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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * arch/arm/include/asm/uaccess.h
4 */
5#ifndef _ASMARM_UACCESS_H
6#define _ASMARM_UACCESS_H
7
8/*
9 * User space memory access functions
10 */
11#include <linux/string.h>
12#include <asm/memory.h>
13#include <asm/domain.h>
14#include <asm/unified.h>
15#include <asm/compiler.h>
16
17#include <asm/extable.h>
18
19/*
20 * These two functions allow hooking accesses to userspace to increase
21 * system integrity by ensuring that the kernel can not inadvertantly
22 * perform such accesses (eg, via list poison values) which could then
23 * be exploited for priviledge escalation.
24 */
25static __always_inline unsigned int uaccess_save_and_enable(void)
26{
27#ifdef CONFIG_CPU_SW_DOMAIN_PAN
28 unsigned int old_domain = get_domain();
29
30 /* Set the current domain access to permit user accesses */
31 set_domain((old_domain & ~domain_mask(DOMAIN_USER)) |
32 domain_val(DOMAIN_USER, DOMAIN_CLIENT));
33
34 return old_domain;
35#else
36 return 0;
37#endif
38}
39
40static __always_inline void uaccess_restore(unsigned int flags)
41{
42#ifdef CONFIG_CPU_SW_DOMAIN_PAN
43 /* Restore the user access mask */
44 set_domain(flags);
45#endif
46}
47
48/*
49 * These two are intentionally not defined anywhere - if the kernel
50 * code generates any references to them, that's a bug.
51 */
52extern int __get_user_bad(void);
53extern int __put_user_bad(void);
54
55/*
56 * Note that this is actually 0x1,0000,0000
57 */
58#define KERNEL_DS 0x00000000
59
60#ifdef CONFIG_MMU
61
62#define USER_DS TASK_SIZE
63#define get_fs() (current_thread_info()->addr_limit)
64
65static inline void set_fs(mm_segment_t fs)
66{
67 current_thread_info()->addr_limit = fs;
68
69 /*
70 * Prevent a mispredicted conditional call to set_fs from forwarding
71 * the wrong address limit to access_ok under speculation.
72 */
73 dsb(nsh);
74 isb();
75
76 modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
77}
78
79#define segment_eq(a, b) ((a) == (b))
80
81/* We use 33-bit arithmetic here... */
82#define __range_ok(addr, size) ({ \
83 unsigned long flag, roksum; \
84 __chk_user_ptr(addr); \
85 __asm__(".syntax unified\n" \
86 "adds %1, %2, %3; sbcscc %1, %1, %0; movcc %0, #0" \
87 : "=&r" (flag), "=&r" (roksum) \
88 : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
89 : "cc"); \
90 flag; })
91
92/*
93 * This is a type: either unsigned long, if the argument fits into
94 * that type, or otherwise unsigned long long.
95 */
96#define __inttype(x) \
97 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
98
99/*
100 * Sanitise a uaccess pointer such that it becomes NULL if addr+size
101 * is above the current addr_limit.
102 */
103#define uaccess_mask_range_ptr(ptr, size) \
104 ((__typeof__(ptr))__uaccess_mask_range_ptr(ptr, size))
105static inline void __user *__uaccess_mask_range_ptr(const void __user *ptr,
106 size_t size)
107{
108 void __user *safe_ptr = (void __user *)ptr;
109 unsigned long tmp;
110
111 asm volatile(
112 " .syntax unified\n"
113 " sub %1, %3, #1\n"
114 " subs %1, %1, %0\n"
115 " addhs %1, %1, #1\n"
116 " subshs %1, %1, %2\n"
117 " movlo %0, #0\n"
118 : "+r" (safe_ptr), "=&r" (tmp)
119 : "r" (size), "r" (current_thread_info()->addr_limit)
120 : "cc");
121
122 csdb();
123 return safe_ptr;
124}
125
126/*
127 * Single-value transfer routines. They automatically use the right
128 * size if we just have the right pointer type. Note that the functions
129 * which read from user space (*get_*) need to take care not to leak
130 * kernel data even if the calling code is buggy and fails to check
131 * the return value. This means zeroing out the destination variable
132 * or buffer on error. Normally this is done out of line by the
133 * fixup code, but there are a few places where it intrudes on the
134 * main code path. When we only write to user space, there is no
135 * problem.
136 */
137extern int __get_user_1(void *);
138extern int __get_user_2(void *);
139extern int __get_user_4(void *);
140extern int __get_user_32t_8(void *);
141extern int __get_user_8(void *);
142extern int __get_user_64t_1(void *);
143extern int __get_user_64t_2(void *);
144extern int __get_user_64t_4(void *);
145
146#define __GUP_CLOBBER_1 "lr", "cc"
147#ifdef CONFIG_CPU_USE_DOMAINS
148#define __GUP_CLOBBER_2 "ip", "lr", "cc"
149#else
150#define __GUP_CLOBBER_2 "lr", "cc"
151#endif
152#define __GUP_CLOBBER_4 "lr", "cc"
153#define __GUP_CLOBBER_32t_8 "lr", "cc"
154#define __GUP_CLOBBER_8 "lr", "cc"
155
156#define __get_user_x(__r2, __p, __e, __l, __s) \
157 __asm__ __volatile__ ( \
158 __asmeq("%0", "r0") __asmeq("%1", "r2") \
159 __asmeq("%3", "r1") \
160 "bl __get_user_" #__s \
161 : "=&r" (__e), "=r" (__r2) \
162 : "0" (__p), "r" (__l) \
163 : __GUP_CLOBBER_##__s)
164
165/* narrowing a double-word get into a single 32bit word register: */
166#ifdef __ARMEB__
167#define __get_user_x_32t(__r2, __p, __e, __l, __s) \
168 __get_user_x(__r2, __p, __e, __l, 32t_8)
169#else
170#define __get_user_x_32t __get_user_x
171#endif
172
173/*
174 * storing result into proper least significant word of 64bit target var,
175 * different only for big endian case where 64 bit __r2 lsw is r3:
176 */
177#ifdef __ARMEB__
178#define __get_user_x_64t(__r2, __p, __e, __l, __s) \
179 __asm__ __volatile__ ( \
180 __asmeq("%0", "r0") __asmeq("%1", "r2") \
181 __asmeq("%3", "r1") \
182 "bl __get_user_64t_" #__s \
183 : "=&r" (__e), "=r" (__r2) \
184 : "0" (__p), "r" (__l) \
185 : __GUP_CLOBBER_##__s)
186#else
187#define __get_user_x_64t __get_user_x
188#endif
189
190
191#define __get_user_check(x, p) \
192 ({ \
193 unsigned long __limit = current_thread_info()->addr_limit - 1; \
194 register typeof(*(p)) __user *__p asm("r0") = (p); \
195 register __inttype(x) __r2 asm("r2"); \
196 register unsigned long __l asm("r1") = __limit; \
197 register int __e asm("r0"); \
198 unsigned int __ua_flags = uaccess_save_and_enable(); \
199 switch (sizeof(*(__p))) { \
200 case 1: \
201 if (sizeof((x)) >= 8) \
202 __get_user_x_64t(__r2, __p, __e, __l, 1); \
203 else \
204 __get_user_x(__r2, __p, __e, __l, 1); \
205 break; \
206 case 2: \
207 if (sizeof((x)) >= 8) \
208 __get_user_x_64t(__r2, __p, __e, __l, 2); \
209 else \
210 __get_user_x(__r2, __p, __e, __l, 2); \
211 break; \
212 case 4: \
213 if (sizeof((x)) >= 8) \
214 __get_user_x_64t(__r2, __p, __e, __l, 4); \
215 else \
216 __get_user_x(__r2, __p, __e, __l, 4); \
217 break; \
218 case 8: \
219 if (sizeof((x)) < 8) \
220 __get_user_x_32t(__r2, __p, __e, __l, 4); \
221 else \
222 __get_user_x(__r2, __p, __e, __l, 8); \
223 break; \
224 default: __e = __get_user_bad(); break; \
225 } \
226 uaccess_restore(__ua_flags); \
227 x = (typeof(*(p))) __r2; \
228 __e; \
229 })
230
231#define get_user(x, p) \
232 ({ \
233 might_fault(); \
234 __get_user_check(x, p); \
235 })
236
237extern int __put_user_1(void *, unsigned int);
238extern int __put_user_2(void *, unsigned int);
239extern int __put_user_4(void *, unsigned int);
240extern int __put_user_8(void *, unsigned long long);
241
242#define __put_user_check(__pu_val, __ptr, __err, __s) \
243 ({ \
244 unsigned long __limit = current_thread_info()->addr_limit - 1; \
245 register typeof(__pu_val) __r2 asm("r2") = __pu_val; \
246 register const void __user *__p asm("r0") = __ptr; \
247 register unsigned long __l asm("r1") = __limit; \
248 register int __e asm("r0"); \
249 __asm__ __volatile__ ( \
250 __asmeq("%0", "r0") __asmeq("%2", "r2") \
251 __asmeq("%3", "r1") \
252 "bl __put_user_" #__s \
253 : "=&r" (__e) \
254 : "0" (__p), "r" (__r2), "r" (__l) \
255 : "ip", "lr", "cc"); \
256 __err = __e; \
257 })
258
259#else /* CONFIG_MMU */
260
261/*
262 * uClinux has only one addr space, so has simplified address limits.
263 */
264#define USER_DS KERNEL_DS
265
266#define segment_eq(a, b) (1)
267#define __addr_ok(addr) ((void)(addr), 1)
268#define __range_ok(addr, size) ((void)(addr), 0)
269#define get_fs() (KERNEL_DS)
270
271static inline void set_fs(mm_segment_t fs)
272{
273}
274
275#define get_user(x, p) __get_user(x, p)
276#define __put_user_check __put_user_nocheck
277
278#endif /* CONFIG_MMU */
279
280#define access_ok(addr, size) (__range_ok(addr, size) == 0)
281
282#define user_addr_max() \
283 (uaccess_kernel() ? ~0UL : get_fs())
284
285#ifdef CONFIG_CPU_SPECTRE
286/*
287 * When mitigating Spectre variant 1, it is not worth fixing the non-
288 * verifying accessors, because we need to add verification of the
289 * address space there. Force these to use the standard get_user()
290 * version instead.
291 */
292#define __get_user(x, ptr) get_user(x, ptr)
293#else
294
295/*
296 * The "__xxx" versions of the user access functions do not verify the
297 * address space - it must have been done previously with a separate
298 * "access_ok()" call.
299 *
300 * The "xxx_error" versions set the third argument to EFAULT if an
301 * error occurs, and leave it unchanged on success. Note that these
302 * versions are void (ie, don't return a value as such).
303 */
304#define __get_user(x, ptr) \
305({ \
306 long __gu_err = 0; \
307 __get_user_err((x), (ptr), __gu_err); \
308 __gu_err; \
309})
310
311#define __get_user_err(x, ptr, err) \
312do { \
313 unsigned long __gu_addr = (unsigned long)(ptr); \
314 unsigned long __gu_val; \
315 unsigned int __ua_flags; \
316 __chk_user_ptr(ptr); \
317 might_fault(); \
318 __ua_flags = uaccess_save_and_enable(); \
319 switch (sizeof(*(ptr))) { \
320 case 1: __get_user_asm_byte(__gu_val, __gu_addr, err); break; \
321 case 2: __get_user_asm_half(__gu_val, __gu_addr, err); break; \
322 case 4: __get_user_asm_word(__gu_val, __gu_addr, err); break; \
323 default: (__gu_val) = __get_user_bad(); \
324 } \
325 uaccess_restore(__ua_flags); \
326 (x) = (__typeof__(*(ptr)))__gu_val; \
327} while (0)
328
329#define __get_user_asm(x, addr, err, instr) \
330 __asm__ __volatile__( \
331 "1: " TUSER(instr) " %1, [%2], #0\n" \
332 "2:\n" \
333 " .pushsection .text.fixup,\"ax\"\n" \
334 " .align 2\n" \
335 "3: mov %0, %3\n" \
336 " mov %1, #0\n" \
337 " b 2b\n" \
338 " .popsection\n" \
339 " .pushsection __ex_table,\"a\"\n" \
340 " .align 3\n" \
341 " .long 1b, 3b\n" \
342 " .popsection" \
343 : "+r" (err), "=&r" (x) \
344 : "r" (addr), "i" (-EFAULT) \
345 : "cc")
346
347#define __get_user_asm_byte(x, addr, err) \
348 __get_user_asm(x, addr, err, ldrb)
349
350#if __LINUX_ARM_ARCH__ >= 6
351
352#define __get_user_asm_half(x, addr, err) \
353 __get_user_asm(x, addr, err, ldrh)
354
355#else
356
357#ifndef __ARMEB__
358#define __get_user_asm_half(x, __gu_addr, err) \
359({ \
360 unsigned long __b1, __b2; \
361 __get_user_asm_byte(__b1, __gu_addr, err); \
362 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
363 (x) = __b1 | (__b2 << 8); \
364})
365#else
366#define __get_user_asm_half(x, __gu_addr, err) \
367({ \
368 unsigned long __b1, __b2; \
369 __get_user_asm_byte(__b1, __gu_addr, err); \
370 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
371 (x) = (__b1 << 8) | __b2; \
372})
373#endif
374
375#endif /* __LINUX_ARM_ARCH__ >= 6 */
376
377#define __get_user_asm_word(x, addr, err) \
378 __get_user_asm(x, addr, err, ldr)
379#endif
380
381
382#define __put_user_switch(x, ptr, __err, __fn) \
383 do { \
384 const __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
385 __typeof__(*(ptr)) __pu_val = (x); \
386 unsigned int __ua_flags; \
387 might_fault(); \
388 __ua_flags = uaccess_save_and_enable(); \
389 switch (sizeof(*(ptr))) { \
390 case 1: __fn(__pu_val, __pu_ptr, __err, 1); break; \
391 case 2: __fn(__pu_val, __pu_ptr, __err, 2); break; \
392 case 4: __fn(__pu_val, __pu_ptr, __err, 4); break; \
393 case 8: __fn(__pu_val, __pu_ptr, __err, 8); break; \
394 default: __err = __put_user_bad(); break; \
395 } \
396 uaccess_restore(__ua_flags); \
397 } while (0)
398
399#define put_user(x, ptr) \
400({ \
401 int __pu_err = 0; \
402 __put_user_switch((x), (ptr), __pu_err, __put_user_check); \
403 __pu_err; \
404})
405
406#ifdef CONFIG_CPU_SPECTRE
407/*
408 * When mitigating Spectre variant 1.1, all accessors need to include
409 * verification of the address space.
410 */
411#define __put_user(x, ptr) put_user(x, ptr)
412
413#else
414#define __put_user(x, ptr) \
415({ \
416 long __pu_err = 0; \
417 __put_user_switch((x), (ptr), __pu_err, __put_user_nocheck); \
418 __pu_err; \
419})
420
421#define __put_user_nocheck(x, __pu_ptr, __err, __size) \
422 do { \
423 unsigned long __pu_addr = (unsigned long)__pu_ptr; \
424 __put_user_nocheck_##__size(x, __pu_addr, __err); \
425 } while (0)
426
427#define __put_user_nocheck_1 __put_user_asm_byte
428#define __put_user_nocheck_2 __put_user_asm_half
429#define __put_user_nocheck_4 __put_user_asm_word
430#define __put_user_nocheck_8 __put_user_asm_dword
431
432#define __put_user_asm(x, __pu_addr, err, instr) \
433 __asm__ __volatile__( \
434 "1: " TUSER(instr) " %1, [%2], #0\n" \
435 "2:\n" \
436 " .pushsection .text.fixup,\"ax\"\n" \
437 " .align 2\n" \
438 "3: mov %0, %3\n" \
439 " b 2b\n" \
440 " .popsection\n" \
441 " .pushsection __ex_table,\"a\"\n" \
442 " .align 3\n" \
443 " .long 1b, 3b\n" \
444 " .popsection" \
445 : "+r" (err) \
446 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
447 : "cc")
448
449#define __put_user_asm_byte(x, __pu_addr, err) \
450 __put_user_asm(x, __pu_addr, err, strb)
451
452#if __LINUX_ARM_ARCH__ >= 6
453
454#define __put_user_asm_half(x, __pu_addr, err) \
455 __put_user_asm(x, __pu_addr, err, strh)
456
457#else
458
459#ifndef __ARMEB__
460#define __put_user_asm_half(x, __pu_addr, err) \
461({ \
462 unsigned long __temp = (__force unsigned long)(x); \
463 __put_user_asm_byte(__temp, __pu_addr, err); \
464 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
465})
466#else
467#define __put_user_asm_half(x, __pu_addr, err) \
468({ \
469 unsigned long __temp = (__force unsigned long)(x); \
470 __put_user_asm_byte(__temp >> 8, __pu_addr, err); \
471 __put_user_asm_byte(__temp, __pu_addr + 1, err); \
472})
473#endif
474
475#endif /* __LINUX_ARM_ARCH__ >= 6 */
476
477#define __put_user_asm_word(x, __pu_addr, err) \
478 __put_user_asm(x, __pu_addr, err, str)
479
480#ifndef __ARMEB__
481#define __reg_oper0 "%R2"
482#define __reg_oper1 "%Q2"
483#else
484#define __reg_oper0 "%Q2"
485#define __reg_oper1 "%R2"
486#endif
487
488#define __put_user_asm_dword(x, __pu_addr, err) \
489 __asm__ __volatile__( \
490 ARM( "1: " TUSER(str) " " __reg_oper1 ", [%1], #4\n" ) \
491 ARM( "2: " TUSER(str) " " __reg_oper0 ", [%1]\n" ) \
492 THUMB( "1: " TUSER(str) " " __reg_oper1 ", [%1]\n" ) \
493 THUMB( "2: " TUSER(str) " " __reg_oper0 ", [%1, #4]\n" ) \
494 "3:\n" \
495 " .pushsection .text.fixup,\"ax\"\n" \
496 " .align 2\n" \
497 "4: mov %0, %3\n" \
498 " b 3b\n" \
499 " .popsection\n" \
500 " .pushsection __ex_table,\"a\"\n" \
501 " .align 3\n" \
502 " .long 1b, 4b\n" \
503 " .long 2b, 4b\n" \
504 " .popsection" \
505 : "+r" (err), "+r" (__pu_addr) \
506 : "r" (x), "i" (-EFAULT) \
507 : "cc")
508
509#endif /* !CONFIG_CPU_SPECTRE */
510
511#ifdef CONFIG_MMU
512extern unsigned long __must_check
513arm_copy_from_user(void *to, const void __user *from, unsigned long n);
514
515static inline unsigned long __must_check
516raw_copy_from_user(void *to, const void __user *from, unsigned long n)
517{
518 unsigned int __ua_flags;
519
520 __ua_flags = uaccess_save_and_enable();
521 n = arm_copy_from_user(to, from, n);
522 uaccess_restore(__ua_flags);
523 return n;
524}
525
526extern unsigned long __must_check
527arm_copy_to_user(void __user *to, const void *from, unsigned long n);
528extern unsigned long __must_check
529__copy_to_user_std(void __user *to, const void *from, unsigned long n);
530
531static inline unsigned long __must_check
532raw_copy_to_user(void __user *to, const void *from, unsigned long n)
533{
534#ifndef CONFIG_UACCESS_WITH_MEMCPY
535 unsigned int __ua_flags;
536 __ua_flags = uaccess_save_and_enable();
537 n = arm_copy_to_user(to, from, n);
538 uaccess_restore(__ua_flags);
539 return n;
540#else
541 return arm_copy_to_user(to, from, n);
542#endif
543}
544
545extern unsigned long __must_check
546arm_clear_user(void __user *addr, unsigned long n);
547extern unsigned long __must_check
548__clear_user_std(void __user *addr, unsigned long n);
549
550static inline unsigned long __must_check
551__clear_user(void __user *addr, unsigned long n)
552{
553 unsigned int __ua_flags = uaccess_save_and_enable();
554 n = arm_clear_user(addr, n);
555 uaccess_restore(__ua_flags);
556 return n;
557}
558
559#else
560static inline unsigned long
561raw_copy_from_user(void *to, const void __user *from, unsigned long n)
562{
563 memcpy(to, (const void __force *)from, n);
564 return 0;
565}
566static inline unsigned long
567raw_copy_to_user(void __user *to, const void *from, unsigned long n)
568{
569 memcpy((void __force *)to, from, n);
570 return 0;
571}
572#define __clear_user(addr, n) (memset((void __force *)addr, 0, n), 0)
573#endif
574#define INLINE_COPY_TO_USER
575#define INLINE_COPY_FROM_USER
576
577static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
578{
579 if (access_ok(to, n))
580 n = __clear_user(to, n);
581 return n;
582}
583
584/* These are from lib/ code, and use __get_user() and friends */
585extern long strncpy_from_user(char *dest, const char __user *src, long count);
586
587extern __must_check long strnlen_user(const char __user *str, long n);
588
589#endif /* _ASMARM_UACCESS_H */
1/*
2 * arch/arm/include/asm/uaccess.h
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8#ifndef _ASMARM_UACCESS_H
9#define _ASMARM_UACCESS_H
10
11/*
12 * User space memory access functions
13 */
14#include <linux/string.h>
15#include <asm/memory.h>
16#include <asm/domain.h>
17#include <asm/unified.h>
18#include <asm/compiler.h>
19
20#include <asm/extable.h>
21
22/*
23 * These two functions allow hooking accesses to userspace to increase
24 * system integrity by ensuring that the kernel can not inadvertantly
25 * perform such accesses (eg, via list poison values) which could then
26 * be exploited for priviledge escalation.
27 */
28static inline unsigned int uaccess_save_and_enable(void)
29{
30#ifdef CONFIG_CPU_SW_DOMAIN_PAN
31 unsigned int old_domain = get_domain();
32
33 /* Set the current domain access to permit user accesses */
34 set_domain((old_domain & ~domain_mask(DOMAIN_USER)) |
35 domain_val(DOMAIN_USER, DOMAIN_CLIENT));
36
37 return old_domain;
38#else
39 return 0;
40#endif
41}
42
43static inline void uaccess_restore(unsigned int flags)
44{
45#ifdef CONFIG_CPU_SW_DOMAIN_PAN
46 /* Restore the user access mask */
47 set_domain(flags);
48#endif
49}
50
51/*
52 * These two are intentionally not defined anywhere - if the kernel
53 * code generates any references to them, that's a bug.
54 */
55extern int __get_user_bad(void);
56extern int __put_user_bad(void);
57
58/*
59 * Note that this is actually 0x1,0000,0000
60 */
61#define KERNEL_DS 0x00000000
62#define get_ds() (KERNEL_DS)
63
64#ifdef CONFIG_MMU
65
66#define USER_DS TASK_SIZE
67#define get_fs() (current_thread_info()->addr_limit)
68
69static inline void set_fs(mm_segment_t fs)
70{
71 current_thread_info()->addr_limit = fs;
72 modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
73}
74
75#define segment_eq(a, b) ((a) == (b))
76
77/* We use 33-bit arithmetic here... */
78#define __range_ok(addr, size) ({ \
79 unsigned long flag, roksum; \
80 __chk_user_ptr(addr); \
81 __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
82 : "=&r" (flag), "=&r" (roksum) \
83 : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
84 : "cc"); \
85 flag; })
86
87/*
88 * Single-value transfer routines. They automatically use the right
89 * size if we just have the right pointer type. Note that the functions
90 * which read from user space (*get_*) need to take care not to leak
91 * kernel data even if the calling code is buggy and fails to check
92 * the return value. This means zeroing out the destination variable
93 * or buffer on error. Normally this is done out of line by the
94 * fixup code, but there are a few places where it intrudes on the
95 * main code path. When we only write to user space, there is no
96 * problem.
97 */
98extern int __get_user_1(void *);
99extern int __get_user_2(void *);
100extern int __get_user_4(void *);
101extern int __get_user_32t_8(void *);
102extern int __get_user_8(void *);
103extern int __get_user_64t_1(void *);
104extern int __get_user_64t_2(void *);
105extern int __get_user_64t_4(void *);
106
107#define __GUP_CLOBBER_1 "lr", "cc"
108#ifdef CONFIG_CPU_USE_DOMAINS
109#define __GUP_CLOBBER_2 "ip", "lr", "cc"
110#else
111#define __GUP_CLOBBER_2 "lr", "cc"
112#endif
113#define __GUP_CLOBBER_4 "lr", "cc"
114#define __GUP_CLOBBER_32t_8 "lr", "cc"
115#define __GUP_CLOBBER_8 "lr", "cc"
116
117#define __get_user_x(__r2, __p, __e, __l, __s) \
118 __asm__ __volatile__ ( \
119 __asmeq("%0", "r0") __asmeq("%1", "r2") \
120 __asmeq("%3", "r1") \
121 "bl __get_user_" #__s \
122 : "=&r" (__e), "=r" (__r2) \
123 : "0" (__p), "r" (__l) \
124 : __GUP_CLOBBER_##__s)
125
126/* narrowing a double-word get into a single 32bit word register: */
127#ifdef __ARMEB__
128#define __get_user_x_32t(__r2, __p, __e, __l, __s) \
129 __get_user_x(__r2, __p, __e, __l, 32t_8)
130#else
131#define __get_user_x_32t __get_user_x
132#endif
133
134/*
135 * storing result into proper least significant word of 64bit target var,
136 * different only for big endian case where 64 bit __r2 lsw is r3:
137 */
138#ifdef __ARMEB__
139#define __get_user_x_64t(__r2, __p, __e, __l, __s) \
140 __asm__ __volatile__ ( \
141 __asmeq("%0", "r0") __asmeq("%1", "r2") \
142 __asmeq("%3", "r1") \
143 "bl __get_user_64t_" #__s \
144 : "=&r" (__e), "=r" (__r2) \
145 : "0" (__p), "r" (__l) \
146 : __GUP_CLOBBER_##__s)
147#else
148#define __get_user_x_64t __get_user_x
149#endif
150
151
152#define __get_user_check(x, p) \
153 ({ \
154 unsigned long __limit = current_thread_info()->addr_limit - 1; \
155 register const typeof(*(p)) __user *__p asm("r0") = (p);\
156 register typeof(x) __r2 asm("r2"); \
157 register unsigned long __l asm("r1") = __limit; \
158 register int __e asm("r0"); \
159 unsigned int __ua_flags = uaccess_save_and_enable(); \
160 switch (sizeof(*(__p))) { \
161 case 1: \
162 if (sizeof((x)) >= 8) \
163 __get_user_x_64t(__r2, __p, __e, __l, 1); \
164 else \
165 __get_user_x(__r2, __p, __e, __l, 1); \
166 break; \
167 case 2: \
168 if (sizeof((x)) >= 8) \
169 __get_user_x_64t(__r2, __p, __e, __l, 2); \
170 else \
171 __get_user_x(__r2, __p, __e, __l, 2); \
172 break; \
173 case 4: \
174 if (sizeof((x)) >= 8) \
175 __get_user_x_64t(__r2, __p, __e, __l, 4); \
176 else \
177 __get_user_x(__r2, __p, __e, __l, 4); \
178 break; \
179 case 8: \
180 if (sizeof((x)) < 8) \
181 __get_user_x_32t(__r2, __p, __e, __l, 4); \
182 else \
183 __get_user_x(__r2, __p, __e, __l, 8); \
184 break; \
185 default: __e = __get_user_bad(); break; \
186 } \
187 uaccess_restore(__ua_flags); \
188 x = (typeof(*(p))) __r2; \
189 __e; \
190 })
191
192#define get_user(x, p) \
193 ({ \
194 might_fault(); \
195 __get_user_check(x, p); \
196 })
197
198extern int __put_user_1(void *, unsigned int);
199extern int __put_user_2(void *, unsigned int);
200extern int __put_user_4(void *, unsigned int);
201extern int __put_user_8(void *, unsigned long long);
202
203#define __put_user_check(__pu_val, __ptr, __err, __s) \
204 ({ \
205 unsigned long __limit = current_thread_info()->addr_limit - 1; \
206 register typeof(__pu_val) __r2 asm("r2") = __pu_val; \
207 register const void __user *__p asm("r0") = __ptr; \
208 register unsigned long __l asm("r1") = __limit; \
209 register int __e asm("r0"); \
210 __asm__ __volatile__ ( \
211 __asmeq("%0", "r0") __asmeq("%2", "r2") \
212 __asmeq("%3", "r1") \
213 "bl __put_user_" #__s \
214 : "=&r" (__e) \
215 : "0" (__p), "r" (__r2), "r" (__l) \
216 : "ip", "lr", "cc"); \
217 __err = __e; \
218 })
219
220#else /* CONFIG_MMU */
221
222/*
223 * uClinux has only one addr space, so has simplified address limits.
224 */
225#define USER_DS KERNEL_DS
226
227#define segment_eq(a, b) (1)
228#define __addr_ok(addr) ((void)(addr), 1)
229#define __range_ok(addr, size) ((void)(addr), 0)
230#define get_fs() (KERNEL_DS)
231
232static inline void set_fs(mm_segment_t fs)
233{
234}
235
236#define get_user(x, p) __get_user(x, p)
237#define __put_user_check __put_user_nocheck
238
239#endif /* CONFIG_MMU */
240
241#define access_ok(type, addr, size) (__range_ok(addr, size) == 0)
242
243#define user_addr_max() \
244 (uaccess_kernel() ? ~0UL : get_fs())
245
246/*
247 * The "__xxx" versions of the user access functions do not verify the
248 * address space - it must have been done previously with a separate
249 * "access_ok()" call.
250 *
251 * The "xxx_error" versions set the third argument to EFAULT if an
252 * error occurs, and leave it unchanged on success. Note that these
253 * versions are void (ie, don't return a value as such).
254 */
255#define __get_user(x, ptr) \
256({ \
257 long __gu_err = 0; \
258 __get_user_err((x), (ptr), __gu_err); \
259 __gu_err; \
260})
261
262#define __get_user_error(x, ptr, err) \
263({ \
264 __get_user_err((x), (ptr), err); \
265 (void) 0; \
266})
267
268#define __get_user_err(x, ptr, err) \
269do { \
270 unsigned long __gu_addr = (unsigned long)(ptr); \
271 unsigned long __gu_val; \
272 unsigned int __ua_flags; \
273 __chk_user_ptr(ptr); \
274 might_fault(); \
275 __ua_flags = uaccess_save_and_enable(); \
276 switch (sizeof(*(ptr))) { \
277 case 1: __get_user_asm_byte(__gu_val, __gu_addr, err); break; \
278 case 2: __get_user_asm_half(__gu_val, __gu_addr, err); break; \
279 case 4: __get_user_asm_word(__gu_val, __gu_addr, err); break; \
280 default: (__gu_val) = __get_user_bad(); \
281 } \
282 uaccess_restore(__ua_flags); \
283 (x) = (__typeof__(*(ptr)))__gu_val; \
284} while (0)
285
286#define __get_user_asm(x, addr, err, instr) \
287 __asm__ __volatile__( \
288 "1: " TUSER(instr) " %1, [%2], #0\n" \
289 "2:\n" \
290 " .pushsection .text.fixup,\"ax\"\n" \
291 " .align 2\n" \
292 "3: mov %0, %3\n" \
293 " mov %1, #0\n" \
294 " b 2b\n" \
295 " .popsection\n" \
296 " .pushsection __ex_table,\"a\"\n" \
297 " .align 3\n" \
298 " .long 1b, 3b\n" \
299 " .popsection" \
300 : "+r" (err), "=&r" (x) \
301 : "r" (addr), "i" (-EFAULT) \
302 : "cc")
303
304#define __get_user_asm_byte(x, addr, err) \
305 __get_user_asm(x, addr, err, ldrb)
306
307#ifndef __ARMEB__
308#define __get_user_asm_half(x, __gu_addr, err) \
309({ \
310 unsigned long __b1, __b2; \
311 __get_user_asm_byte(__b1, __gu_addr, err); \
312 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
313 (x) = __b1 | (__b2 << 8); \
314})
315#else
316#define __get_user_asm_half(x, __gu_addr, err) \
317({ \
318 unsigned long __b1, __b2; \
319 __get_user_asm_byte(__b1, __gu_addr, err); \
320 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
321 (x) = (__b1 << 8) | __b2; \
322})
323#endif
324
325#define __get_user_asm_word(x, addr, err) \
326 __get_user_asm(x, addr, err, ldr)
327
328
329#define __put_user_switch(x, ptr, __err, __fn) \
330 do { \
331 const __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
332 __typeof__(*(ptr)) __pu_val = (x); \
333 unsigned int __ua_flags; \
334 might_fault(); \
335 __ua_flags = uaccess_save_and_enable(); \
336 switch (sizeof(*(ptr))) { \
337 case 1: __fn(__pu_val, __pu_ptr, __err, 1); break; \
338 case 2: __fn(__pu_val, __pu_ptr, __err, 2); break; \
339 case 4: __fn(__pu_val, __pu_ptr, __err, 4); break; \
340 case 8: __fn(__pu_val, __pu_ptr, __err, 8); break; \
341 default: __err = __put_user_bad(); break; \
342 } \
343 uaccess_restore(__ua_flags); \
344 } while (0)
345
346#define put_user(x, ptr) \
347({ \
348 int __pu_err = 0; \
349 __put_user_switch((x), (ptr), __pu_err, __put_user_check); \
350 __pu_err; \
351})
352
353#define __put_user(x, ptr) \
354({ \
355 long __pu_err = 0; \
356 __put_user_switch((x), (ptr), __pu_err, __put_user_nocheck); \
357 __pu_err; \
358})
359
360#define __put_user_error(x, ptr, err) \
361({ \
362 __put_user_switch((x), (ptr), (err), __put_user_nocheck); \
363 (void) 0; \
364})
365
366#define __put_user_nocheck(x, __pu_ptr, __err, __size) \
367 do { \
368 unsigned long __pu_addr = (unsigned long)__pu_ptr; \
369 __put_user_nocheck_##__size(x, __pu_addr, __err); \
370 } while (0)
371
372#define __put_user_nocheck_1 __put_user_asm_byte
373#define __put_user_nocheck_2 __put_user_asm_half
374#define __put_user_nocheck_4 __put_user_asm_word
375#define __put_user_nocheck_8 __put_user_asm_dword
376
377#define __put_user_asm(x, __pu_addr, err, instr) \
378 __asm__ __volatile__( \
379 "1: " TUSER(instr) " %1, [%2], #0\n" \
380 "2:\n" \
381 " .pushsection .text.fixup,\"ax\"\n" \
382 " .align 2\n" \
383 "3: mov %0, %3\n" \
384 " b 2b\n" \
385 " .popsection\n" \
386 " .pushsection __ex_table,\"a\"\n" \
387 " .align 3\n" \
388 " .long 1b, 3b\n" \
389 " .popsection" \
390 : "+r" (err) \
391 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
392 : "cc")
393
394#define __put_user_asm_byte(x, __pu_addr, err) \
395 __put_user_asm(x, __pu_addr, err, strb)
396
397#ifndef __ARMEB__
398#define __put_user_asm_half(x, __pu_addr, err) \
399({ \
400 unsigned long __temp = (__force unsigned long)(x); \
401 __put_user_asm_byte(__temp, __pu_addr, err); \
402 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
403})
404#else
405#define __put_user_asm_half(x, __pu_addr, err) \
406({ \
407 unsigned long __temp = (__force unsigned long)(x); \
408 __put_user_asm_byte(__temp >> 8, __pu_addr, err); \
409 __put_user_asm_byte(__temp, __pu_addr + 1, err); \
410})
411#endif
412
413#define __put_user_asm_word(x, __pu_addr, err) \
414 __put_user_asm(x, __pu_addr, err, str)
415
416#ifndef __ARMEB__
417#define __reg_oper0 "%R2"
418#define __reg_oper1 "%Q2"
419#else
420#define __reg_oper0 "%Q2"
421#define __reg_oper1 "%R2"
422#endif
423
424#define __put_user_asm_dword(x, __pu_addr, err) \
425 __asm__ __volatile__( \
426 ARM( "1: " TUSER(str) " " __reg_oper1 ", [%1], #4\n" ) \
427 ARM( "2: " TUSER(str) " " __reg_oper0 ", [%1]\n" ) \
428 THUMB( "1: " TUSER(str) " " __reg_oper1 ", [%1]\n" ) \
429 THUMB( "2: " TUSER(str) " " __reg_oper0 ", [%1, #4]\n" ) \
430 "3:\n" \
431 " .pushsection .text.fixup,\"ax\"\n" \
432 " .align 2\n" \
433 "4: mov %0, %3\n" \
434 " b 3b\n" \
435 " .popsection\n" \
436 " .pushsection __ex_table,\"a\"\n" \
437 " .align 3\n" \
438 " .long 1b, 4b\n" \
439 " .long 2b, 4b\n" \
440 " .popsection" \
441 : "+r" (err), "+r" (__pu_addr) \
442 : "r" (x), "i" (-EFAULT) \
443 : "cc")
444
445
446#ifdef CONFIG_MMU
447extern unsigned long __must_check
448arm_copy_from_user(void *to, const void __user *from, unsigned long n);
449
450static inline unsigned long __must_check
451raw_copy_from_user(void *to, const void __user *from, unsigned long n)
452{
453 unsigned int __ua_flags;
454
455 __ua_flags = uaccess_save_and_enable();
456 n = arm_copy_from_user(to, from, n);
457 uaccess_restore(__ua_flags);
458 return n;
459}
460
461extern unsigned long __must_check
462arm_copy_to_user(void __user *to, const void *from, unsigned long n);
463extern unsigned long __must_check
464__copy_to_user_std(void __user *to, const void *from, unsigned long n);
465
466static inline unsigned long __must_check
467raw_copy_to_user(void __user *to, const void *from, unsigned long n)
468{
469#ifndef CONFIG_UACCESS_WITH_MEMCPY
470 unsigned int __ua_flags;
471 __ua_flags = uaccess_save_and_enable();
472 n = arm_copy_to_user(to, from, n);
473 uaccess_restore(__ua_flags);
474 return n;
475#else
476 return arm_copy_to_user(to, from, n);
477#endif
478}
479
480extern unsigned long __must_check
481arm_clear_user(void __user *addr, unsigned long n);
482extern unsigned long __must_check
483__clear_user_std(void __user *addr, unsigned long n);
484
485static inline unsigned long __must_check
486__clear_user(void __user *addr, unsigned long n)
487{
488 unsigned int __ua_flags = uaccess_save_and_enable();
489 n = arm_clear_user(addr, n);
490 uaccess_restore(__ua_flags);
491 return n;
492}
493
494#else
495static inline unsigned long
496raw_copy_from_user(void *to, const void __user *from, unsigned long n)
497{
498 memcpy(to, (const void __force *)from, n);
499 return 0;
500}
501static inline unsigned long
502raw_copy_to_user(void __user *to, const void *from, unsigned long n)
503{
504 memcpy((void __force *)to, from, n);
505 return 0;
506}
507#define __clear_user(addr, n) (memset((void __force *)addr, 0, n), 0)
508#endif
509#define INLINE_COPY_TO_USER
510#define INLINE_COPY_FROM_USER
511
512static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
513{
514 if (access_ok(VERIFY_WRITE, to, n))
515 n = __clear_user(to, n);
516 return n;
517}
518
519/* These are from lib/ code, and use __get_user() and friends */
520extern long strncpy_from_user(char *dest, const char __user *src, long count);
521
522extern __must_check long strnlen_user(const char __user *str, long n);
523
524#endif /* _ASMARM_UACCESS_H */