely(!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))))
- return -EFAULT;
key->private.mm = mm;
key->private.address = address;
get_futex_key_refs(key);
put_page(page);
/* serialize against __split_huge_page_splitting() */
local_irq_disable();
- if (likely(__get_user_pages_fast(address, 1, 1, &page) == 1)) {
+ if (likely(__get_user_pages_fast(address, 1, !ro, &page) == 1)) {
page_head = compound_head(page);
/*
* page_head is valid pointer but we must pin
{
struct futex_pi_state *pi_state = NULL;
struct futex_q *this, *next;
- struct plist_head *head;
struct task_struct *p;
pid_t pid = uval & FUTEX_TID_MASK;
- head = &hb->chain;
-
- plist_for_each_entry_safe(this, next, head, list) {
+ plist_for_each_entry_safe(this, next, &hb->chain, list) {
if (match_futex(&this->key, key)) {
/*
* Another waiter already exists - bump up
{
struct futex_hash_bucket *hb;
struct futex_q *this, *next;
- struct plist_head *head;
union futex_key key = FUTEX_KEY_INIT;
int ret;
hb = hash_futex(&key);
spin_lock(&hb->lock);
- head = &hb->chain;
- plist_for_each_entry_safe(this, next, head, list) {
+ plist_for_each_entry_safe(this, next, &hb->chain, list) {
if (match_futex (&this->key, &key)) {
if (this->pi_state || this->rt_waiter) {
ret = -EINVAL;
{
union futex_key key1 = FUTEX_KEY_INIT, key2 = FUTEX_KEY_INIT;
struct futex_hash_bucket *hb1, *hb2;
- struct plist_head *head;
struct futex_q *this, *next;
int ret, op_ret;
goto retry;
}
- head = &hb1->chain;
-
- plist_for_each_entry_safe(this, next, head, list) {
+ plist_for_each_entry_safe(this, next, &hb1->chain, list) {
if (match_futex (&this->key, &key1)) {
if (this->pi_state || this->rt_waiter) {
ret = -EINVAL;
}
if (op_ret > 0) {
- head = &hb2->chain;
-
op_ret = 0;
- plist_for_each_entry_safe(this, next, head, list) {
+ plist_for_each_entry_safe(this, next, &hb2->chain, list) {
if (match_futex (&this->key, &key2)) {
if (this->pi_state || this->rt_waiter) {
ret = -EINVAL;
int drop_count = 0, task_count = 0, ret;
struct futex_pi_state *pi_state = NULL;
struct futex_hash_bucket *hb1, *hb2;
- struct plist_head *head1;
struct futex_q *this, *next;
u32 curval2;
}
}
- head1 = &hb1->chain;
- plist_for_each_entry_safe(this, next, head1, list) {
+ plist_for_each_entry_safe(this, next, &hb1->chain, list) {
if (task_count - nr_wake >= nr_requeue)
break;
}
static inline void
-queue_unlock(struct futex_q *q, struct futex_hash_bucket *hb)
+queue_unlock(struct futex_hash_bucket *hb)
__releases(&hb->lock)
{
spin_unlock(&hb->lock);
ret = get_futex_value_locked(&uval, uaddr);
if (ret) {
- queue_unlock(q, *hb);
+ queue_unlock(*hb);
ret = get_user(uval, uaddr);
if (ret)
}
if (uval != val) {
- queue_unlock(q, *hb);
+ queue_unlock(*hb);
ret = -EWOULDBLOCK;
}
* Task is exiting and we just wait for the
* exit to complete.
*/
- queue_unlock(&q, hb);
+ queue_unlock(hb);
put_futex_key(&q.key);
cond_resched();
goto retry;
goto out_put_key;
out_unlock_put_key:
- queue_unlock(&q, hb);
+ queue_unlock(hb);
out_put_key:
put_futex_key(&q.key);
return ret != -EINTR ? ret : -ERESTARTNOINTR;
uaddr_faulted:
- queue_unlock(&q, hb);
+ queue_unlock(hb);
ret = fault_in_user_writeable(uaddr);
if (ret)
{
struct futex_hash_bucket *hb;
struct futex_q *this, *next;
- struct plist_head *head;
union futex_key key = FUTEX_KEY_INIT;
u32 uval, vpid = task_pid_vnr(current);
int ret;
* Ok, other tasks may need to be woken up - check waiters
* and do the wakeup if necessary:
*/
- head = &hb->chain;
-
- plist_for_each_entry_safe(this, next, head, list) {
+ plist_for_each_entry_safe(this, next, &hb->chain, list) {
if (!match_futex (&this->key, &key))
continue;
ret = wake_futex_pi(uaddr, uval, this);
static int __init futex_init(void)
{
u32 curval;
- int i;
+ unsigned long i;
+
+#if CONFIG_BASE_SMALL
+ futex_hashsize = 16;
+#else
+ futex_hashsize = roundup_pow_of_two(256 * num_possible_cpus());
+#endif
+
+ futex_queues = alloc_large_system_hash("futex", sizeof(*futex_queues),
+ futex_hashsize, 0,
+ futex_hashsize < 256 ? HASH_SMALL : 0,
+ NULL, NULL, futex_hashsize, futex_hashsize);
/*
* This will fail and we want it. Some arch implementations do
if (cmpxchg_futex_value_locked(&curval, NULL, 0, 0) == -EFAULT)
futex_cmpxchg_enabled = 1;
- for (i = 0; i < ARRAY_SIZE(futex_queues); i++) {
+ for (i = 0; i < futex_hashsize; i++) {
plist_head_init(&futex_queues[i].chain);
spin_lock_init(&futex_queues[i].lock);
}