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Avoid beyond bounds copy while caching ACL
[zen-stable.git] / arch / s390 / lib / uaccess_std.c
blobbb1a7eed42ce4cbef8350dca7a8eb85269fb1966
1 /*
2 * arch/s390/lib/uaccess_std.c
3 *
4 * Standard user space access functions based on mvcp/mvcs and doing
5 * interesting things in the secondary space mode.
6 *
7 * Copyright (C) IBM Corp. 2006
8 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
9 * Gerald Schaefer (gerald.schaefer@de.ibm.com)
10 */
11
12 #include <linux/errno.h>
13 #include <linux/mm.h>
14 #include <linux/uaccess.h>
15 #include <asm/futex.h>
16 #include "uaccess.h"
17
18 #ifndef __s390x__
19 #define AHI "ahi"
20 #define ALR "alr"
21 #define CLR "clr"
22 #define LHI "lhi"
23 #define SLR "slr"
24 #else
25 #define AHI "aghi"
26 #define ALR "algr"
27 #define CLR "clgr"
28 #define LHI "lghi"
29 #define SLR "slgr"
30 #endif
31
32 size_t copy_from_user_std(size_t size, const void __user *ptr, void *x)
33 {
34 unsigned long tmp1, tmp2;
35
36 tmp1 = -256UL;
37 asm volatile(
38 "0: mvcp 0(%0,%2),0(%1),%3\n"
39 "10:jz 8f\n"
40 "1:"ALR" %0,%3\n"
41 " la %1,256(%1)\n"
42 " la %2,256(%2)\n"
43 "2: mvcp 0(%0,%2),0(%1),%3\n"
44 "11:jnz 1b\n"
45 " j 8f\n"
46 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
47 " "LHI" %3,-4096\n"
48 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
49 " "SLR" %4,%1\n"
50 " "CLR" %0,%4\n" /* copy crosses next page boundary? */
51 " jnh 5f\n"
52 "4: mvcp 0(%4,%2),0(%1),%3\n"
53 "12:"SLR" %0,%4\n"
54 " "ALR" %2,%4\n"
55 "5:"LHI" %4,-1\n"
56 " "ALR" %4,%0\n" /* copy remaining size, subtract 1 */
57 " bras %3,7f\n" /* memset loop */
58 " xc 0(1,%2),0(%2)\n"
59 "6: xc 0(256,%2),0(%2)\n"
60 " la %2,256(%2)\n"
61 "7:"AHI" %4,-256\n"
62 " jnm 6b\n"
63 " ex %4,0(%3)\n"
64 " j 9f\n"
65 "8:"SLR" %0,%0\n"
66 "9: \n"
67 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b)
68 EX_TABLE(10b,3b) EX_TABLE(11b,3b) EX_TABLE(12b,5b)
69 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
70 : : "cc", "memory");
71 return size;
72 }
73
74 static size_t copy_from_user_std_check(size_t size, const void __user *ptr,
75 void *x)
76 {
77 if (size <= 1024)
78 return copy_from_user_std(size, ptr, x);
79 return copy_from_user_pt(size, ptr, x);
80 }
81
82 size_t copy_to_user_std(size_t size, void __user *ptr, const void *x)
83 {
84 unsigned long tmp1, tmp2;
85
86 tmp1 = -256UL;
87 asm volatile(
88 "0: mvcs 0(%0,%1),0(%2),%3\n"
89 "7: jz 5f\n"
90 "1:"ALR" %0,%3\n"
91 " la %1,256(%1)\n"
92 " la %2,256(%2)\n"
93 "2: mvcs 0(%0,%1),0(%2),%3\n"
94 "8: jnz 1b\n"
95 " j 5f\n"
96 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
97 " "LHI" %3,-4096\n"
98 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
99 " "SLR" %4,%1\n"
100 " "CLR" %0,%4\n" /* copy crosses next page boundary? */
101 " jnh 6f\n"
102 "4: mvcs 0(%4,%1),0(%2),%3\n"
103 "9:"SLR" %0,%4\n"
104 " j 6f\n"
105 "5:"SLR" %0,%0\n"
106 "6: \n"
107 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
108 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
109 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
110 : : "cc", "memory");
111 return size;
112 }
113
114 static size_t copy_to_user_std_check(size_t size, void __user *ptr,
115 const void *x)
116 {
117 if (size <= 1024)
118 return copy_to_user_std(size, ptr, x);
119 return copy_to_user_pt(size, ptr, x);
120 }
121
122 static size_t copy_in_user_std(size_t size, void __user *to,
123 const void __user *from)
124 {
125 unsigned long tmp1;
126
127 asm volatile(
128 " sacf 256\n"
129 " "AHI" %0,-1\n"
130 " jo 5f\n"
131 " bras %3,3f\n"
132 "0:"AHI" %0,257\n"
133 "1: mvc 0(1,%1),0(%2)\n"
134 " la %1,1(%1)\n"
135 " la %2,1(%2)\n"
136 " "AHI" %0,-1\n"
137 " jnz 1b\n"
138 " j 5f\n"
139 "2: mvc 0(256,%1),0(%2)\n"
140 " la %1,256(%1)\n"
141 " la %2,256(%2)\n"
142 "3:"AHI" %0,-256\n"
143 " jnm 2b\n"
144 "4: ex %0,1b-0b(%3)\n"
145 "5: "SLR" %0,%0\n"
146 "6: sacf 0\n"
147 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
148 : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
149 : : "cc", "memory");
150 return size;
151 }
152
153 static size_t clear_user_std(size_t size, void __user *to)
154 {
155 unsigned long tmp1, tmp2;
156
157 asm volatile(
158 " sacf 256\n"
159 " "AHI" %0,-1\n"
160 " jo 5f\n"
161 " bras %3,3f\n"
162 " xc 0(1,%1),0(%1)\n"
163 "0:"AHI" %0,257\n"
164 " la %2,255(%1)\n" /* %2 = ptr + 255 */
165 " srl %2,12\n"
166 " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */
167 " "SLR" %2,%1\n"
168 " "CLR" %0,%2\n" /* clear crosses next page boundary? */
169 " jnh 5f\n"
170 " "AHI" %2,-1\n"
171 "1: ex %2,0(%3)\n"
172 " "AHI" %2,1\n"
173 " "SLR" %0,%2\n"
174 " j 5f\n"
175 "2: xc 0(256,%1),0(%1)\n"
176 " la %1,256(%1)\n"
177 "3:"AHI" %0,-256\n"
178 " jnm 2b\n"
179 "4: ex %0,0(%3)\n"
180 "5: "SLR" %0,%0\n"
181 "6: sacf 0\n"
182 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
183 : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
184 : : "cc", "memory");
185 return size;
186 }
187
188 size_t strnlen_user_std(size_t size, const char __user *src)
189 {
190 register unsigned long reg0 asm("0") = 0UL;
191 unsigned long tmp1, tmp2;
192
193 asm volatile(
194 " la %2,0(%1)\n"
195 " la %3,0(%0,%1)\n"
196 " "SLR" %0,%0\n"
197 " sacf 256\n"
198 "0: srst %3,%2\n"
199 " jo 0b\n"
200 " la %0,1(%3)\n" /* strnlen_user results includes \0 */
201 " "SLR" %0,%1\n"
202 "1: sacf 0\n"
203 EX_TABLE(0b,1b)
204 : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
205 : "d" (reg0) : "cc", "memory");
206 return size;
207 }
208
209 size_t strncpy_from_user_std(size_t size, const char __user *src, char *dst)
210 {
211 register unsigned long reg0 asm("0") = 0UL;
212 unsigned long tmp1, tmp2;
213
214 asm volatile(
215 " la %3,0(%1)\n"
216 " la %4,0(%0,%1)\n"
217 " sacf 256\n"
218 "0: srst %4,%3\n"
219 " jo 0b\n"
220 " sacf 0\n"
221 " la %0,0(%4)\n"
222 " jh 1f\n" /* found \0 in string ? */
223 " "AHI" %4,1\n" /* include \0 in copy */
224 "1:"SLR" %0,%1\n" /* %0 = return length (without \0) */
225 " "SLR" %4,%1\n" /* %4 = copy length (including \0) */
226 "2: mvcp 0(%4,%2),0(%1),%5\n"
227 " jz 9f\n"
228 "3:"AHI" %4,-256\n"
229 " la %1,256(%1)\n"
230 " la %2,256(%2)\n"
231 "4: mvcp 0(%4,%2),0(%1),%5\n"
232 " jnz 3b\n"
233 " j 9f\n"
234 "7: sacf 0\n"
235 "8:"LHI" %0,%6\n"
236 "9:\n"
237 EX_TABLE(0b,7b) EX_TABLE(2b,8b) EX_TABLE(4b,8b)
238 : "+a" (size), "+a" (src), "+d" (dst), "=a" (tmp1), "=a" (tmp2)
239 : "d" (reg0), "K" (-EFAULT) : "cc", "memory");
240 return size;
241 }
242
243 #define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg) \
244 asm volatile( \
245 " sacf 256\n" \
246 "0: l %1,0(%6)\n" \
247 "1:"insn \
248 "2: cs %1,%2,0(%6)\n" \
249 "3: jl 1b\n" \
250 " lhi %0,0\n" \
251 "4: sacf 0\n" \
252 EX_TABLE(0b,4b) EX_TABLE(2b,4b) EX_TABLE(3b,4b) \
253 : "=d" (ret), "=&d" (oldval), "=&d" (newval), \
254 "=m" (*uaddr) \
255 : "0" (-EFAULT), "d" (oparg), "a" (uaddr), \
256 "m" (*uaddr) : "cc");
257
258 int futex_atomic_op_std(int op, u32 __user *uaddr, int oparg, int *old)
259 {
260 int oldval = 0, newval, ret;
261
262 switch (op) {
263 case FUTEX_OP_SET:
264 __futex_atomic_op("lr %2,%5\n",
265 ret, oldval, newval, uaddr, oparg);
266 break;
267 case FUTEX_OP_ADD:
268 __futex_atomic_op("lr %2,%1\nar %2,%5\n",
269 ret, oldval, newval, uaddr, oparg);
270 break;
271 case FUTEX_OP_OR:
272 __futex_atomic_op("lr %2,%1\nor %2,%5\n",
273 ret, oldval, newval, uaddr, oparg);
274 break;
275 case FUTEX_OP_ANDN:
276 __futex_atomic_op("lr %2,%1\nnr %2,%5\n",
277 ret, oldval, newval, uaddr, oparg);
278 break;
279 case FUTEX_OP_XOR:
280 __futex_atomic_op("lr %2,%1\nxr %2,%5\n",
281 ret, oldval, newval, uaddr, oparg);
282 break;
283 default:
284 ret = -ENOSYS;
285 }
286 *old = oldval;
287 return ret;
288 }
289
290 int futex_atomic_cmpxchg_std(u32 *uval, u32 __user *uaddr,
291 u32 oldval, u32 newval)
292 {
293 int ret;
294
295 asm volatile(
296 " sacf 256\n"
297 "0: cs %1,%4,0(%5)\n"
298 "1: la %0,0\n"
299 "2: sacf 0\n"
300 EX_TABLE(0b,2b) EX_TABLE(1b,2b)
301 : "=d" (ret), "+d" (oldval), "=m" (*uaddr)
302 : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
303 : "cc", "memory" );
304 *uval = oldval;
305 return ret;
306 }
307
308 struct uaccess_ops uaccess_std = {
309 .copy_from_user = copy_from_user_std_check,
310 .copy_from_user_small = copy_from_user_std,
311 .copy_to_user = copy_to_user_std_check,
312 .copy_to_user_small = copy_to_user_std,
313 .copy_in_user = copy_in_user_std,
314 .clear_user = clear_user_std,
315 .strnlen_user = strnlen_user_std,
316 .strncpy_from_user = strncpy_from_user_std,
317 .futex_atomic_op = futex_atomic_op_std,
318 .futex_atomic_cmpxchg = futex_atomic_cmpxchg_std,
319 };