1 /* uaccess.h: userspace accessor functions
3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #ifndef _ASM_UACCESS_H
13 #define _ASM_UACCESS_H
16 * User space memory access functions
18 #include <linux/sched.h>
20 #include <asm/segment.h>
21 #include <asm/sections.h>
23 #define HAVE_ARCH_UNMAPPED_AREA /* we decide where to put mmaps */
25 #define __ptr(x) ((unsigned long *)(x))
28 #define VERIFY_WRITE 1
30 #define __addr_ok(addr) ((unsigned long)(addr) < get_addr_limit())
33 * check that a range of addresses falls within the current address limit
35 static inline int ___range_ok(unsigned long addr, unsigned long size)
38 int flag = -EFAULT, tmp;
41 " addcc %3,%2,%1,icc0 \n" /* set C-flag if addr+size>4GB */
42 " subcc.p %1,%4,gr0,icc1 \n" /* jump if addr+size>limit */
45 " setlos #0,%0 \n" /* mark okay */
47 : "=r"(flag), "=&r"(tmp)
48 : "r"(addr), "r"(size), "r"(get_addr_limit()), "0"(flag)
55 if (addr < memory_start ||
57 size > memory_end - memory_start ||
58 addr + size > memory_end)
65 #define __range_ok(addr,size) ___range_ok((unsigned long) (addr), (unsigned long) (size))
67 #define access_ok(type,addr,size) (__range_ok((addr), (size)) == 0)
68 #define __access_ok(addr,size) (__range_ok((addr), (size)) == 0)
70 static inline int verify_area(int type, const void * addr, unsigned long size)
72 return __range_ok(addr, size);
76 * The exception table consists of pairs of addresses: the first is the
77 * address of an instruction that is allowed to fault, and the second is
78 * the address at which the program should continue. No registers are
79 * modified, so it is entirely up to the continuation code to figure out
82 * All the routines below use bits of fixup code that are out of line
83 * with the main instruction path. This means when everything is well,
84 * we don't even have to jump over them. Further, they do not intrude
85 * on our cache or tlb entries.
87 struct exception_table_entry
89 unsigned long insn, fixup;
92 /* Returns 0 if exception not found and fixup otherwise. */
93 extern unsigned long search_exception_table(unsigned long);
97 * These are the main single-value transfer routines. They automatically
98 * use the right size if we just have the right pointer type.
100 #define __put_user(x, ptr) \
104 typeof(*(ptr)) __pu_val = (x); \
106 switch (sizeof (*(ptr))) { \
108 __put_user_asm(__pu_err, __pu_val, ptr, "b", "r"); \
111 __put_user_asm(__pu_err, __pu_val, ptr, "h", "r"); \
114 __put_user_asm(__pu_err, __pu_val, ptr, "", "r"); \
117 __put_user_asm(__pu_err, __pu_val, ptr, "d", "e"); \
120 __pu_err = __put_user_bad(); \
126 #define put_user(x, ptr) \
128 typeof(&*ptr) _p = (ptr); \
131 _e = __range_ok(_p, sizeof(*_p)); \
133 _e = __put_user((x), _p); \
137 extern int __put_user_bad(void);
140 * Tell gcc we read from memory instead of writing: this is because
141 * we do not write to any memory gcc knows about, so there are no
147 #define __put_user_asm(err,x,ptr,dsize,constraint) \
149 asm volatile("1: st"dsize"%I1 %2,%M1 \n" \
152 "3: setlos %3,%0 \n" \
155 ".section __ex_table,\"a\" \n" \
160 : "m" (*__ptr(ptr)), constraint (x), "i"(-EFAULT), "0"(err) \
166 #define __put_user_asm(err,x,ptr,bwl,con) \
168 asm(" st"bwl"%I0 %1,%M0 \n" \
171 : "m" (*__ptr(ptr)), con (x) \
177 /*****************************************************************************/
181 #define __get_user(x, ptr) \
183 typeof(*(ptr)) __gu_val = 0; \
186 switch (sizeof(*(ptr))) { \
188 __get_user_asm(__gu_err, __gu_val, ptr, "ub", "=r"); \
191 __get_user_asm(__gu_err, __gu_val, ptr, "uh", "=r"); \
194 __get_user_asm(__gu_err, __gu_val, ptr, "", "=r"); \
197 __get_user_asm(__gu_err, __gu_val, ptr, "d", "=e"); \
200 __gu_err = __get_user_bad(); \
207 #define get_user(x, ptr) \
209 typeof(&*ptr) _p = (ptr); \
212 _e = __range_ok(_p, sizeof(*_p)); \
213 if (likely(_e == 0)) \
214 _e = __get_user((x), _p); \
216 (x) = (typeof(x)) 0; \
220 extern int __get_user_bad(void);
224 #define __get_user_asm(err,x,ptr,dtype,constraint) \
226 asm("1: ld"dtype"%I2 %M2,%1 \n" \
229 "3: setlos %3,%0 \n" \
233 ".section __ex_table,\"a\" \n" \
237 : "=r" (err), constraint (x) \
238 : "m" (*__ptr(ptr)), "i"(-EFAULT), "0"(err) \
244 #define __get_user_asm(err,x,ptr,bwl,con) \
245 asm(" ld"bwl"%I1 %M1,%0 \n" \
252 /*****************************************************************************/
257 extern long __memset_user(void *dst, unsigned long count);
258 extern long __memcpy_user(void *dst, const void *src, unsigned long count);
260 #define clear_user(dst,count) __memset_user((dst), (count))
261 #define __copy_from_user_inatomic(to, from, n) __memcpy_user((to), (from), (n))
262 #define __copy_to_user_inatomic(to, from, n) __memcpy_user((to), (from), (n))
266 #define clear_user(dst,count) (memset((dst), 0, (count)), 0)
267 #define __copy_from_user_inatomic(to, from, n) (memcpy((to), (from), (n)), 0)
268 #define __copy_to_user_inatomic(to, from, n) (memcpy((to), (from), (n)), 0)
272 static inline unsigned long __must_check
273 __copy_to_user(void __user *to, const void *from, unsigned long n)
276 return __copy_to_user_inatomic(to, from, n);
279 static inline unsigned long
280 __copy_from_user(void *to, const void __user *from, unsigned long n)
283 return __copy_from_user_inatomic(to, from, n);
286 static inline long copy_from_user(void *to, const void *from, unsigned long n)
288 unsigned long ret = n;
290 if (likely(__access_ok(from, n)))
291 ret = __copy_from_user(to, from, n);
293 if (unlikely(ret != 0))
294 memset(to + (n - ret), 0, ret);
299 static inline long copy_to_user(void *to, const void *from, unsigned long n)
301 return likely(__access_ok(to, n)) ? __copy_to_user(to, from, n) : n;
304 #define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n)) return retval; })
305 #define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n)) return retval; })
307 extern long strncpy_from_user(char *dst, const char *src, long count);
308 extern long strnlen_user(const char *src, long count);
310 #define strlen_user(str) strnlen_user(str, 32767)
312 extern unsigned long search_exception_table(unsigned long addr);
314 #define copy_to_user_page(vma, page, vaddr, dst, src, len) memcpy(dst, src, len)
315 #define copy_from_user_page(vma, page, vaddr, dst, src, len) memcpy(dst, src, len)
317 #endif /* _ASM_UACCESS_H */