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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/kernel.h>
12#include <linux/string.h>
13#include <asm/page.h>
14#include <asm/domain.h>
15#include <linux/unaligned.h>
16#include <asm/unified.h>
17#include <asm/pgtable.h>
18#include <asm/proc-fns.h>
19#include <asm/compiler.h>
20
21#include <asm/extable.h>
22
23/*
24 * These two functions allow hooking accesses to userspace to increase
25 * system integrity by ensuring that the kernel can not inadvertantly
26 * perform such accesses (eg, via list poison values) which could then
27 * be exploited for priviledge escalation.
28 */
29#if defined(CONFIG_CPU_SW_DOMAIN_PAN)
30
31static __always_inline unsigned int uaccess_save_and_enable(void)
32{
33 unsigned int old_domain = get_domain();
34
35 /* Set the current domain access to permit user accesses */
36 set_domain((old_domain & ~domain_mask(DOMAIN_USER)) |
37 domain_val(DOMAIN_USER, DOMAIN_CLIENT));
38
39 return old_domain;
40}
41
42static __always_inline void uaccess_restore(unsigned int flags)
43{
44 /* Restore the user access mask */
45 set_domain(flags);
46}
47
48#elif defined(CONFIG_CPU_TTBR0_PAN)
49
50static __always_inline unsigned int uaccess_save_and_enable(void)
51{
52 unsigned int old_ttbcr = cpu_get_ttbcr();
53
54 /*
55 * Enable TTBR0 page table walks (T0SZ = 0, EDP0 = 0) and ASID from
56 * TTBR0 (A1 = 0).
57 */
58 cpu_set_ttbcr(old_ttbcr & ~(TTBCR_A1 | TTBCR_EPD0 | TTBCR_T0SZ_MASK));
59 isb();
60
61 return old_ttbcr;
62}
63
64static inline void uaccess_restore(unsigned int flags)
65{
66 cpu_set_ttbcr(flags);
67 isb();
68}
69
70#else
71
72static inline unsigned int uaccess_save_and_enable(void)
73{
74 return 0;
75}
76
77static inline void uaccess_restore(unsigned int flags)
78{
79}
80
81#endif
82
83/*
84 * These two are intentionally not defined anywhere - if the kernel
85 * code generates any references to them, that's a bug.
86 */
87extern int __get_user_bad(void);
88extern int __put_user_bad(void);
89
90#ifdef CONFIG_MMU
91
92/*
93 * This is a type: either unsigned long, if the argument fits into
94 * that type, or otherwise unsigned long long.
95 */
96#define __inttype(x) \
97 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
98
99/*
100 * Sanitise a uaccess pointer such that it becomes NULL if addr+size
101 * is above the current addr_limit.
102 */
103#define uaccess_mask_range_ptr(ptr, size) \
104 ((__typeof__(ptr))__uaccess_mask_range_ptr(ptr, size))
105static inline void __user *__uaccess_mask_range_ptr(const void __user *ptr,
106 size_t size)
107{
108 void __user *safe_ptr = (void __user *)ptr;
109 unsigned long tmp;
110
111 asm volatile(
112 " .syntax unified\n"
113 " sub %1, %3, #1\n"
114 " subs %1, %1, %0\n"
115 " addhs %1, %1, #1\n"
116 " subshs %1, %1, %2\n"
117 " movlo %0, #0\n"
118 : "+r" (safe_ptr), "=&r" (tmp)
119 : "r" (size), "r" (TASK_SIZE)
120 : "cc");
121
122 csdb();
123 return safe_ptr;
124}
125
126/*
127 * Single-value transfer routines. They automatically use the right
128 * size if we just have the right pointer type. Note that the functions
129 * which read from user space (*get_*) need to take care not to leak
130 * kernel data even if the calling code is buggy and fails to check
131 * the return value. This means zeroing out the destination variable
132 * or buffer on error. Normally this is done out of line by the
133 * fixup code, but there are a few places where it intrudes on the
134 * main code path. When we only write to user space, there is no
135 * problem.
136 */
137extern int __get_user_1(void *);
138extern int __get_user_2(void *);
139extern int __get_user_4(void *);
140extern int __get_user_32t_8(void *);
141extern int __get_user_8(void *);
142extern int __get_user_64t_1(void *);
143extern int __get_user_64t_2(void *);
144extern int __get_user_64t_4(void *);
145
146#define __get_user_x(__r2, __p, __e, __l, __s) \
147 __asm__ __volatile__ ( \
148 __asmeq("%0", "r0") __asmeq("%1", "r2") \
149 __asmeq("%3", "r1") \
150 "bl __get_user_" #__s \
151 : "=&r" (__e), "=r" (__r2) \
152 : "0" (__p), "r" (__l) \
153 : "ip", "lr", "cc")
154
155/* narrowing a double-word get into a single 32bit word register: */
156#ifdef __ARMEB__
157#define __get_user_x_32t(__r2, __p, __e, __l, __s) \
158 __get_user_x(__r2, __p, __e, __l, 32t_8)
159#else
160#define __get_user_x_32t __get_user_x
161#endif
162
163/*
164 * storing result into proper least significant word of 64bit target var,
165 * different only for big endian case where 64 bit __r2 lsw is r3:
166 */
167#ifdef __ARMEB__
168#define __get_user_x_64t(__r2, __p, __e, __l, __s) \
169 __asm__ __volatile__ ( \
170 __asmeq("%0", "r0") __asmeq("%1", "r2") \
171 __asmeq("%3", "r1") \
172 "bl __get_user_64t_" #__s \
173 : "=&r" (__e), "=r" (__r2) \
174 : "0" (__p), "r" (__l) \
175 : "ip", "lr", "cc")
176#else
177#define __get_user_x_64t __get_user_x
178#endif
179
180
181#define __get_user_check(x, p) \
182 ({ \
183 unsigned long __limit = TASK_SIZE - 1; \
184 register typeof(*(p)) __user *__p asm("r0") = (p); \
185 register __inttype(x) __r2 asm("r2"); \
186 register unsigned long __l asm("r1") = __limit; \
187 register int __e asm("r0"); \
188 unsigned int __ua_flags = uaccess_save_and_enable(); \
189 int __tmp_e; \
190 switch (sizeof(*(__p))) { \
191 case 1: \
192 if (sizeof((x)) >= 8) \
193 __get_user_x_64t(__r2, __p, __e, __l, 1); \
194 else \
195 __get_user_x(__r2, __p, __e, __l, 1); \
196 break; \
197 case 2: \
198 if (sizeof((x)) >= 8) \
199 __get_user_x_64t(__r2, __p, __e, __l, 2); \
200 else \
201 __get_user_x(__r2, __p, __e, __l, 2); \
202 break; \
203 case 4: \
204 if (sizeof((x)) >= 8) \
205 __get_user_x_64t(__r2, __p, __e, __l, 4); \
206 else \
207 __get_user_x(__r2, __p, __e, __l, 4); \
208 break; \
209 case 8: \
210 if (sizeof((x)) < 8) \
211 __get_user_x_32t(__r2, __p, __e, __l, 4); \
212 else \
213 __get_user_x(__r2, __p, __e, __l, 8); \
214 break; \
215 default: __e = __get_user_bad(); break; \
216 } \
217 __tmp_e = __e; \
218 uaccess_restore(__ua_flags); \
219 x = (typeof(*(p))) __r2; \
220 __tmp_e; \
221 })
222
223#define get_user(x, p) \
224 ({ \
225 might_fault(); \
226 __get_user_check(x, p); \
227 })
228
229extern int __put_user_1(void *, unsigned int);
230extern int __put_user_2(void *, unsigned int);
231extern int __put_user_4(void *, unsigned int);
232extern int __put_user_8(void *, unsigned long long);
233
234#define __put_user_check(__pu_val, __ptr, __err, __s) \
235 ({ \
236 unsigned long __limit = TASK_SIZE - 1; \
237 register typeof(__pu_val) __r2 asm("r2") = __pu_val; \
238 register const void __user *__p asm("r0") = __ptr; \
239 register unsigned long __l asm("r1") = __limit; \
240 register int __e asm("r0"); \
241 __asm__ __volatile__ ( \
242 __asmeq("%0", "r0") __asmeq("%2", "r2") \
243 __asmeq("%3", "r1") \
244 "bl __put_user_" #__s \
245 : "=&r" (__e) \
246 : "0" (__p), "r" (__r2), "r" (__l) \
247 : "ip", "lr", "cc"); \
248 __err = __e; \
249 })
250
251#else /* CONFIG_MMU */
252
253#define get_user(x, p) __get_user(x, p)
254#define __put_user_check __put_user_nocheck
255
256#endif /* CONFIG_MMU */
257
258#include <asm-generic/access_ok.h>
259
260#ifdef CONFIG_CPU_SPECTRE
261/*
262 * When mitigating Spectre variant 1, it is not worth fixing the non-
263 * verifying accessors, because we need to add verification of the
264 * address space there. Force these to use the standard get_user()
265 * version instead.
266 */
267#define __get_user(x, ptr) get_user(x, ptr)
268#else
269
270/*
271 * The "__xxx" versions of the user access functions do not verify the
272 * address space - it must have been done previously with a separate
273 * "access_ok()" call.
274 *
275 * The "xxx_error" versions set the third argument to EFAULT if an
276 * error occurs, and leave it unchanged on success. Note that these
277 * versions are void (ie, don't return a value as such).
278 */
279#define __get_user(x, ptr) \
280({ \
281 long __gu_err = 0; \
282 __get_user_err((x), (ptr), __gu_err, TUSER()); \
283 __gu_err; \
284})
285
286#define __get_user_err(x, ptr, err, __t) \
287do { \
288 unsigned long __gu_addr = (unsigned long)(ptr); \
289 unsigned long __gu_val; \
290 unsigned int __ua_flags; \
291 __chk_user_ptr(ptr); \
292 might_fault(); \
293 __ua_flags = uaccess_save_and_enable(); \
294 switch (sizeof(*(ptr))) { \
295 case 1: __get_user_asm_byte(__gu_val, __gu_addr, err, __t); break; \
296 case 2: __get_user_asm_half(__gu_val, __gu_addr, err, __t); break; \
297 case 4: __get_user_asm_word(__gu_val, __gu_addr, err, __t); break; \
298 default: (__gu_val) = __get_user_bad(); \
299 } \
300 uaccess_restore(__ua_flags); \
301 (x) = (__typeof__(*(ptr)))__gu_val; \
302} while (0)
303#endif
304
305#define __get_user_asm(x, addr, err, instr) \
306 __asm__ __volatile__( \
307 "1: " instr " %1, [%2], #0\n" \
308 "2:\n" \
309 " .pushsection .text.fixup,\"ax\"\n" \
310 " .align 2\n" \
311 "3: mov %0, %3\n" \
312 " mov %1, #0\n" \
313 " b 2b\n" \
314 " .popsection\n" \
315 " .pushsection __ex_table,\"a\"\n" \
316 " .align 3\n" \
317 " .long 1b, 3b\n" \
318 " .popsection" \
319 : "+r" (err), "=&r" (x) \
320 : "r" (addr), "i" (-EFAULT) \
321 : "cc")
322
323#define __get_user_asm_byte(x, addr, err, __t) \
324 __get_user_asm(x, addr, err, "ldrb" __t)
325
326#if __LINUX_ARM_ARCH__ >= 6
327
328#define __get_user_asm_half(x, addr, err, __t) \
329 __get_user_asm(x, addr, err, "ldrh" __t)
330
331#else
332
333#ifndef __ARMEB__
334#define __get_user_asm_half(x, __gu_addr, err, __t) \
335({ \
336 unsigned long __b1, __b2; \
337 __get_user_asm_byte(__b1, __gu_addr, err, __t); \
338 __get_user_asm_byte(__b2, __gu_addr + 1, err, __t); \
339 (x) = __b1 | (__b2 << 8); \
340})
341#else
342#define __get_user_asm_half(x, __gu_addr, err, __t) \
343({ \
344 unsigned long __b1, __b2; \
345 __get_user_asm_byte(__b1, __gu_addr, err, __t); \
346 __get_user_asm_byte(__b2, __gu_addr + 1, err, __t); \
347 (x) = (__b1 << 8) | __b2; \
348})
349#endif
350
351#endif /* __LINUX_ARM_ARCH__ >= 6 */
352
353#define __get_user_asm_word(x, addr, err, __t) \
354 __get_user_asm(x, addr, err, "ldr" __t)
355
356#define __put_user_switch(x, ptr, __err, __fn) \
357 do { \
358 const __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
359 __typeof__(*(ptr)) __pu_val = (x); \
360 unsigned int __ua_flags; \
361 might_fault(); \
362 __ua_flags = uaccess_save_and_enable(); \
363 switch (sizeof(*(ptr))) { \
364 case 1: __fn(__pu_val, __pu_ptr, __err, 1); break; \
365 case 2: __fn(__pu_val, __pu_ptr, __err, 2); break; \
366 case 4: __fn(__pu_val, __pu_ptr, __err, 4); break; \
367 case 8: __fn(__pu_val, __pu_ptr, __err, 8); break; \
368 default: __err = __put_user_bad(); break; \
369 } \
370 uaccess_restore(__ua_flags); \
371 } while (0)
372
373#define put_user(x, ptr) \
374({ \
375 int __pu_err = 0; \
376 __put_user_switch((x), (ptr), __pu_err, __put_user_check); \
377 __pu_err; \
378})
379
380#ifdef CONFIG_CPU_SPECTRE
381/*
382 * When mitigating Spectre variant 1.1, all accessors need to include
383 * verification of the address space.
384 */
385#define __put_user(x, ptr) put_user(x, ptr)
386
387#else
388#define __put_user(x, ptr) \
389({ \
390 long __pu_err = 0; \
391 __put_user_switch((x), (ptr), __pu_err, __put_user_nocheck); \
392 __pu_err; \
393})
394
395#define __put_user_nocheck(x, __pu_ptr, __err, __size) \
396 do { \
397 unsigned long __pu_addr = (unsigned long)__pu_ptr; \
398 __put_user_nocheck_##__size(x, __pu_addr, __err, TUSER());\
399 } while (0)
400
401#define __put_user_nocheck_1 __put_user_asm_byte
402#define __put_user_nocheck_2 __put_user_asm_half
403#define __put_user_nocheck_4 __put_user_asm_word
404#define __put_user_nocheck_8 __put_user_asm_dword
405
406#endif /* !CONFIG_CPU_SPECTRE */
407
408#define __put_user_asm(x, __pu_addr, err, instr) \
409 __asm__ __volatile__( \
410 "1: " instr " %1, [%2], #0\n" \
411 "2:\n" \
412 " .pushsection .text.fixup,\"ax\"\n" \
413 " .align 2\n" \
414 "3: mov %0, %3\n" \
415 " b 2b\n" \
416 " .popsection\n" \
417 " .pushsection __ex_table,\"a\"\n" \
418 " .align 3\n" \
419 " .long 1b, 3b\n" \
420 " .popsection" \
421 : "+r" (err) \
422 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
423 : "cc")
424
425#define __put_user_asm_byte(x, __pu_addr, err, __t) \
426 __put_user_asm(x, __pu_addr, err, "strb" __t)
427
428#if __LINUX_ARM_ARCH__ >= 6
429
430#define __put_user_asm_half(x, __pu_addr, err, __t) \
431 __put_user_asm(x, __pu_addr, err, "strh" __t)
432
433#else
434
435#ifndef __ARMEB__
436#define __put_user_asm_half(x, __pu_addr, err, __t) \
437({ \
438 unsigned long __temp = (__force unsigned long)(x); \
439 __put_user_asm_byte(__temp, __pu_addr, err, __t); \
440 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err, __t);\
441})
442#else
443#define __put_user_asm_half(x, __pu_addr, err, __t) \
444({ \
445 unsigned long __temp = (__force unsigned long)(x); \
446 __put_user_asm_byte(__temp >> 8, __pu_addr, err, __t); \
447 __put_user_asm_byte(__temp, __pu_addr + 1, err, __t); \
448})
449#endif
450
451#endif /* __LINUX_ARM_ARCH__ >= 6 */
452
453#define __put_user_asm_word(x, __pu_addr, err, __t) \
454 __put_user_asm(x, __pu_addr, err, "str" __t)
455
456#ifndef __ARMEB__
457#define __reg_oper0 "%R2"
458#define __reg_oper1 "%Q2"
459#else
460#define __reg_oper0 "%Q2"
461#define __reg_oper1 "%R2"
462#endif
463
464#define __put_user_asm_dword(x, __pu_addr, err, __t) \
465 __asm__ __volatile__( \
466 ARM( "1: str" __t " " __reg_oper1 ", [%1], #4\n" ) \
467 ARM( "2: str" __t " " __reg_oper0 ", [%1]\n" ) \
468 THUMB( "1: str" __t " " __reg_oper1 ", [%1]\n" ) \
469 THUMB( "2: str" __t " " __reg_oper0 ", [%1, #4]\n" ) \
470 "3:\n" \
471 " .pushsection .text.fixup,\"ax\"\n" \
472 " .align 2\n" \
473 "4: mov %0, %3\n" \
474 " b 3b\n" \
475 " .popsection\n" \
476 " .pushsection __ex_table,\"a\"\n" \
477 " .align 3\n" \
478 " .long 1b, 4b\n" \
479 " .long 2b, 4b\n" \
480 " .popsection" \
481 : "+r" (err), "+r" (__pu_addr) \
482 : "r" (x), "i" (-EFAULT) \
483 : "cc")
484
485#define __get_kernel_nofault(dst, src, type, err_label) \
486do { \
487 const type *__pk_ptr = (src); \
488 unsigned long __src = (unsigned long)(__pk_ptr); \
489 type __val; \
490 int __err = 0; \
491 switch (sizeof(type)) { \
492 case 1: __get_user_asm_byte(__val, __src, __err, ""); break; \
493 case 2: __get_user_asm_half(__val, __src, __err, ""); break; \
494 case 4: __get_user_asm_word(__val, __src, __err, ""); break; \
495 case 8: { \
496 u32 *__v32 = (u32*)&__val; \
497 __get_user_asm_word(__v32[0], __src, __err, ""); \
498 if (__err) \
499 break; \
500 __get_user_asm_word(__v32[1], __src+4, __err, ""); \
501 break; \
502 } \
503 default: __err = __get_user_bad(); break; \
504 } \
505 if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) \
506 put_unaligned(__val, (type *)(dst)); \
507 else \
508 *(type *)(dst) = __val; /* aligned by caller */ \
509 if (__err) \
510 goto err_label; \
511} while (0)
512
513#define __put_kernel_nofault(dst, src, type, err_label) \
514do { \
515 const type *__pk_ptr = (dst); \
516 unsigned long __dst = (unsigned long)__pk_ptr; \
517 int __err = 0; \
518 type __val = IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) \
519 ? get_unaligned((type *)(src)) \
520 : *(type *)(src); /* aligned by caller */ \
521 switch (sizeof(type)) { \
522 case 1: __put_user_asm_byte(__val, __dst, __err, ""); break; \
523 case 2: __put_user_asm_half(__val, __dst, __err, ""); break; \
524 case 4: __put_user_asm_word(__val, __dst, __err, ""); break; \
525 case 8: __put_user_asm_dword(__val, __dst, __err, ""); break; \
526 default: __err = __put_user_bad(); break; \
527 } \
528 if (__err) \
529 goto err_label; \
530} while (0)
531
532#ifdef CONFIG_MMU
533extern unsigned long __must_check
534arm_copy_from_user(void *to, const void __user *from, unsigned long n);
535
536static inline unsigned long __must_check
537raw_copy_from_user(void *to, const void __user *from, unsigned long n)
538{
539 unsigned int __ua_flags;
540
541 __ua_flags = uaccess_save_and_enable();
542 n = arm_copy_from_user(to, from, n);
543 uaccess_restore(__ua_flags);
544 return n;
545}
546
547extern unsigned long __must_check
548arm_copy_to_user(void __user *to, const void *from, unsigned long n);
549extern unsigned long __must_check
550__copy_to_user_std(void __user *to, const void *from, unsigned long n);
551
552static inline unsigned long __must_check
553raw_copy_to_user(void __user *to, const void *from, unsigned long n)
554{
555#ifndef CONFIG_UACCESS_WITH_MEMCPY
556 unsigned int __ua_flags;
557 __ua_flags = uaccess_save_and_enable();
558 n = arm_copy_to_user(to, from, n);
559 uaccess_restore(__ua_flags);
560 return n;
561#else
562 return arm_copy_to_user(to, from, n);
563#endif
564}
565
566extern unsigned long __must_check
567arm_clear_user(void __user *addr, unsigned long n);
568extern unsigned long __must_check
569__clear_user_std(void __user *addr, unsigned long n);
570
571static inline unsigned long __must_check
572__clear_user(void __user *addr, unsigned long n)
573{
574 unsigned int __ua_flags = uaccess_save_and_enable();
575 n = arm_clear_user(addr, n);
576 uaccess_restore(__ua_flags);
577 return n;
578}
579
580#else
581static inline unsigned long
582raw_copy_from_user(void *to, const void __user *from, unsigned long n)
583{
584 memcpy(to, (const void __force *)from, n);
585 return 0;
586}
587static inline unsigned long
588raw_copy_to_user(void __user *to, const void *from, unsigned long n)
589{
590 memcpy((void __force *)to, from, n);
591 return 0;
592}
593#define __clear_user(addr, n) (memset((void __force *)addr, 0, n), 0)
594#endif
595#define INLINE_COPY_TO_USER
596#define INLINE_COPY_FROM_USER
597
598static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
599{
600 if (access_ok(to, n))
601 n = __clear_user(to, n);
602 return n;
603}
604
605/* These are from lib/ code, and use __get_user() and friends */
606extern long strncpy_from_user(char *dest, const char __user *src, long count);
607
608extern __must_check long strnlen_user(const char __user *str, long n);
609
610#endif /* _ASMARM_UACCESS_H */