#include "rtmutex_common.h"
+int __read_mostly futex_cmpxchg_enabled;
+
#define FUTEX_HASHBITS (CONFIG_BASE_SMALL ? 4 : 8)
/*
/* Optional priority inheritance state: */
struct futex_pi_state *pi_state;
struct task_struct *task;
+
+ /* Bitset for the optional bitmasked wakeup */
+ u32 bitset;
};
/*
struct futex_hash_bucket *hb;
union futex_key key;
+ if (!futex_cmpxchg_enabled)
+ return;
/*
* We are a ZOMBIE and nobody can enqueue itself on
* pi_state_list anymore, but we have to be careful
* to this virtual address:
*/
static int futex_wake(u32 __user *uaddr, struct rw_semaphore *fshared,
- int nr_wake)
+ int nr_wake, u32 bitset)
{
struct futex_hash_bucket *hb;
struct futex_q *this, *next;
union futex_key key;
int ret;
+ if (!bitset)
+ return -EINVAL;
+
futex_lock_mm(fshared);
ret = get_futex_key(uaddr, fshared, &key);
ret = -EINVAL;
break;
}
+
+ /* Check if one of the bits is set in both bitsets */
+ if (!(this->bitset & bitset))
+ continue;
+
wake_futex(this);
if (++ret >= nr_wake)
break;
static long futex_wait_restart(struct restart_block *restart);
static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared,
- u32 val, ktime_t *abs_time)
+ u32 val, ktime_t *abs_time, u32 bitset)
{
struct task_struct *curr = current;
DECLARE_WAITQUEUE(wait, curr);
struct hrtimer_sleeper t;
int rem = 0;
+ if (!bitset)
+ return -EINVAL;
+
q.pi_state = NULL;
+ q.bitset = bitset;
retry:
futex_lock_mm(fshared);
t.timer.expires = *abs_time;
hrtimer_start(&t.timer, t.timer.expires, HRTIMER_MODE_ABS);
+ if (!hrtimer_active(&t.timer))
+ t.task = NULL;
/*
* the timer could have already expired, in which
restart->futex.uaddr = (u32 *)uaddr;
restart->futex.val = val;
restart->futex.time = abs_time->tv64;
+ restart->futex.bitset = bitset;
restart->futex.flags = 0;
if (fshared)
restart->fn = do_no_restart_syscall;
if (restart->futex.flags & FLAGS_SHARED)
fshared = ¤t->mm->mmap_sem;
- return (long)futex_wait(uaddr, fshared, restart->futex.val, &t);
+ return (long)futex_wait(uaddr, fshared, restart->futex.val, &t,
+ restart->futex.bitset);
}
owner = rt_mutex_owner(&q.pi_state->pi_mutex);
res = fixup_pi_state_owner(uaddr, &q, owner);
- WARN_ON(rt_mutex_owner(&q.pi_state->pi_mutex) !=
- owner);
-
/* propagate -EFAULT, if the fixup failed */
if (res)
ret = res;
sys_set_robust_list(struct robust_list_head __user *head,
size_t len)
{
+ if (!futex_cmpxchg_enabled)
+ return -ENOSYS;
/*
* The kernel knows only one size for now:
*/
struct robust_list_head __user *head;
unsigned long ret;
+ if (!futex_cmpxchg_enabled)
+ return -ENOSYS;
+
if (!pid)
head = current->robust_list;
else {
* PI futexes happens in exit_pi_state():
*/
if (!pi && (uval & FUTEX_WAITERS))
- futex_wake(uaddr, &curr->mm->mmap_sem, 1);
+ futex_wake(uaddr, &curr->mm->mmap_sem, 1,
+ FUTEX_BITSET_MATCH_ANY);
}
return 0;
}
unsigned long futex_offset;
int rc;
+ if (!futex_cmpxchg_enabled)
+ return;
+
/*
* Fetch the list head (which was registered earlier, via
* sys_set_robust_list()):
long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
u32 __user *uaddr2, u32 val2, u32 val3)
{
- int ret;
+ int ret = -ENOSYS;
int cmd = op & FUTEX_CMD_MASK;
struct rw_semaphore *fshared = NULL;
switch (cmd) {
case FUTEX_WAIT:
- ret = futex_wait(uaddr, fshared, val, timeout);
+ val3 = FUTEX_BITSET_MATCH_ANY;
+ case FUTEX_WAIT_BITSET:
+ ret = futex_wait(uaddr, fshared, val, timeout, val3);
break;
case FUTEX_WAKE:
- ret = futex_wake(uaddr, fshared, val);
+ val3 = FUTEX_BITSET_MATCH_ANY;
+ case FUTEX_WAKE_BITSET:
+ ret = futex_wake(uaddr, fshared, val, val3);
break;
case FUTEX_FD:
/* non-zero val means F_SETOWN(getpid()) & F_SETSIG(val) */
ret = futex_wake_op(uaddr, fshared, uaddr2, val, val2, val3);
break;
case FUTEX_LOCK_PI:
- ret = futex_lock_pi(uaddr, fshared, val, timeout, 0);
+ if (futex_cmpxchg_enabled)
+ ret = futex_lock_pi(uaddr, fshared, val, timeout, 0);
break;
case FUTEX_UNLOCK_PI:
- ret = futex_unlock_pi(uaddr, fshared);
+ if (futex_cmpxchg_enabled)
+ ret = futex_unlock_pi(uaddr, fshared);
break;
case FUTEX_TRYLOCK_PI:
- ret = futex_lock_pi(uaddr, fshared, 0, timeout, 1);
+ if (futex_cmpxchg_enabled)
+ ret = futex_lock_pi(uaddr, fshared, 0, timeout, 1);
break;
default:
ret = -ENOSYS;
u32 val2 = 0;
int cmd = op & FUTEX_CMD_MASK;
- if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI)) {
+ if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI ||
+ cmd == FUTEX_WAIT_BITSET)) {
if (copy_from_user(&ts, utime, sizeof(ts)) != 0)
return -EFAULT;
if (!timespec_valid(&ts))
t = timespec_to_ktime(ts);
if (cmd == FUTEX_WAIT)
- t = ktime_add(ktime_get(), t);
+ t = ktime_add_safe(ktime_get(), t);
tp = &t;
}
/*
.kill_sb = kill_anon_super,
};
-static int __init init(void)
+static int __init futex_init(void)
{
- int i = register_filesystem(&futex_fs_type);
+ u32 curval;
+ int i;
+
+ /*
+ * This will fail and we want it. Some arch implementations do
+ * runtime detection of the futex_atomic_cmpxchg_inatomic()
+ * functionality. We want to know that before we call in any
+ * of the complex code paths. Also we want to prevent
+ * registration of robust lists in that case. NULL is
+ * guaranteed to fault and we get -EFAULT on functional
+ * implementation, the non functional ones will return
+ * -ENOSYS.
+ */
+ curval = cmpxchg_futex_value_locked(NULL, 0, 0);
+ if (curval == -EFAULT)
+ futex_cmpxchg_enabled = 1;
+ for (i = 0; i < ARRAY_SIZE(futex_queues); i++) {
+ plist_head_init(&futex_queues[i].chain, &futex_queues[i].lock);
+ spin_lock_init(&futex_queues[i].lock);
+ }
+
+ i = register_filesystem(&futex_fs_type);
if (i)
return i;
return PTR_ERR(futex_mnt);
}
- for (i = 0; i < ARRAY_SIZE(futex_queues); i++) {
- plist_head_init(&futex_queues[i].chain, &futex_queues[i].lock);
- spin_lock_init(&futex_queues[i].lock);
- }
return 0;
}
-__initcall(init);
+__initcall(futex_init);
git.samba.org / sfrench / cifs-2.6.git / blobdiff