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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/uaccess.h>
12#include <linux/export.h>
13#include <linux/mm.h>
14#include <asm/asm-extable.h>
15
16#ifdef CONFIG_DEBUG_ENTRY
17void debug_user_asce(int exit)
18{
19 unsigned long cr1, cr7;
20
21 __ctl_store(cr1, 1, 1);
22 __ctl_store(cr7, 7, 7);
23 if (cr1 == S390_lowcore.kernel_asce && cr7 == S390_lowcore.user_asce)
24 return;
25 panic("incorrect ASCE on kernel %s\n"
26 "cr1: %016lx cr7: %016lx\n"
27 "kernel: %016llx user: %016llx\n",
28 exit ? "exit" : "entry", cr1, cr7,
29 S390_lowcore.kernel_asce, S390_lowcore.user_asce);
30
31}
32#endif /*CONFIG_DEBUG_ENTRY */
33
34static unsigned long raw_copy_from_user_key(void *to, const void __user *from,
35 unsigned long size, unsigned long key)
36{
37 unsigned long tmp1, tmp2;
38 union oac spec = {
39 .oac2.key = key,
40 .oac2.as = PSW_BITS_AS_SECONDARY,
41 .oac2.k = 1,
42 .oac2.a = 1,
43 };
44
45 tmp1 = -4096UL;
46 asm volatile(
47 " lr 0,%[spec]\n"
48 "0: mvcos 0(%2),0(%1),%0\n"
49 "6: jz 4f\n"
50 "1: algr %0,%3\n"
51 " slgr %1,%3\n"
52 " slgr %2,%3\n"
53 " j 0b\n"
54 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
55 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
56 " slgr %4,%1\n"
57 " clgr %0,%4\n" /* copy crosses next page boundary? */
58 " jnh 5f\n"
59 "3: mvcos 0(%2),0(%1),%4\n"
60 "7: slgr %0,%4\n"
61 " j 5f\n"
62 "4: slgr %0,%0\n"
63 "5:\n"
64 EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
65 : "+a" (size), "+a" (from), "+a" (to), "+a" (tmp1), "=a" (tmp2)
66 : [spec] "d" (spec.val)
67 : "cc", "memory", "0");
68 return size;
69}
70
71unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
72{
73 return raw_copy_from_user_key(to, from, n, 0);
74}
75EXPORT_SYMBOL(raw_copy_from_user);
76
77unsigned long _copy_from_user_key(void *to, const void __user *from,
78 unsigned long n, unsigned long key)
79{
80 unsigned long res = n;
81
82 might_fault();
83 if (!should_fail_usercopy()) {
84 instrument_copy_from_user_before(to, from, n);
85 res = raw_copy_from_user_key(to, from, n, key);
86 instrument_copy_from_user_after(to, from, n, res);
87 }
88 if (unlikely(res))
89 memset(to + (n - res), 0, res);
90 return res;
91}
92EXPORT_SYMBOL(_copy_from_user_key);
93
94static unsigned long raw_copy_to_user_key(void __user *to, const void *from,
95 unsigned long size, unsigned long key)
96{
97 unsigned long tmp1, tmp2;
98 union oac spec = {
99 .oac1.key = key,
100 .oac1.as = PSW_BITS_AS_SECONDARY,
101 .oac1.k = 1,
102 .oac1.a = 1,
103 };
104
105 tmp1 = -4096UL;
106 asm volatile(
107 " lr 0,%[spec]\n"
108 "0: mvcos 0(%1),0(%2),%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: mvcos 0(%1),0(%2),%4\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" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
126 : [spec] "d" (spec.val)
127 : "cc", "memory", "0");
128 return size;
129}
130
131unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
132{
133 return raw_copy_to_user_key(to, from, n, 0);
134}
135EXPORT_SYMBOL(raw_copy_to_user);
136
137unsigned long _copy_to_user_key(void __user *to, const void *from,
138 unsigned long n, unsigned long key)
139{
140 might_fault();
141 if (should_fail_usercopy())
142 return n;
143 instrument_copy_to_user(to, from, n);
144 return raw_copy_to_user_key(to, from, n, key);
145}
146EXPORT_SYMBOL(_copy_to_user_key);
147
148unsigned long __clear_user(void __user *to, unsigned long size)
149{
150 unsigned long tmp1, tmp2;
151 union oac spec = {
152 .oac1.as = PSW_BITS_AS_SECONDARY,
153 .oac1.a = 1,
154 };
155
156 tmp1 = -4096UL;
157 asm volatile(
158 " lr 0,%[spec]\n"
159 "0: mvcos 0(%1),0(%4),%0\n"
160 "6: jz 4f\n"
161 "1: algr %0,%2\n"
162 " slgr %1,%2\n"
163 " j 0b\n"
164 "2: la %3,4095(%1)\n"/* %4 = to + 4095 */
165 " nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
166 " slgr %3,%1\n"
167 " clgr %0,%3\n" /* copy crosses next page boundary? */
168 " jnh 5f\n"
169 "3: mvcos 0(%1),0(%4),%3\n"
170 "7: slgr %0,%3\n"
171 " j 5f\n"
172 "4: slgr %0,%0\n"
173 "5:\n"
174 EX_TABLE(0b,2b) EX_TABLE(6b,2b) EX_TABLE(3b,5b) EX_TABLE(7b,5b)
175 : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
176 : "a" (empty_zero_page), [spec] "d" (spec.val)
177 : "cc", "memory", "0");
178 return size;
179}
180EXPORT_SYMBOL(__clear_user);
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#ifdef CONFIG_DEBUG_ENTRY
20void debug_user_asce(int exit)
21{
22 unsigned long cr1, cr7;
23
24 __ctl_store(cr1, 1, 1);
25 __ctl_store(cr7, 7, 7);
26 if (cr1 == S390_lowcore.kernel_asce && cr7 == S390_lowcore.user_asce)
27 return;
28 panic("incorrect ASCE on kernel %s\n"
29 "cr1: %016lx cr7: %016lx\n"
30 "kernel: %016llx user: %016llx\n",
31 exit ? "exit" : "entry", cr1, cr7,
32 S390_lowcore.kernel_asce, S390_lowcore.user_asce);
33
34}
35#endif /*CONFIG_DEBUG_ENTRY */
36
37#ifndef CONFIG_HAVE_MARCH_Z10_FEATURES
38static DEFINE_STATIC_KEY_FALSE(have_mvcos);
39
40static int __init uaccess_init(void)
41{
42 if (test_facility(27))
43 static_branch_enable(&have_mvcos);
44 return 0;
45}
46early_initcall(uaccess_init);
47
48static inline int copy_with_mvcos(void)
49{
50 if (static_branch_likely(&have_mvcos))
51 return 1;
52 return 0;
53}
54#else
55static inline int copy_with_mvcos(void)
56{
57 return 1;
58}
59#endif
60
61static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
62 unsigned long size)
63{
64 unsigned long tmp1, tmp2;
65
66 tmp1 = -4096UL;
67 asm volatile(
68 " lghi 0,%[spec]\n"
69 "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
70 "6: jz 4f\n"
71 "1: algr %0,%3\n"
72 " slgr %1,%3\n"
73 " slgr %2,%3\n"
74 " j 0b\n"
75 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
76 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
77 " slgr %4,%1\n"
78 " clgr %0,%4\n" /* copy crosses next page boundary? */
79 " jnh 5f\n"
80 "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
81 "7: slgr %0,%4\n"
82 " j 5f\n"
83 "4: slgr %0,%0\n"
84 "5:\n"
85 EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
86 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
87 : [spec] "K" (0x81UL)
88 : "cc", "memory", "0");
89 return size;
90}
91
92static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
93 unsigned long size)
94{
95 unsigned long tmp1, tmp2;
96
97 tmp1 = -256UL;
98 asm volatile(
99 " sacf 0\n"
100 "0: mvcp 0(%0,%2),0(%1),%3\n"
101 "7: jz 5f\n"
102 "1: algr %0,%3\n"
103 " la %1,256(%1)\n"
104 " la %2,256(%2)\n"
105 "2: mvcp 0(%0,%2),0(%1),%3\n"
106 "8: jnz 1b\n"
107 " j 5f\n"
108 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
109 " lghi %3,-4096\n"
110 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
111 " slgr %4,%1\n"
112 " clgr %0,%4\n" /* copy crosses next page boundary? */
113 " jnh 6f\n"
114 "4: mvcp 0(%4,%2),0(%1),%3\n"
115 "9: slgr %0,%4\n"
116 " j 6f\n"
117 "5: slgr %0,%0\n"
118 "6: sacf 768\n"
119 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
120 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
121 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
122 : : "cc", "memory");
123 return size;
124}
125
126unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
127{
128 if (copy_with_mvcos())
129 return copy_from_user_mvcos(to, from, n);
130 return copy_from_user_mvcp(to, from, n);
131}
132EXPORT_SYMBOL(raw_copy_from_user);
133
134static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
135 unsigned long size)
136{
137 unsigned long tmp1, tmp2;
138
139 tmp1 = -4096UL;
140 asm volatile(
141 " llilh 0,%[spec]\n"
142 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
143 "6: jz 4f\n"
144 "1: algr %0,%3\n"
145 " slgr %1,%3\n"
146 " slgr %2,%3\n"
147 " j 0b\n"
148 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
149 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
150 " slgr %4,%1\n"
151 " clgr %0,%4\n" /* copy crosses next page boundary? */
152 " jnh 5f\n"
153 "3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
154 "7: slgr %0,%4\n"
155 " j 5f\n"
156 "4: slgr %0,%0\n"
157 "5:\n"
158 EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
159 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
160 : [spec] "K" (0x81UL)
161 : "cc", "memory", "0");
162 return size;
163}
164
165static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
166 unsigned long size)
167{
168 unsigned long tmp1, tmp2;
169
170 tmp1 = -256UL;
171 asm volatile(
172 " sacf 0\n"
173 "0: mvcs 0(%0,%1),0(%2),%3\n"
174 "7: jz 5f\n"
175 "1: algr %0,%3\n"
176 " la %1,256(%1)\n"
177 " la %2,256(%2)\n"
178 "2: mvcs 0(%0,%1),0(%2),%3\n"
179 "8: jnz 1b\n"
180 " j 5f\n"
181 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
182 " lghi %3,-4096\n"
183 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
184 " slgr %4,%1\n"
185 " clgr %0,%4\n" /* copy crosses next page boundary? */
186 " jnh 6f\n"
187 "4: mvcs 0(%4,%1),0(%2),%3\n"
188 "9: slgr %0,%4\n"
189 " j 6f\n"
190 "5: slgr %0,%0\n"
191 "6: sacf 768\n"
192 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
193 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
194 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
195 : : "cc", "memory");
196 return size;
197}
198
199unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
200{
201 if (copy_with_mvcos())
202 return copy_to_user_mvcos(to, from, n);
203 return copy_to_user_mvcs(to, from, n);
204}
205EXPORT_SYMBOL(raw_copy_to_user);
206
207static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from,
208 unsigned long size)
209{
210 unsigned long tmp1, tmp2;
211
212 tmp1 = -4096UL;
213 /* FIXME: copy with reduced length. */
214 asm volatile(
215 " lgr 0,%[spec]\n"
216 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
217 " jz 2f\n"
218 "1: algr %0,%3\n"
219 " slgr %1,%3\n"
220 " slgr %2,%3\n"
221 " j 0b\n"
222 "2:slgr %0,%0\n"
223 "3: \n"
224 EX_TABLE(0b,3b)
225 : "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
226 : [spec] "d" (0x810081UL)
227 : "cc", "memory", "0");
228 return size;
229}
230
231static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from,
232 unsigned long size)
233{
234 unsigned long tmp1;
235
236 asm volatile(
237 " sacf 256\n"
238 " aghi %0,-1\n"
239 " jo 5f\n"
240 " bras %3,3f\n"
241 "0: aghi %0,257\n"
242 "1: mvc 0(1,%1),0(%2)\n"
243 " la %1,1(%1)\n"
244 " la %2,1(%2)\n"
245 " aghi %0,-1\n"
246 " jnz 1b\n"
247 " j 5f\n"
248 "2: mvc 0(256,%1),0(%2)\n"
249 " la %1,256(%1)\n"
250 " la %2,256(%2)\n"
251 "3: aghi %0,-256\n"
252 " jnm 2b\n"
253 "4: ex %0,1b-0b(%3)\n"
254 "5: slgr %0,%0\n"
255 "6: sacf 768\n"
256 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
257 : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
258 : : "cc", "memory");
259 return size;
260}
261
262unsigned long raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
263{
264 if (copy_with_mvcos())
265 return copy_in_user_mvcos(to, from, n);
266 return copy_in_user_mvc(to, from, n);
267}
268EXPORT_SYMBOL(raw_copy_in_user);
269
270static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
271{
272 unsigned long tmp1, tmp2;
273
274 tmp1 = -4096UL;
275 asm volatile(
276 " llilh 0,%[spec]\n"
277 "0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
278 " jz 4f\n"
279 "1: algr %0,%2\n"
280 " slgr %1,%2\n"
281 " j 0b\n"
282 "2: la %3,4095(%1)\n"/* %4 = to + 4095 */
283 " nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
284 " slgr %3,%1\n"
285 " clgr %0,%3\n" /* copy crosses next page boundary? */
286 " jnh 5f\n"
287 "3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
288 " slgr %0,%3\n"
289 " j 5f\n"
290 "4: slgr %0,%0\n"
291 "5:\n"
292 EX_TABLE(0b,2b) EX_TABLE(3b,5b)
293 : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
294 : "a" (empty_zero_page), [spec] "K" (0x81UL)
295 : "cc", "memory", "0");
296 return size;
297}
298
299static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
300{
301 unsigned long tmp1, tmp2;
302
303 asm volatile(
304 " sacf 256\n"
305 " aghi %0,-1\n"
306 " jo 5f\n"
307 " bras %3,3f\n"
308 " xc 0(1,%1),0(%1)\n"
309 "0: aghi %0,257\n"
310 " la %2,255(%1)\n" /* %2 = ptr + 255 */
311 " srl %2,12\n"
312 " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */
313 " slgr %2,%1\n"
314 " clgr %0,%2\n" /* clear crosses next page boundary? */
315 " jnh 5f\n"
316 " aghi %2,-1\n"
317 "1: ex %2,0(%3)\n"
318 " aghi %2,1\n"
319 " slgr %0,%2\n"
320 " j 5f\n"
321 "2: xc 0(256,%1),0(%1)\n"
322 " la %1,256(%1)\n"
323 "3: aghi %0,-256\n"
324 " jnm 2b\n"
325 "4: ex %0,0(%3)\n"
326 "5: slgr %0,%0\n"
327 "6: sacf 768\n"
328 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
329 : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
330 : : "cc", "memory");
331 return size;
332}
333
334unsigned long __clear_user(void __user *to, unsigned long size)
335{
336 if (copy_with_mvcos())
337 return clear_user_mvcos(to, size);
338 return clear_user_xc(to, size);
339}
340EXPORT_SYMBOL(__clear_user);
341
342static inline unsigned long strnlen_user_srst(const char __user *src,
343 unsigned long size)
344{
345 unsigned long tmp1, tmp2;
346
347 asm volatile(
348 " lghi 0,0\n"
349 " la %2,0(%1)\n"
350 " la %3,0(%0,%1)\n"
351 " slgr %0,%0\n"
352 " sacf 256\n"
353 "0: srst %3,%2\n"
354 " jo 0b\n"
355 " la %0,1(%3)\n" /* strnlen_user results includes \0 */
356 " slgr %0,%1\n"
357 "1: sacf 768\n"
358 EX_TABLE(0b,1b)
359 : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
360 :
361 : "cc", "memory", "0");
362 return size;
363}
364
365unsigned long __strnlen_user(const char __user *src, unsigned long size)
366{
367 if (unlikely(!size))
368 return 0;
369 return strnlen_user_srst(src, size);
370}
371EXPORT_SYMBOL(__strnlen_user);
372
373long __strncpy_from_user(char *dst, const char __user *src, long size)
374{
375 size_t done, len, offset, len_str;
376
377 if (unlikely(size <= 0))
378 return 0;
379 done = 0;
380 do {
381 offset = (size_t)src & (L1_CACHE_BYTES - 1);
382 len = min(size - done, L1_CACHE_BYTES - offset);
383 if (copy_from_user(dst, src, len))
384 return -EFAULT;
385 len_str = strnlen(dst, len);
386 done += len_str;
387 src += len_str;
388 dst += len_str;
389 } while ((len_str == len) && (done < size));
390 return done;
391}
392EXPORT_SYMBOL(__strncpy_from_user);