futex.h

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#ifndef _ASM_GENERIC_FUTEX_H
#define _ASM_GENERIC_FUTEX_H

#include <linux/futex.h>
#include <linux/uaccess.h>
#include <asm/errno.h>

static inline int
futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
{
    int op = (encoded_op >> 28) & 7;
    int cmp = (encoded_op >> 24) & 15;
    int oparg = (encoded_op << 8) >> 20;
    int cmparg = (encoded_op << 20) >> 20;
    int oldval = 0, ret;
    if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
        oparg = 1 << oparg;

    if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
        return -EFAULT;

    pagefault_disable();

    switch (op) {
    case FUTEX_OP_SET:
    case FUTEX_OP_ADD:
    case FUTEX_OP_OR:
    case FUTEX_OP_ANDN:
    case FUTEX_OP_XOR:
    default:
        ret = -ENOSYS;
    }

    pagefault_enable();

    if (!ret) {
        switch (cmp) {
        case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
        case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
        case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
        case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
        case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
        case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
        default: ret = -ENOSYS;
        }
    }
    return ret;
}

static inline int
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
                  u32 oldval, u32 newval)
{
    return -ENOSYS;
}

#endif