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

   1#ifndef _ASM_GENERIC_FUTEX_H
   2#define _ASM_GENERIC_FUTEX_H
   3
   4#include <linux/futex.h>
   5#include <linux/uaccess.h>
   6#include <asm/errno.h>
   7
   8static inline int
   9futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
  10{
  11        int op = (encoded_op >> 28) & 7;
  12        int cmp = (encoded_op >> 24) & 15;
  13        int oparg = (encoded_op << 8) >> 20;
  14        int cmparg = (encoded_op << 20) >> 20;
  15        int oldval = 0, ret;
  16        if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  17                oparg = 1 << oparg;
  18
  19        if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
  20                return -EFAULT;
  21
  22        pagefault_disable();
  23
  24        switch (op) {
  25        case FUTEX_OP_SET:
  26        case FUTEX_OP_ADD:
  27        case FUTEX_OP_OR:
  28        case FUTEX_OP_ANDN:
  29        case FUTEX_OP_XOR:
  30        default:
  31                ret = -ENOSYS;
  32        }
  33
  34        pagefault_enable();
  35
  36        if (!ret) {
  37                switch (cmp) {
  38                case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
  39                case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
  40                case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
  41                case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
  42                case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
  43                case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
  44                default: ret = -ENOSYS;
  45                }
  46        }
  47        return ret;
  48}
  49
  50static inline int
  51futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  52                              u32 oldval, u32 newval)
  53{
  54        return -ENOSYS;
  55}
  56
  57#endif
  58