LXR linux/include/asm-generic/futex.h

   1#ifndef _ASM_GENERIC_FUTEX_H
   2#define _ASM_GENERIC_FUTEX_H
   3
   4#ifdef __KERNEL__
   5
   6#include <linux/futex.h>
   7#include <asm/errno.h>
   8#include <asm/uaccess.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
  52static inline int
  53futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
  54{
  55        return -ENOSYS;
  56}
  57
  58#endif
  59#endif
  60