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Merge tag 'soc-for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
[deliverable/linux.git] / arch / s390 / lib / uaccess.c
1 /*
2 * Standard user space access functions based on mvcp/mvcs and doing
3 * interesting things in the secondary space mode.
4 *
5 * Copyright IBM Corp. 2006,2014
6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
7 * Gerald Schaefer (gerald.schaefer@de.ibm.com)
8 */
9
10 #include <linux/jump_label.h>
11 #include <linux/uaccess.h>
12 #include <linux/export.h>
13 #include <linux/errno.h>
14 #include <linux/mm.h>
15 #include <asm/mmu_context.h>
16 #include <asm/facility.h>
17
18 #ifndef CONFIG_64BIT
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 static struct static_key have_mvcos = STATIC_KEY_INIT_FALSE;
33
34 static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
35 unsigned long size)
36 {
37 register unsigned long reg0 asm("0") = 0x81UL;
38 unsigned long tmp1, tmp2;
39
40 tmp1 = -4096UL;
41 asm volatile(
42 "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
43 "9: jz 7f\n"
44 "1:"ALR" %0,%3\n"
45 " "SLR" %1,%3\n"
46 " "SLR" %2,%3\n"
47 " j 0b\n"
48 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
49 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
50 " "SLR" %4,%1\n"
51 " "CLR" %0,%4\n" /* copy crosses next page boundary? */
52 " jnh 4f\n"
53 "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
54 "10:"SLR" %0,%4\n"
55 " "ALR" %2,%4\n"
56 "4:"LHI" %4,-1\n"
57 " "ALR" %4,%0\n" /* copy remaining size, subtract 1 */
58 " bras %3,6f\n" /* memset loop */
59 " xc 0(1,%2),0(%2)\n"
60 "5: xc 0(256,%2),0(%2)\n"
61 " la %2,256(%2)\n"
62 "6:"AHI" %4,-256\n"
63 " jnm 5b\n"
64 " ex %4,0(%3)\n"
65 " j 8f\n"
66 "7:"SLR" %0,%0\n"
67 "8:\n"
68 EX_TABLE(0b,2b) EX_TABLE(3b,4b) EX_TABLE(9b,2b) EX_TABLE(10b,4b)
69 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
70 : "d" (reg0) : "cc", "memory");
71 return size;
72 }
73
74 static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
75 unsigned long size)
76 {
77 unsigned long tmp1, tmp2;
78
79 load_kernel_asce();
80 tmp1 = -256UL;
81 asm volatile(
82 " sacf 0\n"
83 "0: mvcp 0(%0,%2),0(%1),%3\n"
84 "10:jz 8f\n"
85 "1:"ALR" %0,%3\n"
86 " la %1,256(%1)\n"
87 " la %2,256(%2)\n"
88 "2: mvcp 0(%0,%2),0(%1),%3\n"
89 "11:jnz 1b\n"
90 " j 8f\n"
91 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
92 " "LHI" %3,-4096\n"
93 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
94 " "SLR" %4,%1\n"
95 " "CLR" %0,%4\n" /* copy crosses next page boundary? */
96 " jnh 5f\n"
97 "4: mvcp 0(%4,%2),0(%1),%3\n"
98 "12:"SLR" %0,%4\n"
99 " "ALR" %2,%4\n"
100 "5:"LHI" %4,-1\n"
101 " "ALR" %4,%0\n" /* copy remaining size, subtract 1 */
102 " bras %3,7f\n" /* memset loop */
103 " xc 0(1,%2),0(%2)\n"
104 "6: xc 0(256,%2),0(%2)\n"
105 " la %2,256(%2)\n"
106 "7:"AHI" %4,-256\n"
107 " jnm 6b\n"
108 " ex %4,0(%3)\n"
109 " j 9f\n"
110 "8:"SLR" %0,%0\n"
111 "9: sacf 768\n"
112 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b)
113 EX_TABLE(10b,3b) EX_TABLE(11b,3b) EX_TABLE(12b,5b)
114 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
115 : : "cc", "memory");
116 return size;
117 }
118
119 unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
120 {
121 if (static_key_false(&have_mvcos))
122 return copy_from_user_mvcos(to, from, n);
123 return copy_from_user_mvcp(to, from, n);
124 }
125 EXPORT_SYMBOL(__copy_from_user);
126
127 static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
128 unsigned long size)
129 {
130 register unsigned long reg0 asm("0") = 0x810000UL;
131 unsigned long tmp1, tmp2;
132
133 tmp1 = -4096UL;
134 asm volatile(
135 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
136 "6: jz 4f\n"
137 "1:"ALR" %0,%3\n"
138 " "SLR" %1,%3\n"
139 " "SLR" %2,%3\n"
140 " j 0b\n"
141 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
142 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
143 " "SLR" %4,%1\n"
144 " "CLR" %0,%4\n" /* copy crosses next page boundary? */
145 " jnh 5f\n"
146 "3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
147 "7:"SLR" %0,%4\n"
148 " j 5f\n"
149 "4:"SLR" %0,%0\n"
150 "5:\n"
151 EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
152 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
153 : "d" (reg0) : "cc", "memory");
154 return size;
155 }
156
157 static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
158 unsigned long size)
159 {
160 unsigned long tmp1, tmp2;
161
162 load_kernel_asce();
163 tmp1 = -256UL;
164 asm volatile(
165 " sacf 0\n"
166 "0: mvcs 0(%0,%1),0(%2),%3\n"
167 "7: jz 5f\n"
168 "1:"ALR" %0,%3\n"
169 " la %1,256(%1)\n"
170 " la %2,256(%2)\n"
171 "2: mvcs 0(%0,%1),0(%2),%3\n"
172 "8: jnz 1b\n"
173 " j 5f\n"
174 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
175 " "LHI" %3,-4096\n"
176 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
177 " "SLR" %4,%1\n"
178 " "CLR" %0,%4\n" /* copy crosses next page boundary? */
179 " jnh 6f\n"
180 "4: mvcs 0(%4,%1),0(%2),%3\n"
181 "9:"SLR" %0,%4\n"
182 " j 6f\n"
183 "5:"SLR" %0,%0\n"
184 "6: sacf 768\n"
185 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
186 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
187 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
188 : : "cc", "memory");
189 return size;
190 }
191
192 unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
193 {
194 if (static_key_false(&have_mvcos))
195 return copy_to_user_mvcos(to, from, n);
196 return copy_to_user_mvcs(to, from, n);
197 }
198 EXPORT_SYMBOL(__copy_to_user);
199
200 static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from,
201 unsigned long size)
202 {
203 register unsigned long reg0 asm("0") = 0x810081UL;
204 unsigned long tmp1, tmp2;
205
206 tmp1 = -4096UL;
207 /* FIXME: copy with reduced length. */
208 asm volatile(
209 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
210 " jz 2f\n"
211 "1:"ALR" %0,%3\n"
212 " "SLR" %1,%3\n"
213 " "SLR" %2,%3\n"
214 " j 0b\n"
215 "2:"SLR" %0,%0\n"
216 "3: \n"
217 EX_TABLE(0b,3b)
218 : "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
219 : "d" (reg0) : "cc", "memory");
220 return size;
221 }
222
223 static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from,
224 unsigned long size)
225 {
226 unsigned long tmp1;
227
228 load_kernel_asce();
229 asm volatile(
230 " sacf 256\n"
231 " "AHI" %0,-1\n"
232 " jo 5f\n"
233 " bras %3,3f\n"
234 "0:"AHI" %0,257\n"
235 "1: mvc 0(1,%1),0(%2)\n"
236 " la %1,1(%1)\n"
237 " la %2,1(%2)\n"
238 " "AHI" %0,-1\n"
239 " jnz 1b\n"
240 " j 5f\n"
241 "2: mvc 0(256,%1),0(%2)\n"
242 " la %1,256(%1)\n"
243 " la %2,256(%2)\n"
244 "3:"AHI" %0,-256\n"
245 " jnm 2b\n"
246 "4: ex %0,1b-0b(%3)\n"
247 "5: "SLR" %0,%0\n"
248 "6: sacf 768\n"
249 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
250 : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
251 : : "cc", "memory");
252 return size;
253 }
254
255 unsigned long __copy_in_user(void __user *to, const void __user *from, unsigned long n)
256 {
257 if (static_key_false(&have_mvcos))
258 return copy_in_user_mvcos(to, from, n);
259 return copy_in_user_mvc(to, from, n);
260 }
261 EXPORT_SYMBOL(__copy_in_user);
262
263 static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
264 {
265 register unsigned long reg0 asm("0") = 0x810000UL;
266 unsigned long tmp1, tmp2;
267
268 tmp1 = -4096UL;
269 asm volatile(
270 "0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
271 " jz 4f\n"
272 "1:"ALR" %0,%2\n"
273 " "SLR" %1,%2\n"
274 " j 0b\n"
275 "2: la %3,4095(%1)\n"/* %4 = to + 4095 */
276 " nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
277 " "SLR" %3,%1\n"
278 " "CLR" %0,%3\n" /* copy crosses next page boundary? */
279 " jnh 5f\n"
280 "3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
281 " "SLR" %0,%3\n"
282 " j 5f\n"
283 "4:"SLR" %0,%0\n"
284 "5:\n"
285 EX_TABLE(0b,2b) EX_TABLE(3b,5b)
286 : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
287 : "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
288 return size;
289 }
290
291 static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
292 {
293 unsigned long tmp1, tmp2;
294
295 load_kernel_asce();
296 asm volatile(
297 " sacf 256\n"
298 " "AHI" %0,-1\n"
299 " jo 5f\n"
300 " bras %3,3f\n"
301 " xc 0(1,%1),0(%1)\n"
302 "0:"AHI" %0,257\n"
303 " la %2,255(%1)\n" /* %2 = ptr + 255 */
304 " srl %2,12\n"
305 " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */
306 " "SLR" %2,%1\n"
307 " "CLR" %0,%2\n" /* clear crosses next page boundary? */
308 " jnh 5f\n"
309 " "AHI" %2,-1\n"
310 "1: ex %2,0(%3)\n"
311 " "AHI" %2,1\n"
312 " "SLR" %0,%2\n"
313 " j 5f\n"
314 "2: xc 0(256,%1),0(%1)\n"
315 " la %1,256(%1)\n"
316 "3:"AHI" %0,-256\n"
317 " jnm 2b\n"
318 "4: ex %0,0(%3)\n"
319 "5: "SLR" %0,%0\n"
320 "6: sacf 768\n"
321 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
322 : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
323 : : "cc", "memory");
324 return size;
325 }
326
327 unsigned long __clear_user(void __user *to, unsigned long size)
328 {
329 if (static_key_false(&have_mvcos))
330 return clear_user_mvcos(to, size);
331 return clear_user_xc(to, size);
332 }
333 EXPORT_SYMBOL(__clear_user);
334
335 static inline unsigned long strnlen_user_srst(const char __user *src,
336 unsigned long size)
337 {
338 register unsigned long reg0 asm("0") = 0;
339 unsigned long tmp1, tmp2;
340
341 asm volatile(
342 " la %2,0(%1)\n"
343 " la %3,0(%0,%1)\n"
344 " "SLR" %0,%0\n"
345 " sacf 256\n"
346 "0: srst %3,%2\n"
347 " jo 0b\n"
348 " la %0,1(%3)\n" /* strnlen_user results includes \0 */
349 " "SLR" %0,%1\n"
350 "1: sacf 768\n"
351 EX_TABLE(0b,1b)
352 : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
353 : "d" (reg0) : "cc", "memory");
354 return size;
355 }
356
357 unsigned long __strnlen_user(const char __user *src, unsigned long size)
358 {
359 if (unlikely(!size))
360 return 0;
361 load_kernel_asce();
362 return strnlen_user_srst(src, size);
363 }
364 EXPORT_SYMBOL(__strnlen_user);
365
366 long __strncpy_from_user(char *dst, const char __user *src, long size)
367 {
368 size_t done, len, offset, len_str;
369
370 if (unlikely(size <= 0))
371 return 0;
372 done = 0;
373 do {
374 offset = (size_t)src & ~PAGE_MASK;
375 len = min(size - done, PAGE_SIZE - offset);
376 if (copy_from_user(dst, src, len))
377 return -EFAULT;
378 len_str = strnlen(dst, len);
379 done += len_str;
380 src += len_str;
381 dst += len_str;
382 } while ((len_str == len) && (done < size));
383 return done;
384 }
385 EXPORT_SYMBOL(__strncpy_from_user);
386
387 /*
388 * The "old" uaccess variant without mvcos can be enforced with the
389 * uaccess_primary kernel parameter. This is mainly for debugging purposes.
390 */
391 static int uaccess_primary __initdata;
392
393 static int __init parse_uaccess_pt(char *__unused)
394 {
395 uaccess_primary = 1;
396 return 0;
397 }
398 early_param("uaccess_primary", parse_uaccess_pt);
399
400 static int __init uaccess_init(void)
401 {
402 if (IS_ENABLED(CONFIG_64BIT) && !uaccess_primary && test_facility(27))
403 static_key_slow_inc(&have_mvcos);
404 return 0;
405 }
406 early_initcall(uaccess_init);
Linux kernel - Deliverables
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