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1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 03, 04 by Ralf Baechle
7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
8 * Copyright (C) 2007 Maciej W. Rozycki
9 * Copyright (C) 2014, Imagination Technologies Ltd.
10 */
11#ifndef _ASM_UACCESS_H
12#define _ASM_UACCESS_H
13
14#include <linux/kernel.h>
15#include <linux/string.h>
16#include <asm/asm-eva.h>
17#include <asm/extable.h>
18
19/*
20 * The fs value determines whether argument validity checking should be
21 * performed or not. If get_fs() == USER_DS, checking is performed, with
22 * get_fs() == KERNEL_DS, checking is bypassed.
23 *
24 * For historical reasons, these macros are grossly misnamed.
25 */
26#ifdef CONFIG_32BIT
27
28#ifdef CONFIG_KVM_GUEST
29#define __UA_LIMIT 0x40000000UL
30#else
31#define __UA_LIMIT 0x80000000UL
32#endif
33
34#define __UA_ADDR ".word"
35#define __UA_LA "la"
36#define __UA_ADDU "addu"
37#define __UA_t0 "$8"
38#define __UA_t1 "$9"
39
40#endif /* CONFIG_32BIT */
41
42#ifdef CONFIG_64BIT
43
44extern u64 __ua_limit;
45
46#define __UA_LIMIT __ua_limit
47
48#define __UA_ADDR ".dword"
49#define __UA_LA "dla"
50#define __UA_ADDU "daddu"
51#define __UA_t0 "$12"
52#define __UA_t1 "$13"
53
54#endif /* CONFIG_64BIT */
55
56/*
57 * USER_DS is a bitmask that has the bits set that may not be set in a valid
58 * userspace address. Note that we limit 32-bit userspace to 0x7fff8000 but
59 * the arithmetic we're doing only works if the limit is a power of two, so
60 * we use 0x80000000 here on 32-bit kernels. If a process passes an invalid
61 * address in this range it's the process's problem, not ours :-)
62 */
63
64#ifdef CONFIG_KVM_GUEST
65#define KERNEL_DS ((mm_segment_t) { 0x80000000UL })
66#define USER_DS ((mm_segment_t) { 0xC0000000UL })
67#else
68#define KERNEL_DS ((mm_segment_t) { 0UL })
69#define USER_DS ((mm_segment_t) { __UA_LIMIT })
70#endif
71
72#define get_fs() (current_thread_info()->addr_limit)
73#define set_fs(x) (current_thread_info()->addr_limit = (x))
74
75#define segment_eq(a, b) ((a).seg == (b).seg)
76
77/*
78 * eva_kernel_access() - determine whether kernel memory access on an EVA system
79 *
80 * Determines whether memory accesses should be performed to kernel memory
81 * on a system using Extended Virtual Addressing (EVA).
82 *
83 * Return: true if a kernel memory access on an EVA system, else false.
84 */
85static inline bool eva_kernel_access(void)
86{
87 if (!IS_ENABLED(CONFIG_EVA))
88 return false;
89
90 return uaccess_kernel();
91}
92
93/*
94 * Is a address valid? This does a straightforward calculation rather
95 * than tests.
96 *
97 * Address valid if:
98 * - "addr" doesn't have any high-bits set
99 * - AND "size" doesn't have any high-bits set
100 * - AND "addr+size" doesn't have any high-bits set
101 * - OR we are in kernel mode.
102 *
103 * __ua_size() is a trick to avoid runtime checking of positive constant
104 * sizes; for those we already know at compile time that the size is ok.
105 */
106#define __ua_size(size) \
107 ((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size))
108
109/*
110 * access_ok: - Checks if a user space pointer is valid
111 * @addr: User space pointer to start of block to check
112 * @size: Size of block to check
113 *
114 * Context: User context only. This function may sleep if pagefaults are
115 * enabled.
116 *
117 * Checks if a pointer to a block of memory in user space is valid.
118 *
119 * Returns true (nonzero) if the memory block may be valid, false (zero)
120 * if it is definitely invalid.
121 *
122 * Note that, depending on architecture, this function probably just
123 * checks that the pointer is in the user space range - after calling
124 * this function, memory access functions may still return -EFAULT.
125 */
126
127static inline int __access_ok(const void __user *p, unsigned long size)
128{
129 unsigned long addr = (unsigned long)p;
130 return (get_fs().seg & (addr | (addr + size) | __ua_size(size))) == 0;
131}
132
133#define access_ok(addr, size) \
134 likely(__access_ok((addr), (size)))
135
136/*
137 * put_user: - Write a simple value into user space.
138 * @x: Value to copy to user space.
139 * @ptr: Destination address, in user space.
140 *
141 * Context: User context only. This function may sleep if pagefaults are
142 * enabled.
143 *
144 * This macro copies a single simple value from kernel space to user
145 * space. It supports simple types like char and int, but not larger
146 * data types like structures or arrays.
147 *
148 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
149 * to the result of dereferencing @ptr.
150 *
151 * Returns zero on success, or -EFAULT on error.
152 */
153#define put_user(x,ptr) \
154 __put_user_check((x), (ptr), sizeof(*(ptr)))
155
156/*
157 * get_user: - Get a simple variable from user space.
158 * @x: Variable to store result.
159 * @ptr: Source address, in user space.
160 *
161 * Context: User context only. This function may sleep if pagefaults are
162 * enabled.
163 *
164 * This macro copies a single simple variable from user space to kernel
165 * space. It supports simple types like char and int, but not larger
166 * data types like structures or arrays.
167 *
168 * @ptr must have pointer-to-simple-variable type, and the result of
169 * dereferencing @ptr must be assignable to @x without a cast.
170 *
171 * Returns zero on success, or -EFAULT on error.
172 * On error, the variable @x is set to zero.
173 */
174#define get_user(x,ptr) \
175 __get_user_check((x), (ptr), sizeof(*(ptr)))
176
177/*
178 * __put_user: - Write a simple value into user space, with less checking.
179 * @x: Value to copy to user space.
180 * @ptr: Destination address, in user space.
181 *
182 * Context: User context only. This function may sleep if pagefaults are
183 * enabled.
184 *
185 * This macro copies a single simple value from kernel space to user
186 * space. It supports simple types like char and int, but not larger
187 * data types like structures or arrays.
188 *
189 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
190 * to the result of dereferencing @ptr.
191 *
192 * Caller must check the pointer with access_ok() before calling this
193 * function.
194 *
195 * Returns zero on success, or -EFAULT on error.
196 */
197#define __put_user(x,ptr) \
198 __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
199
200/*
201 * __get_user: - Get a simple variable from user space, with less checking.
202 * @x: Variable to store result.
203 * @ptr: Source address, in user space.
204 *
205 * Context: User context only. This function may sleep if pagefaults are
206 * enabled.
207 *
208 * This macro copies a single simple variable from user space to kernel
209 * space. It supports simple types like char and int, but not larger
210 * data types like structures or arrays.
211 *
212 * @ptr must have pointer-to-simple-variable type, and the result of
213 * dereferencing @ptr must be assignable to @x without a cast.
214 *
215 * Caller must check the pointer with access_ok() before calling this
216 * function.
217 *
218 * Returns zero on success, or -EFAULT on error.
219 * On error, the variable @x is set to zero.
220 */
221#define __get_user(x,ptr) \
222 __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
223
224struct __large_struct { unsigned long buf[100]; };
225#define __m(x) (*(struct __large_struct __user *)(x))
226
227/*
228 * Yuck. We need two variants, one for 64bit operation and one
229 * for 32 bit mode and old iron.
230 */
231#ifndef CONFIG_EVA
232#define __get_kernel_common(val, size, ptr) __get_user_common(val, size, ptr)
233#else
234/*
235 * Kernel specific functions for EVA. We need to use normal load instructions
236 * to read data from kernel when operating in EVA mode. We use these macros to
237 * avoid redefining __get_user_asm for EVA.
238 */
239#undef _loadd
240#undef _loadw
241#undef _loadh
242#undef _loadb
243#ifdef CONFIG_32BIT
244#define _loadd _loadw
245#else
246#define _loadd(reg, addr) "ld " reg ", " addr
247#endif
248#define _loadw(reg, addr) "lw " reg ", " addr
249#define _loadh(reg, addr) "lh " reg ", " addr
250#define _loadb(reg, addr) "lb " reg ", " addr
251
252#define __get_kernel_common(val, size, ptr) \
253do { \
254 switch (size) { \
255 case 1: __get_data_asm(val, _loadb, ptr); break; \
256 case 2: __get_data_asm(val, _loadh, ptr); break; \
257 case 4: __get_data_asm(val, _loadw, ptr); break; \
258 case 8: __GET_DW(val, _loadd, ptr); break; \
259 default: __get_user_unknown(); break; \
260 } \
261} while (0)
262#endif
263
264#ifdef CONFIG_32BIT
265#define __GET_DW(val, insn, ptr) __get_data_asm_ll32(val, insn, ptr)
266#endif
267#ifdef CONFIG_64BIT
268#define __GET_DW(val, insn, ptr) __get_data_asm(val, insn, ptr)
269#endif
270
271extern void __get_user_unknown(void);
272
273#define __get_user_common(val, size, ptr) \
274do { \
275 switch (size) { \
276 case 1: __get_data_asm(val, user_lb, ptr); break; \
277 case 2: __get_data_asm(val, user_lh, ptr); break; \
278 case 4: __get_data_asm(val, user_lw, ptr); break; \
279 case 8: __GET_DW(val, user_ld, ptr); break; \
280 default: __get_user_unknown(); break; \
281 } \
282} while (0)
283
284#define __get_user_nocheck(x, ptr, size) \
285({ \
286 int __gu_err; \
287 \
288 if (eva_kernel_access()) { \
289 __get_kernel_common((x), size, ptr); \
290 } else { \
291 __chk_user_ptr(ptr); \
292 __get_user_common((x), size, ptr); \
293 } \
294 __gu_err; \
295})
296
297#define __get_user_check(x, ptr, size) \
298({ \
299 int __gu_err = -EFAULT; \
300 const __typeof__(*(ptr)) __user * __gu_ptr = (ptr); \
301 \
302 might_fault(); \
303 if (likely(access_ok( __gu_ptr, size))) { \
304 if (eva_kernel_access()) \
305 __get_kernel_common((x), size, __gu_ptr); \
306 else \
307 __get_user_common((x), size, __gu_ptr); \
308 } else \
309 (x) = 0; \
310 \
311 __gu_err; \
312})
313
314#define __get_data_asm(val, insn, addr) \
315{ \
316 long __gu_tmp; \
317 \
318 __asm__ __volatile__( \
319 "1: "insn("%1", "%3")" \n" \
320 "2: \n" \
321 " .insn \n" \
322 " .section .fixup,\"ax\" \n" \
323 "3: li %0, %4 \n" \
324 " move %1, $0 \n" \
325 " j 2b \n" \
326 " .previous \n" \
327 " .section __ex_table,\"a\" \n" \
328 " "__UA_ADDR "\t1b, 3b \n" \
329 " .previous \n" \
330 : "=r" (__gu_err), "=r" (__gu_tmp) \
331 : "0" (0), "o" (__m(addr)), "i" (-EFAULT)); \
332 \
333 (val) = (__typeof__(*(addr))) __gu_tmp; \
334}
335
336/*
337 * Get a long long 64 using 32 bit registers.
338 */
339#define __get_data_asm_ll32(val, insn, addr) \
340{ \
341 union { \
342 unsigned long long l; \
343 __typeof__(*(addr)) t; \
344 } __gu_tmp; \
345 \
346 __asm__ __volatile__( \
347 "1: " insn("%1", "(%3)")" \n" \
348 "2: " insn("%D1", "4(%3)")" \n" \
349 "3: \n" \
350 " .insn \n" \
351 " .section .fixup,\"ax\" \n" \
352 "4: li %0, %4 \n" \
353 " move %1, $0 \n" \
354 " move %D1, $0 \n" \
355 " j 3b \n" \
356 " .previous \n" \
357 " .section __ex_table,\"a\" \n" \
358 " " __UA_ADDR " 1b, 4b \n" \
359 " " __UA_ADDR " 2b, 4b \n" \
360 " .previous \n" \
361 : "=r" (__gu_err), "=&r" (__gu_tmp.l) \
362 : "0" (0), "r" (addr), "i" (-EFAULT)); \
363 \
364 (val) = __gu_tmp.t; \
365}
366
367#ifndef CONFIG_EVA
368#define __put_kernel_common(ptr, size) __put_user_common(ptr, size)
369#else
370/*
371 * Kernel specific functions for EVA. We need to use normal load instructions
372 * to read data from kernel when operating in EVA mode. We use these macros to
373 * avoid redefining __get_data_asm for EVA.
374 */
375#undef _stored
376#undef _storew
377#undef _storeh
378#undef _storeb
379#ifdef CONFIG_32BIT
380#define _stored _storew
381#else
382#define _stored(reg, addr) "ld " reg ", " addr
383#endif
384
385#define _storew(reg, addr) "sw " reg ", " addr
386#define _storeh(reg, addr) "sh " reg ", " addr
387#define _storeb(reg, addr) "sb " reg ", " addr
388
389#define __put_kernel_common(ptr, size) \
390do { \
391 switch (size) { \
392 case 1: __put_data_asm(_storeb, ptr); break; \
393 case 2: __put_data_asm(_storeh, ptr); break; \
394 case 4: __put_data_asm(_storew, ptr); break; \
395 case 8: __PUT_DW(_stored, ptr); break; \
396 default: __put_user_unknown(); break; \
397 } \
398} while(0)
399#endif
400
401/*
402 * Yuck. We need two variants, one for 64bit operation and one
403 * for 32 bit mode and old iron.
404 */
405#ifdef CONFIG_32BIT
406#define __PUT_DW(insn, ptr) __put_data_asm_ll32(insn, ptr)
407#endif
408#ifdef CONFIG_64BIT
409#define __PUT_DW(insn, ptr) __put_data_asm(insn, ptr)
410#endif
411
412#define __put_user_common(ptr, size) \
413do { \
414 switch (size) { \
415 case 1: __put_data_asm(user_sb, ptr); break; \
416 case 2: __put_data_asm(user_sh, ptr); break; \
417 case 4: __put_data_asm(user_sw, ptr); break; \
418 case 8: __PUT_DW(user_sd, ptr); break; \
419 default: __put_user_unknown(); break; \
420 } \
421} while (0)
422
423#define __put_user_nocheck(x, ptr, size) \
424({ \
425 __typeof__(*(ptr)) __pu_val; \
426 int __pu_err = 0; \
427 \
428 __pu_val = (x); \
429 if (eva_kernel_access()) { \
430 __put_kernel_common(ptr, size); \
431 } else { \
432 __chk_user_ptr(ptr); \
433 __put_user_common(ptr, size); \
434 } \
435 __pu_err; \
436})
437
438#define __put_user_check(x, ptr, size) \
439({ \
440 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
441 __typeof__(*(ptr)) __pu_val = (x); \
442 int __pu_err = -EFAULT; \
443 \
444 might_fault(); \
445 if (likely(access_ok( __pu_addr, size))) { \
446 if (eva_kernel_access()) \
447 __put_kernel_common(__pu_addr, size); \
448 else \
449 __put_user_common(__pu_addr, size); \
450 } \
451 \
452 __pu_err; \
453})
454
455#define __put_data_asm(insn, ptr) \
456{ \
457 __asm__ __volatile__( \
458 "1: "insn("%z2", "%3")" # __put_data_asm \n" \
459 "2: \n" \
460 " .insn \n" \
461 " .section .fixup,\"ax\" \n" \
462 "3: li %0, %4 \n" \
463 " j 2b \n" \
464 " .previous \n" \
465 " .section __ex_table,\"a\" \n" \
466 " " __UA_ADDR " 1b, 3b \n" \
467 " .previous \n" \
468 : "=r" (__pu_err) \
469 : "0" (0), "Jr" (__pu_val), "o" (__m(ptr)), \
470 "i" (-EFAULT)); \
471}
472
473#define __put_data_asm_ll32(insn, ptr) \
474{ \
475 __asm__ __volatile__( \
476 "1: "insn("%2", "(%3)")" # __put_data_asm_ll32 \n" \
477 "2: "insn("%D2", "4(%3)")" \n" \
478 "3: \n" \
479 " .insn \n" \
480 " .section .fixup,\"ax\" \n" \
481 "4: li %0, %4 \n" \
482 " j 3b \n" \
483 " .previous \n" \
484 " .section __ex_table,\"a\" \n" \
485 " " __UA_ADDR " 1b, 4b \n" \
486 " " __UA_ADDR " 2b, 4b \n" \
487 " .previous" \
488 : "=r" (__pu_err) \
489 : "0" (0), "r" (__pu_val), "r" (ptr), \
490 "i" (-EFAULT)); \
491}
492
493extern void __put_user_unknown(void);
494
495/*
496 * We're generating jump to subroutines which will be outside the range of
497 * jump instructions
498 */
499#ifdef MODULE
500#define __MODULE_JAL(destination) \
501 ".set\tnoat\n\t" \
502 __UA_LA "\t$1, " #destination "\n\t" \
503 "jalr\t$1\n\t" \
504 ".set\tat\n\t"
505#else
506#define __MODULE_JAL(destination) \
507 "jal\t" #destination "\n\t"
508#endif
509
510#if defined(CONFIG_CPU_DADDI_WORKAROUNDS) || (defined(CONFIG_EVA) && \
511 defined(CONFIG_CPU_HAS_PREFETCH))
512#define DADDI_SCRATCH "$3"
513#else
514#define DADDI_SCRATCH "$0"
515#endif
516
517extern size_t __copy_user(void *__to, const void *__from, size_t __n);
518
519#define __invoke_copy_from(func, to, from, n) \
520({ \
521 register void *__cu_to_r __asm__("$4"); \
522 register const void __user *__cu_from_r __asm__("$5"); \
523 register long __cu_len_r __asm__("$6"); \
524 \
525 __cu_to_r = (to); \
526 __cu_from_r = (from); \
527 __cu_len_r = (n); \
528 __asm__ __volatile__( \
529 ".set\tnoreorder\n\t" \
530 __MODULE_JAL(func) \
531 ".set\tnoat\n\t" \
532 __UA_ADDU "\t$1, %1, %2\n\t" \
533 ".set\tat\n\t" \
534 ".set\treorder" \
535 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
536 : \
537 : "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31", \
538 DADDI_SCRATCH, "memory"); \
539 __cu_len_r; \
540})
541
542#define __invoke_copy_to(func, to, from, n) \
543({ \
544 register void __user *__cu_to_r __asm__("$4"); \
545 register const void *__cu_from_r __asm__("$5"); \
546 register long __cu_len_r __asm__("$6"); \
547 \
548 __cu_to_r = (to); \
549 __cu_from_r = (from); \
550 __cu_len_r = (n); \
551 __asm__ __volatile__( \
552 __MODULE_JAL(func) \
553 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
554 : \
555 : "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31", \
556 DADDI_SCRATCH, "memory"); \
557 __cu_len_r; \
558})
559
560#define __invoke_copy_from_kernel(to, from, n) \
561 __invoke_copy_from(__copy_user, to, from, n)
562
563#define __invoke_copy_to_kernel(to, from, n) \
564 __invoke_copy_to(__copy_user, to, from, n)
565
566#define ___invoke_copy_in_kernel(to, from, n) \
567 __invoke_copy_from(__copy_user, to, from, n)
568
569#ifndef CONFIG_EVA
570#define __invoke_copy_from_user(to, from, n) \
571 __invoke_copy_from(__copy_user, to, from, n)
572
573#define __invoke_copy_to_user(to, from, n) \
574 __invoke_copy_to(__copy_user, to, from, n)
575
576#define ___invoke_copy_in_user(to, from, n) \
577 __invoke_copy_from(__copy_user, to, from, n)
578
579#else
580
581/* EVA specific functions */
582
583extern size_t __copy_from_user_eva(void *__to, const void *__from,
584 size_t __n);
585extern size_t __copy_to_user_eva(void *__to, const void *__from,
586 size_t __n);
587extern size_t __copy_in_user_eva(void *__to, const void *__from, size_t __n);
588
589/*
590 * Source or destination address is in userland. We need to go through
591 * the TLB
592 */
593#define __invoke_copy_from_user(to, from, n) \
594 __invoke_copy_from(__copy_from_user_eva, to, from, n)
595
596#define __invoke_copy_to_user(to, from, n) \
597 __invoke_copy_to(__copy_to_user_eva, to, from, n)
598
599#define ___invoke_copy_in_user(to, from, n) \
600 __invoke_copy_from(__copy_in_user_eva, to, from, n)
601
602#endif /* CONFIG_EVA */
603
604static inline unsigned long
605raw_copy_to_user(void __user *to, const void *from, unsigned long n)
606{
607 if (eva_kernel_access())
608 return __invoke_copy_to_kernel(to, from, n);
609 else
610 return __invoke_copy_to_user(to, from, n);
611}
612
613static inline unsigned long
614raw_copy_from_user(void *to, const void __user *from, unsigned long n)
615{
616 if (eva_kernel_access())
617 return __invoke_copy_from_kernel(to, from, n);
618 else
619 return __invoke_copy_from_user(to, from, n);
620}
621
622#define INLINE_COPY_FROM_USER
623#define INLINE_COPY_TO_USER
624
625static inline unsigned long
626raw_copy_in_user(void __user*to, const void __user *from, unsigned long n)
627{
628 if (eva_kernel_access())
629 return ___invoke_copy_in_kernel(to, from, n);
630 else
631 return ___invoke_copy_in_user(to, from, n);
632}
633
634extern __kernel_size_t __bzero_kernel(void __user *addr, __kernel_size_t size);
635extern __kernel_size_t __bzero(void __user *addr, __kernel_size_t size);
636
637/*
638 * __clear_user: - Zero a block of memory in user space, with less checking.
639 * @to: Destination address, in user space.
640 * @n: Number of bytes to zero.
641 *
642 * Zero a block of memory in user space. Caller must check
643 * the specified block with access_ok() before calling this function.
644 *
645 * Returns number of bytes that could not be cleared.
646 * On success, this will be zero.
647 */
648static inline __kernel_size_t
649__clear_user(void __user *addr, __kernel_size_t size)
650{
651 __kernel_size_t res;
652
653#ifdef CONFIG_CPU_MICROMIPS
654/* micromips memset / bzero also clobbers t7 & t8 */
655#define bzero_clobbers "$4", "$5", "$6", __UA_t0, __UA_t1, "$15", "$24", "$31"
656#else
657#define bzero_clobbers "$4", "$5", "$6", __UA_t0, __UA_t1, "$31"
658#endif /* CONFIG_CPU_MICROMIPS */
659
660 if (eva_kernel_access()) {
661 __asm__ __volatile__(
662 "move\t$4, %1\n\t"
663 "move\t$5, $0\n\t"
664 "move\t$6, %2\n\t"
665 __MODULE_JAL(__bzero_kernel)
666 "move\t%0, $6"
667 : "=r" (res)
668 : "r" (addr), "r" (size)
669 : bzero_clobbers);
670 } else {
671 might_fault();
672 __asm__ __volatile__(
673 "move\t$4, %1\n\t"
674 "move\t$5, $0\n\t"
675 "move\t$6, %2\n\t"
676 __MODULE_JAL(__bzero)
677 "move\t%0, $6"
678 : "=r" (res)
679 : "r" (addr), "r" (size)
680 : bzero_clobbers);
681 }
682
683 return res;
684}
685
686#define clear_user(addr,n) \
687({ \
688 void __user * __cl_addr = (addr); \
689 unsigned long __cl_size = (n); \
690 if (__cl_size && access_ok(__cl_addr, __cl_size)) \
691 __cl_size = __clear_user(__cl_addr, __cl_size); \
692 __cl_size; \
693})
694
695extern long __strncpy_from_kernel_asm(char *__to, const char __user *__from, long __len);
696extern long __strncpy_from_user_asm(char *__to, const char __user *__from, long __len);
697
698/*
699 * strncpy_from_user: - Copy a NUL terminated string from userspace.
700 * @dst: Destination address, in kernel space. This buffer must be at
701 * least @count bytes long.
702 * @src: Source address, in user space.
703 * @count: Maximum number of bytes to copy, including the trailing NUL.
704 *
705 * Copies a NUL-terminated string from userspace to kernel space.
706 *
707 * On success, returns the length of the string (not including the trailing
708 * NUL).
709 *
710 * If access to userspace fails, returns -EFAULT (some data may have been
711 * copied).
712 *
713 * If @count is smaller than the length of the string, copies @count bytes
714 * and returns @count.
715 */
716static inline long
717strncpy_from_user(char *__to, const char __user *__from, long __len)
718{
719 long res;
720
721 if (eva_kernel_access()) {
722 __asm__ __volatile__(
723 "move\t$4, %1\n\t"
724 "move\t$5, %2\n\t"
725 "move\t$6, %3\n\t"
726 __MODULE_JAL(__strncpy_from_kernel_asm)
727 "move\t%0, $2"
728 : "=r" (res)
729 : "r" (__to), "r" (__from), "r" (__len)
730 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
731 } else {
732 might_fault();
733 __asm__ __volatile__(
734 "move\t$4, %1\n\t"
735 "move\t$5, %2\n\t"
736 "move\t$6, %3\n\t"
737 __MODULE_JAL(__strncpy_from_user_asm)
738 "move\t%0, $2"
739 : "=r" (res)
740 : "r" (__to), "r" (__from), "r" (__len)
741 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
742 }
743
744 return res;
745}
746
747extern long __strnlen_kernel_asm(const char __user *s, long n);
748extern long __strnlen_user_asm(const char __user *s, long n);
749
750/*
751 * strnlen_user: - Get the size of a string in user space.
752 * @str: The string to measure.
753 *
754 * Context: User context only. This function may sleep if pagefaults are
755 * enabled.
756 *
757 * Get the size of a NUL-terminated string in user space.
758 *
759 * Returns the size of the string INCLUDING the terminating NUL.
760 * On exception, returns 0.
761 * If the string is too long, returns a value greater than @n.
762 */
763static inline long strnlen_user(const char __user *s, long n)
764{
765 long res;
766
767 might_fault();
768 if (eva_kernel_access()) {
769 __asm__ __volatile__(
770 "move\t$4, %1\n\t"
771 "move\t$5, %2\n\t"
772 __MODULE_JAL(__strnlen_kernel_asm)
773 "move\t%0, $2"
774 : "=r" (res)
775 : "r" (s), "r" (n)
776 : "$2", "$4", "$5", __UA_t0, "$31");
777 } else {
778 __asm__ __volatile__(
779 "move\t$4, %1\n\t"
780 "move\t$5, %2\n\t"
781 __MODULE_JAL(__strnlen_user_asm)
782 "move\t%0, $2"
783 : "=r" (res)
784 : "r" (s), "r" (n)
785 : "$2", "$4", "$5", __UA_t0, "$31");
786 }
787
788 return res;
789}
790
791#endif /* _ASM_UACCESS_H */
1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 03, 04 by Ralf Baechle
7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
8 * Copyright (C) 2007 Maciej W. Rozycki
9 * Copyright (C) 2014, Imagination Technologies Ltd.
10 */
11#ifndef _ASM_UACCESS_H
12#define _ASM_UACCESS_H
13
14#include <linux/kernel.h>
15#include <linux/string.h>
16#include <asm/asm-eva.h>
17#include <asm/extable.h>
18
19#ifdef CONFIG_32BIT
20
21#define __UA_LIMIT 0x80000000UL
22#define TASK_SIZE_MAX KSEG0
23
24#define __UA_ADDR ".word"
25#define __UA_LA "la"
26#define __UA_ADDU "addu"
27#define __UA_t0 "$8"
28#define __UA_t1 "$9"
29
30#endif /* CONFIG_32BIT */
31
32#ifdef CONFIG_64BIT
33
34extern u64 __ua_limit;
35
36#define __UA_LIMIT __ua_limit
37#define TASK_SIZE_MAX XKSSEG
38
39#define __UA_ADDR ".dword"
40#define __UA_LA "dla"
41#define __UA_ADDU "daddu"
42#define __UA_t0 "$12"
43#define __UA_t1 "$13"
44
45#endif /* CONFIG_64BIT */
46
47#include <asm-generic/access_ok.h>
48
49/*
50 * put_user: - Write a simple value into user space.
51 * @x: Value to copy to user space.
52 * @ptr: Destination address, in user space.
53 *
54 * Context: User context only. This function may sleep if pagefaults are
55 * enabled.
56 *
57 * This macro copies a single simple value from kernel space to user
58 * space. It supports simple types like char and int, but not larger
59 * data types like structures or arrays.
60 *
61 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
62 * to the result of dereferencing @ptr.
63 *
64 * Returns zero on success, or -EFAULT on error.
65 */
66#define put_user(x, ptr) \
67({ \
68 __typeof__(*(ptr)) __user *__p = (ptr); \
69 \
70 might_fault(); \
71 access_ok(__p, sizeof(*__p)) ? __put_user((x), __p) : -EFAULT; \
72})
73
74/*
75 * get_user: - Get a simple variable from user space.
76 * @x: Variable to store result.
77 * @ptr: Source address, in user space.
78 *
79 * Context: User context only. This function may sleep if pagefaults are
80 * enabled.
81 *
82 * This macro copies a single simple variable from user space to kernel
83 * space. It supports simple types like char and int, but not larger
84 * data types like structures or arrays.
85 *
86 * @ptr must have pointer-to-simple-variable type, and the result of
87 * dereferencing @ptr must be assignable to @x without a cast.
88 *
89 * Returns zero on success, or -EFAULT on error.
90 * On error, the variable @x is set to zero.
91 */
92#define get_user(x, ptr) \
93({ \
94 const __typeof__(*(ptr)) __user *__p = (ptr); \
95 \
96 might_fault(); \
97 access_ok(__p, sizeof(*__p)) ? __get_user((x), __p) : \
98 ((x) = 0, -EFAULT); \
99})
100
101/*
102 * __put_user: - Write a simple value into user space, with less checking.
103 * @x: Value to copy to user space.
104 * @ptr: Destination address, in user space.
105 *
106 * Context: User context only. This function may sleep if pagefaults are
107 * enabled.
108 *
109 * This macro copies a single simple value from kernel space to user
110 * space. It supports simple types like char and int, but not larger
111 * data types like structures or arrays.
112 *
113 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
114 * to the result of dereferencing @ptr.
115 *
116 * Caller must check the pointer with access_ok() before calling this
117 * function.
118 *
119 * Returns zero on success, or -EFAULT on error.
120 */
121#define __put_user(x, ptr) \
122({ \
123 __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
124 __typeof__(*(ptr)) __pu_val = (x); \
125 int __pu_err = 0; \
126 \
127 __chk_user_ptr(__pu_ptr); \
128 switch (sizeof(*__pu_ptr)) { \
129 case 1: \
130 __put_data_asm(user_sb, __pu_ptr); \
131 break; \
132 case 2: \
133 __put_data_asm(user_sh, __pu_ptr); \
134 break; \
135 case 4: \
136 __put_data_asm(user_sw, __pu_ptr); \
137 break; \
138 case 8: \
139 __PUT_DW(user_sd, __pu_ptr); \
140 break; \
141 default: \
142 BUILD_BUG(); \
143 } \
144 \
145 __pu_err; \
146})
147
148/*
149 * __get_user: - Get a simple variable from user space, with less checking.
150 * @x: Variable to store result.
151 * @ptr: Source address, in user space.
152 *
153 * Context: User context only. This function may sleep if pagefaults are
154 * enabled.
155 *
156 * This macro copies a single simple variable from user space to kernel
157 * space. It supports simple types like char and int, but not larger
158 * data types like structures or arrays.
159 *
160 * @ptr must have pointer-to-simple-variable type, and the result of
161 * dereferencing @ptr must be assignable to @x without a cast.
162 *
163 * Caller must check the pointer with access_ok() before calling this
164 * function.
165 *
166 * Returns zero on success, or -EFAULT on error.
167 * On error, the variable @x is set to zero.
168 */
169#define __get_user(x, ptr) \
170({ \
171 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
172 int __gu_err = 0; \
173 \
174 __chk_user_ptr(__gu_ptr); \
175 switch (sizeof(*__gu_ptr)) { \
176 case 1: \
177 __get_data_asm((x), user_lb, __gu_ptr); \
178 break; \
179 case 2: \
180 __get_data_asm((x), user_lh, __gu_ptr); \
181 break; \
182 case 4: \
183 __get_data_asm((x), user_lw, __gu_ptr); \
184 break; \
185 case 8: \
186 __GET_DW((x), user_ld, __gu_ptr); \
187 break; \
188 default: \
189 BUILD_BUG(); \
190 } \
191 \
192 __gu_err; \
193})
194
195struct __large_struct { unsigned long buf[100]; };
196#define __m(x) (*(struct __large_struct __user *)(x))
197
198#ifdef CONFIG_32BIT
199#define __GET_DW(val, insn, ptr) __get_data_asm_ll32(val, insn, ptr)
200#endif
201#ifdef CONFIG_64BIT
202#define __GET_DW(val, insn, ptr) __get_data_asm(val, insn, ptr)
203#endif
204
205#define __get_data_asm(val, insn, addr) \
206{ \
207 long __gu_tmp; \
208 \
209 __asm__ __volatile__( \
210 "1: "insn("%1", "%3")" \n" \
211 "2: \n" \
212 " .insn \n" \
213 " .section .fixup,\"ax\" \n" \
214 "3: li %0, %4 \n" \
215 " move %1, $0 \n" \
216 " j 2b \n" \
217 " .previous \n" \
218 " .section __ex_table,\"a\" \n" \
219 " "__UA_ADDR "\t1b, 3b \n" \
220 " .previous \n" \
221 : "=r" (__gu_err), "=r" (__gu_tmp) \
222 : "0" (0), "o" (__m(addr)), "i" (-EFAULT)); \
223 \
224 (val) = (__typeof__(*(addr))) __gu_tmp; \
225}
226
227/*
228 * Get a long long 64 using 32 bit registers.
229 */
230#define __get_data_asm_ll32(val, insn, addr) \
231{ \
232 union { \
233 unsigned long long l; \
234 __typeof__(*(addr)) t; \
235 } __gu_tmp; \
236 \
237 __asm__ __volatile__( \
238 "1: " insn("%1", "(%3)")" \n" \
239 "2: " insn("%D1", "4(%3)")" \n" \
240 "3: \n" \
241 " .insn \n" \
242 " .section .fixup,\"ax\" \n" \
243 "4: li %0, %4 \n" \
244 " move %1, $0 \n" \
245 " move %D1, $0 \n" \
246 " j 3b \n" \
247 " .previous \n" \
248 " .section __ex_table,\"a\" \n" \
249 " " __UA_ADDR " 1b, 4b \n" \
250 " " __UA_ADDR " 2b, 4b \n" \
251 " .previous \n" \
252 : "=r" (__gu_err), "=&r" (__gu_tmp.l) \
253 : "0" (0), "r" (addr), "i" (-EFAULT)); \
254 \
255 (val) = __gu_tmp.t; \
256}
257
258#define __get_kernel_nofault(dst, src, type, err_label) \
259do { \
260 int __gu_err; \
261 \
262 switch (sizeof(type)) { \
263 case 1: \
264 __get_data_asm(*(type *)(dst), kernel_lb, \
265 (__force type *)(src)); \
266 break; \
267 case 2: \
268 __get_data_asm(*(type *)(dst), kernel_lh, \
269 (__force type *)(src)); \
270 break; \
271 case 4: \
272 __get_data_asm(*(type *)(dst), kernel_lw, \
273 (__force type *)(src)); \
274 break; \
275 case 8: \
276 __GET_DW(*(type *)(dst), kernel_ld, \
277 (__force type *)(src)); \
278 break; \
279 default: \
280 BUILD_BUG(); \
281 break; \
282 } \
283 if (unlikely(__gu_err)) \
284 goto err_label; \
285} while (0)
286
287/*
288 * Yuck. We need two variants, one for 64bit operation and one
289 * for 32 bit mode and old iron.
290 */
291#ifdef CONFIG_32BIT
292#define __PUT_DW(insn, ptr) __put_data_asm_ll32(insn, ptr)
293#endif
294#ifdef CONFIG_64BIT
295#define __PUT_DW(insn, ptr) __put_data_asm(insn, ptr)
296#endif
297
298#define __put_data_asm(insn, ptr) \
299{ \
300 __asm__ __volatile__( \
301 "1: "insn("%z2", "%3")" # __put_data_asm \n" \
302 "2: \n" \
303 " .insn \n" \
304 " .section .fixup,\"ax\" \n" \
305 "3: li %0, %4 \n" \
306 " j 2b \n" \
307 " .previous \n" \
308 " .section __ex_table,\"a\" \n" \
309 " " __UA_ADDR " 1b, 3b \n" \
310 " .previous \n" \
311 : "=r" (__pu_err) \
312 : "0" (0), "Jr" (__pu_val), "o" (__m(ptr)), \
313 "i" (-EFAULT)); \
314}
315
316#define __put_data_asm_ll32(insn, ptr) \
317{ \
318 __asm__ __volatile__( \
319 "1: "insn("%2", "(%3)")" # __put_data_asm_ll32 \n" \
320 "2: "insn("%D2", "4(%3)")" \n" \
321 "3: \n" \
322 " .insn \n" \
323 " .section .fixup,\"ax\" \n" \
324 "4: li %0, %4 \n" \
325 " j 3b \n" \
326 " .previous \n" \
327 " .section __ex_table,\"a\" \n" \
328 " " __UA_ADDR " 1b, 4b \n" \
329 " " __UA_ADDR " 2b, 4b \n" \
330 " .previous" \
331 : "=r" (__pu_err) \
332 : "0" (0), "r" (__pu_val), "r" (ptr), \
333 "i" (-EFAULT)); \
334}
335
336#define __put_kernel_nofault(dst, src, type, err_label) \
337do { \
338 type __pu_val; \
339 int __pu_err = 0; \
340 \
341 __pu_val = *(__force type *)(src); \
342 switch (sizeof(type)) { \
343 case 1: \
344 __put_data_asm(kernel_sb, (type *)(dst)); \
345 break; \
346 case 2: \
347 __put_data_asm(kernel_sh, (type *)(dst)); \
348 break; \
349 case 4: \
350 __put_data_asm(kernel_sw, (type *)(dst)) \
351 break; \
352 case 8: \
353 __PUT_DW(kernel_sd, (type *)(dst)); \
354 break; \
355 default: \
356 BUILD_BUG(); \
357 break; \
358 } \
359 if (unlikely(__pu_err)) \
360 goto err_label; \
361} while (0)
362
363
364/*
365 * We're generating jump to subroutines which will be outside the range of
366 * jump instructions
367 */
368#ifdef MODULE
369#define __MODULE_JAL(destination) \
370 ".set\tnoat\n\t" \
371 __UA_LA "\t$1, " #destination "\n\t" \
372 "jalr\t$1\n\t" \
373 ".set\tat\n\t"
374#else
375#define __MODULE_JAL(destination) \
376 "jal\t" #destination "\n\t"
377#endif
378
379#if defined(CONFIG_CPU_DADDI_WORKAROUNDS) || (defined(CONFIG_EVA) && \
380 defined(CONFIG_CPU_HAS_PREFETCH))
381#define DADDI_SCRATCH "$3"
382#else
383#define DADDI_SCRATCH "$0"
384#endif
385
386extern size_t __raw_copy_from_user(void *__to, const void *__from, size_t __n);
387extern size_t __raw_copy_to_user(void *__to, const void *__from, size_t __n);
388
389static inline unsigned long
390raw_copy_from_user(void *to, const void __user *from, unsigned long n)
391{
392 register void *__cu_to_r __asm__("$4");
393 register const void __user *__cu_from_r __asm__("$5");
394 register long __cu_len_r __asm__("$6");
395
396 __cu_to_r = to;
397 __cu_from_r = from;
398 __cu_len_r = n;
399
400 __asm__ __volatile__(
401 ".set\tnoreorder\n\t"
402 __MODULE_JAL(__raw_copy_from_user)
403 ".set\tnoat\n\t"
404 __UA_ADDU "\t$1, %1, %2\n\t"
405 ".set\tat\n\t"
406 ".set\treorder"
407 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)
408 :
409 : "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",
410 DADDI_SCRATCH, "memory");
411
412 return __cu_len_r;
413}
414
415static inline unsigned long
416raw_copy_to_user(void __user *to, const void *from, unsigned long n)
417{
418 register void __user *__cu_to_r __asm__("$4");
419 register const void *__cu_from_r __asm__("$5");
420 register long __cu_len_r __asm__("$6");
421
422 __cu_to_r = (to);
423 __cu_from_r = (from);
424 __cu_len_r = (n);
425
426 __asm__ __volatile__(
427 __MODULE_JAL(__raw_copy_to_user)
428 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)
429 :
430 : "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",
431 DADDI_SCRATCH, "memory");
432
433 return __cu_len_r;
434}
435
436#define INLINE_COPY_FROM_USER
437#define INLINE_COPY_TO_USER
438
439extern __kernel_size_t __bzero(void __user *addr, __kernel_size_t size);
440
441/*
442 * __clear_user: - Zero a block of memory in user space, with less checking.
443 * @to: Destination address, in user space.
444 * @n: Number of bytes to zero.
445 *
446 * Zero a block of memory in user space. Caller must check
447 * the specified block with access_ok() before calling this function.
448 *
449 * Returns number of bytes that could not be cleared.
450 * On success, this will be zero.
451 */
452static inline __kernel_size_t
453__clear_user(void __user *addr, __kernel_size_t size)
454{
455 __kernel_size_t res;
456
457#ifdef CONFIG_CPU_MICROMIPS
458/* micromips memset / bzero also clobbers t7 & t8 */
459#define bzero_clobbers "$4", "$5", "$6", __UA_t0, __UA_t1, "$15", "$24", "$31"
460#else
461#define bzero_clobbers "$4", "$5", "$6", __UA_t0, __UA_t1, "$31"
462#endif /* CONFIG_CPU_MICROMIPS */
463
464 might_fault();
465 __asm__ __volatile__(
466 "move\t$4, %1\n\t"
467 "move\t$5, $0\n\t"
468 "move\t$6, %2\n\t"
469 __MODULE_JAL(__bzero)
470 "move\t%0, $6"
471 : "=r" (res)
472 : "r" (addr), "r" (size)
473 : bzero_clobbers);
474
475 return res;
476}
477
478#define clear_user(addr,n) \
479({ \
480 void __user * __cl_addr = (addr); \
481 unsigned long __cl_size = (n); \
482 if (__cl_size && access_ok(__cl_addr, __cl_size)) \
483 __cl_size = __clear_user(__cl_addr, __cl_size); \
484 __cl_size; \
485})
486
487extern long __strncpy_from_user_asm(char *__to, const char __user *__from, long __len);
488
489/*
490 * strncpy_from_user: - Copy a NUL terminated string from userspace.
491 * @dst: Destination address, in kernel space. This buffer must be at
492 * least @count bytes long.
493 * @src: Source address, in user space.
494 * @count: Maximum number of bytes to copy, including the trailing NUL.
495 *
496 * Copies a NUL-terminated string from userspace to kernel space.
497 *
498 * On success, returns the length of the string (not including the trailing
499 * NUL).
500 *
501 * If access to userspace fails, returns -EFAULT (some data may have been
502 * copied).
503 *
504 * If @count is smaller than the length of the string, copies @count bytes
505 * and returns @count.
506 */
507static inline long
508strncpy_from_user(char *__to, const char __user *__from, long __len)
509{
510 long res;
511
512 if (!access_ok(__from, __len))
513 return -EFAULT;
514
515 might_fault();
516 __asm__ __volatile__(
517 "move\t$4, %1\n\t"
518 "move\t$5, %2\n\t"
519 "move\t$6, %3\n\t"
520 __MODULE_JAL(__strncpy_from_user_asm)
521 "move\t%0, $2"
522 : "=r" (res)
523 : "r" (__to), "r" (__from), "r" (__len)
524 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
525
526 return res;
527}
528
529extern long __strnlen_user_asm(const char __user *s, long n);
530
531/*
532 * strnlen_user: - Get the size of a string in user space.
533 * @str: The string to measure.
534 *
535 * Context: User context only. This function may sleep if pagefaults are
536 * enabled.
537 *
538 * Get the size of a NUL-terminated string in user space.
539 *
540 * Returns the size of the string INCLUDING the terminating NUL.
541 * On exception, returns 0.
542 * If the string is too long, returns a value greater than @n.
543 */
544static inline long strnlen_user(const char __user *s, long n)
545{
546 long res;
547
548 if (!access_ok(s, 1))
549 return 0;
550
551 might_fault();
552 __asm__ __volatile__(
553 "move\t$4, %1\n\t"
554 "move\t$5, %2\n\t"
555 __MODULE_JAL(__strnlen_user_asm)
556 "move\t%0, $2"
557 : "=r" (res)
558 : "r" (s), "r" (n)
559 : "$2", "$4", "$5", __UA_t0, "$31");
560
561 return res;
562}
563
564#endif /* _ASM_UACCESS_H */