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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/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 uaccess_kernel() (get_fs() == KERNEL_DS)
80
81/*
82 * We use 33-bit arithmetic here. Success returns zero, failure returns
83 * addr_limit. We take advantage that addr_limit will be zero for KERNEL_DS,
84 * so this will always return success in that case.
85 */
86#define __range_ok(addr, size) ({ \
87 unsigned long flag, roksum; \
88 __chk_user_ptr(addr); \
89 __asm__(".syntax unified\n" \
90 "adds %1, %2, %3; sbcscc %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 * This is a type: either unsigned long, if the argument fits into
98 * that type, or otherwise unsigned long long.
99 */
100#define __inttype(x) \
101 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
102
103/*
104 * Sanitise a uaccess pointer such that it becomes NULL if addr+size
105 * is above the current addr_limit.
106 */
107#define uaccess_mask_range_ptr(ptr, size) \
108 ((__typeof__(ptr))__uaccess_mask_range_ptr(ptr, size))
109static inline void __user *__uaccess_mask_range_ptr(const void __user *ptr,
110 size_t size)
111{
112 void __user *safe_ptr = (void __user *)ptr;
113 unsigned long tmp;
114
115 asm volatile(
116 " .syntax unified\n"
117 " sub %1, %3, #1\n"
118 " subs %1, %1, %0\n"
119 " addhs %1, %1, #1\n"
120 " subshs %1, %1, %2\n"
121 " movlo %0, #0\n"
122 : "+r" (safe_ptr), "=&r" (tmp)
123 : "r" (size), "r" (current_thread_info()->addr_limit)
124 : "cc");
125
126 csdb();
127 return safe_ptr;
128}
129
130/*
131 * Single-value transfer routines. They automatically use the right
132 * size if we just have the right pointer type. Note that the functions
133 * which read from user space (*get_*) need to take care not to leak
134 * kernel data even if the calling code is buggy and fails to check
135 * the return value. This means zeroing out the destination variable
136 * or buffer on error. Normally this is done out of line by the
137 * fixup code, but there are a few places where it intrudes on the
138 * main code path. When we only write to user space, there is no
139 * problem.
140 */
141extern int __get_user_1(void *);
142extern int __get_user_2(void *);
143extern int __get_user_4(void *);
144extern int __get_user_32t_8(void *);
145extern int __get_user_8(void *);
146extern int __get_user_64t_1(void *);
147extern int __get_user_64t_2(void *);
148extern int __get_user_64t_4(void *);
149
150#define __GUP_CLOBBER_1 "lr", "cc"
151#ifdef CONFIG_CPU_USE_DOMAINS
152#define __GUP_CLOBBER_2 "ip", "lr", "cc"
153#else
154#define __GUP_CLOBBER_2 "lr", "cc"
155#endif
156#define __GUP_CLOBBER_4 "lr", "cc"
157#define __GUP_CLOBBER_32t_8 "lr", "cc"
158#define __GUP_CLOBBER_8 "lr", "cc"
159
160#define __get_user_x(__r2, __p, __e, __l, __s) \
161 __asm__ __volatile__ ( \
162 __asmeq("%0", "r0") __asmeq("%1", "r2") \
163 __asmeq("%3", "r1") \
164 "bl __get_user_" #__s \
165 : "=&r" (__e), "=r" (__r2) \
166 : "0" (__p), "r" (__l) \
167 : __GUP_CLOBBER_##__s)
168
169/* narrowing a double-word get into a single 32bit word register: */
170#ifdef __ARMEB__
171#define __get_user_x_32t(__r2, __p, __e, __l, __s) \
172 __get_user_x(__r2, __p, __e, __l, 32t_8)
173#else
174#define __get_user_x_32t __get_user_x
175#endif
176
177/*
178 * storing result into proper least significant word of 64bit target var,
179 * different only for big endian case where 64 bit __r2 lsw is r3:
180 */
181#ifdef __ARMEB__
182#define __get_user_x_64t(__r2, __p, __e, __l, __s) \
183 __asm__ __volatile__ ( \
184 __asmeq("%0", "r0") __asmeq("%1", "r2") \
185 __asmeq("%3", "r1") \
186 "bl __get_user_64t_" #__s \
187 : "=&r" (__e), "=r" (__r2) \
188 : "0" (__p), "r" (__l) \
189 : __GUP_CLOBBER_##__s)
190#else
191#define __get_user_x_64t __get_user_x
192#endif
193
194
195#define __get_user_check(x, p) \
196 ({ \
197 unsigned long __limit = current_thread_info()->addr_limit - 1; \
198 register typeof(*(p)) __user *__p asm("r0") = (p); \
199 register __inttype(x) __r2 asm("r2"); \
200 register unsigned long __l asm("r1") = __limit; \
201 register int __e asm("r0"); \
202 unsigned int __ua_flags = uaccess_save_and_enable(); \
203 switch (sizeof(*(__p))) { \
204 case 1: \
205 if (sizeof((x)) >= 8) \
206 __get_user_x_64t(__r2, __p, __e, __l, 1); \
207 else \
208 __get_user_x(__r2, __p, __e, __l, 1); \
209 break; \
210 case 2: \
211 if (sizeof((x)) >= 8) \
212 __get_user_x_64t(__r2, __p, __e, __l, 2); \
213 else \
214 __get_user_x(__r2, __p, __e, __l, 2); \
215 break; \
216 case 4: \
217 if (sizeof((x)) >= 8) \
218 __get_user_x_64t(__r2, __p, __e, __l, 4); \
219 else \
220 __get_user_x(__r2, __p, __e, __l, 4); \
221 break; \
222 case 8: \
223 if (sizeof((x)) < 8) \
224 __get_user_x_32t(__r2, __p, __e, __l, 4); \
225 else \
226 __get_user_x(__r2, __p, __e, __l, 8); \
227 break; \
228 default: __e = __get_user_bad(); break; \
229 } \
230 uaccess_restore(__ua_flags); \
231 x = (typeof(*(p))) __r2; \
232 __e; \
233 })
234
235#define get_user(x, p) \
236 ({ \
237 might_fault(); \
238 __get_user_check(x, p); \
239 })
240
241extern int __put_user_1(void *, unsigned int);
242extern int __put_user_2(void *, unsigned int);
243extern int __put_user_4(void *, unsigned int);
244extern int __put_user_8(void *, unsigned long long);
245
246#define __put_user_check(__pu_val, __ptr, __err, __s) \
247 ({ \
248 unsigned long __limit = current_thread_info()->addr_limit - 1; \
249 register typeof(__pu_val) __r2 asm("r2") = __pu_val; \
250 register const void __user *__p asm("r0") = __ptr; \
251 register unsigned long __l asm("r1") = __limit; \
252 register int __e asm("r0"); \
253 __asm__ __volatile__ ( \
254 __asmeq("%0", "r0") __asmeq("%2", "r2") \
255 __asmeq("%3", "r1") \
256 "bl __put_user_" #__s \
257 : "=&r" (__e) \
258 : "0" (__p), "r" (__r2), "r" (__l) \
259 : "ip", "lr", "cc"); \
260 __err = __e; \
261 })
262
263#else /* CONFIG_MMU */
264
265/*
266 * uClinux has only one addr space, so has simplified address limits.
267 */
268#define USER_DS KERNEL_DS
269
270#define uaccess_kernel() (true)
271#define __addr_ok(addr) ((void)(addr), 1)
272#define __range_ok(addr, size) ((void)(addr), 0)
273#define get_fs() (KERNEL_DS)
274
275static inline void set_fs(mm_segment_t fs)
276{
277}
278
279#define get_user(x, p) __get_user(x, p)
280#define __put_user_check __put_user_nocheck
281
282#endif /* CONFIG_MMU */
283
284#define access_ok(addr, size) (__range_ok(addr, size) == 0)
285
286#define user_addr_max() \
287 (uaccess_kernel() ? ~0UL : get_fs())
288
289#ifdef CONFIG_CPU_SPECTRE
290/*
291 * When mitigating Spectre variant 1, it is not worth fixing the non-
292 * verifying accessors, because we need to add verification of the
293 * address space there. Force these to use the standard get_user()
294 * version instead.
295 */
296#define __get_user(x, ptr) get_user(x, ptr)
297#else
298
299/*
300 * The "__xxx" versions of the user access functions do not verify the
301 * address space - it must have been done previously with a separate
302 * "access_ok()" call.
303 *
304 * The "xxx_error" versions set the third argument to EFAULT if an
305 * error occurs, and leave it unchanged on success. Note that these
306 * versions are void (ie, don't return a value as such).
307 */
308#define __get_user(x, ptr) \
309({ \
310 long __gu_err = 0; \
311 __get_user_err((x), (ptr), __gu_err); \
312 __gu_err; \
313})
314
315#define __get_user_err(x, ptr, err) \
316do { \
317 unsigned long __gu_addr = (unsigned long)(ptr); \
318 unsigned long __gu_val; \
319 unsigned int __ua_flags; \
320 __chk_user_ptr(ptr); \
321 might_fault(); \
322 __ua_flags = uaccess_save_and_enable(); \
323 switch (sizeof(*(ptr))) { \
324 case 1: __get_user_asm_byte(__gu_val, __gu_addr, err); break; \
325 case 2: __get_user_asm_half(__gu_val, __gu_addr, err); break; \
326 case 4: __get_user_asm_word(__gu_val, __gu_addr, err); break; \
327 default: (__gu_val) = __get_user_bad(); \
328 } \
329 uaccess_restore(__ua_flags); \
330 (x) = (__typeof__(*(ptr)))__gu_val; \
331} while (0)
332
333#define __get_user_asm(x, addr, err, instr) \
334 __asm__ __volatile__( \
335 "1: " TUSER(instr) " %1, [%2], #0\n" \
336 "2:\n" \
337 " .pushsection .text.fixup,\"ax\"\n" \
338 " .align 2\n" \
339 "3: mov %0, %3\n" \
340 " mov %1, #0\n" \
341 " b 2b\n" \
342 " .popsection\n" \
343 " .pushsection __ex_table,\"a\"\n" \
344 " .align 3\n" \
345 " .long 1b, 3b\n" \
346 " .popsection" \
347 : "+r" (err), "=&r" (x) \
348 : "r" (addr), "i" (-EFAULT) \
349 : "cc")
350
351#define __get_user_asm_byte(x, addr, err) \
352 __get_user_asm(x, addr, err, ldrb)
353
354#if __LINUX_ARM_ARCH__ >= 6
355
356#define __get_user_asm_half(x, addr, err) \
357 __get_user_asm(x, addr, err, ldrh)
358
359#else
360
361#ifndef __ARMEB__
362#define __get_user_asm_half(x, __gu_addr, err) \
363({ \
364 unsigned long __b1, __b2; \
365 __get_user_asm_byte(__b1, __gu_addr, err); \
366 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
367 (x) = __b1 | (__b2 << 8); \
368})
369#else
370#define __get_user_asm_half(x, __gu_addr, err) \
371({ \
372 unsigned long __b1, __b2; \
373 __get_user_asm_byte(__b1, __gu_addr, err); \
374 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
375 (x) = (__b1 << 8) | __b2; \
376})
377#endif
378
379#endif /* __LINUX_ARM_ARCH__ >= 6 */
380
381#define __get_user_asm_word(x, addr, err) \
382 __get_user_asm(x, addr, err, ldr)
383#endif
384
385
386#define __put_user_switch(x, ptr, __err, __fn) \
387 do { \
388 const __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
389 __typeof__(*(ptr)) __pu_val = (x); \
390 unsigned int __ua_flags; \
391 might_fault(); \
392 __ua_flags = uaccess_save_and_enable(); \
393 switch (sizeof(*(ptr))) { \
394 case 1: __fn(__pu_val, __pu_ptr, __err, 1); break; \
395 case 2: __fn(__pu_val, __pu_ptr, __err, 2); break; \
396 case 4: __fn(__pu_val, __pu_ptr, __err, 4); break; \
397 case 8: __fn(__pu_val, __pu_ptr, __err, 8); break; \
398 default: __err = __put_user_bad(); break; \
399 } \
400 uaccess_restore(__ua_flags); \
401 } while (0)
402
403#define put_user(x, ptr) \
404({ \
405 int __pu_err = 0; \
406 __put_user_switch((x), (ptr), __pu_err, __put_user_check); \
407 __pu_err; \
408})
409
410#ifdef CONFIG_CPU_SPECTRE
411/*
412 * When mitigating Spectre variant 1.1, all accessors need to include
413 * verification of the address space.
414 */
415#define __put_user(x, ptr) put_user(x, ptr)
416
417#else
418#define __put_user(x, ptr) \
419({ \
420 long __pu_err = 0; \
421 __put_user_switch((x), (ptr), __pu_err, __put_user_nocheck); \
422 __pu_err; \
423})
424
425#define __put_user_nocheck(x, __pu_ptr, __err, __size) \
426 do { \
427 unsigned long __pu_addr = (unsigned long)__pu_ptr; \
428 __put_user_nocheck_##__size(x, __pu_addr, __err); \
429 } while (0)
430
431#define __put_user_nocheck_1 __put_user_asm_byte
432#define __put_user_nocheck_2 __put_user_asm_half
433#define __put_user_nocheck_4 __put_user_asm_word
434#define __put_user_nocheck_8 __put_user_asm_dword
435
436#define __put_user_asm(x, __pu_addr, err, instr) \
437 __asm__ __volatile__( \
438 "1: " TUSER(instr) " %1, [%2], #0\n" \
439 "2:\n" \
440 " .pushsection .text.fixup,\"ax\"\n" \
441 " .align 2\n" \
442 "3: mov %0, %3\n" \
443 " b 2b\n" \
444 " .popsection\n" \
445 " .pushsection __ex_table,\"a\"\n" \
446 " .align 3\n" \
447 " .long 1b, 3b\n" \
448 " .popsection" \
449 : "+r" (err) \
450 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
451 : "cc")
452
453#define __put_user_asm_byte(x, __pu_addr, err) \
454 __put_user_asm(x, __pu_addr, err, strb)
455
456#if __LINUX_ARM_ARCH__ >= 6
457
458#define __put_user_asm_half(x, __pu_addr, err) \
459 __put_user_asm(x, __pu_addr, err, strh)
460
461#else
462
463#ifndef __ARMEB__
464#define __put_user_asm_half(x, __pu_addr, err) \
465({ \
466 unsigned long __temp = (__force unsigned long)(x); \
467 __put_user_asm_byte(__temp, __pu_addr, err); \
468 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
469})
470#else
471#define __put_user_asm_half(x, __pu_addr, err) \
472({ \
473 unsigned long __temp = (__force unsigned long)(x); \
474 __put_user_asm_byte(__temp >> 8, __pu_addr, err); \
475 __put_user_asm_byte(__temp, __pu_addr + 1, err); \
476})
477#endif
478
479#endif /* __LINUX_ARM_ARCH__ >= 6 */
480
481#define __put_user_asm_word(x, __pu_addr, err) \
482 __put_user_asm(x, __pu_addr, err, str)
483
484#ifndef __ARMEB__
485#define __reg_oper0 "%R2"
486#define __reg_oper1 "%Q2"
487#else
488#define __reg_oper0 "%Q2"
489#define __reg_oper1 "%R2"
490#endif
491
492#define __put_user_asm_dword(x, __pu_addr, err) \
493 __asm__ __volatile__( \
494 ARM( "1: " TUSER(str) " " __reg_oper1 ", [%1], #4\n" ) \
495 ARM( "2: " TUSER(str) " " __reg_oper0 ", [%1]\n" ) \
496 THUMB( "1: " TUSER(str) " " __reg_oper1 ", [%1]\n" ) \
497 THUMB( "2: " TUSER(str) " " __reg_oper0 ", [%1, #4]\n" ) \
498 "3:\n" \
499 " .pushsection .text.fixup,\"ax\"\n" \
500 " .align 2\n" \
501 "4: mov %0, %3\n" \
502 " b 3b\n" \
503 " .popsection\n" \
504 " .pushsection __ex_table,\"a\"\n" \
505 " .align 3\n" \
506 " .long 1b, 4b\n" \
507 " .long 2b, 4b\n" \
508 " .popsection" \
509 : "+r" (err), "+r" (__pu_addr) \
510 : "r" (x), "i" (-EFAULT) \
511 : "cc")
512
513#endif /* !CONFIG_CPU_SPECTRE */
514
515#ifdef CONFIG_MMU
516extern unsigned long __must_check
517arm_copy_from_user(void *to, const void __user *from, unsigned long n);
518
519static inline unsigned long __must_check
520raw_copy_from_user(void *to, const void __user *from, unsigned long n)
521{
522 unsigned int __ua_flags;
523
524 __ua_flags = uaccess_save_and_enable();
525 n = arm_copy_from_user(to, from, n);
526 uaccess_restore(__ua_flags);
527 return n;
528}
529
530extern unsigned long __must_check
531arm_copy_to_user(void __user *to, const void *from, unsigned long n);
532extern unsigned long __must_check
533__copy_to_user_std(void __user *to, const void *from, unsigned long n);
534
535static inline unsigned long __must_check
536raw_copy_to_user(void __user *to, const void *from, unsigned long n)
537{
538#ifndef CONFIG_UACCESS_WITH_MEMCPY
539 unsigned int __ua_flags;
540 __ua_flags = uaccess_save_and_enable();
541 n = arm_copy_to_user(to, from, n);
542 uaccess_restore(__ua_flags);
543 return n;
544#else
545 return arm_copy_to_user(to, from, n);
546#endif
547}
548
549extern unsigned long __must_check
550arm_clear_user(void __user *addr, unsigned long n);
551extern unsigned long __must_check
552__clear_user_std(void __user *addr, unsigned long n);
553
554static inline unsigned long __must_check
555__clear_user(void __user *addr, unsigned long n)
556{
557 unsigned int __ua_flags = uaccess_save_and_enable();
558 n = arm_clear_user(addr, n);
559 uaccess_restore(__ua_flags);
560 return n;
561}
562
563#else
564static inline unsigned long
565raw_copy_from_user(void *to, const void __user *from, unsigned long n)
566{
567 memcpy(to, (const void __force *)from, n);
568 return 0;
569}
570static inline unsigned long
571raw_copy_to_user(void __user *to, const void *from, unsigned long n)
572{
573 memcpy((void __force *)to, from, n);
574 return 0;
575}
576#define __clear_user(addr, n) (memset((void __force *)addr, 0, n), 0)
577#endif
578#define INLINE_COPY_TO_USER
579#define INLINE_COPY_FROM_USER
580
581static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
582{
583 if (access_ok(to, n))
584 n = __clear_user(to, n);
585 return n;
586}
587
588/* These are from lib/ code, and use __get_user() and friends */
589extern long strncpy_from_user(char *dest, const char __user *src, long count);
590
591extern __must_check long strnlen_user(const char __user *str, long n);
592
593#endif /* _ASMARM_UACCESS_H */