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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#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
23#include <asm-generic/uaccess-unaligned.h>
24#else
25#define __get_user_unaligned __get_user
26#define __put_user_unaligned __put_user
27#endif
28
29#define VERIFY_READ 0
30#define VERIFY_WRITE 1
31
32/*
33 * The exception table consists of pairs of addresses: the first is the
34 * address of an instruction that is allowed to fault, and the second is
35 * the address at which the program should continue. No registers are
36 * modified, so it is entirely up to the continuation code to figure out
37 * what to do.
38 *
39 * All the routines below use bits of fixup code that are out of line
40 * with the main instruction path. This means when everything is well,
41 * we don't even have to jump over them. Further, they do not intrude
42 * on our cache or tlb entries.
43 */
44
45struct exception_table_entry
46{
47 unsigned long insn, fixup;
48};
49
50extern int fixup_exception(struct pt_regs *regs);
51
52/*
53 * These two are intentionally not defined anywhere - if the kernel
54 * code generates any references to them, that's a bug.
55 */
56extern int __get_user_bad(void);
57extern int __put_user_bad(void);
58
59/*
60 * Note that this is actually 0x1,0000,0000
61 */
62#define KERNEL_DS 0x00000000
63#define get_ds() (KERNEL_DS)
64
65#ifdef CONFIG_MMU
66
67#define USER_DS TASK_SIZE
68#define get_fs() (current_thread_info()->addr_limit)
69
70static inline void set_fs(mm_segment_t fs)
71{
72 current_thread_info()->addr_limit = fs;
73 modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
74}
75
76#define segment_eq(a,b) ((a) == (b))
77
78#define __addr_ok(addr) ({ \
79 unsigned long flag; \
80 __asm__("cmp %2, %0; movlo %0, #0" \
81 : "=&r" (flag) \
82 : "0" (current_thread_info()->addr_limit), "r" (addr) \
83 : "cc"); \
84 (flag == 0); })
85
86/* We use 33-bit arithmetic here... */
87#define __range_ok(addr,size) ({ \
88 unsigned long flag, roksum; \
89 __chk_user_ptr(addr); \
90 __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
91 : "=&r" (flag), "=&r" (roksum) \
92 : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
93 : "cc"); \
94 flag; })
95
96/*
97 * Single-value transfer routines. They automatically use the right
98 * size if we just have the right pointer type. Note that the functions
99 * which read from user space (*get_*) need to take care not to leak
100 * kernel data even if the calling code is buggy and fails to check
101 * the return value. This means zeroing out the destination variable
102 * or buffer on error. Normally this is done out of line by the
103 * fixup code, but there are a few places where it intrudes on the
104 * main code path. When we only write to user space, there is no
105 * problem.
106 */
107extern int __get_user_1(void *);
108extern int __get_user_2(void *);
109extern int __get_user_4(void *);
110
111#define __GUP_CLOBBER_1 "lr", "cc"
112#ifdef CONFIG_CPU_USE_DOMAINS
113#define __GUP_CLOBBER_2 "ip", "lr", "cc"
114#else
115#define __GUP_CLOBBER_2 "lr", "cc"
116#endif
117#define __GUP_CLOBBER_4 "lr", "cc"
118
119#define __get_user_x(__r2,__p,__e,__l,__s) \
120 __asm__ __volatile__ ( \
121 __asmeq("%0", "r0") __asmeq("%1", "r2") \
122 __asmeq("%3", "r1") \
123 "bl __get_user_" #__s \
124 : "=&r" (__e), "=r" (__r2) \
125 : "0" (__p), "r" (__l) \
126 : __GUP_CLOBBER_##__s)
127
128#define __get_user_check(x,p) \
129 ({ \
130 unsigned long __limit = current_thread_info()->addr_limit - 1; \
131 register const typeof(*(p)) __user *__p asm("r0") = (p);\
132 register unsigned long __r2 asm("r2"); \
133 register unsigned long __l asm("r1") = __limit; \
134 register int __e asm("r0"); \
135 switch (sizeof(*(__p))) { \
136 case 1: \
137 __get_user_x(__r2, __p, __e, __l, 1); \
138 break; \
139 case 2: \
140 __get_user_x(__r2, __p, __e, __l, 2); \
141 break; \
142 case 4: \
143 __get_user_x(__r2, __p, __e, __l, 4); \
144 break; \
145 default: __e = __get_user_bad(); break; \
146 } \
147 x = (typeof(*(p))) __r2; \
148 __e; \
149 })
150
151#define get_user(x,p) \
152 ({ \
153 might_fault(); \
154 __get_user_check(x,p); \
155 })
156
157extern int __put_user_1(void *, unsigned int);
158extern int __put_user_2(void *, unsigned int);
159extern int __put_user_4(void *, unsigned int);
160extern int __put_user_8(void *, unsigned long long);
161
162#define __put_user_x(__r2,__p,__e,__l,__s) \
163 __asm__ __volatile__ ( \
164 __asmeq("%0", "r0") __asmeq("%2", "r2") \
165 __asmeq("%3", "r1") \
166 "bl __put_user_" #__s \
167 : "=&r" (__e) \
168 : "0" (__p), "r" (__r2), "r" (__l) \
169 : "ip", "lr", "cc")
170
171#define __put_user_check(x,p) \
172 ({ \
173 unsigned long __limit = current_thread_info()->addr_limit - 1; \
174 const typeof(*(p)) __user *__tmp_p = (p); \
175 register const typeof(*(p)) __r2 asm("r2") = (x); \
176 register const typeof(*(p)) __user *__p asm("r0") = __tmp_p; \
177 register unsigned long __l asm("r1") = __limit; \
178 register int __e asm("r0"); \
179 switch (sizeof(*(__p))) { \
180 case 1: \
181 __put_user_x(__r2, __p, __e, __l, 1); \
182 break; \
183 case 2: \
184 __put_user_x(__r2, __p, __e, __l, 2); \
185 break; \
186 case 4: \
187 __put_user_x(__r2, __p, __e, __l, 4); \
188 break; \
189 case 8: \
190 __put_user_x(__r2, __p, __e, __l, 8); \
191 break; \
192 default: __e = __put_user_bad(); break; \
193 } \
194 __e; \
195 })
196
197#define put_user(x,p) \
198 ({ \
199 might_fault(); \
200 __put_user_check(x,p); \
201 })
202
203#else /* CONFIG_MMU */
204
205/*
206 * uClinux has only one addr space, so has simplified address limits.
207 */
208#define USER_DS KERNEL_DS
209
210#define segment_eq(a,b) (1)
211#define __addr_ok(addr) ((void)(addr),1)
212#define __range_ok(addr,size) ((void)(addr),0)
213#define get_fs() (KERNEL_DS)
214
215static inline void set_fs(mm_segment_t fs)
216{
217}
218
219#define get_user(x,p) __get_user(x,p)
220#define put_user(x,p) __put_user(x,p)
221
222#endif /* CONFIG_MMU */
223
224#define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
225
226#define user_addr_max() \
227 (segment_eq(get_fs(), USER_DS) ? TASK_SIZE : ~0UL)
228
229/*
230 * The "__xxx" versions of the user access functions do not verify the
231 * address space - it must have been done previously with a separate
232 * "access_ok()" call.
233 *
234 * The "xxx_error" versions set the third argument to EFAULT if an
235 * error occurs, and leave it unchanged on success. Note that these
236 * versions are void (ie, don't return a value as such).
237 */
238#define __get_user(x,ptr) \
239({ \
240 long __gu_err = 0; \
241 __get_user_err((x),(ptr),__gu_err); \
242 __gu_err; \
243})
244
245#define __get_user_error(x,ptr,err) \
246({ \
247 __get_user_err((x),(ptr),err); \
248 (void) 0; \
249})
250
251#define __get_user_err(x,ptr,err) \
252do { \
253 unsigned long __gu_addr = (unsigned long)(ptr); \
254 unsigned long __gu_val; \
255 __chk_user_ptr(ptr); \
256 might_fault(); \
257 switch (sizeof(*(ptr))) { \
258 case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \
259 case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \
260 case 4: __get_user_asm_word(__gu_val,__gu_addr,err); break; \
261 default: (__gu_val) = __get_user_bad(); \
262 } \
263 (x) = (__typeof__(*(ptr)))__gu_val; \
264} while (0)
265
266#define __get_user_asm_byte(x,addr,err) \
267 __asm__ __volatile__( \
268 "1: " TUSER(ldrb) " %1,[%2],#0\n" \
269 "2:\n" \
270 " .pushsection .fixup,\"ax\"\n" \
271 " .align 2\n" \
272 "3: mov %0, %3\n" \
273 " mov %1, #0\n" \
274 " b 2b\n" \
275 " .popsection\n" \
276 " .pushsection __ex_table,\"a\"\n" \
277 " .align 3\n" \
278 " .long 1b, 3b\n" \
279 " .popsection" \
280 : "+r" (err), "=&r" (x) \
281 : "r" (addr), "i" (-EFAULT) \
282 : "cc")
283
284#ifndef __ARMEB__
285#define __get_user_asm_half(x,__gu_addr,err) \
286({ \
287 unsigned long __b1, __b2; \
288 __get_user_asm_byte(__b1, __gu_addr, err); \
289 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
290 (x) = __b1 | (__b2 << 8); \
291})
292#else
293#define __get_user_asm_half(x,__gu_addr,err) \
294({ \
295 unsigned long __b1, __b2; \
296 __get_user_asm_byte(__b1, __gu_addr, err); \
297 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
298 (x) = (__b1 << 8) | __b2; \
299})
300#endif
301
302#define __get_user_asm_word(x,addr,err) \
303 __asm__ __volatile__( \
304 "1: " TUSER(ldr) " %1,[%2],#0\n" \
305 "2:\n" \
306 " .pushsection .fixup,\"ax\"\n" \
307 " .align 2\n" \
308 "3: mov %0, %3\n" \
309 " mov %1, #0\n" \
310 " b 2b\n" \
311 " .popsection\n" \
312 " .pushsection __ex_table,\"a\"\n" \
313 " .align 3\n" \
314 " .long 1b, 3b\n" \
315 " .popsection" \
316 : "+r" (err), "=&r" (x) \
317 : "r" (addr), "i" (-EFAULT) \
318 : "cc")
319
320#define __put_user(x,ptr) \
321({ \
322 long __pu_err = 0; \
323 __put_user_err((x),(ptr),__pu_err); \
324 __pu_err; \
325})
326
327#define __put_user_error(x,ptr,err) \
328({ \
329 __put_user_err((x),(ptr),err); \
330 (void) 0; \
331})
332
333#define __put_user_err(x,ptr,err) \
334do { \
335 unsigned long __pu_addr = (unsigned long)(ptr); \
336 __typeof__(*(ptr)) __pu_val = (x); \
337 __chk_user_ptr(ptr); \
338 might_fault(); \
339 switch (sizeof(*(ptr))) { \
340 case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \
341 case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \
342 case 4: __put_user_asm_word(__pu_val,__pu_addr,err); break; \
343 case 8: __put_user_asm_dword(__pu_val,__pu_addr,err); break; \
344 default: __put_user_bad(); \
345 } \
346} while (0)
347
348#define __put_user_asm_byte(x,__pu_addr,err) \
349 __asm__ __volatile__( \
350 "1: " TUSER(strb) " %1,[%2],#0\n" \
351 "2:\n" \
352 " .pushsection .fixup,\"ax\"\n" \
353 " .align 2\n" \
354 "3: mov %0, %3\n" \
355 " b 2b\n" \
356 " .popsection\n" \
357 " .pushsection __ex_table,\"a\"\n" \
358 " .align 3\n" \
359 " .long 1b, 3b\n" \
360 " .popsection" \
361 : "+r" (err) \
362 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
363 : "cc")
364
365#ifndef __ARMEB__
366#define __put_user_asm_half(x,__pu_addr,err) \
367({ \
368 unsigned long __temp = (unsigned long)(x); \
369 __put_user_asm_byte(__temp, __pu_addr, err); \
370 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
371})
372#else
373#define __put_user_asm_half(x,__pu_addr,err) \
374({ \
375 unsigned long __temp = (unsigned long)(x); \
376 __put_user_asm_byte(__temp >> 8, __pu_addr, err); \
377 __put_user_asm_byte(__temp, __pu_addr + 1, err); \
378})
379#endif
380
381#define __put_user_asm_word(x,__pu_addr,err) \
382 __asm__ __volatile__( \
383 "1: " TUSER(str) " %1,[%2],#0\n" \
384 "2:\n" \
385 " .pushsection .fixup,\"ax\"\n" \
386 " .align 2\n" \
387 "3: mov %0, %3\n" \
388 " b 2b\n" \
389 " .popsection\n" \
390 " .pushsection __ex_table,\"a\"\n" \
391 " .align 3\n" \
392 " .long 1b, 3b\n" \
393 " .popsection" \
394 : "+r" (err) \
395 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
396 : "cc")
397
398#ifndef __ARMEB__
399#define __reg_oper0 "%R2"
400#define __reg_oper1 "%Q2"
401#else
402#define __reg_oper0 "%Q2"
403#define __reg_oper1 "%R2"
404#endif
405
406#define __put_user_asm_dword(x,__pu_addr,err) \
407 __asm__ __volatile__( \
408 ARM( "1: " TUSER(str) " " __reg_oper1 ", [%1], #4\n" ) \
409 ARM( "2: " TUSER(str) " " __reg_oper0 ", [%1]\n" ) \
410 THUMB( "1: " TUSER(str) " " __reg_oper1 ", [%1]\n" ) \
411 THUMB( "2: " TUSER(str) " " __reg_oper0 ", [%1, #4]\n" ) \
412 "3:\n" \
413 " .pushsection .fixup,\"ax\"\n" \
414 " .align 2\n" \
415 "4: mov %0, %3\n" \
416 " b 3b\n" \
417 " .popsection\n" \
418 " .pushsection __ex_table,\"a\"\n" \
419 " .align 3\n" \
420 " .long 1b, 4b\n" \
421 " .long 2b, 4b\n" \
422 " .popsection" \
423 : "+r" (err), "+r" (__pu_addr) \
424 : "r" (x), "i" (-EFAULT) \
425 : "cc")
426
427
428#ifdef CONFIG_MMU
429extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
430extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
431extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n);
432extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
433extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n);
434#else
435#define __copy_from_user(to,from,n) (memcpy(to, (void __force *)from, n), 0)
436#define __copy_to_user(to,from,n) (memcpy((void __force *)to, from, n), 0)
437#define __clear_user(addr,n) (memset((void __force *)addr, 0, n), 0)
438#endif
439
440static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
441{
442 if (access_ok(VERIFY_READ, from, n))
443 n = __copy_from_user(to, from, n);
444 else /* security hole - plug it */
445 memset(to, 0, n);
446 return n;
447}
448
449static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
450{
451 if (access_ok(VERIFY_WRITE, to, n))
452 n = __copy_to_user(to, from, n);
453 return n;
454}
455
456#define __copy_to_user_inatomic __copy_to_user
457#define __copy_from_user_inatomic __copy_from_user
458
459static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
460{
461 if (access_ok(VERIFY_WRITE, to, n))
462 n = __clear_user(to, n);
463 return n;
464}
465
466extern long strncpy_from_user(char *dest, const char __user *src, long count);
467
468extern __must_check long strlen_user(const char __user *str);
469extern __must_check long strnlen_user(const char __user *str, long n);
470
471#endif /* _ASMARM_UACCESS_H */
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/unaligned.h>
15#include <asm/unified.h>
16#include <asm/compiler.h>
17
18#include <asm/extable.h>
19
20/*
21 * These two functions allow hooking accesses to userspace to increase
22 * system integrity by ensuring that the kernel can not inadvertantly
23 * perform such accesses (eg, via list poison values) which could then
24 * be exploited for priviledge escalation.
25 */
26static __always_inline unsigned int uaccess_save_and_enable(void)
27{
28#ifdef CONFIG_CPU_SW_DOMAIN_PAN
29 unsigned int old_domain = get_domain();
30
31 /* Set the current domain access to permit user accesses */
32 set_domain((old_domain & ~domain_mask(DOMAIN_USER)) |
33 domain_val(DOMAIN_USER, DOMAIN_CLIENT));
34
35 return old_domain;
36#else
37 return 0;
38#endif
39}
40
41static __always_inline void uaccess_restore(unsigned int flags)
42{
43#ifdef CONFIG_CPU_SW_DOMAIN_PAN
44 /* Restore the user access mask */
45 set_domain(flags);
46#endif
47}
48
49/*
50 * These two are intentionally not defined anywhere - if the kernel
51 * code generates any references to them, that's a bug.
52 */
53extern int __get_user_bad(void);
54extern int __put_user_bad(void);
55
56#ifdef CONFIG_MMU
57
58/*
59 * This is a type: either unsigned long, if the argument fits into
60 * that type, or otherwise unsigned long long.
61 */
62#define __inttype(x) \
63 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
64
65/*
66 * Sanitise a uaccess pointer such that it becomes NULL if addr+size
67 * is above the current addr_limit.
68 */
69#define uaccess_mask_range_ptr(ptr, size) \
70 ((__typeof__(ptr))__uaccess_mask_range_ptr(ptr, size))
71static inline void __user *__uaccess_mask_range_ptr(const void __user *ptr,
72 size_t size)
73{
74 void __user *safe_ptr = (void __user *)ptr;
75 unsigned long tmp;
76
77 asm volatile(
78 " .syntax unified\n"
79 " sub %1, %3, #1\n"
80 " subs %1, %1, %0\n"
81 " addhs %1, %1, #1\n"
82 " subshs %1, %1, %2\n"
83 " movlo %0, #0\n"
84 : "+r" (safe_ptr), "=&r" (tmp)
85 : "r" (size), "r" (TASK_SIZE)
86 : "cc");
87
88 csdb();
89 return safe_ptr;
90}
91
92/*
93 * Single-value transfer routines. They automatically use the right
94 * size if we just have the right pointer type. Note that the functions
95 * which read from user space (*get_*) need to take care not to leak
96 * kernel data even if the calling code is buggy and fails to check
97 * the return value. This means zeroing out the destination variable
98 * or buffer on error. Normally this is done out of line by the
99 * fixup code, but there are a few places where it intrudes on the
100 * main code path. When we only write to user space, there is no
101 * problem.
102 */
103extern int __get_user_1(void *);
104extern int __get_user_2(void *);
105extern int __get_user_4(void *);
106extern int __get_user_32t_8(void *);
107extern int __get_user_8(void *);
108extern int __get_user_64t_1(void *);
109extern int __get_user_64t_2(void *);
110extern int __get_user_64t_4(void *);
111
112#define __GUP_CLOBBER_1 "lr", "cc"
113#ifdef CONFIG_CPU_USE_DOMAINS
114#define __GUP_CLOBBER_2 "ip", "lr", "cc"
115#else
116#define __GUP_CLOBBER_2 "lr", "cc"
117#endif
118#define __GUP_CLOBBER_4 "lr", "cc"
119#define __GUP_CLOBBER_32t_8 "lr", "cc"
120#define __GUP_CLOBBER_8 "lr", "cc"
121
122#define __get_user_x(__r2, __p, __e, __l, __s) \
123 __asm__ __volatile__ ( \
124 __asmeq("%0", "r0") __asmeq("%1", "r2") \
125 __asmeq("%3", "r1") \
126 "bl __get_user_" #__s \
127 : "=&r" (__e), "=r" (__r2) \
128 : "0" (__p), "r" (__l) \
129 : __GUP_CLOBBER_##__s)
130
131/* narrowing a double-word get into a single 32bit word register: */
132#ifdef __ARMEB__
133#define __get_user_x_32t(__r2, __p, __e, __l, __s) \
134 __get_user_x(__r2, __p, __e, __l, 32t_8)
135#else
136#define __get_user_x_32t __get_user_x
137#endif
138
139/*
140 * storing result into proper least significant word of 64bit target var,
141 * different only for big endian case where 64 bit __r2 lsw is r3:
142 */
143#ifdef __ARMEB__
144#define __get_user_x_64t(__r2, __p, __e, __l, __s) \
145 __asm__ __volatile__ ( \
146 __asmeq("%0", "r0") __asmeq("%1", "r2") \
147 __asmeq("%3", "r1") \
148 "bl __get_user_64t_" #__s \
149 : "=&r" (__e), "=r" (__r2) \
150 : "0" (__p), "r" (__l) \
151 : __GUP_CLOBBER_##__s)
152#else
153#define __get_user_x_64t __get_user_x
154#endif
155
156
157#define __get_user_check(x, p) \
158 ({ \
159 unsigned long __limit = TASK_SIZE - 1; \
160 register typeof(*(p)) __user *__p asm("r0") = (p); \
161 register __inttype(x) __r2 asm("r2"); \
162 register unsigned long __l asm("r1") = __limit; \
163 register int __e asm("r0"); \
164 unsigned int __ua_flags = uaccess_save_and_enable(); \
165 int __tmp_e; \
166 switch (sizeof(*(__p))) { \
167 case 1: \
168 if (sizeof((x)) >= 8) \
169 __get_user_x_64t(__r2, __p, __e, __l, 1); \
170 else \
171 __get_user_x(__r2, __p, __e, __l, 1); \
172 break; \
173 case 2: \
174 if (sizeof((x)) >= 8) \
175 __get_user_x_64t(__r2, __p, __e, __l, 2); \
176 else \
177 __get_user_x(__r2, __p, __e, __l, 2); \
178 break; \
179 case 4: \
180 if (sizeof((x)) >= 8) \
181 __get_user_x_64t(__r2, __p, __e, __l, 4); \
182 else \
183 __get_user_x(__r2, __p, __e, __l, 4); \
184 break; \
185 case 8: \
186 if (sizeof((x)) < 8) \
187 __get_user_x_32t(__r2, __p, __e, __l, 4); \
188 else \
189 __get_user_x(__r2, __p, __e, __l, 8); \
190 break; \
191 default: __e = __get_user_bad(); break; \
192 } \
193 __tmp_e = __e; \
194 uaccess_restore(__ua_flags); \
195 x = (typeof(*(p))) __r2; \
196 __tmp_e; \
197 })
198
199#define get_user(x, p) \
200 ({ \
201 might_fault(); \
202 __get_user_check(x, p); \
203 })
204
205extern int __put_user_1(void *, unsigned int);
206extern int __put_user_2(void *, unsigned int);
207extern int __put_user_4(void *, unsigned int);
208extern int __put_user_8(void *, unsigned long long);
209
210#define __put_user_check(__pu_val, __ptr, __err, __s) \
211 ({ \
212 unsigned long __limit = TASK_SIZE - 1; \
213 register typeof(__pu_val) __r2 asm("r2") = __pu_val; \
214 register const void __user *__p asm("r0") = __ptr; \
215 register unsigned long __l asm("r1") = __limit; \
216 register int __e asm("r0"); \
217 __asm__ __volatile__ ( \
218 __asmeq("%0", "r0") __asmeq("%2", "r2") \
219 __asmeq("%3", "r1") \
220 "bl __put_user_" #__s \
221 : "=&r" (__e) \
222 : "0" (__p), "r" (__r2), "r" (__l) \
223 : "ip", "lr", "cc"); \
224 __err = __e; \
225 })
226
227#else /* CONFIG_MMU */
228
229#define get_user(x, p) __get_user(x, p)
230#define __put_user_check __put_user_nocheck
231
232#endif /* CONFIG_MMU */
233
234#include <asm-generic/access_ok.h>
235
236#ifdef CONFIG_CPU_SPECTRE
237/*
238 * When mitigating Spectre variant 1, it is not worth fixing the non-
239 * verifying accessors, because we need to add verification of the
240 * address space there. Force these to use the standard get_user()
241 * version instead.
242 */
243#define __get_user(x, ptr) get_user(x, ptr)
244#else
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, TUSER()); \
259 __gu_err; \
260})
261
262#define __get_user_err(x, ptr, err, __t) \
263do { \
264 unsigned long __gu_addr = (unsigned long)(ptr); \
265 unsigned long __gu_val; \
266 unsigned int __ua_flags; \
267 __chk_user_ptr(ptr); \
268 might_fault(); \
269 __ua_flags = uaccess_save_and_enable(); \
270 switch (sizeof(*(ptr))) { \
271 case 1: __get_user_asm_byte(__gu_val, __gu_addr, err, __t); break; \
272 case 2: __get_user_asm_half(__gu_val, __gu_addr, err, __t); break; \
273 case 4: __get_user_asm_word(__gu_val, __gu_addr, err, __t); break; \
274 default: (__gu_val) = __get_user_bad(); \
275 } \
276 uaccess_restore(__ua_flags); \
277 (x) = (__typeof__(*(ptr)))__gu_val; \
278} while (0)
279#endif
280
281#define __get_user_asm(x, addr, err, instr) \
282 __asm__ __volatile__( \
283 "1: " instr " %1, [%2], #0\n" \
284 "2:\n" \
285 " .pushsection .text.fixup,\"ax\"\n" \
286 " .align 2\n" \
287 "3: mov %0, %3\n" \
288 " mov %1, #0\n" \
289 " b 2b\n" \
290 " .popsection\n" \
291 " .pushsection __ex_table,\"a\"\n" \
292 " .align 3\n" \
293 " .long 1b, 3b\n" \
294 " .popsection" \
295 : "+r" (err), "=&r" (x) \
296 : "r" (addr), "i" (-EFAULT) \
297 : "cc")
298
299#define __get_user_asm_byte(x, addr, err, __t) \
300 __get_user_asm(x, addr, err, "ldrb" __t)
301
302#if __LINUX_ARM_ARCH__ >= 6
303
304#define __get_user_asm_half(x, addr, err, __t) \
305 __get_user_asm(x, addr, err, "ldrh" __t)
306
307#else
308
309#ifndef __ARMEB__
310#define __get_user_asm_half(x, __gu_addr, err, __t) \
311({ \
312 unsigned long __b1, __b2; \
313 __get_user_asm_byte(__b1, __gu_addr, err, __t); \
314 __get_user_asm_byte(__b2, __gu_addr + 1, err, __t); \
315 (x) = __b1 | (__b2 << 8); \
316})
317#else
318#define __get_user_asm_half(x, __gu_addr, err, __t) \
319({ \
320 unsigned long __b1, __b2; \
321 __get_user_asm_byte(__b1, __gu_addr, err, __t); \
322 __get_user_asm_byte(__b2, __gu_addr + 1, err, __t); \
323 (x) = (__b1 << 8) | __b2; \
324})
325#endif
326
327#endif /* __LINUX_ARM_ARCH__ >= 6 */
328
329#define __get_user_asm_word(x, addr, err, __t) \
330 __get_user_asm(x, addr, err, "ldr" __t)
331
332#define __put_user_switch(x, ptr, __err, __fn) \
333 do { \
334 const __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
335 __typeof__(*(ptr)) __pu_val = (x); \
336 unsigned int __ua_flags; \
337 might_fault(); \
338 __ua_flags = uaccess_save_and_enable(); \
339 switch (sizeof(*(ptr))) { \
340 case 1: __fn(__pu_val, __pu_ptr, __err, 1); break; \
341 case 2: __fn(__pu_val, __pu_ptr, __err, 2); break; \
342 case 4: __fn(__pu_val, __pu_ptr, __err, 4); break; \
343 case 8: __fn(__pu_val, __pu_ptr, __err, 8); break; \
344 default: __err = __put_user_bad(); break; \
345 } \
346 uaccess_restore(__ua_flags); \
347 } while (0)
348
349#define put_user(x, ptr) \
350({ \
351 int __pu_err = 0; \
352 __put_user_switch((x), (ptr), __pu_err, __put_user_check); \
353 __pu_err; \
354})
355
356#ifdef CONFIG_CPU_SPECTRE
357/*
358 * When mitigating Spectre variant 1.1, all accessors need to include
359 * verification of the address space.
360 */
361#define __put_user(x, ptr) put_user(x, ptr)
362
363#else
364#define __put_user(x, ptr) \
365({ \
366 long __pu_err = 0; \
367 __put_user_switch((x), (ptr), __pu_err, __put_user_nocheck); \
368 __pu_err; \
369})
370
371#define __put_user_nocheck(x, __pu_ptr, __err, __size) \
372 do { \
373 unsigned long __pu_addr = (unsigned long)__pu_ptr; \
374 __put_user_nocheck_##__size(x, __pu_addr, __err, TUSER());\
375 } while (0)
376
377#define __put_user_nocheck_1 __put_user_asm_byte
378#define __put_user_nocheck_2 __put_user_asm_half
379#define __put_user_nocheck_4 __put_user_asm_word
380#define __put_user_nocheck_8 __put_user_asm_dword
381
382#endif /* !CONFIG_CPU_SPECTRE */
383
384#define __put_user_asm(x, __pu_addr, err, instr) \
385 __asm__ __volatile__( \
386 "1: " instr " %1, [%2], #0\n" \
387 "2:\n" \
388 " .pushsection .text.fixup,\"ax\"\n" \
389 " .align 2\n" \
390 "3: mov %0, %3\n" \
391 " b 2b\n" \
392 " .popsection\n" \
393 " .pushsection __ex_table,\"a\"\n" \
394 " .align 3\n" \
395 " .long 1b, 3b\n" \
396 " .popsection" \
397 : "+r" (err) \
398 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
399 : "cc")
400
401#define __put_user_asm_byte(x, __pu_addr, err, __t) \
402 __put_user_asm(x, __pu_addr, err, "strb" __t)
403
404#if __LINUX_ARM_ARCH__ >= 6
405
406#define __put_user_asm_half(x, __pu_addr, err, __t) \
407 __put_user_asm(x, __pu_addr, err, "strh" __t)
408
409#else
410
411#ifndef __ARMEB__
412#define __put_user_asm_half(x, __pu_addr, err, __t) \
413({ \
414 unsigned long __temp = (__force unsigned long)(x); \
415 __put_user_asm_byte(__temp, __pu_addr, err, __t); \
416 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err, __t);\
417})
418#else
419#define __put_user_asm_half(x, __pu_addr, err, __t) \
420({ \
421 unsigned long __temp = (__force unsigned long)(x); \
422 __put_user_asm_byte(__temp >> 8, __pu_addr, err, __t); \
423 __put_user_asm_byte(__temp, __pu_addr + 1, err, __t); \
424})
425#endif
426
427#endif /* __LINUX_ARM_ARCH__ >= 6 */
428
429#define __put_user_asm_word(x, __pu_addr, err, __t) \
430 __put_user_asm(x, __pu_addr, err, "str" __t)
431
432#ifndef __ARMEB__
433#define __reg_oper0 "%R2"
434#define __reg_oper1 "%Q2"
435#else
436#define __reg_oper0 "%Q2"
437#define __reg_oper1 "%R2"
438#endif
439
440#define __put_user_asm_dword(x, __pu_addr, err, __t) \
441 __asm__ __volatile__( \
442 ARM( "1: str" __t " " __reg_oper1 ", [%1], #4\n" ) \
443 ARM( "2: str" __t " " __reg_oper0 ", [%1]\n" ) \
444 THUMB( "1: str" __t " " __reg_oper1 ", [%1]\n" ) \
445 THUMB( "2: str" __t " " __reg_oper0 ", [%1, #4]\n" ) \
446 "3:\n" \
447 " .pushsection .text.fixup,\"ax\"\n" \
448 " .align 2\n" \
449 "4: mov %0, %3\n" \
450 " b 3b\n" \
451 " .popsection\n" \
452 " .pushsection __ex_table,\"a\"\n" \
453 " .align 3\n" \
454 " .long 1b, 4b\n" \
455 " .long 2b, 4b\n" \
456 " .popsection" \
457 : "+r" (err), "+r" (__pu_addr) \
458 : "r" (x), "i" (-EFAULT) \
459 : "cc")
460
461#define __get_kernel_nofault(dst, src, type, err_label) \
462do { \
463 const type *__pk_ptr = (src); \
464 unsigned long __src = (unsigned long)(__pk_ptr); \
465 type __val; \
466 int __err = 0; \
467 switch (sizeof(type)) { \
468 case 1: __get_user_asm_byte(__val, __src, __err, ""); break; \
469 case 2: __get_user_asm_half(__val, __src, __err, ""); break; \
470 case 4: __get_user_asm_word(__val, __src, __err, ""); break; \
471 case 8: { \
472 u32 *__v32 = (u32*)&__val; \
473 __get_user_asm_word(__v32[0], __src, __err, ""); \
474 if (__err) \
475 break; \
476 __get_user_asm_word(__v32[1], __src+4, __err, ""); \
477 break; \
478 } \
479 default: __err = __get_user_bad(); break; \
480 } \
481 if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) \
482 put_unaligned(__val, (type *)(dst)); \
483 else \
484 *(type *)(dst) = __val; /* aligned by caller */ \
485 if (__err) \
486 goto err_label; \
487} while (0)
488
489#define __put_kernel_nofault(dst, src, type, err_label) \
490do { \
491 const type *__pk_ptr = (dst); \
492 unsigned long __dst = (unsigned long)__pk_ptr; \
493 int __err = 0; \
494 type __val = IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) \
495 ? get_unaligned((type *)(src)) \
496 : *(type *)(src); /* aligned by caller */ \
497 switch (sizeof(type)) { \
498 case 1: __put_user_asm_byte(__val, __dst, __err, ""); break; \
499 case 2: __put_user_asm_half(__val, __dst, __err, ""); break; \
500 case 4: __put_user_asm_word(__val, __dst, __err, ""); break; \
501 case 8: __put_user_asm_dword(__val, __dst, __err, ""); break; \
502 default: __err = __put_user_bad(); break; \
503 } \
504 if (__err) \
505 goto err_label; \
506} while (0)
507
508#ifdef CONFIG_MMU
509extern unsigned long __must_check
510arm_copy_from_user(void *to, const void __user *from, unsigned long n);
511
512static inline unsigned long __must_check
513raw_copy_from_user(void *to, const void __user *from, unsigned long n)
514{
515 unsigned int __ua_flags;
516
517 __ua_flags = uaccess_save_and_enable();
518 n = arm_copy_from_user(to, from, n);
519 uaccess_restore(__ua_flags);
520 return n;
521}
522
523extern unsigned long __must_check
524arm_copy_to_user(void __user *to, const void *from, unsigned long n);
525extern unsigned long __must_check
526__copy_to_user_std(void __user *to, const void *from, unsigned long n);
527
528static inline unsigned long __must_check
529raw_copy_to_user(void __user *to, const void *from, unsigned long n)
530{
531#ifndef CONFIG_UACCESS_WITH_MEMCPY
532 unsigned int __ua_flags;
533 __ua_flags = uaccess_save_and_enable();
534 n = arm_copy_to_user(to, from, n);
535 uaccess_restore(__ua_flags);
536 return n;
537#else
538 return arm_copy_to_user(to, from, n);
539#endif
540}
541
542extern unsigned long __must_check
543arm_clear_user(void __user *addr, unsigned long n);
544extern unsigned long __must_check
545__clear_user_std(void __user *addr, unsigned long n);
546
547static inline unsigned long __must_check
548__clear_user(void __user *addr, unsigned long n)
549{
550 unsigned int __ua_flags = uaccess_save_and_enable();
551 n = arm_clear_user(addr, n);
552 uaccess_restore(__ua_flags);
553 return n;
554}
555
556#else
557static inline unsigned long
558raw_copy_from_user(void *to, const void __user *from, unsigned long n)
559{
560 memcpy(to, (const void __force *)from, n);
561 return 0;
562}
563static inline unsigned long
564raw_copy_to_user(void __user *to, const void *from, unsigned long n)
565{
566 memcpy((void __force *)to, from, n);
567 return 0;
568}
569#define __clear_user(addr, n) (memset((void __force *)addr, 0, n), 0)
570#endif
571#define INLINE_COPY_TO_USER
572#define INLINE_COPY_FROM_USER
573
574static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
575{
576 if (access_ok(to, n))
577 n = __clear_user(to, n);
578 return n;
579}
580
581/* These are from lib/ code, and use __get_user() and friends */
582extern long strncpy_from_user(char *dest, const char __user *src, long count);
583
584extern __must_check long strnlen_user(const char __user *str, long n);
585
586#endif /* _ASMARM_UACCESS_H */