2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
15 #ifndef _ASM_TILE_UACCESS_H
16 #define _ASM_TILE_UACCESS_H
19 * User space memory access functions
21 #include <linux/sched.h>
23 #include <asm-generic/uaccess-unaligned.h>
24 #include <asm/processor.h>
28 #define VERIFY_WRITE 1
31 * The fs value determines whether argument validity checking should be
32 * performed or not. If get_fs() == USER_DS, checking is performed, with
33 * get_fs() == KERNEL_DS, checking is bypassed.
35 * For historical reasons, these macros are grossly misnamed.
37 #define MAKE_MM_SEG(a) ((mm_segment_t) { (a) })
39 #define KERNEL_DS MAKE_MM_SEG(-1UL)
40 #define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
42 #define get_ds() (KERNEL_DS)
43 #define get_fs() (current_thread_info()->addr_limit)
44 #define set_fs(x) (current_thread_info()->addr_limit = (x))
46 #define segment_eq(a, b) ((a).seg == (b).seg)
50 * We could allow mapping all 16 MB at 0xfc000000, but we set up a
51 * special hack in arch_setup_additional_pages() to auto-create a mapping
52 * for the first 16 KB, and it would seem strange to have different
53 * user-accessible semantics for memory at 0xfc000000 and above 0xfc004000.
55 static inline int is_arch_mappable_range(unsigned long addr,
58 return (addr >= MEM_USER_INTRPT &&
59 addr < (MEM_USER_INTRPT + INTRPT_SIZE) &&
60 size <= (MEM_USER_INTRPT + INTRPT_SIZE) - addr);
62 #define is_arch_mappable_range is_arch_mappable_range
64 #define is_arch_mappable_range(addr, size) 0
68 * Test whether a block of memory is a valid user space address.
69 * Returns 0 if the range is valid, nonzero otherwise.
71 int __range_ok(unsigned long addr, unsigned long size);
74 * access_ok: - Checks if a user space pointer is valid
75 * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
76 * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
77 * to write to a block, it is always safe to read from it.
78 * @addr: User space pointer to start of block to check
79 * @size: Size of block to check
81 * Context: User context only. This function may sleep if pagefaults are
84 * Checks if a pointer to a block of memory in user space is valid.
86 * Returns true (nonzero) if the memory block may be valid, false (zero)
87 * if it is definitely invalid.
89 * Note that, depending on architecture, this function probably just
90 * checks that the pointer is in the user space range - after calling
91 * this function, memory access functions may still return -EFAULT.
93 #define access_ok(type, addr, size) ({ \
94 __chk_user_ptr(addr); \
95 likely(__range_ok((unsigned long)(addr), (size)) == 0); \
99 * The exception table consists of pairs of addresses: the first is the
100 * address of an instruction that is allowed to fault, and the second is
101 * the address at which the program should continue. No registers are
102 * modified, so it is entirely up to the continuation code to figure out
105 * All the routines below use bits of fixup code that are out of line
106 * with the main instruction path. This means when everything is well,
107 * we don't even have to jump over them. Further, they do not intrude
108 * on our cache or tlb entries.
111 struct exception_table_entry {
112 unsigned long insn, fixup;
115 extern int fixup_exception(struct pt_regs *regs);
118 * This is a type: either unsigned long, if the argument fits into
119 * that type, or otherwise unsigned long long.
121 #define __inttype(x) \
122 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
125 * Support macros for __get_user().
126 * Note that __get_user() and __put_user() assume proper alignment.
130 #define _ASM_PTR ".quad"
131 #define _ASM_ALIGN ".align 8"
133 #define _ASM_PTR ".long"
134 #define _ASM_ALIGN ".align 4"
137 #define __get_user_asm(OP, x, ptr, ret) \
138 asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n" \
139 ".pushsection .fixup,\"ax\"\n" \
140 "0: { movei %1, 0; movei %0, %3 }\n" \
142 ".section __ex_table,\"a\"\n" \
144 _ASM_PTR " 1b, 0b\n" \
147 : "=r" (ret), "=r" (x) \
148 : "r" (ptr), "i" (-EFAULT))
151 #define __get_user_1(x, ptr, ret) __get_user_asm(ld1u, x, ptr, ret)
152 #define __get_user_2(x, ptr, ret) __get_user_asm(ld2u, x, ptr, ret)
153 #define __get_user_4(x, ptr, ret) __get_user_asm(ld4s, x, ptr, ret)
154 #define __get_user_8(x, ptr, ret) __get_user_asm(ld, x, ptr, ret)
156 #define __get_user_1(x, ptr, ret) __get_user_asm(lb_u, x, ptr, ret)
157 #define __get_user_2(x, ptr, ret) __get_user_asm(lh_u, x, ptr, ret)
158 #define __get_user_4(x, ptr, ret) __get_user_asm(lw, x, ptr, ret)
159 #ifdef __LITTLE_ENDIAN
160 #define __lo32(a, b) a
161 #define __hi32(a, b) b
163 #define __lo32(a, b) b
164 #define __hi32(a, b) a
166 #define __get_user_8(x, ptr, ret) \
168 unsigned int __a, __b; \
169 asm volatile("1: { lw %1, %3; addi %2, %3, 4 }\n" \
170 "2: { lw %2, %2; movei %0, 0 }\n" \
171 ".pushsection .fixup,\"ax\"\n" \
172 "0: { movei %1, 0; movei %2, 0 }\n" \
173 "{ movei %0, %4; j 9f }\n" \
174 ".section __ex_table,\"a\"\n" \
180 : "=r" (ret), "=r" (__a), "=&r" (__b) \
181 : "r" (ptr), "i" (-EFAULT)); \
182 (x) = (__force __typeof(x))(__inttype(x)) \
183 (((u64)__hi32(__a, __b) << 32) | \
188 extern int __get_user_bad(void)
189 __attribute__((warning("sizeof __get_user argument not 1, 2, 4 or 8")));
192 * __get_user: - Get a simple variable from user space, with less checking.
193 * @x: Variable to store result.
194 * @ptr: Source address, in user space.
196 * Context: User context only. This function may sleep if pagefaults are
199 * This macro copies a single simple variable from user space to kernel
200 * space. It supports simple types like char and int, but not larger
201 * data types like structures or arrays.
203 * @ptr must have pointer-to-simple-variable type, and the result of
204 * dereferencing @ptr must be assignable to @x without a cast.
206 * Returns zero on success, or -EFAULT on error.
207 * On error, the variable @x is set to zero.
209 * Caller must check the pointer with access_ok() before calling this
212 #define __get_user(x, ptr) \
216 __chk_user_ptr(ptr); \
217 switch (sizeof(*(ptr))) { \
218 case 1: __get_user_1(_x, ptr, __ret); break; \
219 case 2: __get_user_2(_x, ptr, __ret); break; \
220 case 4: __get_user_4(_x, ptr, __ret); break; \
221 case 8: __get_user_8(_x, ptr, __ret); break; \
222 default: __ret = __get_user_bad(); break; \
224 (x) = (typeof(*(ptr))) _x; \
228 /* Support macros for __put_user(). */
230 #define __put_user_asm(OP, x, ptr, ret) \
231 asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n" \
232 ".pushsection .fixup,\"ax\"\n" \
233 "0: { movei %0, %3; j 9f }\n" \
234 ".section __ex_table,\"a\"\n" \
236 _ASM_PTR " 1b, 0b\n" \
240 : "r" (ptr), "r" (x), "i" (-EFAULT))
243 #define __put_user_1(x, ptr, ret) __put_user_asm(st1, x, ptr, ret)
244 #define __put_user_2(x, ptr, ret) __put_user_asm(st2, x, ptr, ret)
245 #define __put_user_4(x, ptr, ret) __put_user_asm(st4, x, ptr, ret)
246 #define __put_user_8(x, ptr, ret) __put_user_asm(st, x, ptr, ret)
248 #define __put_user_1(x, ptr, ret) __put_user_asm(sb, x, ptr, ret)
249 #define __put_user_2(x, ptr, ret) __put_user_asm(sh, x, ptr, ret)
250 #define __put_user_4(x, ptr, ret) __put_user_asm(sw, x, ptr, ret)
251 #define __put_user_8(x, ptr, ret) \
253 u64 __x = (__force __inttype(x))(x); \
254 int __lo = (int) __x, __hi = (int) (__x >> 32); \
255 asm volatile("1: { sw %1, %2; addi %0, %1, 4 }\n" \
256 "2: { sw %0, %3; movei %0, 0 }\n" \
257 ".pushsection .fixup,\"ax\"\n" \
258 "0: { movei %0, %4; j 9f }\n" \
259 ".section __ex_table,\"a\"\n" \
266 : "r" (ptr), "r" (__lo32(__lo, __hi)), \
267 "r" (__hi32(__lo, __hi)), "i" (-EFAULT)); \
271 extern int __put_user_bad(void)
272 __attribute__((warning("sizeof __put_user argument not 1, 2, 4 or 8")));
275 * __put_user: - Write a simple value into user space, with less checking.
276 * @x: Value to copy to user space.
277 * @ptr: Destination address, in user space.
279 * Context: User context only. This function may sleep if pagefaults are
282 * This macro copies a single simple value from kernel space to user
283 * space. It supports simple types like char and int, but not larger
284 * data types like structures or arrays.
286 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
287 * to the result of dereferencing @ptr.
289 * Caller must check the pointer with access_ok() before calling this
292 * Returns zero on success, or -EFAULT on error.
294 #define __put_user(x, ptr) \
297 typeof(*(ptr)) _x = (x); \
298 __chk_user_ptr(ptr); \
299 switch (sizeof(*(ptr))) { \
300 case 1: __put_user_1(_x, ptr, __ret); break; \
301 case 2: __put_user_2(_x, ptr, __ret); break; \
302 case 4: __put_user_4(_x, ptr, __ret); break; \
303 case 8: __put_user_8(_x, ptr, __ret); break; \
304 default: __ret = __put_user_bad(); break; \
310 * The versions of get_user and put_user without initial underscores
311 * check the address of their arguments to make sure they are not
314 #define put_user(x, ptr) \
316 __typeof__(*(ptr)) __user *__Pu_addr = (ptr); \
317 access_ok(VERIFY_WRITE, (__Pu_addr), sizeof(*(__Pu_addr))) ? \
318 __put_user((x), (__Pu_addr)) : \
322 #define get_user(x, ptr) \
324 __typeof__(*(ptr)) const __user *__Gu_addr = (ptr); \
325 access_ok(VERIFY_READ, (__Gu_addr), sizeof(*(__Gu_addr))) ? \
326 __get_user((x), (__Gu_addr)) : \
327 ((x) = 0, -EFAULT); \
331 * __copy_to_user() - copy data into user space, with less checking.
332 * @to: Destination address, in user space.
333 * @from: Source address, in kernel space.
334 * @n: Number of bytes to copy.
336 * Context: User context only. This function may sleep if pagefaults are
339 * Copy data from kernel space to user space. Caller must check
340 * the specified block with access_ok() before calling this function.
342 * Returns number of bytes that could not be copied.
343 * On success, this will be zero.
345 * An alternate version - __copy_to_user_inatomic() - is designed
346 * to be called from atomic context, typically bracketed by calls
347 * to pagefault_disable() and pagefault_enable().
349 extern unsigned long __must_check __copy_to_user_inatomic(
350 void __user *to, const void *from, unsigned long n);
352 static inline unsigned long __must_check
353 __copy_to_user(void __user *to, const void *from, unsigned long n)
356 return __copy_to_user_inatomic(to, from, n);
359 static inline unsigned long __must_check
360 copy_to_user(void __user *to, const void *from, unsigned long n)
362 if (access_ok(VERIFY_WRITE, to, n))
363 n = __copy_to_user(to, from, n);
368 * __copy_from_user() - copy data from user space, with less checking.
369 * @to: Destination address, in kernel space.
370 * @from: Source address, in user space.
371 * @n: Number of bytes to copy.
373 * Context: User context only. This function may sleep if pagefaults are
376 * Copy data from user space to kernel space. Caller must check
377 * the specified block with access_ok() before calling this function.
379 * Returns number of bytes that could not be copied.
380 * On success, this will be zero.
382 * If some data could not be copied, this function will pad the copied
383 * data to the requested size using zero bytes.
385 * An alternate version - __copy_from_user_inatomic() - is designed
386 * to be called from atomic context, typically bracketed by calls
387 * to pagefault_disable() and pagefault_enable(). This version
388 * does *NOT* pad with zeros.
390 extern unsigned long __must_check __copy_from_user_inatomic(
391 void *to, const void __user *from, unsigned long n);
392 extern unsigned long __must_check __copy_from_user_zeroing(
393 void *to, const void __user *from, unsigned long n);
395 static inline unsigned long __must_check
396 __copy_from_user(void *to, const void __user *from, unsigned long n)
399 return __copy_from_user_zeroing(to, from, n);
402 static inline unsigned long __must_check
403 _copy_from_user(void *to, const void __user *from, unsigned long n)
405 if (access_ok(VERIFY_READ, from, n))
406 n = __copy_from_user(to, from, n);
412 #ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
414 * There are still unprovable places in the generic code as of 2.6.34, so this
415 * option is not really compatible with -Werror, which is more useful in
418 extern void copy_from_user_overflow(void)
419 __compiletime_warning("copy_from_user() size is not provably correct");
421 static inline unsigned long __must_check copy_from_user(void *to,
422 const void __user *from,
425 int sz = __compiletime_object_size(to);
427 if (likely(sz == -1 || sz >= n))
428 n = _copy_from_user(to, from, n);
430 copy_from_user_overflow();
435 #define copy_from_user _copy_from_user
440 * __copy_in_user() - copy data within user space, with less checking.
441 * @to: Destination address, in user space.
442 * @from: Source address, in user space.
443 * @n: Number of bytes to copy.
445 * Context: User context only. This function may sleep if pagefaults are
448 * Copy data from user space to user space. Caller must check
449 * the specified blocks with access_ok() before calling this function.
451 * Returns number of bytes that could not be copied.
452 * On success, this will be zero.
454 extern unsigned long __copy_in_user_inatomic(
455 void __user *to, const void __user *from, unsigned long n);
457 static inline unsigned long __must_check
458 __copy_in_user(void __user *to, const void __user *from, unsigned long n)
461 return __copy_in_user_inatomic(to, from, n);
464 static inline unsigned long __must_check
465 copy_in_user(void __user *to, const void __user *from, unsigned long n)
467 if (access_ok(VERIFY_WRITE, to, n) && access_ok(VERIFY_READ, from, n))
468 n = __copy_in_user(to, from, n);
475 * strlen_user: - Get the size of a string in user space.
476 * @str: The string to measure.
478 * Context: User context only. This function may sleep.
480 * Get the size of a NUL-terminated string in user space.
482 * Returns the size of the string INCLUDING the terminating NUL.
483 * On exception, returns 0.
485 * If there is a limit on the length of a valid string, you may wish to
486 * consider using strnlen_user() instead.
488 extern long strnlen_user_asm(const char __user *str, long n);
489 static inline long __must_check strnlen_user(const char __user *str, long n)
492 return strnlen_user_asm(str, n);
494 #define strlen_user(str) strnlen_user(str, LONG_MAX)
497 * strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
498 * @dst: Destination address, in kernel space. This buffer must be at
499 * least @count bytes long.
500 * @src: Source address, in user space.
501 * @count: Maximum number of bytes to copy, including the trailing NUL.
503 * Copies a NUL-terminated string from userspace to kernel space.
504 * Caller must check the specified block with access_ok() before calling
507 * On success, returns the length of the string (not including the trailing
510 * If access to userspace fails, returns -EFAULT (some data may have been
513 * If @count is smaller than the length of the string, copies @count bytes
514 * and returns @count.
516 extern long strncpy_from_user_asm(char *dst, const char __user *src, long);
517 static inline long __must_check __strncpy_from_user(
518 char *dst, const char __user *src, long count)
521 return strncpy_from_user_asm(dst, src, count);
523 static inline long __must_check strncpy_from_user(
524 char *dst, const char __user *src, long count)
526 if (access_ok(VERIFY_READ, src, 1))
527 return __strncpy_from_user(dst, src, count);
532 * clear_user: - Zero a block of memory in user space.
533 * @mem: Destination address, in user space.
534 * @len: Number of bytes to zero.
536 * Zero a block of memory in user space.
538 * Returns number of bytes that could not be cleared.
539 * On success, this will be zero.
541 extern unsigned long clear_user_asm(void __user *mem, unsigned long len);
542 static inline unsigned long __must_check __clear_user(
543 void __user *mem, unsigned long len)
546 return clear_user_asm(mem, len);
548 static inline unsigned long __must_check clear_user(
549 void __user *mem, unsigned long len)
551 if (access_ok(VERIFY_WRITE, mem, len))
552 return __clear_user(mem, len);
557 * flush_user: - Flush a block of memory in user space from cache.
558 * @mem: Destination address, in user space.
559 * @len: Number of bytes to flush.
561 * Returns number of bytes that could not be flushed.
562 * On success, this will be zero.
564 extern unsigned long flush_user_asm(void __user *mem, unsigned long len);
565 static inline unsigned long __must_check __flush_user(
566 void __user *mem, unsigned long len)
571 retval = flush_user_asm(mem, len);
576 static inline unsigned long __must_check flush_user(
577 void __user *mem, unsigned long len)
579 if (access_ok(VERIFY_WRITE, mem, len))
580 return __flush_user(mem, len);
585 * finv_user: - Flush-inval a block of memory in user space from cache.
586 * @mem: Destination address, in user space.
587 * @len: Number of bytes to invalidate.
589 * Returns number of bytes that could not be flush-invalidated.
590 * On success, this will be zero.
592 extern unsigned long finv_user_asm(void __user *mem, unsigned long len);
593 static inline unsigned long __must_check __finv_user(
594 void __user *mem, unsigned long len)
599 retval = finv_user_asm(mem, len);
603 static inline unsigned long __must_check finv_user(
604 void __user *mem, unsigned long len)
606 if (access_ok(VERIFY_WRITE, mem, len))
607 return __finv_user(mem, len);
611 #endif /* _ASM_TILE_UACCESS_H */