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[linux/fpc-iii.git] / arch / tile / include / asm / uaccess.h
blobb6cde3209b963d76ba35815d45b003ef929691f2
1 /*
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
12 * more details.
15 #ifndef _ASM_TILE_UACCESS_H
16 #define _ASM_TILE_UACCESS_H
19 * User space memory access functions
21 #include <linux/sched.h>
22 #include <linux/mm.h>
23 #include <asm-generic/uaccess-unaligned.h>
24 #include <asm/processor.h>
25 #include <asm/page.h>
27 #define VERIFY_READ 0
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)
48 #ifndef __tilegx__
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,
56 unsigned long size)
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
63 #else
64 #define is_arch_mappable_range(addr, size) 0
65 #endif
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);
73 /**
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.
83 * Checks if a pointer to a block of memory in user space is valid.
85 * Returns true (nonzero) if the memory block may be valid, false (zero)
86 * if it is definitely invalid.
88 * Note that, depending on architecture, this function probably just
89 * checks that the pointer is in the user space range - after calling
90 * this function, memory access functions may still return -EFAULT.
92 #define access_ok(type, addr, size) ({ \
93 __chk_user_ptr(addr); \
94 likely(__range_ok((unsigned long)(addr), (size)) == 0); \
98 * The exception table consists of pairs of addresses: the first is the
99 * address of an instruction that is allowed to fault, and the second is
100 * the address at which the program should continue. No registers are
101 * modified, so it is entirely up to the continuation code to figure out
102 * what to do.
104 * All the routines below use bits of fixup code that are out of line
105 * with the main instruction path. This means when everything is well,
106 * we don't even have to jump over them. Further, they do not intrude
107 * on our cache or tlb entries.
110 struct exception_table_entry {
111 unsigned long insn, fixup;
114 extern int fixup_exception(struct pt_regs *regs);
117 * Support macros for __get_user().
119 * Implementation note: The "case 8" logic of casting to the type of
120 * the result of subtracting the value from itself is basically a way
121 * of keeping all integer types the same, but casting any pointers to
122 * ptrdiff_t, i.e. also an integer type. This way there are no
123 * questionable casts seen by the compiler on an ILP32 platform.
125 * Note that __get_user() and __put_user() assume proper alignment.
128 #ifdef __LP64__
129 #define _ASM_PTR ".quad"
130 #define _ASM_ALIGN ".align 8"
131 #else
132 #define _ASM_PTR ".long"
133 #define _ASM_ALIGN ".align 4"
134 #endif
136 #define __get_user_asm(OP, x, ptr, ret) \
137 asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n" \
138 ".pushsection .fixup,\"ax\"\n" \
139 "0: { movei %1, 0; movei %0, %3 }\n" \
140 "j 9f\n" \
141 ".section __ex_table,\"a\"\n" \
142 _ASM_ALIGN "\n" \
143 _ASM_PTR " 1b, 0b\n" \
144 ".popsection\n" \
145 "9:" \
146 : "=r" (ret), "=r" (x) \
147 : "r" (ptr), "i" (-EFAULT))
149 #ifdef __tilegx__
150 #define __get_user_1(x, ptr, ret) __get_user_asm(ld1u, x, ptr, ret)
151 #define __get_user_2(x, ptr, ret) __get_user_asm(ld2u, x, ptr, ret)
152 #define __get_user_4(x, ptr, ret) __get_user_asm(ld4s, x, ptr, ret)
153 #define __get_user_8(x, ptr, ret) __get_user_asm(ld, x, ptr, ret)
154 #else
155 #define __get_user_1(x, ptr, ret) __get_user_asm(lb_u, x, ptr, ret)
156 #define __get_user_2(x, ptr, ret) __get_user_asm(lh_u, x, ptr, ret)
157 #define __get_user_4(x, ptr, ret) __get_user_asm(lw, x, ptr, ret)
158 #ifdef __LITTLE_ENDIAN
159 #define __lo32(a, b) a
160 #define __hi32(a, b) b
161 #else
162 #define __lo32(a, b) b
163 #define __hi32(a, b) a
164 #endif
165 #define __get_user_8(x, ptr, ret) \
166 ({ \
167 unsigned int __a, __b; \
168 asm volatile("1: { lw %1, %3; addi %2, %3, 4 }\n" \
169 "2: { lw %2, %2; movei %0, 0 }\n" \
170 ".pushsection .fixup,\"ax\"\n" \
171 "0: { movei %1, 0; movei %2, 0 }\n" \
172 "{ movei %0, %4; j 9f }\n" \
173 ".section __ex_table,\"a\"\n" \
174 ".align 4\n" \
175 ".word 1b, 0b\n" \
176 ".word 2b, 0b\n" \
177 ".popsection\n" \
178 "9:" \
179 : "=r" (ret), "=r" (__a), "=&r" (__b) \
180 : "r" (ptr), "i" (-EFAULT)); \
181 (x) = (__typeof(x))(__typeof((x)-(x))) \
182 (((u64)__hi32(__a, __b) << 32) | \
183 __lo32(__a, __b)); \
185 #endif
187 extern int __get_user_bad(void)
188 __attribute__((warning("sizeof __get_user argument not 1, 2, 4 or 8")));
191 * __get_user: - Get a simple variable from user space, with less checking.
192 * @x: Variable to store result.
193 * @ptr: Source address, in user space.
195 * Context: User context only. This function may sleep.
197 * This macro copies a single simple variable from user space to kernel
198 * space. It supports simple types like char and int, but not larger
199 * data types like structures or arrays.
201 * @ptr must have pointer-to-simple-variable type, and the result of
202 * dereferencing @ptr must be assignable to @x without a cast.
204 * Returns zero on success, or -EFAULT on error.
205 * On error, the variable @x is set to zero.
207 * Caller must check the pointer with access_ok() before calling this
208 * function.
210 #define __get_user(x, ptr) \
211 ({ \
212 int __ret; \
213 __chk_user_ptr(ptr); \
214 switch (sizeof(*(ptr))) { \
215 case 1: __get_user_1(x, ptr, __ret); break; \
216 case 2: __get_user_2(x, ptr, __ret); break; \
217 case 4: __get_user_4(x, ptr, __ret); break; \
218 case 8: __get_user_8(x, ptr, __ret); break; \
219 default: __ret = __get_user_bad(); break; \
221 __ret; \
224 /* Support macros for __put_user(). */
226 #define __put_user_asm(OP, x, ptr, ret) \
227 asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n" \
228 ".pushsection .fixup,\"ax\"\n" \
229 "0: { movei %0, %3; j 9f }\n" \
230 ".section __ex_table,\"a\"\n" \
231 _ASM_ALIGN "\n" \
232 _ASM_PTR " 1b, 0b\n" \
233 ".popsection\n" \
234 "9:" \
235 : "=r" (ret) \
236 : "r" (ptr), "r" (x), "i" (-EFAULT))
238 #ifdef __tilegx__
239 #define __put_user_1(x, ptr, ret) __put_user_asm(st1, x, ptr, ret)
240 #define __put_user_2(x, ptr, ret) __put_user_asm(st2, x, ptr, ret)
241 #define __put_user_4(x, ptr, ret) __put_user_asm(st4, x, ptr, ret)
242 #define __put_user_8(x, ptr, ret) __put_user_asm(st, x, ptr, ret)
243 #else
244 #define __put_user_1(x, ptr, ret) __put_user_asm(sb, x, ptr, ret)
245 #define __put_user_2(x, ptr, ret) __put_user_asm(sh, x, ptr, ret)
246 #define __put_user_4(x, ptr, ret) __put_user_asm(sw, x, ptr, ret)
247 #define __put_user_8(x, ptr, ret) \
248 ({ \
249 u64 __x = (__typeof((x)-(x)))(x); \
250 int __lo = (int) __x, __hi = (int) (__x >> 32); \
251 asm volatile("1: { sw %1, %2; addi %0, %1, 4 }\n" \
252 "2: { sw %0, %3; movei %0, 0 }\n" \
253 ".pushsection .fixup,\"ax\"\n" \
254 "0: { movei %0, %4; j 9f }\n" \
255 ".section __ex_table,\"a\"\n" \
256 ".align 4\n" \
257 ".word 1b, 0b\n" \
258 ".word 2b, 0b\n" \
259 ".popsection\n" \
260 "9:" \
261 : "=&r" (ret) \
262 : "r" (ptr), "r" (__lo32(__lo, __hi)), \
263 "r" (__hi32(__lo, __hi)), "i" (-EFAULT)); \
265 #endif
267 extern int __put_user_bad(void)
268 __attribute__((warning("sizeof __put_user argument not 1, 2, 4 or 8")));
271 * __put_user: - Write a simple value into user space, with less checking.
272 * @x: Value to copy to user space.
273 * @ptr: Destination address, in user space.
275 * Context: User context only. This function may sleep.
277 * This macro copies a single simple value from kernel space to user
278 * space. It supports simple types like char and int, but not larger
279 * data types like structures or arrays.
281 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
282 * to the result of dereferencing @ptr.
284 * Caller must check the pointer with access_ok() before calling this
285 * function.
287 * Returns zero on success, or -EFAULT on error.
289 #define __put_user(x, ptr) \
290 ({ \
291 int __ret; \
292 __chk_user_ptr(ptr); \
293 switch (sizeof(*(ptr))) { \
294 case 1: __put_user_1(x, ptr, __ret); break; \
295 case 2: __put_user_2(x, ptr, __ret); break; \
296 case 4: __put_user_4(x, ptr, __ret); break; \
297 case 8: __put_user_8(x, ptr, __ret); break; \
298 default: __ret = __put_user_bad(); break; \
300 __ret; \
304 * The versions of get_user and put_user without initial underscores
305 * check the address of their arguments to make sure they are not
306 * in kernel space.
308 #define put_user(x, ptr) \
309 ({ \
310 __typeof__(*(ptr)) __user *__Pu_addr = (ptr); \
311 access_ok(VERIFY_WRITE, (__Pu_addr), sizeof(*(__Pu_addr))) ? \
312 __put_user((x), (__Pu_addr)) : \
313 -EFAULT; \
316 #define get_user(x, ptr) \
317 ({ \
318 __typeof__(*(ptr)) const __user *__Gu_addr = (ptr); \
319 access_ok(VERIFY_READ, (__Gu_addr), sizeof(*(__Gu_addr))) ? \
320 __get_user((x), (__Gu_addr)) : \
321 ((x) = 0, -EFAULT); \
325 * __copy_to_user() - copy data into user space, with less checking.
326 * @to: Destination address, in user space.
327 * @from: Source address, in kernel space.
328 * @n: Number of bytes to copy.
330 * Context: User context only. This function may sleep.
332 * Copy data from kernel space to user space. Caller must check
333 * the specified block with access_ok() before calling this function.
335 * Returns number of bytes that could not be copied.
336 * On success, this will be zero.
338 * An alternate version - __copy_to_user_inatomic() - is designed
339 * to be called from atomic context, typically bracketed by calls
340 * to pagefault_disable() and pagefault_enable().
342 extern unsigned long __must_check __copy_to_user_inatomic(
343 void __user *to, const void *from, unsigned long n);
345 static inline unsigned long __must_check
346 __copy_to_user(void __user *to, const void *from, unsigned long n)
348 might_fault();
349 return __copy_to_user_inatomic(to, from, n);
352 static inline unsigned long __must_check
353 copy_to_user(void __user *to, const void *from, unsigned long n)
355 if (access_ok(VERIFY_WRITE, to, n))
356 n = __copy_to_user(to, from, n);
357 return n;
361 * __copy_from_user() - copy data from user space, with less checking.
362 * @to: Destination address, in kernel space.
363 * @from: Source address, in user space.
364 * @n: Number of bytes to copy.
366 * Context: User context only. This function may sleep.
368 * Copy data from user space to kernel space. Caller must check
369 * the specified block with access_ok() before calling this function.
371 * Returns number of bytes that could not be copied.
372 * On success, this will be zero.
374 * If some data could not be copied, this function will pad the copied
375 * data to the requested size using zero bytes.
377 * An alternate version - __copy_from_user_inatomic() - is designed
378 * to be called from atomic context, typically bracketed by calls
379 * to pagefault_disable() and pagefault_enable(). This version
380 * does *NOT* pad with zeros.
382 extern unsigned long __must_check __copy_from_user_inatomic(
383 void *to, const void __user *from, unsigned long n);
384 extern unsigned long __must_check __copy_from_user_zeroing(
385 void *to, const void __user *from, unsigned long n);
387 static inline unsigned long __must_check
388 __copy_from_user(void *to, const void __user *from, unsigned long n)
390 might_fault();
391 return __copy_from_user_zeroing(to, from, n);
394 static inline unsigned long __must_check
395 _copy_from_user(void *to, const void __user *from, unsigned long n)
397 if (access_ok(VERIFY_READ, from, n))
398 n = __copy_from_user(to, from, n);
399 else
400 memset(to, 0, n);
401 return n;
404 #ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
406 * There are still unprovable places in the generic code as of 2.6.34, so this
407 * option is not really compatible with -Werror, which is more useful in
408 * general.
410 extern void copy_from_user_overflow(void)
411 __compiletime_warning("copy_from_user() size is not provably correct");
413 static inline unsigned long __must_check copy_from_user(void *to,
414 const void __user *from,
415 unsigned long n)
417 int sz = __compiletime_object_size(to);
419 if (likely(sz == -1 || sz >= n))
420 n = _copy_from_user(to, from, n);
421 else
422 copy_from_user_overflow();
424 return n;
426 #else
427 #define copy_from_user _copy_from_user
428 #endif
430 #ifdef __tilegx__
432 * __copy_in_user() - copy data within user space, with less checking.
433 * @to: Destination address, in user space.
434 * @from: Source address, in user space.
435 * @n: Number of bytes to copy.
437 * Context: User context only. This function may sleep.
439 * Copy data from user space to user space. Caller must check
440 * the specified blocks with access_ok() before calling this function.
442 * Returns number of bytes that could not be copied.
443 * On success, this will be zero.
445 extern unsigned long __copy_in_user_inatomic(
446 void __user *to, const void __user *from, unsigned long n);
448 static inline unsigned long __must_check
449 __copy_in_user(void __user *to, const void __user *from, unsigned long n)
451 might_fault();
452 return __copy_in_user_inatomic(to, from, n);
455 static inline unsigned long __must_check
456 copy_in_user(void __user *to, const void __user *from, unsigned long n)
458 if (access_ok(VERIFY_WRITE, to, n) && access_ok(VERIFY_READ, from, n))
459 n = __copy_in_user(to, from, n);
460 return n;
462 #endif
466 * strlen_user: - Get the size of a string in user space.
467 * @str: The string to measure.
469 * Context: User context only. This function may sleep.
471 * Get the size of a NUL-terminated string in user space.
473 * Returns the size of the string INCLUDING the terminating NUL.
474 * On exception, returns 0.
476 * If there is a limit on the length of a valid string, you may wish to
477 * consider using strnlen_user() instead.
479 extern long strnlen_user_asm(const char __user *str, long n);
480 static inline long __must_check strnlen_user(const char __user *str, long n)
482 might_fault();
483 return strnlen_user_asm(str, n);
485 #define strlen_user(str) strnlen_user(str, LONG_MAX)
488 * strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
489 * @dst: Destination address, in kernel space. This buffer must be at
490 * least @count bytes long.
491 * @src: Source address, in user space.
492 * @count: Maximum number of bytes to copy, including the trailing NUL.
494 * Copies a NUL-terminated string from userspace to kernel space.
495 * Caller must check the specified block with access_ok() before calling
496 * this function.
498 * On success, returns the length of the string (not including the trailing
499 * NUL).
501 * If access to userspace fails, returns -EFAULT (some data may have been
502 * copied).
504 * If @count is smaller than the length of the string, copies @count bytes
505 * and returns @count.
507 extern long strncpy_from_user_asm(char *dst, const char __user *src, long);
508 static inline long __must_check __strncpy_from_user(
509 char *dst, const char __user *src, long count)
511 might_fault();
512 return strncpy_from_user_asm(dst, src, count);
514 static inline long __must_check strncpy_from_user(
515 char *dst, const char __user *src, long count)
517 if (access_ok(VERIFY_READ, src, 1))
518 return __strncpy_from_user(dst, src, count);
519 return -EFAULT;
523 * clear_user: - Zero a block of memory in user space.
524 * @mem: Destination address, in user space.
525 * @len: Number of bytes to zero.
527 * Zero a block of memory in user space.
529 * Returns number of bytes that could not be cleared.
530 * On success, this will be zero.
532 extern unsigned long clear_user_asm(void __user *mem, unsigned long len);
533 static inline unsigned long __must_check __clear_user(
534 void __user *mem, unsigned long len)
536 might_fault();
537 return clear_user_asm(mem, len);
539 static inline unsigned long __must_check clear_user(
540 void __user *mem, unsigned long len)
542 if (access_ok(VERIFY_WRITE, mem, len))
543 return __clear_user(mem, len);
544 return len;
548 * flush_user: - Flush a block of memory in user space from cache.
549 * @mem: Destination address, in user space.
550 * @len: Number of bytes to flush.
552 * Returns number of bytes that could not be flushed.
553 * On success, this will be zero.
555 extern unsigned long flush_user_asm(void __user *mem, unsigned long len);
556 static inline unsigned long __must_check __flush_user(
557 void __user *mem, unsigned long len)
559 int retval;
561 might_fault();
562 retval = flush_user_asm(mem, len);
563 mb_incoherent();
564 return retval;
567 static inline unsigned long __must_check flush_user(
568 void __user *mem, unsigned long len)
570 if (access_ok(VERIFY_WRITE, mem, len))
571 return __flush_user(mem, len);
572 return len;
576 * finv_user: - Flush-inval a block of memory in user space from cache.
577 * @mem: Destination address, in user space.
578 * @len: Number of bytes to invalidate.
580 * Returns number of bytes that could not be flush-invalidated.
581 * On success, this will be zero.
583 extern unsigned long finv_user_asm(void __user *mem, unsigned long len);
584 static inline unsigned long __must_check __finv_user(
585 void __user *mem, unsigned long len)
587 int retval;
589 might_fault();
590 retval = finv_user_asm(mem, len);
591 mb_incoherent();
592 return retval;
594 static inline unsigned long __must_check finv_user(
595 void __user *mem, unsigned long len)
597 if (access_ok(VERIFY_WRITE, mem, len))
598 return __finv_user(mem, len);
599 return len;
602 #endif /* _ASM_TILE_UACCESS_H */