X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Ffutex.c;h=9dc591ab681a92c87209463e922f1a06e8d9bfa7;hb=2cfae2739bda8fc5d934977c0ab19f6df1dd6d6c;hp=5c3f45d07c534a7ecc07f50c427e8390809cf165;hpb=14dc5249728ff699b1ca4dac01ad416a350a147a;p=linux-2.6 diff --git a/kernel/futex.c b/kernel/futex.c index 5c3f45d07c..9dc591ab68 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -52,6 +52,10 @@ #include #include #include +#include +#include +#include + #include #include "rtmutex_common.h" @@ -177,8 +181,8 @@ static inline int match_futex(union futex_key *key1, union futex_key *key2) * For other futexes, it points to ¤t->mm->mmap_sem and * caller must have taken the reader lock. but NOT any spinlocks. */ -int get_futex_key(u32 __user *uaddr, struct rw_semaphore *fshared, - union futex_key *key) +static int get_futex_key(u32 __user *uaddr, struct rw_semaphore *fshared, + union futex_key *key) { unsigned long address = (unsigned long)uaddr; struct mm_struct *mm = current->mm; @@ -264,14 +268,13 @@ int get_futex_key(u32 __user *uaddr, struct rw_semaphore *fshared, } return err; } -EXPORT_SYMBOL_GPL(get_futex_key); /* * Take a reference to the resource addressed by a key. * Can be called while holding spinlocks. * */ -inline void get_futex_key_refs(union futex_key *key) +static void get_futex_key_refs(union futex_key *key) { if (key->both.ptr == 0) return; @@ -284,15 +287,14 @@ inline void get_futex_key_refs(union futex_key *key) break; } } -EXPORT_SYMBOL_GPL(get_futex_key_refs); /* * Drop a reference to the resource addressed by a key. * The hash bucket spinlock must not be held. */ -void drop_futex_key_refs(union futex_key *key) +static void drop_futex_key_refs(union futex_key *key) { - if (key->both.ptr == 0) + if (!key->both.ptr) return; switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) { case FUT_OFF_INODE: @@ -303,7 +305,6 @@ void drop_futex_key_refs(union futex_key *key) break; } } -EXPORT_SYMBOL_GPL(drop_futex_key_refs); static u32 cmpxchg_futex_value_locked(u32 __user *uaddr, u32 uval, u32 newval) { @@ -346,15 +347,20 @@ 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) @@ -437,8 +443,7 @@ static struct task_struct * futex_find_get_task(pid_t pid) struct task_struct *p; rcu_read_lock(); - p = find_task_by_pid(pid); - + p = find_task_by_vpid(pid); if (!p || ((current->euid != p->euid) && (current->euid != p->uid))) p = ERR_PTR(-ESRCH); else @@ -647,7 +652,7 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this) if (!(uval & FUTEX_OWNER_DIED)) { int ret = 0; - newval = FUTEX_WAITERS | new_owner->pid; + newval = FUTEX_WAITERS | task_pid_vnr(new_owner); curval = cmpxchg_futex_value_locked(uaddr, uval, newval); @@ -1040,7 +1045,7 @@ static int unqueue_me(struct futex_q *q) retry: lock_ptr = q->lock_ptr; barrier(); - if (lock_ptr != 0) { + if (lock_ptr != NULL) { spin_lock(lock_ptr); /* * q->lock_ptr can change between reading it and @@ -1100,7 +1105,7 @@ static void unqueue_me_pi(struct futex_q *q) static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, struct task_struct *curr) { - u32 newtid = curr->pid | FUTEX_WAITERS; + u32 newtid = task_pid_vnr(curr) | FUTEX_WAITERS; struct futex_pi_state *pi_state = q->pi_state; u32 uval, curval, newval; int ret; @@ -1362,7 +1367,7 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared, * (by doing a 0 -> TID atomic cmpxchg), while holding all * the locks. It will most likely not succeed. */ - newval = current->pid; + newval = task_pid_vnr(current); curval = cmpxchg_futex_value_locked(uaddr, 0, newval); @@ -1373,7 +1378,7 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared, * Detect deadlocks. In case of REQUEUE_PI this is a valid * situation and we return success to user space. */ - if (unlikely((curval & FUTEX_TID_MASK) == current->pid)) { + if (unlikely((curval & FUTEX_TID_MASK) == task_pid_vnr(current))) { ret = -EDEADLK; goto out_unlock_release_sem; } @@ -1402,7 +1407,7 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared, */ if (unlikely(ownerdied || !(curval & FUTEX_TID_MASK))) { /* Keep the OWNER_DIED bit */ - newval = (curval & ~FUTEX_TID_MASK) | current->pid; + newval = (curval & ~FUTEX_TID_MASK) | task_pid_vnr(current); ownerdied = 0; lock_taken = 1; } @@ -1581,7 +1586,7 @@ retry: /* * We release only a lock we actually own: */ - if ((uval & FUTEX_TID_MASK) != current->pid) + if ((uval & FUTEX_TID_MASK) != task_pid_vnr(current)) return -EPERM; /* * First take all the futex related locks: @@ -1602,7 +1607,7 @@ retry_unlocked: * anyone else up: */ if (!(uval & FUTEX_OWNER_DIED)) - uval = cmpxchg_futex_value_locked(uaddr, current->pid, 0); + uval = cmpxchg_futex_value_locked(uaddr, task_pid_vnr(current), 0); if (unlikely(uval == -EFAULT)) @@ -1611,7 +1616,7 @@ retry_unlocked: * Rare case: we managed to release the lock atomically, * no need to wake anyone else up: */ - if (unlikely(uval == current->pid)) + if (unlikely(uval == task_pid_vnr(current))) goto out_unlock; /* @@ -1665,6 +1670,7 @@ pi_faulted: attempt); if (ret) goto out; + uval = 0; goto retry_unlocked; } @@ -1847,7 +1853,7 @@ sys_get_robust_list(int pid, struct robust_list_head __user * __user *head_ptr, ret = -ESRCH; rcu_read_lock(); - p = find_task_by_pid(pid); + p = find_task_by_vpid(pid); if (!p) goto err_unlock; ret = -EPERM; @@ -1880,7 +1886,7 @@ retry: if (get_user(uval, uaddr)) return -1; - if ((uval & FUTEX_TID_MASK) == curr->pid) { + if ((uval & FUTEX_TID_MASK) == task_pid_vnr(curr)) { /* * Ok, this dying thread is truly holding a futex * of interest. Set the OWNER_DIED bit atomically @@ -1937,9 +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 @@ -1959,11 +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: @@ -1972,11 +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: */ @@ -1985,6 +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, @@ -2055,8 +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); @@ -2066,7 +2080,7 @@ static int futexfs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct vfsmount *mnt) { - return get_sb_pseudo(fs_type, "futex", NULL, 0xBAD1DEA, mnt); + return get_sb_pseudo(fs_type, "futex", NULL, FUTEXFS_SUPER_MAGIC, mnt); } static struct file_system_type futex_fs_type = {