LXR linux/arch/parisc/include/asm/futex.h

   1#ifndef _ASM_PARISC_FUTEX_H
   2#define _ASM_PARISC_FUTEX_H
   3
   4#ifdef __KERNEL__
   5
   6#include <linux/futex.h>
   7#include <linux/uaccess.h>
   8#include <asm/errno.h>
   9
  10static inline int
  11futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
  12{
  13        int op = (encoded_op >> 28) & 7;
  14        int cmp = (encoded_op >> 24) & 15;
  15        int oparg = (encoded_op << 8) >> 20;
  16        int cmparg = (encoded_op << 20) >> 20;
  17        int oldval = 0, ret;
  18        if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  19                oparg = 1 << oparg;
  20
  21        if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
  22                return -EFAULT;
  23
  24        pagefault_disable();
  25
  26        switch (op) {
  27        case FUTEX_OP_SET:
  28        case FUTEX_OP_ADD:
  29        case FUTEX_OP_OR:
  30        case FUTEX_OP_ANDN:
  31        case FUTEX_OP_XOR:
  32        default:
  33                ret = -ENOSYS;
  34        }
  35
  36        pagefault_enable();
  37
  38        if (!ret) {
  39                switch (cmp) {
  40                case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
  41                case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
  42                case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
  43                case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
  44                case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
  45                case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
  46                default: ret = -ENOSYS;
  47                }
  48        }
  49        return ret;
  50}
  51
  52/* Non-atomic version */
  53static inline int
  54futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
  55{
  56        int err = 0;
  57        int uval;
  58
  59        /* futex.c wants to do a cmpxchg_inatomic on kernel NULL, which is
  60         * our gateway page, and causes no end of trouble...
  61         */
  62        if (segment_eq(KERNEL_DS, get_fs()) && !uaddr)
  63                return -EFAULT;
  64
  65        if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
  66                return -EFAULT;
  67
  68        err = get_user(uval, uaddr);
  69        if (err) return -EFAULT;
  70        if (uval == oldval)
  71                err = put_user(newval, uaddr);
  72        if (err) return -EFAULT;
  73        return uval;
  74}
  75
  76#endif /*__KERNEL__*/
  77#endif /*_ASM_PARISC_FUTEX_H*/
  78