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[GitHub/LineageOS/G12/android_kernel_amlogic_linux-4.9.git] /
1 #ifndef _ASM_FUTEX_H
2 #define _ASM_FUTEX_H
3
4 #ifdef __KERNEL__
5
6 #include <linux/futex.h>
7 #include <asm/errno.h>
8 #include <asm/uaccess.h>
9
10 static inline int
11 futex_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 inc_preempt_count();
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 dec_preempt_count();
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 #endif
53 #endif