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
   8 static inline int
   9 futex_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
  50 static inline int
  51 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  52                               u32 oldval, u32 newval)
  53 {
  54         return -ENOSYS;
  55 }
  56
  57 #endif