summaryrefslogtreecommitdiffstats
path: root/kernel/futex.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/futex.c')
-rw-r--r--kernel/futex.c245
1 files changed, 130 insertions, 115 deletions
diff --git a/kernel/futex.c b/kernel/futex.c
index e1a380c77a5..50356fb5d72 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -63,7 +63,7 @@ union futex_key {
int offset;
} shared;
struct {
- unsigned long uaddr;
+ unsigned long address;
struct mm_struct *mm;
int offset;
} private;
@@ -87,13 +87,13 @@ struct futex_q {
struct list_head list;
wait_queue_head_t waiters;
- /* Which hash list lock to use. */
+ /* Which hash list lock to use: */
spinlock_t *lock_ptr;
- /* Key which the futex is hashed on. */
+ /* Key which the futex is hashed on: */
union futex_key key;
- /* For fd, sigio sent using these. */
+ /* For fd, sigio sent using these: */
int fd;
struct file *filp;
};
@@ -144,8 +144,9 @@ static inline int match_futex(union futex_key *key1, union futex_key *key2)
*
* Should be called with &current->mm->mmap_sem but NOT any spinlocks.
*/
-static int get_futex_key(unsigned long uaddr, union futex_key *key)
+static int get_futex_key(u32 __user *uaddr, union futex_key *key)
{
+ unsigned long address = (unsigned long)uaddr;
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
struct page *page;
@@ -154,16 +155,16 @@ static int get_futex_key(unsigned long uaddr, union futex_key *key)
/*
* The futex address must be "naturally" aligned.
*/
- key->both.offset = uaddr % PAGE_SIZE;
+ key->both.offset = address % PAGE_SIZE;
if (unlikely((key->both.offset % sizeof(u32)) != 0))
return -EINVAL;
- uaddr -= key->both.offset;
+ address -= key->both.offset;
/*
* The futex is hashed differently depending on whether
* it's in a shared or private mapping. So check vma first.
*/
- vma = find_extend_vma(mm, uaddr);
+ vma = find_extend_vma(mm, address);
if (unlikely(!vma))
return -EFAULT;
@@ -184,7 +185,7 @@ static int get_futex_key(unsigned long uaddr, union futex_key *key)
*/
if (likely(!(vma->vm_flags & VM_MAYSHARE))) {
key->private.mm = mm;
- key->private.uaddr = uaddr;
+ key->private.address = address;
return 0;
}
@@ -194,7 +195,7 @@ static int get_futex_key(unsigned long uaddr, union futex_key *key)
key->shared.inode = vma->vm_file->f_dentry->d_inode;
key->both.offset++; /* Bit 0 of offset indicates inode-based key. */
if (likely(!(vma->vm_flags & VM_NONLINEAR))) {
- key->shared.pgoff = (((uaddr - vma->vm_start) >> PAGE_SHIFT)
+ key->shared.pgoff = (((address - vma->vm_start) >> PAGE_SHIFT)
+ vma->vm_pgoff);
return 0;
}
@@ -205,7 +206,7 @@ static int get_futex_key(unsigned long uaddr, union futex_key *key)
* from swap. But that's a lot of code to duplicate here
* for a rare case, so we simply fetch the page.
*/
- err = get_user_pages(current, mm, uaddr, 1, 0, 0, &page, NULL);
+ err = get_user_pages(current, mm, address, 1, 0, 0, &page, NULL);
if (err >= 0) {
key->shared.pgoff =
page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
@@ -246,12 +247,12 @@ static void drop_key_refs(union futex_key *key)
}
}
-static inline int get_futex_value_locked(int *dest, int __user *from)
+static inline int get_futex_value_locked(u32 *dest, u32 __user *from)
{
int ret;
inc_preempt_count();
- ret = __copy_from_user_inatomic(dest, from, sizeof(int));
+ ret = __copy_from_user_inatomic(dest, from, sizeof(u32));
dec_preempt_count();
return ret ? -EFAULT : 0;
@@ -288,12 +289,12 @@ static void wake_futex(struct futex_q *q)
* Wake up all waiters hashed on the physical page that is mapped
* to this virtual address:
*/
-static int futex_wake(unsigned long uaddr, int nr_wake)
+static int futex_wake(u32 __user *uaddr, int nr_wake)
{
- union futex_key key;
- struct futex_hash_bucket *bh;
- struct list_head *head;
+ struct futex_hash_bucket *hb;
struct futex_q *this, *next;
+ struct list_head *head;
+ union futex_key key;
int ret;
down_read(&current->mm->mmap_sem);
@@ -302,9 +303,9 @@ static int futex_wake(unsigned long uaddr, int nr_wake)
if (unlikely(ret != 0))
goto out;
- bh = hash_futex(&key);
- spin_lock(&bh->lock);
- head = &bh->chain;
+ hb = hash_futex(&key);
+ spin_lock(&hb->lock);
+ head = &hb->chain;
list_for_each_entry_safe(this, next, head, list) {
if (match_futex (&this->key, &key)) {
@@ -314,7 +315,7 @@ static int futex_wake(unsigned long uaddr, int nr_wake)
}
}
- spin_unlock(&bh->lock);
+ spin_unlock(&hb->lock);
out:
up_read(&current->mm->mmap_sem);
return ret;
@@ -324,10 +325,12 @@ out:
* Wake up all waiters hashed on the physical page that is mapped
* to this virtual address:
*/
-static int futex_wake_op(unsigned long uaddr1, unsigned long uaddr2, int nr_wake, int nr_wake2, int op)
+static int
+futex_wake_op(u32 __user *uaddr1, u32 __user *uaddr2,
+ int nr_wake, int nr_wake2, int op)
{
union futex_key key1, key2;
- struct futex_hash_bucket *bh1, *bh2;
+ struct futex_hash_bucket *hb1, *hb2;
struct list_head *head;
struct futex_q *this, *next;
int ret, op_ret, attempt = 0;
@@ -342,27 +345,29 @@ retryfull:
if (unlikely(ret != 0))
goto out;
- bh1 = hash_futex(&key1);
- bh2 = hash_futex(&key2);
+ hb1 = hash_futex(&key1);
+ hb2 = hash_futex(&key2);
retry:
- if (bh1 < bh2)
- spin_lock(&bh1->lock);
- spin_lock(&bh2->lock);
- if (bh1 > bh2)
- spin_lock(&bh1->lock);
+ if (hb1 < hb2)
+ spin_lock(&hb1->lock);
+ spin_lock(&hb2->lock);
+ if (hb1 > hb2)
+ spin_lock(&hb1->lock);
- op_ret = futex_atomic_op_inuser(op, (int __user *)uaddr2);
+ op_ret = futex_atomic_op_inuser(op, uaddr2);
if (unlikely(op_ret < 0)) {
- int dummy;
+ u32 dummy;
- spin_unlock(&bh1->lock);
- if (bh1 != bh2)
- spin_unlock(&bh2->lock);
+ spin_unlock(&hb1->lock);
+ if (hb1 != hb2)
+ spin_unlock(&hb2->lock);
#ifndef CONFIG_MMU
- /* we don't get EFAULT from MMU faults if we don't have an MMU,
- * but we might get them from range checking */
+ /*
+ * we don't get EFAULT from MMU faults if we don't have an MMU,
+ * but we might get them from range checking
+ */
ret = op_ret;
goto out;
#endif
@@ -372,23 +377,26 @@ retry:
goto out;
}
- /* futex_atomic_op_inuser needs to both read and write
+ /*
+ * futex_atomic_op_inuser needs to both read and write
* *(int __user *)uaddr2, but we can't modify it
* non-atomically. Therefore, if get_user below is not
* enough, we need to handle the fault ourselves, while
- * still holding the mmap_sem. */
+ * still holding the mmap_sem.
+ */
if (attempt++) {
struct vm_area_struct * vma;
struct mm_struct *mm = current->mm;
+ unsigned long address = (unsigned long)uaddr2;
ret = -EFAULT;
if (attempt >= 2 ||
- !(vma = find_vma(mm, uaddr2)) ||
- vma->vm_start > uaddr2 ||
+ !(vma = find_vma(mm, address)) ||
+ vma->vm_start > address ||
!(vma->vm_flags & VM_WRITE))
goto out;
- switch (handle_mm_fault(mm, vma, uaddr2, 1)) {
+ switch (handle_mm_fault(mm, vma, address, 1)) {
case VM_FAULT_MINOR:
current->min_flt++;
break;
@@ -401,18 +409,20 @@ retry:
goto retry;
}
- /* If we would have faulted, release mmap_sem,
- * fault it in and start all over again. */
+ /*
+ * If we would have faulted, release mmap_sem,
+ * fault it in and start all over again.
+ */
up_read(&current->mm->mmap_sem);
- ret = get_user(dummy, (int __user *)uaddr2);
+ ret = get_user(dummy, uaddr2);
if (ret)
return ret;
goto retryfull;
}
- head = &bh1->chain;
+ head = &hb1->chain;
list_for_each_entry_safe(this, next, head, list) {
if (match_futex (&this->key, &key1)) {
@@ -423,7 +433,7 @@ retry:
}
if (op_ret > 0) {
- head = &bh2->chain;
+ head = &hb2->chain;
op_ret = 0;
list_for_each_entry_safe(this, next, head, list) {
@@ -436,9 +446,9 @@ retry:
ret += op_ret;
}
- spin_unlock(&bh1->lock);
- if (bh1 != bh2)
- spin_unlock(&bh2->lock);
+ spin_unlock(&hb1->lock);
+ if (hb1 != hb2)
+ spin_unlock(&hb2->lock);
out:
up_read(&current->mm->mmap_sem);
return ret;
@@ -448,11 +458,11 @@ out:
* Requeue all waiters hashed on one physical page to another
* physical page.
*/
-static int futex_requeue(unsigned long uaddr1, unsigned long uaddr2,
- int nr_wake, int nr_requeue, int *valp)
+static int futex_requeue(u32 __user *uaddr1, u32 __user *uaddr2,
+ int nr_wake, int nr_requeue, u32 *cmpval)
{
union futex_key key1, key2;
- struct futex_hash_bucket *bh1, *bh2;
+ struct futex_hash_bucket *hb1, *hb2;
struct list_head *head1;
struct futex_q *this, *next;
int ret, drop_count = 0;
@@ -467,68 +477,69 @@ static int futex_requeue(unsigned long uaddr1, unsigned long uaddr2,
if (unlikely(ret != 0))
goto out;
- bh1 = hash_futex(&key1);
- bh2 = hash_futex(&key2);
+ hb1 = hash_futex(&key1);
+ hb2 = hash_futex(&key2);
- if (bh1 < bh2)
- spin_lock(&bh1->lock);
- spin_lock(&bh2->lock);
- if (bh1 > bh2)
- spin_lock(&bh1->lock);
+ if (hb1 < hb2)
+ spin_lock(&hb1->lock);
+ spin_lock(&hb2->lock);
+ if (hb1 > hb2)
+ spin_lock(&hb1->lock);
- if (likely(valp != NULL)) {
- int curval;
+ if (likely(cmpval != NULL)) {
+ u32 curval;
- ret = get_futex_value_locked(&curval, (int __user *)uaddr1);
+ ret = get_futex_value_locked(&curval, uaddr1);
if (unlikely(ret)) {
- spin_unlock(&bh1->lock);
- if (bh1 != bh2)
- spin_unlock(&bh2->lock);
+ spin_unlock(&hb1->lock);
+ if (hb1 != hb2)
+ spin_unlock(&hb2->lock);
- /* If we would have faulted, release mmap_sem, fault
+ /*
+ * If we would have faulted, release mmap_sem, fault
* it in and start all over again.
*/
up_read(&current->mm->mmap_sem);
- ret = get_user(curval, (int __user *)uaddr1);
+ ret = get_user(curval, uaddr1);
if (!ret)
goto retry;
return ret;
}
- if (curval != *valp) {
+ if (curval != *cmpval) {
ret = -EAGAIN;
goto out_unlock;
}
}
- head1 = &bh1->chain;
+ head1 = &hb1->chain;
list_for_each_entry_safe(this, next, head1, list) {
if (!match_futex (&this->key, &key1))
continue;
if (++ret <= nr_wake) {
wake_futex(this);
} else {
- list_move_tail(&this->list, &bh2->chain);
- this->lock_ptr = &bh2->lock;
+ list_move_tail(&this->list, &hb2->chain);
+ this->lock_ptr = &hb2->lock;
this->key = key2;
get_key_refs(&key2);
drop_count++;
if (ret - nr_wake >= nr_requeue)
break;
- /* Make sure to stop if key1 == key2 */
- if (head1 == &bh2->chain && head1 != &next->list)
+ /* Make sure to stop if key1 == key2: */
+ if (head1 == &hb2->chain && head1 != &next->list)
head1 = &this->list;
}
}
out_unlock:
- spin_unlock(&bh1->lock);
- if (bh1 != bh2)
- spin_unlock(&bh2->lock);
+ spin_unlock(&hb1->lock);
+ if (hb1 != hb2)
+ spin_unlock(&hb2->lock);
/* drop_key_refs() must be called outside the spinlocks. */
while (--drop_count >= 0)
@@ -543,7 +554,7 @@ out:
static inline struct futex_hash_bucket *
queue_lock(struct futex_q *q, int fd, struct file *filp)
{
- struct futex_hash_bucket *bh;
+ struct futex_hash_bucket *hb;
q->fd = fd;
q->filp = filp;
@@ -551,23 +562,23 @@ queue_lock(struct futex_q *q, int fd, struct file *filp)
init_waitqueue_head(&q->waiters);
get_key_refs(&q->key);
- bh = hash_futex(&q->key);
- q->lock_ptr = &bh->lock;
+ hb = hash_futex(&q->key);
+ q->lock_ptr = &hb->lock;
- spin_lock(&bh->lock);
- return bh;
+ spin_lock(&hb->lock);
+ return hb;
}
-static inline void __queue_me(struct futex_q *q, struct futex_hash_bucket *bh)
+static inline void __queue_me(struct futex_q *q, struct futex_hash_bucket *hb)
{
- list_add_tail(&q->list, &bh->chain);
- spin_unlock(&bh->lock);
+ list_add_tail(&q->list, &hb->chain);
+ spin_unlock(&hb->lock);
}
static inline void
-queue_unlock(struct futex_q *q, struct futex_hash_bucket *bh)
+queue_unlock(struct futex_q *q, struct futex_hash_bucket *hb)
{
- spin_unlock(&bh->lock);
+ spin_unlock(&hb->lock);
drop_key_refs(&q->key);
}
@@ -579,16 +590,17 @@ queue_unlock(struct futex_q *q, struct futex_hash_bucket *bh)
/* The key must be already stored in q->key. */
static void queue_me(struct futex_q *q, int fd, struct file *filp)
{
- struct futex_hash_bucket *bh;
- bh = queue_lock(q, fd, filp);
- __queue_me(q, bh);
+ struct futex_hash_bucket *hb;
+
+ hb = queue_lock(q, fd, filp);
+ __queue_me(q, hb);
}
/* Return 1 if we were still queued (ie. 0 means we were woken) */
static int unqueue_me(struct futex_q *q)
{
- int ret = 0;
spinlock_t *lock_ptr;
+ int ret = 0;
/* In the common case we don't take the spinlock, which is nice. */
retry:
@@ -622,12 +634,13 @@ static int unqueue_me(struct futex_q *q)
return ret;
}
-static int futex_wait(unsigned long uaddr, int val, unsigned long time)
+static int futex_wait(u32 __user *uaddr, u32 val, unsigned long time)
{
DECLARE_WAITQUEUE(wait, current);
- int ret, curval;
+ struct futex_hash_bucket *hb;
struct futex_q q;
- struct futex_hash_bucket *bh;
+ u32 uval;
+ int ret;
retry:
down_read(&current->mm->mmap_sem);
@@ -636,7 +649,7 @@ static int futex_wait(unsigned long uaddr, int val, unsigned long time)
if (unlikely(ret != 0))
goto out_release_sem;
- bh = queue_lock(&q, -1, NULL);
+ hb = queue_lock(&q, -1, NULL);
/*
* Access the page AFTER the futex is queued.
@@ -658,31 +671,31 @@ static int futex_wait(unsigned long uaddr, int val, unsigned long time)
* We hold the mmap semaphore, so the mapping cannot have changed
* since we looked it up in get_futex_key.
*/
-
- ret = get_futex_value_locked(&curval, (int __user *)uaddr);
+ ret = get_futex_value_locked(&uval, uaddr);
if (unlikely(ret)) {
- queue_unlock(&q, bh);
+ queue_unlock(&q, hb);
- /* If we would have faulted, release mmap_sem, fault it in and
+ /*
+ * If we would have faulted, release mmap_sem, fault it in and
* start all over again.
*/
up_read(&current->mm->mmap_sem);
- ret = get_user(curval, (int __user *)uaddr);
+ ret = get_user(uval, uaddr);
if (!ret)
goto retry;
return ret;
}
- if (curval != val) {
+ if (uval != val) {
ret = -EWOULDBLOCK;
- queue_unlock(&q, bh);
+ queue_unlock(&q, hb);
goto out_release_sem;
}
/* Only actually queue if *uaddr contained val. */
- __queue_me(&q, bh);
+ __queue_me(&q, hb);
/*
* Now the futex is queued and we have checked the data, we
@@ -720,8 +733,10 @@ static int futex_wait(unsigned long uaddr, int val, unsigned long time)
return 0;
if (time == 0)
return -ETIMEDOUT;
- /* We expect signal_pending(current), but another thread may
- * have handled it for us already. */
+ /*
+ * We expect signal_pending(current), but another thread may
+ * have handled it for us already.
+ */
return -EINTR;
out_release_sem:
@@ -735,6 +750,7 @@ static int futex_close(struct inode *inode, struct file *filp)
unqueue_me(q);
kfree(q);
+
return 0;
}
@@ -766,7 +782,7 @@ static struct file_operations futex_fops = {
* Signal allows caller to avoid the race which would occur if they
* set the sigio stuff up afterwards.
*/
-static int futex_fd(unsigned long uaddr, int signal)
+static int futex_fd(u32 __user *uaddr, int signal)
{
struct futex_q *q;
struct file *filp;
@@ -937,7 +953,7 @@ retry:
goto retry;
if (uval & FUTEX_WAITERS)
- futex_wake((unsigned long)uaddr, 1);
+ futex_wake(uaddr, 1);
}
return 0;
}
@@ -999,8 +1015,8 @@ void exit_robust_list(struct task_struct *curr)
}
}
-long do_futex(unsigned long uaddr, int op, int val, unsigned long timeout,
- unsigned long uaddr2, int val2, int val3)
+long do_futex(u32 __user *uaddr, int op, u32 val, unsigned long timeout,
+ u32 __user *uaddr2, u32 val2, u32 val3)
{
int ret;
@@ -1031,13 +1047,13 @@ long do_futex(unsigned long uaddr, int op, int val, unsigned long timeout,
}
-asmlinkage long sys_futex(u32 __user *uaddr, int op, int val,
+asmlinkage long sys_futex(u32 __user *uaddr, int op, u32 val,
struct timespec __user *utime, u32 __user *uaddr2,
- int val3)
+ u32 val3)
{
struct timespec t;
unsigned long timeout = MAX_SCHEDULE_TIMEOUT;
- int val2 = 0;
+ u32 val2 = 0;
if (utime && (op == FUTEX_WAIT)) {
if (copy_from_user(&t, utime, sizeof(t)) != 0)
@@ -1050,10 +1066,9 @@ asmlinkage long sys_futex(u32 __user *uaddr, int op, int val,
* requeue parameter in 'utime' if op == FUTEX_REQUEUE.
*/
if (op >= FUTEX_REQUEUE)
- val2 = (int) (unsigned long) utime;
+ val2 = (u32) (unsigned long) utime;
- return do_futex((unsigned long)uaddr, op, val, timeout,
- (unsigned long)uaddr2, val2, val3);
+ return do_futex(uaddr, op, val, timeout, uaddr2, val2, val3);
}
static int futexfs_get_sb(struct file_system_type *fs_type,
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-12 01:52:02 +0000