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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 <linux/thread_info.h>
16#include <asm/errno.h>
17#include <asm/memory.h>
18#include <asm/domain.h>
19#include <asm/unified.h>
20#include <asm/compiler.h>
21
22#define VERIFY_READ 0
23#define VERIFY_WRITE 1
24
25/*
26 * The exception table consists of pairs of addresses: the first is the
27 * address of an instruction that is allowed to fault, and the second is
28 * the address at which the program should continue. No registers are
29 * modified, so it is entirely up to the continuation code to figure out
30 * what to do.
31 *
32 * All the routines below use bits of fixup code that are out of line
33 * with the main instruction path. This means when everything is well,
34 * we don't even have to jump over them. Further, they do not intrude
35 * on our cache or tlb entries.
36 */
37
38struct exception_table_entry
39{
40 unsigned long insn, fixup;
41};
42
43extern int fixup_exception(struct pt_regs *regs);
44
45/*
46 * These two are intentionally not defined anywhere - if the kernel
47 * code generates any references to them, that's a bug.
48 */
49extern int __get_user_bad(void);
50extern int __put_user_bad(void);
51
52/*
53 * Note that this is actually 0x1,0000,0000
54 */
55#define KERNEL_DS 0x00000000
56#define get_ds() (KERNEL_DS)
57
58#ifdef CONFIG_MMU
59
60#define USER_DS TASK_SIZE
61#define get_fs() (current_thread_info()->addr_limit)
62
63static inline void set_fs(mm_segment_t fs)
64{
65 current_thread_info()->addr_limit = fs;
66 modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
67}
68
69#define segment_eq(a,b) ((a) == (b))
70
71#define __addr_ok(addr) ({ \
72 unsigned long flag; \
73 __asm__("cmp %2, %0; movlo %0, #0" \
74 : "=&r" (flag) \
75 : "0" (current_thread_info()->addr_limit), "r" (addr) \
76 : "cc"); \
77 (flag == 0); })
78
79/* We use 33-bit arithmetic here... */
80#define __range_ok(addr,size) ({ \
81 unsigned long flag, roksum; \
82 __chk_user_ptr(addr); \
83 __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
84 : "=&r" (flag), "=&r" (roksum) \
85 : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
86 : "cc"); \
87 flag; })
88
89/*
90 * Single-value transfer routines. They automatically use the right
91 * size if we just have the right pointer type. Note that the functions
92 * which read from user space (*get_*) need to take care not to leak
93 * kernel data even if the calling code is buggy and fails to check
94 * the return value. This means zeroing out the destination variable
95 * or buffer on error. Normally this is done out of line by the
96 * fixup code, but there are a few places where it intrudes on the
97 * main code path. When we only write to user space, there is no
98 * problem.
99 */
100extern int __get_user_1(void *);
101extern int __get_user_2(void *);
102extern int __get_user_4(void *);
103
104#define __GUP_CLOBBER_1 "lr", "cc"
105#ifdef CONFIG_CPU_USE_DOMAINS
106#define __GUP_CLOBBER_2 "ip", "lr", "cc"
107#else
108#define __GUP_CLOBBER_2 "lr", "cc"
109#endif
110#define __GUP_CLOBBER_4 "lr", "cc"
111
112#define __get_user_x(__r2,__p,__e,__l,__s) \
113 __asm__ __volatile__ ( \
114 __asmeq("%0", "r0") __asmeq("%1", "r2") \
115 __asmeq("%3", "r1") \
116 "bl __get_user_" #__s \
117 : "=&r" (__e), "=r" (__r2) \
118 : "0" (__p), "r" (__l) \
119 : __GUP_CLOBBER_##__s)
120
121#define get_user(x,p) \
122 ({ \
123 unsigned long __limit = current_thread_info()->addr_limit - 1; \
124 register const typeof(*(p)) __user *__p asm("r0") = (p);\
125 register unsigned long __r2 asm("r2"); \
126 register unsigned long __l asm("r1") = __limit; \
127 register int __e asm("r0"); \
128 switch (sizeof(*(__p))) { \
129 case 1: \
130 __get_user_x(__r2, __p, __e, __l, 1); \
131 break; \
132 case 2: \
133 __get_user_x(__r2, __p, __e, __l, 2); \
134 break; \
135 case 4: \
136 __get_user_x(__r2, __p, __e, __l, 4); \
137 break; \
138 default: __e = __get_user_bad(); break; \
139 } \
140 x = (typeof(*(p))) __r2; \
141 __e; \
142 })
143
144extern int __put_user_1(void *, unsigned int);
145extern int __put_user_2(void *, unsigned int);
146extern int __put_user_4(void *, unsigned int);
147extern int __put_user_8(void *, unsigned long long);
148
149#define __put_user_x(__r2,__p,__e,__l,__s) \
150 __asm__ __volatile__ ( \
151 __asmeq("%0", "r0") __asmeq("%2", "r2") \
152 __asmeq("%3", "r1") \
153 "bl __put_user_" #__s \
154 : "=&r" (__e) \
155 : "0" (__p), "r" (__r2), "r" (__l) \
156 : "ip", "lr", "cc")
157
158#define put_user(x,p) \
159 ({ \
160 unsigned long __limit = current_thread_info()->addr_limit - 1; \
161 register const typeof(*(p)) __r2 asm("r2") = (x); \
162 register const typeof(*(p)) __user *__p asm("r0") = (p);\
163 register unsigned long __l asm("r1") = __limit; \
164 register int __e asm("r0"); \
165 switch (sizeof(*(__p))) { \
166 case 1: \
167 __put_user_x(__r2, __p, __e, __l, 1); \
168 break; \
169 case 2: \
170 __put_user_x(__r2, __p, __e, __l, 2); \
171 break; \
172 case 4: \
173 __put_user_x(__r2, __p, __e, __l, 4); \
174 break; \
175 case 8: \
176 __put_user_x(__r2, __p, __e, __l, 8); \
177 break; \
178 default: __e = __put_user_bad(); break; \
179 } \
180 __e; \
181 })
182
183#else /* CONFIG_MMU */
184
185/*
186 * uClinux has only one addr space, so has simplified address limits.
187 */
188#define USER_DS KERNEL_DS
189
190#define segment_eq(a,b) (1)
191#define __addr_ok(addr) (1)
192#define __range_ok(addr,size) (0)
193#define get_fs() (KERNEL_DS)
194
195static inline void set_fs(mm_segment_t fs)
196{
197}
198
199#define get_user(x,p) __get_user(x,p)
200#define put_user(x,p) __put_user(x,p)
201
202#endif /* CONFIG_MMU */
203
204#define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
205
206/*
207 * The "__xxx" versions of the user access functions do not verify the
208 * address space - it must have been done previously with a separate
209 * "access_ok()" call.
210 *
211 * The "xxx_error" versions set the third argument to EFAULT if an
212 * error occurs, and leave it unchanged on success. Note that these
213 * versions are void (ie, don't return a value as such).
214 */
215#define __get_user(x,ptr) \
216({ \
217 long __gu_err = 0; \
218 __get_user_err((x),(ptr),__gu_err); \
219 __gu_err; \
220})
221
222#define __get_user_error(x,ptr,err) \
223({ \
224 __get_user_err((x),(ptr),err); \
225 (void) 0; \
226})
227
228#define __get_user_err(x,ptr,err) \
229do { \
230 unsigned long __gu_addr = (unsigned long)(ptr); \
231 unsigned long __gu_val; \
232 __chk_user_ptr(ptr); \
233 switch (sizeof(*(ptr))) { \
234 case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \
235 case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \
236 case 4: __get_user_asm_word(__gu_val,__gu_addr,err); break; \
237 default: (__gu_val) = __get_user_bad(); \
238 } \
239 (x) = (__typeof__(*(ptr)))__gu_val; \
240} while (0)
241
242#define __get_user_asm_byte(x,addr,err) \
243 __asm__ __volatile__( \
244 "1: " TUSER(ldrb) " %1,[%2],#0\n" \
245 "2:\n" \
246 " .pushsection .fixup,\"ax\"\n" \
247 " .align 2\n" \
248 "3: mov %0, %3\n" \
249 " mov %1, #0\n" \
250 " b 2b\n" \
251 " .popsection\n" \
252 " .pushsection __ex_table,\"a\"\n" \
253 " .align 3\n" \
254 " .long 1b, 3b\n" \
255 " .popsection" \
256 : "+r" (err), "=&r" (x) \
257 : "r" (addr), "i" (-EFAULT) \
258 : "cc")
259
260#ifndef __ARMEB__
261#define __get_user_asm_half(x,__gu_addr,err) \
262({ \
263 unsigned long __b1, __b2; \
264 __get_user_asm_byte(__b1, __gu_addr, err); \
265 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
266 (x) = __b1 | (__b2 << 8); \
267})
268#else
269#define __get_user_asm_half(x,__gu_addr,err) \
270({ \
271 unsigned long __b1, __b2; \
272 __get_user_asm_byte(__b1, __gu_addr, err); \
273 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
274 (x) = (__b1 << 8) | __b2; \
275})
276#endif
277
278#define __get_user_asm_word(x,addr,err) \
279 __asm__ __volatile__( \
280 "1: " TUSER(ldr) " %1,[%2],#0\n" \
281 "2:\n" \
282 " .pushsection .fixup,\"ax\"\n" \
283 " .align 2\n" \
284 "3: mov %0, %3\n" \
285 " mov %1, #0\n" \
286 " b 2b\n" \
287 " .popsection\n" \
288 " .pushsection __ex_table,\"a\"\n" \
289 " .align 3\n" \
290 " .long 1b, 3b\n" \
291 " .popsection" \
292 : "+r" (err), "=&r" (x) \
293 : "r" (addr), "i" (-EFAULT) \
294 : "cc")
295
296#define __put_user(x,ptr) \
297({ \
298 long __pu_err = 0; \
299 __put_user_err((x),(ptr),__pu_err); \
300 __pu_err; \
301})
302
303#define __put_user_error(x,ptr,err) \
304({ \
305 __put_user_err((x),(ptr),err); \
306 (void) 0; \
307})
308
309#define __put_user_err(x,ptr,err) \
310do { \
311 unsigned long __pu_addr = (unsigned long)(ptr); \
312 __typeof__(*(ptr)) __pu_val = (x); \
313 __chk_user_ptr(ptr); \
314 switch (sizeof(*(ptr))) { \
315 case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \
316 case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \
317 case 4: __put_user_asm_word(__pu_val,__pu_addr,err); break; \
318 case 8: __put_user_asm_dword(__pu_val,__pu_addr,err); break; \
319 default: __put_user_bad(); \
320 } \
321} while (0)
322
323#define __put_user_asm_byte(x,__pu_addr,err) \
324 __asm__ __volatile__( \
325 "1: " TUSER(strb) " %1,[%2],#0\n" \
326 "2:\n" \
327 " .pushsection .fixup,\"ax\"\n" \
328 " .align 2\n" \
329 "3: mov %0, %3\n" \
330 " b 2b\n" \
331 " .popsection\n" \
332 " .pushsection __ex_table,\"a\"\n" \
333 " .align 3\n" \
334 " .long 1b, 3b\n" \
335 " .popsection" \
336 : "+r" (err) \
337 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
338 : "cc")
339
340#ifndef __ARMEB__
341#define __put_user_asm_half(x,__pu_addr,err) \
342({ \
343 unsigned long __temp = (unsigned long)(x); \
344 __put_user_asm_byte(__temp, __pu_addr, err); \
345 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
346})
347#else
348#define __put_user_asm_half(x,__pu_addr,err) \
349({ \
350 unsigned long __temp = (unsigned long)(x); \
351 __put_user_asm_byte(__temp >> 8, __pu_addr, err); \
352 __put_user_asm_byte(__temp, __pu_addr + 1, err); \
353})
354#endif
355
356#define __put_user_asm_word(x,__pu_addr,err) \
357 __asm__ __volatile__( \
358 "1: " TUSER(str) " %1,[%2],#0\n" \
359 "2:\n" \
360 " .pushsection .fixup,\"ax\"\n" \
361 " .align 2\n" \
362 "3: mov %0, %3\n" \
363 " b 2b\n" \
364 " .popsection\n" \
365 " .pushsection __ex_table,\"a\"\n" \
366 " .align 3\n" \
367 " .long 1b, 3b\n" \
368 " .popsection" \
369 : "+r" (err) \
370 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
371 : "cc")
372
373#ifndef __ARMEB__
374#define __reg_oper0 "%R2"
375#define __reg_oper1 "%Q2"
376#else
377#define __reg_oper0 "%Q2"
378#define __reg_oper1 "%R2"
379#endif
380
381#define __put_user_asm_dword(x,__pu_addr,err) \
382 __asm__ __volatile__( \
383 ARM( "1: " TUSER(str) " " __reg_oper1 ", [%1], #4\n" ) \
384 ARM( "2: " TUSER(str) " " __reg_oper0 ", [%1]\n" ) \
385 THUMB( "1: " TUSER(str) " " __reg_oper1 ", [%1]\n" ) \
386 THUMB( "2: " TUSER(str) " " __reg_oper0 ", [%1, #4]\n" ) \
387 "3:\n" \
388 " .pushsection .fixup,\"ax\"\n" \
389 " .align 2\n" \
390 "4: mov %0, %3\n" \
391 " b 3b\n" \
392 " .popsection\n" \
393 " .pushsection __ex_table,\"a\"\n" \
394 " .align 3\n" \
395 " .long 1b, 4b\n" \
396 " .long 2b, 4b\n" \
397 " .popsection" \
398 : "+r" (err), "+r" (__pu_addr) \
399 : "r" (x), "i" (-EFAULT) \
400 : "cc")
401
402
403#ifdef CONFIG_MMU
404extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
405extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
406extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n);
407extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
408extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n);
409#else
410#define __copy_from_user(to,from,n) (memcpy(to, (void __force *)from, n), 0)
411#define __copy_to_user(to,from,n) (memcpy((void __force *)to, from, n), 0)
412#define __clear_user(addr,n) (memset((void __force *)addr, 0, n), 0)
413#endif
414
415extern unsigned long __must_check __strncpy_from_user(char *to, const char __user *from, unsigned long count);
416extern unsigned long __must_check __strnlen_user(const char __user *s, long n);
417
418static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
419{
420 if (access_ok(VERIFY_READ, from, n))
421 n = __copy_from_user(to, from, n);
422 else /* security hole - plug it */
423 memset(to, 0, n);
424 return n;
425}
426
427static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
428{
429 if (access_ok(VERIFY_WRITE, to, n))
430 n = __copy_to_user(to, from, n);
431 return n;
432}
433
434#define __copy_to_user_inatomic __copy_to_user
435#define __copy_from_user_inatomic __copy_from_user
436
437static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
438{
439 if (access_ok(VERIFY_WRITE, to, n))
440 n = __clear_user(to, n);
441 return n;
442}
443
444static inline long __must_check strncpy_from_user(char *dst, const char __user *src, long count)
445{
446 long res = -EFAULT;
447 if (access_ok(VERIFY_READ, src, 1))
448 res = __strncpy_from_user(dst, src, count);
449 return res;
450}
451
452#define strlen_user(s) strnlen_user(s, ~0UL >> 1)
453
454static inline long __must_check strnlen_user(const char __user *s, long n)
455{
456 unsigned long res = 0;
457
458 if (__addr_ok(s))
459 res = __strnlen_user(s, n);
460
461 return res;
462}
463
464#endif /* _ASMARM_UACCESS_H */