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5c40f7f3 DH |
1 | /* futex.c: futex operations |
2 | * | |
3 | * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells (dhowells@redhat.com) | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/futex.h> | |
e9c1528a | 13 | #include <linux/uaccess.h> |
5c40f7f3 DH |
14 | #include <asm/futex.h> |
15 | #include <asm/errno.h> | |
5c40f7f3 DH |
16 | |
17 | /* | |
18 | * the various futex operations; MMU fault checking is ignored under no-MMU | |
19 | * conditions | |
20 | */ | |
8d7718aa | 21 | static inline int atomic_futex_op_xchg_set(int oparg, u32 __user *uaddr, int *_oldval) |
5c40f7f3 DH |
22 | { |
23 | int oldval, ret; | |
24 | ||
25 | asm("0: \n" | |
26 | " orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */ | |
27 | " ckeq icc3,cc7 \n" | |
28 | "1: ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */ | |
29 | " orcr cc7,cc7,cc3 \n" /* set CC3 to true */ | |
30 | "2: cst.p %3,%M0 ,cc3,#1 \n" | |
31 | " corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */ | |
32 | " beq icc3,#0,0b \n" | |
33 | " setlos 0,%2 \n" | |
34 | "3: \n" | |
35 | ".subsection 2 \n" | |
36 | "4: setlos %5,%2 \n" | |
37 | " bra 3b \n" | |
38 | ".previous \n" | |
39 | ".section __ex_table,\"a\" \n" | |
40 | " .balign 8 \n" | |
41 | " .long 1b,4b \n" | |
42 | " .long 2b,4b \n" | |
43 | ".previous" | |
44 | : "+U"(*uaddr), "=&r"(oldval), "=&r"(ret), "=r"(oparg) | |
45 | : "3"(oparg), "i"(-EFAULT) | |
46 | : "memory", "cc7", "cc3", "icc3" | |
47 | ); | |
48 | ||
49 | *_oldval = oldval; | |
50 | return ret; | |
51 | } | |
52 | ||
8d7718aa | 53 | static inline int atomic_futex_op_xchg_add(int oparg, u32 __user *uaddr, int *_oldval) |
5c40f7f3 DH |
54 | { |
55 | int oldval, ret; | |
56 | ||
57 | asm("0: \n" | |
58 | " orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */ | |
59 | " ckeq icc3,cc7 \n" | |
60 | "1: ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */ | |
61 | " orcr cc7,cc7,cc3 \n" /* set CC3 to true */ | |
62 | " add %1,%3,%3 \n" | |
63 | "2: cst.p %3,%M0 ,cc3,#1 \n" | |
64 | " corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */ | |
65 | " beq icc3,#0,0b \n" | |
66 | " setlos 0,%2 \n" | |
67 | "3: \n" | |
68 | ".subsection 2 \n" | |
69 | "4: setlos %5,%2 \n" | |
70 | " bra 3b \n" | |
71 | ".previous \n" | |
72 | ".section __ex_table,\"a\" \n" | |
73 | " .balign 8 \n" | |
74 | " .long 1b,4b \n" | |
75 | " .long 2b,4b \n" | |
76 | ".previous" | |
77 | : "+U"(*uaddr), "=&r"(oldval), "=&r"(ret), "=r"(oparg) | |
78 | : "3"(oparg), "i"(-EFAULT) | |
79 | : "memory", "cc7", "cc3", "icc3" | |
80 | ); | |
81 | ||
82 | *_oldval = oldval; | |
83 | return ret; | |
84 | } | |
85 | ||
8d7718aa | 86 | static inline int atomic_futex_op_xchg_or(int oparg, u32 __user *uaddr, int *_oldval) |
5c40f7f3 DH |
87 | { |
88 | int oldval, ret; | |
89 | ||
90 | asm("0: \n" | |
91 | " orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */ | |
92 | " ckeq icc3,cc7 \n" | |
93 | "1: ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */ | |
94 | " orcr cc7,cc7,cc3 \n" /* set CC3 to true */ | |
95 | " or %1,%3,%3 \n" | |
96 | "2: cst.p %3,%M0 ,cc3,#1 \n" | |
97 | " corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */ | |
98 | " beq icc3,#0,0b \n" | |
99 | " setlos 0,%2 \n" | |
100 | "3: \n" | |
101 | ".subsection 2 \n" | |
102 | "4: setlos %5,%2 \n" | |
103 | " bra 3b \n" | |
104 | ".previous \n" | |
105 | ".section __ex_table,\"a\" \n" | |
106 | " .balign 8 \n" | |
107 | " .long 1b,4b \n" | |
108 | " .long 2b,4b \n" | |
109 | ".previous" | |
110 | : "+U"(*uaddr), "=&r"(oldval), "=&r"(ret), "=r"(oparg) | |
111 | : "3"(oparg), "i"(-EFAULT) | |
112 | : "memory", "cc7", "cc3", "icc3" | |
113 | ); | |
114 | ||
115 | *_oldval = oldval; | |
116 | return ret; | |
117 | } | |
118 | ||
8d7718aa | 119 | static inline int atomic_futex_op_xchg_and(int oparg, u32 __user *uaddr, int *_oldval) |
5c40f7f3 DH |
120 | { |
121 | int oldval, ret; | |
122 | ||
123 | asm("0: \n" | |
124 | " orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */ | |
125 | " ckeq icc3,cc7 \n" | |
126 | "1: ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */ | |
127 | " orcr cc7,cc7,cc3 \n" /* set CC3 to true */ | |
128 | " and %1,%3,%3 \n" | |
129 | "2: cst.p %3,%M0 ,cc3,#1 \n" | |
130 | " corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */ | |
131 | " beq icc3,#0,0b \n" | |
132 | " setlos 0,%2 \n" | |
133 | "3: \n" | |
134 | ".subsection 2 \n" | |
135 | "4: setlos %5,%2 \n" | |
136 | " bra 3b \n" | |
137 | ".previous \n" | |
138 | ".section __ex_table,\"a\" \n" | |
139 | " .balign 8 \n" | |
140 | " .long 1b,4b \n" | |
141 | " .long 2b,4b \n" | |
142 | ".previous" | |
143 | : "+U"(*uaddr), "=&r"(oldval), "=&r"(ret), "=r"(oparg) | |
144 | : "3"(oparg), "i"(-EFAULT) | |
145 | : "memory", "cc7", "cc3", "icc3" | |
146 | ); | |
147 | ||
148 | *_oldval = oldval; | |
149 | return ret; | |
150 | } | |
151 | ||
8d7718aa | 152 | static inline int atomic_futex_op_xchg_xor(int oparg, u32 __user *uaddr, int *_oldval) |
5c40f7f3 DH |
153 | { |
154 | int oldval, ret; | |
155 | ||
156 | asm("0: \n" | |
157 | " orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */ | |
158 | " ckeq icc3,cc7 \n" | |
159 | "1: ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */ | |
160 | " orcr cc7,cc7,cc3 \n" /* set CC3 to true */ | |
161 | " xor %1,%3,%3 \n" | |
162 | "2: cst.p %3,%M0 ,cc3,#1 \n" | |
163 | " corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */ | |
164 | " beq icc3,#0,0b \n" | |
165 | " setlos 0,%2 \n" | |
166 | "3: \n" | |
167 | ".subsection 2 \n" | |
168 | "4: setlos %5,%2 \n" | |
169 | " bra 3b \n" | |
170 | ".previous \n" | |
171 | ".section __ex_table,\"a\" \n" | |
172 | " .balign 8 \n" | |
173 | " .long 1b,4b \n" | |
174 | " .long 2b,4b \n" | |
175 | ".previous" | |
176 | : "+U"(*uaddr), "=&r"(oldval), "=&r"(ret), "=r"(oparg) | |
177 | : "3"(oparg), "i"(-EFAULT) | |
178 | : "memory", "cc7", "cc3", "icc3" | |
179 | ); | |
180 | ||
181 | *_oldval = oldval; | |
182 | return ret; | |
183 | } | |
184 | ||
185 | /*****************************************************************************/ | |
186 | /* | |
187 | * do the futex operations | |
188 | */ | |
8d7718aa | 189 | int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) |
5c40f7f3 DH |
190 | { |
191 | int op = (encoded_op >> 28) & 7; | |
192 | int cmp = (encoded_op >> 24) & 15; | |
193 | int oparg = (encoded_op << 8) >> 20; | |
194 | int cmparg = (encoded_op << 20) >> 20; | |
195 | int oldval = 0, ret; | |
196 | ||
197 | if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) | |
198 | oparg = 1 << oparg; | |
199 | ||
8d7718aa | 200 | if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) |
5c40f7f3 DH |
201 | return -EFAULT; |
202 | ||
a866374a | 203 | pagefault_disable(); |
5c40f7f3 DH |
204 | |
205 | switch (op) { | |
206 | case FUTEX_OP_SET: | |
207 | ret = atomic_futex_op_xchg_set(oparg, uaddr, &oldval); | |
208 | break; | |
209 | case FUTEX_OP_ADD: | |
210 | ret = atomic_futex_op_xchg_add(oparg, uaddr, &oldval); | |
211 | break; | |
212 | case FUTEX_OP_OR: | |
213 | ret = atomic_futex_op_xchg_or(oparg, uaddr, &oldval); | |
214 | break; | |
215 | case FUTEX_OP_ANDN: | |
216 | ret = atomic_futex_op_xchg_and(~oparg, uaddr, &oldval); | |
217 | break; | |
218 | case FUTEX_OP_XOR: | |
219 | ret = atomic_futex_op_xchg_xor(oparg, uaddr, &oldval); | |
220 | break; | |
221 | default: | |
222 | ret = -ENOSYS; | |
223 | break; | |
224 | } | |
225 | ||
a866374a | 226 | pagefault_enable(); |
5c40f7f3 DH |
227 | |
228 | if (!ret) { | |
229 | switch (cmp) { | |
230 | case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break; | |
231 | case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break; | |
232 | case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break; | |
233 | case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break; | |
234 | case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break; | |
235 | case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break; | |
236 | default: ret = -ENOSYS; break; | |
237 | } | |
238 | } | |
239 | ||
240 | return ret; | |
241 | ||
242 | } /* end futex_atomic_op_inuser() */ |