X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=kernel%2Ffutex.c;h=fcc94e7b40864afcb72170f19d832f8117e517fc;hb=736fad17b89e5e718908abb76ae9bce210a9d5d4;hp=45490bec5831d5a806c1703251f82dec3e599d63;hpb=71d441ddb51941d9d8279bdc858f965711b85c14;p=linux-2.6-omap-h63xx.git diff --git a/kernel/futex.c b/kernel/futex.c index 45490bec583..fcc94e7b408 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -120,6 +120,24 @@ static struct futex_hash_bucket futex_queues[1<mmap_sem, when futex is shared + */ +static inline void futex_lock_mm(struct rw_semaphore *fshared) +{ + if (fshared) + down_read(fshared); +} + +/* + * Release mm->mmap_sem, when the futex is shared + */ +static inline void futex_unlock_mm(struct rw_semaphore *fshared) +{ + if (fshared) + up_read(fshared); +} + /* * We hash on the keys returned from get_futex_key (see below). */ @@ -287,7 +305,18 @@ void drop_futex_key_refs(union futex_key *key) } EXPORT_SYMBOL_GPL(drop_futex_key_refs); -static inline int get_futex_value_locked(u32 *dest, u32 __user *from) +static u32 cmpxchg_futex_value_locked(u32 __user *uaddr, u32 uval, u32 newval) +{ + u32 curval; + + pagefault_disable(); + curval = futex_atomic_cmpxchg_inatomic(uaddr, uval, newval); + pagefault_enable(); + + return curval; +} + +static int get_futex_value_locked(u32 *dest, u32 __user *from) { int ret; @@ -317,15 +346,20 @@ static int futex_handle_fault(unsigned long address, vma = find_vma(mm, address); if (vma && address >= vma->vm_start && (vma->vm_flags & VM_WRITE)) { - switch (handle_mm_fault(mm, vma, address, 1)) { - case VM_FAULT_MINOR: - ret = 0; - current->min_flt++; - break; - case VM_FAULT_MAJOR: + int fault; + fault = handle_mm_fault(mm, vma, address, 1); + if (unlikely((fault & VM_FAULT_ERROR))) { +#if 0 + /* XXX: let's do this when we verify it is OK */ + if (ret & VM_FAULT_OOM) + ret = -ENOMEM; +#endif + } else { ret = 0; - current->maj_flt++; - break; + if (fault & VM_FAULT_MAJOR) + current->maj_flt++; + else + current->min_flt++; } } if (!fshared) @@ -620,9 +654,7 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this) newval = FUTEX_WAITERS | new_owner->pid; - pagefault_disable(); - curval = futex_atomic_cmpxchg_inatomic(uaddr, uval, newval); - pagefault_enable(); + curval = cmpxchg_futex_value_locked(uaddr, uval, newval); if (curval == -EFAULT) ret = -EFAULT; @@ -659,9 +691,7 @@ static int unlock_futex_pi(u32 __user *uaddr, u32 uval) * There is no waiter, so we unlock the futex. The owner died * bit has not to be preserved here. We are the owner: */ - pagefault_disable(); - oldval = futex_atomic_cmpxchg_inatomic(uaddr, uval, 0); - pagefault_enable(); + oldval = cmpxchg_futex_value_locked(uaddr, uval, 0); if (oldval == -EFAULT) return oldval; @@ -700,8 +730,7 @@ static int futex_wake(u32 __user *uaddr, struct rw_semaphore *fshared, union futex_key key; int ret; - if (fshared) - down_read(fshared); + futex_lock_mm(fshared); ret = get_futex_key(uaddr, fshared, &key); if (unlikely(ret != 0)) @@ -725,8 +754,7 @@ static int futex_wake(u32 __user *uaddr, struct rw_semaphore *fshared, spin_unlock(&hb->lock); out: - if (fshared) - up_read(fshared); + futex_unlock_mm(fshared); return ret; } @@ -746,8 +774,7 @@ futex_wake_op(u32 __user *uaddr1, struct rw_semaphore *fshared, int ret, op_ret, attempt = 0; retryfull: - if (fshared) - down_read(fshared); + futex_lock_mm(fshared); ret = get_futex_key(uaddr1, fshared, &key1); if (unlikely(ret != 0)) @@ -793,7 +820,7 @@ retry: */ if (attempt++) { ret = futex_handle_fault((unsigned long)uaddr2, - fshared, attempt); + fshared, attempt); if (ret) goto out; goto retry; @@ -803,8 +830,7 @@ retry: * If we would have faulted, release mmap_sem, * fault it in and start all over again. */ - if (fshared) - up_read(fshared); + futex_unlock_mm(fshared); ret = get_user(dummy, uaddr2); if (ret) @@ -841,8 +867,8 @@ retry: if (hb1 != hb2) spin_unlock(&hb2->lock); out: - if (fshared) - up_read(fshared); + futex_unlock_mm(fshared); + return ret; } @@ -861,8 +887,7 @@ static int futex_requeue(u32 __user *uaddr1, struct rw_semaphore *fshared, int ret, drop_count = 0; retry: - if (fshared) - down_read(fshared); + futex_lock_mm(fshared); ret = get_futex_key(uaddr1, fshared, &key1); if (unlikely(ret != 0)) @@ -890,8 +915,7 @@ static int futex_requeue(u32 __user *uaddr1, struct rw_semaphore *fshared, * If we would have faulted, release mmap_sem, fault * it in and start all over again. */ - if (fshared) - up_read(fshared); + futex_unlock_mm(fshared); ret = get_user(curval, uaddr1); @@ -944,8 +968,7 @@ out_unlock: drop_futex_key_refs(&key1); out: - if (fshared) - up_read(fshared); + futex_unlock_mm(fshared); return ret; } @@ -1113,10 +1136,7 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, while (!ret) { newval = (uval & FUTEX_OWNER_DIED) | newtid; - pagefault_disable(); - curval = futex_atomic_cmpxchg_inatomic(uaddr, - uval, newval); - pagefault_enable(); + curval = cmpxchg_futex_value_locked(uaddr, uval, newval); if (curval == -EFAULT) ret = -EFAULT; @@ -1134,6 +1154,7 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, #define ARG3_SHARED 1 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) { @@ -1148,8 +1169,7 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared, q.pi_state = NULL; retry: - if (fshared) - down_read(fshared); + futex_lock_mm(fshared); ret = get_futex_key(uaddr, fshared, &q.key); if (unlikely(ret != 0)) @@ -1186,8 +1206,7 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared, * If we would have faulted, release mmap_sem, fault it in and * start all over again. */ - if (fshared) - up_read(fshared); + futex_unlock_mm(fshared); ret = get_user(uval, uaddr); @@ -1206,8 +1225,7 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared, * Now the futex is queued and we have checked the data, we * don't want to hold mmap_sem while we sleep. */ - if (fshared) - up_read(fshared); + futex_unlock_mm(fshared); /* * There might have been scheduling since the queue_me(), as we @@ -1285,8 +1303,7 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared, queue_unlock(&q, hb); out_release_sem: - if (fshared) - up_read(fshared); + futex_unlock_mm(fshared); return ret; } @@ -1333,8 +1350,7 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared, q.pi_state = NULL; retry: - if (fshared) - down_read(fshared); + futex_lock_mm(fshared); ret = get_futex_key(uaddr, fshared, &q.key); if (unlikely(ret != 0)) @@ -1353,9 +1369,7 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared, */ newval = current->pid; - pagefault_disable(); - curval = futex_atomic_cmpxchg_inatomic(uaddr, 0, newval); - pagefault_enable(); + curval = cmpxchg_futex_value_locked(uaddr, 0, newval); if (unlikely(curval == -EFAULT)) goto uaddr_faulted; @@ -1398,9 +1412,7 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared, lock_taken = 1; } - pagefault_disable(); - curval = futex_atomic_cmpxchg_inatomic(uaddr, uval, newval); - pagefault_enable(); + curval = cmpxchg_futex_value_locked(uaddr, uval, newval); if (unlikely(curval == -EFAULT)) goto uaddr_faulted; @@ -1428,8 +1440,7 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared, * exit to complete. */ queue_unlock(&q, hb); - if (fshared) - up_read(fshared); + futex_unlock_mm(fshared); cond_resched(); goto retry; @@ -1465,8 +1476,7 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared, * Now the futex is queued and we have checked the data, we * don't want to hold mmap_sem while we sleep. */ - if (fshared) - up_read(fshared); + futex_unlock_mm(fshared); WARN_ON(!q.pi_state); /* @@ -1480,8 +1490,7 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared, ret = ret ? 0 : -EWOULDBLOCK; } - if (fshared) - down_read(fshared); + futex_lock_mm(fshared); spin_lock(q.lock_ptr); if (!ret) { @@ -1518,8 +1527,7 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared, /* Unqueue and drop the lock */ unqueue_me_pi(&q); - if (fshared) - up_read(fshared); + futex_unlock_mm(fshared); return ret != -EINTR ? ret : -ERESTARTNOINTR; @@ -1527,8 +1535,7 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared, queue_unlock(&q, hb); out_release_sem: - if (fshared) - up_read(fshared); + futex_unlock_mm(fshared); return ret; uaddr_faulted: @@ -1550,8 +1557,7 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared, goto retry_unlocked; } - if (fshared) - up_read(fshared); + futex_unlock_mm(fshared); ret = get_user(uval, uaddr); if (!ret && (uval != -EFAULT)) @@ -1585,8 +1591,7 @@ retry: /* * First take all the futex related locks: */ - if (fshared) - down_read(fshared); + futex_lock_mm(fshared); ret = get_futex_key(uaddr, fshared, &key); if (unlikely(ret != 0)) @@ -1601,11 +1606,9 @@ retry_unlocked: * again. If it succeeds then we can return without waking * anyone else up: */ - if (!(uval & FUTEX_OWNER_DIED)) { - pagefault_disable(); - uval = futex_atomic_cmpxchg_inatomic(uaddr, current->pid, 0); - pagefault_enable(); - } + if (!(uval & FUTEX_OWNER_DIED)) + uval = cmpxchg_futex_value_locked(uaddr, current->pid, 0); + if (unlikely(uval == -EFAULT)) goto pi_faulted; @@ -1647,8 +1650,7 @@ retry_unlocked: out_unlock: spin_unlock(&hb->lock); out: - if (fshared) - up_read(fshared); + futex_unlock_mm(fshared); return ret; @@ -1668,11 +1670,11 @@ pi_faulted: attempt); if (ret) goto out; + uval = 0; goto retry_unlocked; } - if (fshared) - up_read(fshared); + futex_unlock_mm(fshared); ret = get_user(uval, uaddr); if (!ret && (uval != -EFAULT)) @@ -1729,8 +1731,8 @@ static int futex_fd(u32 __user *uaddr, int signal) if (printk_timed_ratelimit(&printk_interval, 60 * 60 * 1000)) { printk(KERN_WARNING "Process `%s' used FUTEX_FD, which " - "will be removed from the kernel in June 2007\n", - current->comm); + "will be removed from the kernel in June 2007\n", + current->comm); } ret = -EINVAL; @@ -1908,10 +1910,8 @@ retry: * Wake robust non-PI futexes here. The wakeup of * PI futexes happens in exit_pi_state(): */ - if (!pi) { - if (uval & FUTEX_WAITERS) + if (!pi && (uval & FUTEX_WAITERS)) futex_wake(uaddr, &curr->mm->mmap_sem, 1); - } } return 0; } @@ -1943,9 +1943,10 @@ static inline int fetch_robust_entry(struct robust_list __user **entry, void exit_robust_list(struct task_struct *curr) { struct robust_list_head __user *head = curr->robust_list; - struct robust_list __user *entry, *pending; - unsigned int limit = ROBUST_LIST_LIMIT, pi, pip; + struct robust_list __user *entry, *next_entry, *pending; + unsigned int limit = ROBUST_LIST_LIMIT, pi, next_pi, pip; unsigned long futex_offset; + int rc; /* * Fetch the list head (which was registered earlier, via @@ -1965,11 +1966,13 @@ void exit_robust_list(struct task_struct *curr) if (fetch_robust_entry(&pending, &head->list_op_pending, &pip)) return; - if (pending) - handle_futex_death((void __user *)pending + futex_offset, - curr, pip); - + next_entry = NULL; /* avoid warning with gcc */ while (entry != &head->list) { + /* + * Fetch the next entry in the list before calling + * handle_futex_death: + */ + rc = fetch_robust_entry(&next_entry, &entry->next, &next_pi); /* * A pending lock might already be on the list, so * don't process it twice: @@ -1978,11 +1981,10 @@ void exit_robust_list(struct task_struct *curr) if (handle_futex_death((void __user *)entry + futex_offset, curr, pi)) return; - /* - * Fetch the next entry in the list: - */ - if (fetch_robust_entry(&entry, &entry->next, &pi)) + if (rc) return; + entry = next_entry; + pi = next_pi; /* * Avoid excessively long or circular lists: */ @@ -1991,6 +1993,10 @@ void exit_robust_list(struct task_struct *curr) cond_resched(); } + + if (pending) + handle_futex_death((void __user *)pending + futex_offset, + curr, pip); } long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout, @@ -2061,8 +2067,10 @@ asmlinkage long sys_futex(u32 __user *uaddr, int op, u32 val, } /* * requeue parameter in 'utime' if cmd == FUTEX_REQUEUE. + * number of waiters to wake in 'utime' if cmd == FUTEX_WAKE_OP. */ - if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE) + if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE || + cmd == FUTEX_WAKE_OP) val2 = (u32) (unsigned long) utime; return do_futex(uaddr, op, val, tp, uaddr2, val2, val3);