diff options
Diffstat (limited to 'arch/parisc/include/asm/futex.h')
| -rw-r--r-- | arch/parisc/include/asm/futex.h | 66 |
1 files changed, 34 insertions, 32 deletions
diff --git a/arch/parisc/include/asm/futex.h b/arch/parisc/include/asm/futex.h index d2c3e4106851..3222206cb3ea 100644 --- a/arch/parisc/include/asm/futex.h +++ b/arch/parisc/include/asm/futex.h @@ -2,32 +2,31 @@ #ifndef _ASM_PARISC_FUTEX_H #define _ASM_PARISC_FUTEX_H -#ifdef __KERNEL__ - #include <linux/futex.h> #include <linux/uaccess.h> #include <asm/atomic.h> #include <asm/errno.h> /* The following has to match the LWS code in syscall.S. We have - sixteen four-word locks. */ + * 256 four-word locks. We use bits 20-27 of the futex virtual + * address for the hash index. + */ + +static inline unsigned long _futex_hash_index(unsigned long ua) +{ + return (ua >> 2) & 0x3fc; +} static inline void -_futex_spin_lock_irqsave(u32 __user *uaddr, unsigned long int *flags) +_futex_spin_lock_irqsave(arch_spinlock_t *s, unsigned long *flags) { - extern u32 lws_lock_start[]; - long index = ((long)uaddr & 0xf0) >> 2; - arch_spinlock_t *s = (arch_spinlock_t *)&lws_lock_start[index]; local_irq_save(*flags); arch_spin_lock(s); } static inline void -_futex_spin_unlock_irqrestore(u32 __user *uaddr, unsigned long int *flags) +_futex_spin_unlock_irqrestore(arch_spinlock_t *s, unsigned long *flags) { - extern u32 lws_lock_start[]; - long index = ((long)uaddr & 0xf0) >> 2; - arch_spinlock_t *s = (arch_spinlock_t *)&lws_lock_start[index]; arch_spin_unlock(s); local_irq_restore(*flags); } @@ -35,16 +34,21 @@ _futex_spin_unlock_irqrestore(u32 __user *uaddr, unsigned long int *flags) static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr) { - unsigned long int flags; + extern u32 lws_lock_start[]; + unsigned long ua = (unsigned long)uaddr; + arch_spinlock_t *s; + unsigned long flags; int oldval, ret; u32 tmp; - _futex_spin_lock_irqsave(uaddr, &flags); - pagefault_disable(); + s = (arch_spinlock_t *)&lws_lock_start[_futex_hash_index(ua)]; + _futex_spin_lock_irqsave(s, &flags); - ret = -EFAULT; - if (unlikely(get_user(oldval, uaddr) != 0)) + /* Return -EFAULT if we encounter a page fault or COW break */ + if (unlikely(get_user(oldval, uaddr) != 0)) { + ret = -EFAULT; goto out_pagefault_enable; + } ret = 0; tmp = oldval; @@ -67,14 +71,14 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr) break; default: ret = -ENOSYS; + goto out_pagefault_enable; } - if (ret == 0 && unlikely(put_user(tmp, uaddr) != 0)) + if (unlikely(put_user(tmp, uaddr) != 0)) ret = -EFAULT; out_pagefault_enable: - pagefault_enable(); - _futex_spin_unlock_irqrestore(uaddr, &flags); + _futex_spin_unlock_irqrestore(s, &flags); if (!ret) *oval = oldval; @@ -86,40 +90,38 @@ static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval, u32 newval) { + extern u32 lws_lock_start[]; + unsigned long ua = (unsigned long)uaddr; + arch_spinlock_t *s; u32 val; unsigned long flags; - /* futex.c wants to do a cmpxchg_inatomic on kernel NULL, which is - * our gateway page, and causes no end of trouble... - */ - if (uaccess_kernel() && !uaddr) - return -EFAULT; - if (!access_ok(uaddr, sizeof(u32))) return -EFAULT; /* HPPA has no cmpxchg in hardware and therefore the * best we can do here is use an array of locks. The - * lock selected is based on a hash of the userspace - * address. This should scale to a couple of CPUs. + * lock selected is based on a hash of the virtual + * address of the futex. This should scale to a couple + * of CPUs. */ - _futex_spin_lock_irqsave(uaddr, &flags); + s = (arch_spinlock_t *)&lws_lock_start[_futex_hash_index(ua)]; + _futex_spin_lock_irqsave(s, &flags); if (unlikely(get_user(val, uaddr) != 0)) { - _futex_spin_unlock_irqrestore(uaddr, &flags); + _futex_spin_unlock_irqrestore(s, &flags); return -EFAULT; } if (val == oldval && unlikely(put_user(newval, uaddr) != 0)) { - _futex_spin_unlock_irqrestore(uaddr, &flags); + _futex_spin_unlock_irqrestore(s, &flags); return -EFAULT; } *uval = val; - _futex_spin_unlock_irqrestore(uaddr, &flags); + _futex_spin_unlock_irqrestore(s, &flags); return 0; } -#endif /*__KERNEL__*/ #endif /*_ASM_PARISC_FUTEX_H*/ |