1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
|
#ifndef _ASM_FUTEX_H
#define _ASM_FUTEX_H
#ifdef __KERNEL__
#include <linux/futex.h>
#include <asm/errno.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
__asm__ __volatile ( \
"1: " insn "\n" \
"2: .section .fixup,\"ax\"\n\
3: mov %3, %1\n\
jmp 2b\n\
.previous\n\
.section __ex_table,\"a\"\n\
.align 8\n\
.long 1b,3b\n\
.previous" \
: "=r" (oldval), "=r" (ret), "=m" (*uaddr) \
: "i" (-EFAULT), "m" (*uaddr), "0" (oparg), "1" (0))
#define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \
__asm__ __volatile ( \
"1: movl %2, %0\n\
movl %0, %3\n" \
insn "\n" \
"2: " LOCK_PREFIX "cmpxchgl %3, %2\n\
jnz 1b\n\
3: .section .fixup,\"ax\"\n\
4: mov %5, %1\n\
jmp 3b\n\
.previous\n\
.section __ex_table,\"a\"\n\
.align 8\n\
.long 1b,4b,2b,4b\n\
.previous" \
: "=&a" (oldval), "=&r" (ret), "=m" (*uaddr), \
"=&r" (tem) \
: "r" (oparg), "i" (-EFAULT), "m" (*uaddr), "1" (0))
static inline int
futex_atomic_op_inuser (int encoded_op, int __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, tem;
if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
oparg = 1 << oparg;
if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
inc_preempt_count();
if (op == FUTEX_OP_SET)
__futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg);
else {
#ifndef CONFIG_X86_BSWAP
if (boot_cpu_data.x86 == 3)
ret = -ENOSYS;
else
#endif
switch (op) {
case FUTEX_OP_ADD:
__futex_atomic_op1(LOCK_PREFIX "xaddl %0, %2", ret,
oldval, uaddr, oparg);
break;
case FUTEX_OP_OR:
__futex_atomic_op2("orl %4, %3", ret, oldval, uaddr,
oparg);
break;
case FUTEX_OP_ANDN:
__futex_atomic_op2("andl %4, %3", ret, oldval, uaddr,
~oparg);
break;
case FUTEX_OP_XOR:
__futex_atomic_op2("xorl %4, %3", ret, oldval, uaddr,
oparg);
break;
default:
ret = -ENOSYS;
}
}
dec_preempt_count();
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_inuser(int __user *uaddr, int oldval, int newval)
{
return -ENOSYS;
}
#endif
#endif
|
