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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Standard user space access functions based on mvcp/mvcs and doing
4 * interesting things in the secondary space mode.
5 *
6 * Copyright IBM Corp. 2006,2014
7 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
8 * Gerald Schaefer (gerald.schaefer@de.ibm.com)
9 */
10
11#include <linux/jump_label.h>
12#include <linux/uaccess.h>
13#include <linux/export.h>
14#include <linux/errno.h>
15#include <linux/mm.h>
16#include <asm/mmu_context.h>
17#include <asm/facility.h>
18
19#ifndef CONFIG_HAVE_MARCH_Z10_FEATURES
20static DEFINE_STATIC_KEY_FALSE(have_mvcos);
21
22static int __init uaccess_init(void)
23{
24 if (test_facility(27))
25 static_branch_enable(&have_mvcos);
26 return 0;
27}
28early_initcall(uaccess_init);
29
30static inline int copy_with_mvcos(void)
31{
32 if (static_branch_likely(&have_mvcos))
33 return 1;
34 return 0;
35}
36#else
37static inline int copy_with_mvcos(void)
38{
39 return 1;
40}
41#endif
42
43void set_fs(mm_segment_t fs)
44{
45 current->thread.mm_segment = fs;
46 if (fs == USER_DS) {
47 __ctl_load(S390_lowcore.user_asce, 1, 1);
48 clear_cpu_flag(CIF_ASCE_PRIMARY);
49 } else {
50 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
51 set_cpu_flag(CIF_ASCE_PRIMARY);
52 }
53 if (fs & 1) {
54 if (fs == USER_DS_SACF)
55 __ctl_load(S390_lowcore.user_asce, 7, 7);
56 else
57 __ctl_load(S390_lowcore.kernel_asce, 7, 7);
58 set_cpu_flag(CIF_ASCE_SECONDARY);
59 }
60}
61EXPORT_SYMBOL(set_fs);
62
63mm_segment_t enable_sacf_uaccess(void)
64{
65 mm_segment_t old_fs;
66 unsigned long asce, cr;
67
68 old_fs = current->thread.mm_segment;
69 if (old_fs & 1)
70 return old_fs;
71 current->thread.mm_segment |= 1;
72 asce = S390_lowcore.kernel_asce;
73 if (likely(old_fs == USER_DS)) {
74 __ctl_store(cr, 1, 1);
75 if (cr != S390_lowcore.kernel_asce) {
76 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
77 set_cpu_flag(CIF_ASCE_PRIMARY);
78 }
79 asce = S390_lowcore.user_asce;
80 }
81 __ctl_store(cr, 7, 7);
82 if (cr != asce) {
83 __ctl_load(asce, 7, 7);
84 set_cpu_flag(CIF_ASCE_SECONDARY);
85 }
86 return old_fs;
87}
88EXPORT_SYMBOL(enable_sacf_uaccess);
89
90void disable_sacf_uaccess(mm_segment_t old_fs)
91{
92 current->thread.mm_segment = old_fs;
93 if (old_fs == USER_DS && test_facility(27)) {
94 __ctl_load(S390_lowcore.user_asce, 1, 1);
95 clear_cpu_flag(CIF_ASCE_PRIMARY);
96 }
97}
98EXPORT_SYMBOL(disable_sacf_uaccess);
99
100static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
101 unsigned long size)
102{
103 register unsigned long reg0 asm("0") = 0x01UL;
104 unsigned long tmp1, tmp2;
105
106 tmp1 = -4096UL;
107 asm volatile(
108 "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
109 "6: jz 4f\n"
110 "1: algr %0,%3\n"
111 " slgr %1,%3\n"
112 " slgr %2,%3\n"
113 " j 0b\n"
114 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
115 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
116 " slgr %4,%1\n"
117 " clgr %0,%4\n" /* copy crosses next page boundary? */
118 " jnh 5f\n"
119 "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
120 "7: slgr %0,%4\n"
121 " j 5f\n"
122 "4: slgr %0,%0\n"
123 "5:\n"
124 EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
125 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
126 : "d" (reg0) : "cc", "memory");
127 return size;
128}
129
130static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
131 unsigned long size)
132{
133 unsigned long tmp1, tmp2;
134 mm_segment_t old_fs;
135
136 old_fs = enable_sacf_uaccess();
137 tmp1 = -256UL;
138 asm volatile(
139 " sacf 0\n"
140 "0: mvcp 0(%0,%2),0(%1),%3\n"
141 "7: jz 5f\n"
142 "1: algr %0,%3\n"
143 " la %1,256(%1)\n"
144 " la %2,256(%2)\n"
145 "2: mvcp 0(%0,%2),0(%1),%3\n"
146 "8: jnz 1b\n"
147 " j 5f\n"
148 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
149 " lghi %3,-4096\n"
150 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
151 " slgr %4,%1\n"
152 " clgr %0,%4\n" /* copy crosses next page boundary? */
153 " jnh 6f\n"
154 "4: mvcp 0(%4,%2),0(%1),%3\n"
155 "9: slgr %0,%4\n"
156 " j 6f\n"
157 "5: slgr %0,%0\n"
158 "6: sacf 768\n"
159 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
160 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
161 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
162 : : "cc", "memory");
163 disable_sacf_uaccess(old_fs);
164 return size;
165}
166
167unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
168{
169 if (copy_with_mvcos())
170 return copy_from_user_mvcos(to, from, n);
171 return copy_from_user_mvcp(to, from, n);
172}
173EXPORT_SYMBOL(raw_copy_from_user);
174
175static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
176 unsigned long size)
177{
178 register unsigned long reg0 asm("0") = 0x010000UL;
179 unsigned long tmp1, tmp2;
180
181 tmp1 = -4096UL;
182 asm volatile(
183 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
184 "6: jz 4f\n"
185 "1: algr %0,%3\n"
186 " slgr %1,%3\n"
187 " slgr %2,%3\n"
188 " j 0b\n"
189 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
190 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
191 " slgr %4,%1\n"
192 " clgr %0,%4\n" /* copy crosses next page boundary? */
193 " jnh 5f\n"
194 "3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
195 "7: slgr %0,%4\n"
196 " j 5f\n"
197 "4: slgr %0,%0\n"
198 "5:\n"
199 EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
200 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
201 : "d" (reg0) : "cc", "memory");
202 return size;
203}
204
205static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
206 unsigned long size)
207{
208 unsigned long tmp1, tmp2;
209 mm_segment_t old_fs;
210
211 old_fs = enable_sacf_uaccess();
212 tmp1 = -256UL;
213 asm volatile(
214 " sacf 0\n"
215 "0: mvcs 0(%0,%1),0(%2),%3\n"
216 "7: jz 5f\n"
217 "1: algr %0,%3\n"
218 " la %1,256(%1)\n"
219 " la %2,256(%2)\n"
220 "2: mvcs 0(%0,%1),0(%2),%3\n"
221 "8: jnz 1b\n"
222 " j 5f\n"
223 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
224 " lghi %3,-4096\n"
225 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
226 " slgr %4,%1\n"
227 " clgr %0,%4\n" /* copy crosses next page boundary? */
228 " jnh 6f\n"
229 "4: mvcs 0(%4,%1),0(%2),%3\n"
230 "9: slgr %0,%4\n"
231 " j 6f\n"
232 "5: slgr %0,%0\n"
233 "6: sacf 768\n"
234 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
235 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
236 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
237 : : "cc", "memory");
238 disable_sacf_uaccess(old_fs);
239 return size;
240}
241
242unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
243{
244 if (copy_with_mvcos())
245 return copy_to_user_mvcos(to, from, n);
246 return copy_to_user_mvcs(to, from, n);
247}
248EXPORT_SYMBOL(raw_copy_to_user);
249
250static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from,
251 unsigned long size)
252{
253 register unsigned long reg0 asm("0") = 0x010001UL;
254 unsigned long tmp1, tmp2;
255
256 tmp1 = -4096UL;
257 /* FIXME: copy with reduced length. */
258 asm volatile(
259 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
260 " jz 2f\n"
261 "1: algr %0,%3\n"
262 " slgr %1,%3\n"
263 " slgr %2,%3\n"
264 " j 0b\n"
265 "2:slgr %0,%0\n"
266 "3: \n"
267 EX_TABLE(0b,3b)
268 : "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
269 : "d" (reg0) : "cc", "memory");
270 return size;
271}
272
273static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from,
274 unsigned long size)
275{
276 mm_segment_t old_fs;
277 unsigned long tmp1;
278
279 old_fs = enable_sacf_uaccess();
280 asm volatile(
281 " sacf 256\n"
282 " aghi %0,-1\n"
283 " jo 5f\n"
284 " bras %3,3f\n"
285 "0: aghi %0,257\n"
286 "1: mvc 0(1,%1),0(%2)\n"
287 " la %1,1(%1)\n"
288 " la %2,1(%2)\n"
289 " aghi %0,-1\n"
290 " jnz 1b\n"
291 " j 5f\n"
292 "2: mvc 0(256,%1),0(%2)\n"
293 " la %1,256(%1)\n"
294 " la %2,256(%2)\n"
295 "3: aghi %0,-256\n"
296 " jnm 2b\n"
297 "4: ex %0,1b-0b(%3)\n"
298 "5: slgr %0,%0\n"
299 "6: sacf 768\n"
300 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
301 : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
302 : : "cc", "memory");
303 disable_sacf_uaccess(old_fs);
304 return size;
305}
306
307unsigned long raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
308{
309 if (copy_with_mvcos())
310 return copy_in_user_mvcos(to, from, n);
311 return copy_in_user_mvc(to, from, n);
312}
313EXPORT_SYMBOL(raw_copy_in_user);
314
315static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
316{
317 register unsigned long reg0 asm("0") = 0x010000UL;
318 unsigned long tmp1, tmp2;
319
320 tmp1 = -4096UL;
321 asm volatile(
322 "0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
323 " jz 4f\n"
324 "1: algr %0,%2\n"
325 " slgr %1,%2\n"
326 " j 0b\n"
327 "2: la %3,4095(%1)\n"/* %4 = to + 4095 */
328 " nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
329 " slgr %3,%1\n"
330 " clgr %0,%3\n" /* copy crosses next page boundary? */
331 " jnh 5f\n"
332 "3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
333 " slgr %0,%3\n"
334 " j 5f\n"
335 "4: slgr %0,%0\n"
336 "5:\n"
337 EX_TABLE(0b,2b) EX_TABLE(3b,5b)
338 : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
339 : "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
340 return size;
341}
342
343static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
344{
345 mm_segment_t old_fs;
346 unsigned long tmp1, tmp2;
347
348 old_fs = enable_sacf_uaccess();
349 asm volatile(
350 " sacf 256\n"
351 " aghi %0,-1\n"
352 " jo 5f\n"
353 " bras %3,3f\n"
354 " xc 0(1,%1),0(%1)\n"
355 "0: aghi %0,257\n"
356 " la %2,255(%1)\n" /* %2 = ptr + 255 */
357 " srl %2,12\n"
358 " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */
359 " slgr %2,%1\n"
360 " clgr %0,%2\n" /* clear crosses next page boundary? */
361 " jnh 5f\n"
362 " aghi %2,-1\n"
363 "1: ex %2,0(%3)\n"
364 " aghi %2,1\n"
365 " slgr %0,%2\n"
366 " j 5f\n"
367 "2: xc 0(256,%1),0(%1)\n"
368 " la %1,256(%1)\n"
369 "3: aghi %0,-256\n"
370 " jnm 2b\n"
371 "4: ex %0,0(%3)\n"
372 "5: slgr %0,%0\n"
373 "6: sacf 768\n"
374 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
375 : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
376 : : "cc", "memory");
377 disable_sacf_uaccess(old_fs);
378 return size;
379}
380
381unsigned long __clear_user(void __user *to, unsigned long size)
382{
383 if (copy_with_mvcos())
384 return clear_user_mvcos(to, size);
385 return clear_user_xc(to, size);
386}
387EXPORT_SYMBOL(__clear_user);
388
389static inline unsigned long strnlen_user_srst(const char __user *src,
390 unsigned long size)
391{
392 register unsigned long reg0 asm("0") = 0;
393 unsigned long tmp1, tmp2;
394
395 asm volatile(
396 " la %2,0(%1)\n"
397 " la %3,0(%0,%1)\n"
398 " slgr %0,%0\n"
399 " sacf 256\n"
400 "0: srst %3,%2\n"
401 " jo 0b\n"
402 " la %0,1(%3)\n" /* strnlen_user results includes \0 */
403 " slgr %0,%1\n"
404 "1: sacf 768\n"
405 EX_TABLE(0b,1b)
406 : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
407 : "d" (reg0) : "cc", "memory");
408 return size;
409}
410
411unsigned long __strnlen_user(const char __user *src, unsigned long size)
412{
413 mm_segment_t old_fs;
414 unsigned long len;
415
416 if (unlikely(!size))
417 return 0;
418 old_fs = enable_sacf_uaccess();
419 len = strnlen_user_srst(src, size);
420 disable_sacf_uaccess(old_fs);
421 return len;
422}
423EXPORT_SYMBOL(__strnlen_user);
424
425long __strncpy_from_user(char *dst, const char __user *src, long size)
426{
427 size_t done, len, offset, len_str;
428
429 if (unlikely(size <= 0))
430 return 0;
431 done = 0;
432 do {
433 offset = (size_t)src & (L1_CACHE_BYTES - 1);
434 len = min(size - done, L1_CACHE_BYTES - offset);
435 if (copy_from_user(dst, src, len))
436 return -EFAULT;
437 len_str = strnlen(dst, len);
438 done += len_str;
439 src += len_str;
440 dst += len_str;
441 } while ((len_str == len) && (done < size));
442 return done;
443}
444EXPORT_SYMBOL(__strncpy_from_user);
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
18static DEFINE_STATIC_KEY_FALSE(have_mvcos);
19
20static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
21 unsigned long size)
22{
23 register unsigned long reg0 asm("0") = 0x81UL;
24 unsigned long tmp1, tmp2;
25
26 tmp1 = -4096UL;
27 asm volatile(
28 "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
29 "9: jz 7f\n"
30 "1: algr %0,%3\n"
31 " slgr %1,%3\n"
32 " slgr %2,%3\n"
33 " j 0b\n"
34 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
35 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
36 " slgr %4,%1\n"
37 " clgr %0,%4\n" /* copy crosses next page boundary? */
38 " jnh 4f\n"
39 "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
40 "10:slgr %0,%4\n"
41 " algr %2,%4\n"
42 "4: lghi %4,-1\n"
43 " algr %4,%0\n" /* copy remaining size, subtract 1 */
44 " bras %3,6f\n" /* memset loop */
45 " xc 0(1,%2),0(%2)\n"
46 "5: xc 0(256,%2),0(%2)\n"
47 " la %2,256(%2)\n"
48 "6: aghi %4,-256\n"
49 " jnm 5b\n"
50 " ex %4,0(%3)\n"
51 " j 8f\n"
52 "7: slgr %0,%0\n"
53 "8:\n"
54 EX_TABLE(0b,2b) EX_TABLE(3b,4b) EX_TABLE(9b,2b) EX_TABLE(10b,4b)
55 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
56 : "d" (reg0) : "cc", "memory");
57 return size;
58}
59
60static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
61 unsigned long size)
62{
63 unsigned long tmp1, tmp2;
64
65 load_kernel_asce();
66 tmp1 = -256UL;
67 asm volatile(
68 " sacf 0\n"
69 "0: mvcp 0(%0,%2),0(%1),%3\n"
70 "10:jz 8f\n"
71 "1: algr %0,%3\n"
72 " la %1,256(%1)\n"
73 " la %2,256(%2)\n"
74 "2: mvcp 0(%0,%2),0(%1),%3\n"
75 "11:jnz 1b\n"
76 " j 8f\n"
77 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
78 " lghi %3,-4096\n"
79 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
80 " slgr %4,%1\n"
81 " clgr %0,%4\n" /* copy crosses next page boundary? */
82 " jnh 5f\n"
83 "4: mvcp 0(%4,%2),0(%1),%3\n"
84 "12:slgr %0,%4\n"
85 " algr %2,%4\n"
86 "5: lghi %4,-1\n"
87 " algr %4,%0\n" /* copy remaining size, subtract 1 */
88 " bras %3,7f\n" /* memset loop */
89 " xc 0(1,%2),0(%2)\n"
90 "6: xc 0(256,%2),0(%2)\n"
91 " la %2,256(%2)\n"
92 "7: aghi %4,-256\n"
93 " jnm 6b\n"
94 " ex %4,0(%3)\n"
95 " j 9f\n"
96 "8: slgr %0,%0\n"
97 "9: sacf 768\n"
98 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b)
99 EX_TABLE(10b,3b) EX_TABLE(11b,3b) EX_TABLE(12b,5b)
100 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
101 : : "cc", "memory");
102 return size;
103}
104
105unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
106{
107 check_object_size(to, n, false);
108 if (static_branch_likely(&have_mvcos))
109 return copy_from_user_mvcos(to, from, n);
110 return copy_from_user_mvcp(to, from, n);
111}
112EXPORT_SYMBOL(__copy_from_user);
113
114static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
115 unsigned long size)
116{
117 register unsigned long reg0 asm("0") = 0x810000UL;
118 unsigned long tmp1, tmp2;
119
120 tmp1 = -4096UL;
121 asm volatile(
122 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
123 "6: jz 4f\n"
124 "1: algr %0,%3\n"
125 " slgr %1,%3\n"
126 " slgr %2,%3\n"
127 " j 0b\n"
128 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
129 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
130 " slgr %4,%1\n"
131 " clgr %0,%4\n" /* copy crosses next page boundary? */
132 " jnh 5f\n"
133 "3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
134 "7: slgr %0,%4\n"
135 " j 5f\n"
136 "4: slgr %0,%0\n"
137 "5:\n"
138 EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
139 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
140 : "d" (reg0) : "cc", "memory");
141 return size;
142}
143
144static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
145 unsigned long size)
146{
147 unsigned long tmp1, tmp2;
148
149 load_kernel_asce();
150 tmp1 = -256UL;
151 asm volatile(
152 " sacf 0\n"
153 "0: mvcs 0(%0,%1),0(%2),%3\n"
154 "7: jz 5f\n"
155 "1: algr %0,%3\n"
156 " la %1,256(%1)\n"
157 " la %2,256(%2)\n"
158 "2: mvcs 0(%0,%1),0(%2),%3\n"
159 "8: jnz 1b\n"
160 " j 5f\n"
161 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
162 " lghi %3,-4096\n"
163 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
164 " slgr %4,%1\n"
165 " clgr %0,%4\n" /* copy crosses next page boundary? */
166 " jnh 6f\n"
167 "4: mvcs 0(%4,%1),0(%2),%3\n"
168 "9: slgr %0,%4\n"
169 " j 6f\n"
170 "5: slgr %0,%0\n"
171 "6: sacf 768\n"
172 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
173 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
174 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
175 : : "cc", "memory");
176 return size;
177}
178
179unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
180{
181 check_object_size(from, n, true);
182 if (static_branch_likely(&have_mvcos))
183 return copy_to_user_mvcos(to, from, n);
184 return copy_to_user_mvcs(to, from, n);
185}
186EXPORT_SYMBOL(__copy_to_user);
187
188static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from,
189 unsigned long size)
190{
191 register unsigned long reg0 asm("0") = 0x810081UL;
192 unsigned long tmp1, tmp2;
193
194 tmp1 = -4096UL;
195 /* FIXME: copy with reduced length. */
196 asm volatile(
197 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
198 " jz 2f\n"
199 "1: algr %0,%3\n"
200 " slgr %1,%3\n"
201 " slgr %2,%3\n"
202 " j 0b\n"
203 "2:slgr %0,%0\n"
204 "3: \n"
205 EX_TABLE(0b,3b)
206 : "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
207 : "d" (reg0) : "cc", "memory");
208 return size;
209}
210
211static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from,
212 unsigned long size)
213{
214 unsigned long tmp1;
215
216 load_kernel_asce();
217 asm volatile(
218 " sacf 256\n"
219 " aghi %0,-1\n"
220 " jo 5f\n"
221 " bras %3,3f\n"
222 "0: aghi %0,257\n"
223 "1: mvc 0(1,%1),0(%2)\n"
224 " la %1,1(%1)\n"
225 " la %2,1(%2)\n"
226 " aghi %0,-1\n"
227 " jnz 1b\n"
228 " j 5f\n"
229 "2: mvc 0(256,%1),0(%2)\n"
230 " la %1,256(%1)\n"
231 " la %2,256(%2)\n"
232 "3: aghi %0,-256\n"
233 " jnm 2b\n"
234 "4: ex %0,1b-0b(%3)\n"
235 "5: slgr %0,%0\n"
236 "6: sacf 768\n"
237 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
238 : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
239 : : "cc", "memory");
240 return size;
241}
242
243unsigned long __copy_in_user(void __user *to, const void __user *from, unsigned long n)
244{
245 if (static_branch_likely(&have_mvcos))
246 return copy_in_user_mvcos(to, from, n);
247 return copy_in_user_mvc(to, from, n);
248}
249EXPORT_SYMBOL(__copy_in_user);
250
251static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
252{
253 register unsigned long reg0 asm("0") = 0x810000UL;
254 unsigned long tmp1, tmp2;
255
256 tmp1 = -4096UL;
257 asm volatile(
258 "0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
259 " jz 4f\n"
260 "1: algr %0,%2\n"
261 " slgr %1,%2\n"
262 " j 0b\n"
263 "2: la %3,4095(%1)\n"/* %4 = to + 4095 */
264 " nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
265 " slgr %3,%1\n"
266 " clgr %0,%3\n" /* copy crosses next page boundary? */
267 " jnh 5f\n"
268 "3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
269 " slgr %0,%3\n"
270 " j 5f\n"
271 "4: slgr %0,%0\n"
272 "5:\n"
273 EX_TABLE(0b,2b) EX_TABLE(3b,5b)
274 : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
275 : "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
276 return size;
277}
278
279static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
280{
281 unsigned long tmp1, tmp2;
282
283 load_kernel_asce();
284 asm volatile(
285 " sacf 256\n"
286 " aghi %0,-1\n"
287 " jo 5f\n"
288 " bras %3,3f\n"
289 " xc 0(1,%1),0(%1)\n"
290 "0: aghi %0,257\n"
291 " la %2,255(%1)\n" /* %2 = ptr + 255 */
292 " srl %2,12\n"
293 " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */
294 " slgr %2,%1\n"
295 " clgr %0,%2\n" /* clear crosses next page boundary? */
296 " jnh 5f\n"
297 " aghi %2,-1\n"
298 "1: ex %2,0(%3)\n"
299 " aghi %2,1\n"
300 " slgr %0,%2\n"
301 " j 5f\n"
302 "2: xc 0(256,%1),0(%1)\n"
303 " la %1,256(%1)\n"
304 "3: aghi %0,-256\n"
305 " jnm 2b\n"
306 "4: ex %0,0(%3)\n"
307 "5: slgr %0,%0\n"
308 "6: sacf 768\n"
309 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
310 : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
311 : : "cc", "memory");
312 return size;
313}
314
315unsigned long __clear_user(void __user *to, unsigned long size)
316{
317 if (static_branch_likely(&have_mvcos))
318 return clear_user_mvcos(to, size);
319 return clear_user_xc(to, size);
320}
321EXPORT_SYMBOL(__clear_user);
322
323static inline unsigned long strnlen_user_srst(const char __user *src,
324 unsigned long size)
325{
326 register unsigned long reg0 asm("0") = 0;
327 unsigned long tmp1, tmp2;
328
329 asm volatile(
330 " la %2,0(%1)\n"
331 " la %3,0(%0,%1)\n"
332 " slgr %0,%0\n"
333 " sacf 256\n"
334 "0: srst %3,%2\n"
335 " jo 0b\n"
336 " la %0,1(%3)\n" /* strnlen_user results includes \0 */
337 " slgr %0,%1\n"
338 "1: sacf 768\n"
339 EX_TABLE(0b,1b)
340 : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
341 : "d" (reg0) : "cc", "memory");
342 return size;
343}
344
345unsigned long __strnlen_user(const char __user *src, unsigned long size)
346{
347 if (unlikely(!size))
348 return 0;
349 load_kernel_asce();
350 return strnlen_user_srst(src, size);
351}
352EXPORT_SYMBOL(__strnlen_user);
353
354long __strncpy_from_user(char *dst, const char __user *src, long size)
355{
356 size_t done, len, offset, len_str;
357
358 if (unlikely(size <= 0))
359 return 0;
360 done = 0;
361 do {
362 offset = (size_t)src & ~PAGE_MASK;
363 len = min(size - done, PAGE_SIZE - offset);
364 if (copy_from_user(dst, src, len))
365 return -EFAULT;
366 len_str = strnlen(dst, len);
367 done += len_str;
368 src += len_str;
369 dst += len_str;
370 } while ((len_str == len) && (done < size));
371 return done;
372}
373EXPORT_SYMBOL(__strncpy_from_user);
374
375static int __init uaccess_init(void)
376{
377 if (test_facility(27))
378 static_branch_enable(&have_mvcos);
379 return 0;
380}
381early_initcall(uaccess_init);