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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/system.h>
20#include <asm/unified.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 __get_user_x(__r2,__p,__e,__s,__i...) \
105 __asm__ __volatile__ ( \
106 __asmeq("%0", "r0") __asmeq("%1", "r2") \
107 "bl __get_user_" #__s \
108 : "=&r" (__e), "=r" (__r2) \
109 : "0" (__p) \
110 : __i, "cc")
111
112#define get_user(x,p) \
113 ({ \
114 register const typeof(*(p)) __user *__p asm("r0") = (p);\
115 register unsigned long __r2 asm("r2"); \
116 register int __e asm("r0"); \
117 switch (sizeof(*(__p))) { \
118 case 1: \
119 __get_user_x(__r2, __p, __e, 1, "lr"); \
120 break; \
121 case 2: \
122 __get_user_x(__r2, __p, __e, 2, "r3", "lr"); \
123 break; \
124 case 4: \
125 __get_user_x(__r2, __p, __e, 4, "lr"); \
126 break; \
127 default: __e = __get_user_bad(); break; \
128 } \
129 x = (typeof(*(p))) __r2; \
130 __e; \
131 })
132
133extern int __put_user_1(void *, unsigned int);
134extern int __put_user_2(void *, unsigned int);
135extern int __put_user_4(void *, unsigned int);
136extern int __put_user_8(void *, unsigned long long);
137
138#define __put_user_x(__r2,__p,__e,__s) \
139 __asm__ __volatile__ ( \
140 __asmeq("%0", "r0") __asmeq("%2", "r2") \
141 "bl __put_user_" #__s \
142 : "=&r" (__e) \
143 : "0" (__p), "r" (__r2) \
144 : "ip", "lr", "cc")
145
146#define put_user(x,p) \
147 ({ \
148 register const typeof(*(p)) __r2 asm("r2") = (x); \
149 register const typeof(*(p)) __user *__p asm("r0") = (p);\
150 register int __e asm("r0"); \
151 switch (sizeof(*(__p))) { \
152 case 1: \
153 __put_user_x(__r2, __p, __e, 1); \
154 break; \
155 case 2: \
156 __put_user_x(__r2, __p, __e, 2); \
157 break; \
158 case 4: \
159 __put_user_x(__r2, __p, __e, 4); \
160 break; \
161 case 8: \
162 __put_user_x(__r2, __p, __e, 8); \
163 break; \
164 default: __e = __put_user_bad(); break; \
165 } \
166 __e; \
167 })
168
169#else /* CONFIG_MMU */
170
171/*
172 * uClinux has only one addr space, so has simplified address limits.
173 */
174#define USER_DS KERNEL_DS
175
176#define segment_eq(a,b) (1)
177#define __addr_ok(addr) (1)
178#define __range_ok(addr,size) (0)
179#define get_fs() (KERNEL_DS)
180
181static inline void set_fs(mm_segment_t fs)
182{
183}
184
185#define get_user(x,p) __get_user(x,p)
186#define put_user(x,p) __put_user(x,p)
187
188#endif /* CONFIG_MMU */
189
190#define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
191
192/*
193 * The "__xxx" versions of the user access functions do not verify the
194 * address space - it must have been done previously with a separate
195 * "access_ok()" call.
196 *
197 * The "xxx_error" versions set the third argument to EFAULT if an
198 * error occurs, and leave it unchanged on success. Note that these
199 * versions are void (ie, don't return a value as such).
200 */
201#define __get_user(x,ptr) \
202({ \
203 long __gu_err = 0; \
204 __get_user_err((x),(ptr),__gu_err); \
205 __gu_err; \
206})
207
208#define __get_user_error(x,ptr,err) \
209({ \
210 __get_user_err((x),(ptr),err); \
211 (void) 0; \
212})
213
214#define __get_user_err(x,ptr,err) \
215do { \
216 unsigned long __gu_addr = (unsigned long)(ptr); \
217 unsigned long __gu_val; \
218 __chk_user_ptr(ptr); \
219 switch (sizeof(*(ptr))) { \
220 case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \
221 case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \
222 case 4: __get_user_asm_word(__gu_val,__gu_addr,err); break; \
223 default: (__gu_val) = __get_user_bad(); \
224 } \
225 (x) = (__typeof__(*(ptr)))__gu_val; \
226} while (0)
227
228#define __get_user_asm_byte(x,addr,err) \
229 __asm__ __volatile__( \
230 "1: " T(ldrb) " %1,[%2],#0\n" \
231 "2:\n" \
232 " .pushsection .fixup,\"ax\"\n" \
233 " .align 2\n" \
234 "3: mov %0, %3\n" \
235 " mov %1, #0\n" \
236 " b 2b\n" \
237 " .popsection\n" \
238 " .pushsection __ex_table,\"a\"\n" \
239 " .align 3\n" \
240 " .long 1b, 3b\n" \
241 " .popsection" \
242 : "+r" (err), "=&r" (x) \
243 : "r" (addr), "i" (-EFAULT) \
244 : "cc")
245
246#ifndef __ARMEB__
247#define __get_user_asm_half(x,__gu_addr,err) \
248({ \
249 unsigned long __b1, __b2; \
250 __get_user_asm_byte(__b1, __gu_addr, err); \
251 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
252 (x) = __b1 | (__b2 << 8); \
253})
254#else
255#define __get_user_asm_half(x,__gu_addr,err) \
256({ \
257 unsigned long __b1, __b2; \
258 __get_user_asm_byte(__b1, __gu_addr, err); \
259 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
260 (x) = (__b1 << 8) | __b2; \
261})
262#endif
263
264#define __get_user_asm_word(x,addr,err) \
265 __asm__ __volatile__( \
266 "1: " T(ldr) " %1,[%2],#0\n" \
267 "2:\n" \
268 " .pushsection .fixup,\"ax\"\n" \
269 " .align 2\n" \
270 "3: mov %0, %3\n" \
271 " mov %1, #0\n" \
272 " b 2b\n" \
273 " .popsection\n" \
274 " .pushsection __ex_table,\"a\"\n" \
275 " .align 3\n" \
276 " .long 1b, 3b\n" \
277 " .popsection" \
278 : "+r" (err), "=&r" (x) \
279 : "r" (addr), "i" (-EFAULT) \
280 : "cc")
281
282#define __put_user(x,ptr) \
283({ \
284 long __pu_err = 0; \
285 __put_user_err((x),(ptr),__pu_err); \
286 __pu_err; \
287})
288
289#define __put_user_error(x,ptr,err) \
290({ \
291 __put_user_err((x),(ptr),err); \
292 (void) 0; \
293})
294
295#define __put_user_err(x,ptr,err) \
296do { \
297 unsigned long __pu_addr = (unsigned long)(ptr); \
298 __typeof__(*(ptr)) __pu_val = (x); \
299 __chk_user_ptr(ptr); \
300 switch (sizeof(*(ptr))) { \
301 case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \
302 case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \
303 case 4: __put_user_asm_word(__pu_val,__pu_addr,err); break; \
304 case 8: __put_user_asm_dword(__pu_val,__pu_addr,err); break; \
305 default: __put_user_bad(); \
306 } \
307} while (0)
308
309#define __put_user_asm_byte(x,__pu_addr,err) \
310 __asm__ __volatile__( \
311 "1: " T(strb) " %1,[%2],#0\n" \
312 "2:\n" \
313 " .pushsection .fixup,\"ax\"\n" \
314 " .align 2\n" \
315 "3: mov %0, %3\n" \
316 " b 2b\n" \
317 " .popsection\n" \
318 " .pushsection __ex_table,\"a\"\n" \
319 " .align 3\n" \
320 " .long 1b, 3b\n" \
321 " .popsection" \
322 : "+r" (err) \
323 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
324 : "cc")
325
326#ifndef __ARMEB__
327#define __put_user_asm_half(x,__pu_addr,err) \
328({ \
329 unsigned long __temp = (unsigned long)(x); \
330 __put_user_asm_byte(__temp, __pu_addr, err); \
331 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
332})
333#else
334#define __put_user_asm_half(x,__pu_addr,err) \
335({ \
336 unsigned long __temp = (unsigned long)(x); \
337 __put_user_asm_byte(__temp >> 8, __pu_addr, err); \
338 __put_user_asm_byte(__temp, __pu_addr + 1, err); \
339})
340#endif
341
342#define __put_user_asm_word(x,__pu_addr,err) \
343 __asm__ __volatile__( \
344 "1: " T(str) " %1,[%2],#0\n" \
345 "2:\n" \
346 " .pushsection .fixup,\"ax\"\n" \
347 " .align 2\n" \
348 "3: mov %0, %3\n" \
349 " b 2b\n" \
350 " .popsection\n" \
351 " .pushsection __ex_table,\"a\"\n" \
352 " .align 3\n" \
353 " .long 1b, 3b\n" \
354 " .popsection" \
355 : "+r" (err) \
356 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
357 : "cc")
358
359#ifndef __ARMEB__
360#define __reg_oper0 "%R2"
361#define __reg_oper1 "%Q2"
362#else
363#define __reg_oper0 "%Q2"
364#define __reg_oper1 "%R2"
365#endif
366
367#define __put_user_asm_dword(x,__pu_addr,err) \
368 __asm__ __volatile__( \
369 ARM( "1: " T(str) " " __reg_oper1 ", [%1], #4\n" ) \
370 ARM( "2: " T(str) " " __reg_oper0 ", [%1]\n" ) \
371 THUMB( "1: " T(str) " " __reg_oper1 ", [%1]\n" ) \
372 THUMB( "2: " T(str) " " __reg_oper0 ", [%1, #4]\n" ) \
373 "3:\n" \
374 " .pushsection .fixup,\"ax\"\n" \
375 " .align 2\n" \
376 "4: mov %0, %3\n" \
377 " b 3b\n" \
378 " .popsection\n" \
379 " .pushsection __ex_table,\"a\"\n" \
380 " .align 3\n" \
381 " .long 1b, 4b\n" \
382 " .long 2b, 4b\n" \
383 " .popsection" \
384 : "+r" (err), "+r" (__pu_addr) \
385 : "r" (x), "i" (-EFAULT) \
386 : "cc")
387
388
389#ifdef CONFIG_MMU
390extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
391extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
392extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n);
393extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
394extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n);
395#else
396#define __copy_from_user(to,from,n) (memcpy(to, (void __force *)from, n), 0)
397#define __copy_to_user(to,from,n) (memcpy((void __force *)to, from, n), 0)
398#define __clear_user(addr,n) (memset((void __force *)addr, 0, n), 0)
399#endif
400
401extern unsigned long __must_check __strncpy_from_user(char *to, const char __user *from, unsigned long count);
402extern unsigned long __must_check __strnlen_user(const char __user *s, long n);
403
404static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
405{
406 if (access_ok(VERIFY_READ, from, n))
407 n = __copy_from_user(to, from, n);
408 else /* security hole - plug it */
409 memset(to, 0, n);
410 return n;
411}
412
413static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
414{
415 if (access_ok(VERIFY_WRITE, to, n))
416 n = __copy_to_user(to, from, n);
417 return n;
418}
419
420#define __copy_to_user_inatomic __copy_to_user
421#define __copy_from_user_inatomic __copy_from_user
422
423static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
424{
425 if (access_ok(VERIFY_WRITE, to, n))
426 n = __clear_user(to, n);
427 return n;
428}
429
430static inline long __must_check strncpy_from_user(char *dst, const char __user *src, long count)
431{
432 long res = -EFAULT;
433 if (access_ok(VERIFY_READ, src, 1))
434 res = __strncpy_from_user(dst, src, count);
435 return res;
436}
437
438#define strlen_user(s) strnlen_user(s, ~0UL >> 1)
439
440static inline long __must_check strnlen_user(const char __user *s, long n)
441{
442 unsigned long res = 0;
443
444 if (__addr_ok(s))
445 res = __strnlen_user(s, n);
446
447 return res;
448}
449
450#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 */