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git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/blob - arch/openrisc/include/asm/uaccess.h
4 * Linux architectural port borrowing liberally from similar works of
5 * others. All original copyrights apply as per the original source
8 * OpenRISC implementation:
9 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
10 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
19 #ifndef __ASM_OPENRISC_UACCESS_H
20 #define __ASM_OPENRISC_UACCESS_H
23 * User space memory access functions
25 #include <linux/errno.h>
26 #include <linux/thread_info.h>
27 #include <linux/prefetch.h>
28 #include <linux/string.h>
32 #define VERIFY_WRITE 1
35 * The fs value determines whether argument validity checking should be
36 * performed or not. If get_fs() == USER_DS, checking is performed, with
37 * get_fs() == KERNEL_DS, checking is bypassed.
39 * For historical reasons, these macros are grossly misnamed.
42 /* addr_limit is the maximum accessible address for the task. we misuse
43 * the KERNEL_DS and USER_DS values to both assign and compare the
44 * addr_limit values through the equally misnamed get/set_fs macros.
48 #define KERNEL_DS (~0UL)
49 #define get_ds() (KERNEL_DS)
51 #define USER_DS (TASK_SIZE)
52 #define get_fs() (current_thread_info()->addr_limit)
53 #define set_fs(x) (current_thread_info()->addr_limit = (x))
55 #define segment_eq(a, b) ((a) == (b))
57 /* Ensure that the range from addr to addr+size is all within the process'
60 #define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs()-size))
62 /* Ensure that addr is below task's addr_limit */
63 #define __addr_ok(addr) ((unsigned long) addr < get_fs())
65 #define access_ok(type, addr, size) \
66 __range_ok((unsigned long)addr, (unsigned long)size)
69 * The exception table consists of pairs of addresses: the first is the
70 * address of an instruction that is allowed to fault, and the second is
71 * the address at which the program should continue. No registers are
72 * modified, so it is entirely up to the continuation code to figure out
75 * All the routines below use bits of fixup code that are out of line
76 * with the main instruction path. This means when everything is well,
77 * we don't even have to jump over them. Further, they do not intrude
78 * on our cache or tlb entries.
81 struct exception_table_entry
{
82 unsigned long insn
, fixup
;
86 * These are the main single-value transfer routines. They automatically
87 * use the right size if we just have the right pointer type.
89 * This gets kind of ugly. We want to return _two_ values in "get_user()"
90 * and yet we don't want to do any pointers, because that is too much
91 * of a performance impact. Thus we have a few rather ugly macros here,
92 * and hide all the uglyness from the user.
94 * The "__xxx" versions of the user access functions are versions that
95 * do not verify the address space, that must have been done previously
96 * with a separate "access_ok()" call (this is used when we do multiple
97 * accesses to the same area of user memory).
99 * As we use the same address space for kernel and user data on the
100 * PowerPC, we can just do these as direct assignments. (Of course, the
101 * exception handling means that it's no longer "just"...)
103 #define get_user(x, ptr) \
104 __get_user_check((x), (ptr), sizeof(*(ptr)))
105 #define put_user(x, ptr) \
106 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
108 #define __get_user(x, ptr) \
109 __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
110 #define __put_user(x, ptr) \
111 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
113 extern long __put_user_bad(void);
115 #define __put_user_nocheck(x, ptr, size) \
118 __put_user_size((x), (ptr), (size), __pu_err); \
122 #define __put_user_check(x, ptr, size) \
124 long __pu_err = -EFAULT; \
125 __typeof__(*(ptr)) *__pu_addr = (ptr); \
126 if (access_ok(VERIFY_WRITE, __pu_addr, size)) \
127 __put_user_size((x), __pu_addr, (size), __pu_err); \
131 #define __put_user_size(x, ptr, size, retval) \
135 case 1: __put_user_asm(x, ptr, retval, "l.sb"); break; \
136 case 2: __put_user_asm(x, ptr, retval, "l.sh"); break; \
137 case 4: __put_user_asm(x, ptr, retval, "l.sw"); break; \
138 case 8: __put_user_asm2(x, ptr, retval); break; \
139 default: __put_user_bad(); \
143 struct __large_struct
{
144 unsigned long buf
[100];
146 #define __m(x) (*(struct __large_struct *)(x))
149 * We don't tell gcc that we are accessing memory, but this is OK
150 * because we do not write to any memory gcc knows about, so there
151 * are no aliasing issues.
153 #define __put_user_asm(x, addr, err, op) \
154 __asm__ __volatile__( \
155 "1: "op" 0(%2),%1\n" \
157 ".section .fixup,\"ax\"\n" \
158 "3: l.addi %0,r0,%3\n" \
162 ".section __ex_table,\"a\"\n" \
167 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))
169 #define __put_user_asm2(x, addr, err) \
170 __asm__ __volatile__( \
171 "1: l.sw 0(%2),%1\n" \
172 "2: l.sw 4(%2),%H1\n" \
174 ".section .fixup,\"ax\"\n" \
175 "4: l.addi %0,r0,%3\n" \
179 ".section __ex_table,\"a\"\n" \
185 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))
187 #define __get_user_nocheck(x, ptr, size) \
189 long __gu_err, __gu_val; \
190 __get_user_size(__gu_val, (ptr), (size), __gu_err); \
191 (x) = (__force __typeof__(*(ptr)))__gu_val; \
195 #define __get_user_check(x, ptr, size) \
197 long __gu_err = -EFAULT, __gu_val = 0; \
198 const __typeof__(*(ptr)) * __gu_addr = (ptr); \
199 if (access_ok(VERIFY_READ, __gu_addr, size)) \
200 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
201 (x) = (__force __typeof__(*(ptr)))__gu_val; \
205 extern long __get_user_bad(void);
207 #define __get_user_size(x, ptr, size, retval) \
211 case 1: __get_user_asm(x, ptr, retval, "l.lbz"); break; \
212 case 2: __get_user_asm(x, ptr, retval, "l.lhz"); break; \
213 case 4: __get_user_asm(x, ptr, retval, "l.lwz"); break; \
214 case 8: __get_user_asm2(x, ptr, retval); break; \
215 default: (x) = __get_user_bad(); \
219 #define __get_user_asm(x, addr, err, op) \
220 __asm__ __volatile__( \
221 "1: "op" %1,0(%2)\n" \
223 ".section .fixup,\"ax\"\n" \
224 "3: l.addi %0,r0,%3\n" \
225 " l.addi %1,r0,0\n" \
229 ".section __ex_table,\"a\"\n" \
233 : "=r"(err), "=r"(x) \
234 : "r"(addr), "i"(-EFAULT), "0"(err))
236 #define __get_user_asm2(x, addr, err) \
237 __asm__ __volatile__( \
238 "1: l.lwz %1,0(%2)\n" \
239 "2: l.lwz %H1,4(%2)\n" \
241 ".section .fixup,\"ax\"\n" \
242 "4: l.addi %0,r0,%3\n" \
243 " l.addi %1,r0,0\n" \
244 " l.addi %H1,r0,0\n" \
248 ".section __ex_table,\"a\"\n" \
253 : "=r"(err), "=&r"(x) \
254 : "r"(addr), "i"(-EFAULT), "0"(err))
256 /* more complex routines */
258 extern unsigned long __must_check
259 __copy_tofrom_user(void *to
, const void *from
, unsigned long size
);
261 #define __copy_from_user(to, from, size) \
262 __copy_tofrom_user(to, from, size)
263 #define __copy_to_user(to, from, size) \
264 __copy_tofrom_user(to, from, size)
266 #define __copy_to_user_inatomic __copy_to_user
267 #define __copy_from_user_inatomic __copy_from_user
269 static inline unsigned long
270 copy_from_user(void *to
, const void *from
, unsigned long n
)
272 unsigned long res
= n
;
274 if (likely(access_ok(VERIFY_READ
, from
, n
)))
275 res
= __copy_tofrom_user(to
, from
, n
);
277 memset(to
+ (n
- res
), 0, res
);
281 static inline unsigned long
282 copy_to_user(void *to
, const void *from
, unsigned long n
)
284 if (likely(access_ok(VERIFY_WRITE
, to
, n
)))
285 n
= __copy_tofrom_user(to
, from
, n
);
289 extern unsigned long __clear_user(void *addr
, unsigned long size
);
291 static inline __must_check
unsigned long
292 clear_user(void *addr
, unsigned long size
)
294 if (likely(access_ok(VERIFY_WRITE
, addr
, size
)))
295 size
= __clear_user(addr
, size
);
299 #define user_addr_max() \
300 (segment_eq(get_fs(), USER_DS) ? TASK_SIZE : ~0UL)
302 extern long strncpy_from_user(char *dest
, const char __user
*src
, long count
);
304 extern __must_check
long strlen_user(const char __user
*str
);
305 extern __must_check
long strnlen_user(const char __user
*str
, long n
);
307 #endif /* __ASM_OPENRISC_UACCESS_H */