futex: Sanitize futex ops argument types
[linux-3.10.git] / arch / alpha / include / asm / futex.h
1 #ifndef _ASM_ALPHA_FUTEX_H
2 #define _ASM_ALPHA_FUTEX_H
3
4 #ifdef __KERNEL__
5
6 #include <linux/futex.h>
7 #include <linux/uaccess.h>
8 #include <asm/errno.h>
9 #include <asm/barrier.h>
10
11 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)      \
12         __asm__ __volatile__(                                   \
13                 __ASM_SMP_MB                                    \
14         "1:     ldl_l   %0,0(%2)\n"                             \
15                 insn                                            \
16         "2:     stl_c   %1,0(%2)\n"                             \
17         "       beq     %1,4f\n"                                \
18         "       mov     $31,%1\n"                               \
19         "3:     .subsection 2\n"                                \
20         "4:     br      1b\n"                                   \
21         "       .previous\n"                                    \
22         "       .section __ex_table,\"a\"\n"                    \
23         "       .long   1b-.\n"                                 \
24         "       lda     $31,3b-1b(%1)\n"                        \
25         "       .long   2b-.\n"                                 \
26         "       lda     $31,3b-2b(%1)\n"                        \
27         "       .previous\n"                                    \
28         :       "=&r" (oldval), "=&r"(ret)                      \
29         :       "r" (uaddr), "r"(oparg)                         \
30         :       "memory")
31
32 static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
33 {
34         int op = (encoded_op >> 28) & 7;
35         int cmp = (encoded_op >> 24) & 15;
36         int oparg = (encoded_op << 8) >> 20;
37         int cmparg = (encoded_op << 20) >> 20;
38         int oldval = 0, ret;
39         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
40                 oparg = 1 << oparg;
41
42         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
43                 return -EFAULT;
44
45         pagefault_disable();
46
47         switch (op) {
48         case FUTEX_OP_SET:
49                 __futex_atomic_op("mov %3,%1\n", ret, oldval, uaddr, oparg);
50                 break;
51         case FUTEX_OP_ADD:
52                 __futex_atomic_op("addl %0,%3,%1\n", ret, oldval, uaddr, oparg);
53                 break;
54         case FUTEX_OP_OR:
55                 __futex_atomic_op("or %0,%3,%1\n", ret, oldval, uaddr, oparg);
56                 break;
57         case FUTEX_OP_ANDN:
58                 __futex_atomic_op("andnot %0,%3,%1\n", ret, oldval, uaddr, oparg);
59                 break;
60         case FUTEX_OP_XOR:
61                 __futex_atomic_op("xor %0,%3,%1\n", ret, oldval, uaddr, oparg);
62                 break;
63         default:
64                 ret = -ENOSYS;
65         }
66
67         pagefault_enable();
68
69         if (!ret) {
70                 switch (cmp) {
71                 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
72                 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
73                 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
74                 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
75                 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
76                 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
77                 default: ret = -ENOSYS;
78                 }
79         }
80         return ret;
81 }
82
83 static inline int
84 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
85                               u32 oldval, u32 newval)
86 {
87         int ret = 0, cmp;
88         u32 prev;
89
90         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
91                 return -EFAULT;
92
93         __asm__ __volatile__ (
94                 __ASM_SMP_MB
95         "1:     ldl_l   %1,0(%3)\n"
96         "       cmpeq   %1,%4,%2\n"
97         "       beq     %2,3f\n"
98         "       mov     %5,%2\n"
99         "2:     stl_c   %2,0(%3)\n"
100         "       beq     %2,4f\n"
101         "3:     .subsection 2\n"
102         "4:     br      1b\n"
103         "       .previous\n"
104         "       .section __ex_table,\"a\"\n"
105         "       .long   1b-.\n"
106         "       lda     $31,3b-1b(%0)\n"
107         "       .long   2b-.\n"
108         "       lda     $31,3b-2b(%0)\n"
109         "       .previous\n"
110         :       "+r"(ret), "=&r"(prev), "=&r"(cmp)
111         :       "r"(uaddr), "r"((long)oldval), "r"(newval)
112         :       "memory");
113
114         *uval = prev;
115         return ret;
116 }
117
118 #endif /* __KERNEL__ */
119 #endif /* _ASM_ALPHA_FUTEX_H */