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457f2180 HC |
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 | ||
beef560b | 79 | load_kernel_asce(); |
457f2180 HC |
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 | ||
beef560b | 162 | load_kernel_asce(); |
457f2180 HC |
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 | ||
beef560b | 228 | load_kernel_asce(); |
457f2180 HC |
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 | ||
beef560b | 295 | load_kernel_asce(); |
457f2180 HC |
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 | ||
457f2180 HC |
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 | { | |
fa255f51 HC |
359 | if (unlikely(!size)) |
360 | return 0; | |
beef560b | 361 | load_kernel_asce(); |
457f2180 HC |
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); |