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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_IA64_UACCESS_H
3#define _ASM_IA64_UACCESS_H
4
5/*
6 * This file defines various macros to transfer memory areas across
7 * the user/kernel boundary. This needs to be done carefully because
8 * this code is executed in kernel mode and uses user-specified
9 * addresses. Thus, we need to be careful not to let the user to
10 * trick us into accessing kernel memory that would normally be
11 * inaccessible. This code is also fairly performance sensitive,
12 * so we want to spend as little time doing safety checks as
13 * possible.
14 *
15 * To make matters a bit more interesting, these macros sometimes also
16 * called from within the kernel itself, in which case the address
17 * validity check must be skipped. The get_fs() macro tells us what
18 * to do: if get_fs()==USER_DS, checking is performed, if
19 * get_fs()==KERNEL_DS, checking is bypassed.
20 *
21 * Note that even if the memory area specified by the user is in a
22 * valid address range, it is still possible that we'll get a page
23 * fault while accessing it. This is handled by filling out an
24 * exception handler fixup entry for each instruction that has the
25 * potential to fault. When such a fault occurs, the page fault
26 * handler checks to see whether the faulting instruction has a fixup
27 * associated and, if so, sets r8 to -EFAULT and clears r9 to 0 and
28 * then resumes execution at the continuation point.
29 *
30 * Based on <asm-alpha/uaccess.h>.
31 *
32 * Copyright (C) 1998, 1999, 2001-2004 Hewlett-Packard Co
33 * David Mosberger-Tang <davidm@hpl.hp.com>
34 */
35
36#include <linux/compiler.h>
37#include <linux/page-flags.h>
38
39#include <asm/intrinsics.h>
40#include <linux/pgtable.h>
41#include <asm/io.h>
42#include <asm/extable.h>
43
44/*
45 * For historical reasons, the following macros are grossly misnamed:
46 */
47#define KERNEL_DS ((mm_segment_t) { ~0UL }) /* cf. access_ok() */
48#define USER_DS ((mm_segment_t) { TASK_SIZE-1 }) /* cf. access_ok() */
49
50#define get_fs() (current_thread_info()->addr_limit)
51#define set_fs(x) (current_thread_info()->addr_limit = (x))
52
53#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
54
55/*
56 * When accessing user memory, we need to make sure the entire area really is in
57 * user-level space. In order to do this efficiently, we make sure that the page at
58 * address TASK_SIZE is never valid. We also need to make sure that the address doesn't
59 * point inside the virtually mapped linear page table.
60 */
61static inline int __access_ok(const void __user *p, unsigned long size)
62{
63 unsigned long addr = (unsigned long)p;
64 unsigned long seg = get_fs().seg;
65 return likely(addr <= seg) &&
66 (seg == KERNEL_DS.seg || likely(REGION_OFFSET(addr) < RGN_MAP_LIMIT));
67}
68#define access_ok(addr, size) __access_ok((addr), (size))
69
70/*
71 * These are the main single-value transfer routines. They automatically
72 * use the right size if we just have the right pointer type.
73 *
74 * Careful to not
75 * (a) re-use the arguments for side effects (sizeof/typeof is ok)
76 * (b) require any knowledge of processes at this stage
77 */
78#define put_user(x, ptr) __put_user_check((__typeof__(*(ptr))) (x), (ptr), sizeof(*(ptr)))
79#define get_user(x, ptr) __get_user_check((x), (ptr), sizeof(*(ptr)))
80
81/*
82 * The "__xxx" versions do not do address space checking, useful when
83 * doing multiple accesses to the same area (the programmer has to do the
84 * checks by hand with "access_ok()")
85 */
86#define __put_user(x, ptr) __put_user_nocheck((__typeof__(*(ptr))) (x), (ptr), sizeof(*(ptr)))
87#define __get_user(x, ptr) __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
88
89#ifdef ASM_SUPPORTED
90 struct __large_struct { unsigned long buf[100]; };
91# define __m(x) (*(struct __large_struct __user *)(x))
92
93/* We need to declare the __ex_table section before we can use it in .xdata. */
94asm (".section \"__ex_table\", \"a\"\n\t.previous");
95
96# define __get_user_size(val, addr, n, err) \
97do { \
98 register long __gu_r8 asm ("r8") = 0; \
99 register long __gu_r9 asm ("r9"); \
100 asm ("\n[1:]\tld"#n" %0=%2%P2\t// %0 and %1 get overwritten by exception handler\n" \
101 "\t.xdata4 \"__ex_table\", 1b-., 1f-.+4\n" \
102 "[1:]" \
103 : "=r"(__gu_r9), "=r"(__gu_r8) : "m"(__m(addr)), "1"(__gu_r8)); \
104 (err) = __gu_r8; \
105 (val) = __gu_r9; \
106} while (0)
107
108/*
109 * The "__put_user_size()" macro tells gcc it reads from memory instead of writing it. This
110 * is because they do not write to any memory gcc knows about, so there are no aliasing
111 * issues.
112 */
113# define __put_user_size(val, addr, n, err) \
114do { \
115 register long __pu_r8 asm ("r8") = 0; \
116 asm volatile ("\n[1:]\tst"#n" %1=%r2%P1\t// %0 gets overwritten by exception handler\n" \
117 "\t.xdata4 \"__ex_table\", 1b-., 1f-.\n" \
118 "[1:]" \
119 : "=r"(__pu_r8) : "m"(__m(addr)), "rO"(val), "0"(__pu_r8)); \
120 (err) = __pu_r8; \
121} while (0)
122
123#else /* !ASM_SUPPORTED */
124# define RELOC_TYPE 2 /* ip-rel */
125# define __get_user_size(val, addr, n, err) \
126do { \
127 __ld_user("__ex_table", (unsigned long) addr, n, RELOC_TYPE); \
128 (err) = ia64_getreg(_IA64_REG_R8); \
129 (val) = ia64_getreg(_IA64_REG_R9); \
130} while (0)
131# define __put_user_size(val, addr, n, err) \
132do { \
133 __st_user("__ex_table", (unsigned long) addr, n, RELOC_TYPE, \
134 (__force unsigned long) (val)); \
135 (err) = ia64_getreg(_IA64_REG_R8); \
136} while (0)
137#endif /* !ASM_SUPPORTED */
138
139extern void __get_user_unknown (void);
140
141/*
142 * Evaluating arguments X, PTR, SIZE, and SEGMENT may involve subroutine-calls, which
143 * could clobber r8 and r9 (among others). Thus, be careful not to evaluate it while
144 * using r8/r9.
145 */
146#define __do_get_user(check, x, ptr, size) \
147({ \
148 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
149 __typeof__ (size) __gu_size = (size); \
150 long __gu_err = -EFAULT; \
151 unsigned long __gu_val = 0; \
152 if (!check || __access_ok(__gu_ptr, size)) \
153 switch (__gu_size) { \
154 case 1: __get_user_size(__gu_val, __gu_ptr, 1, __gu_err); break; \
155 case 2: __get_user_size(__gu_val, __gu_ptr, 2, __gu_err); break; \
156 case 4: __get_user_size(__gu_val, __gu_ptr, 4, __gu_err); break; \
157 case 8: __get_user_size(__gu_val, __gu_ptr, 8, __gu_err); break; \
158 default: __get_user_unknown(); break; \
159 } \
160 (x) = (__force __typeof__(*(__gu_ptr))) __gu_val; \
161 __gu_err; \
162})
163
164#define __get_user_nocheck(x, ptr, size) __do_get_user(0, x, ptr, size)
165#define __get_user_check(x, ptr, size) __do_get_user(1, x, ptr, size)
166
167extern void __put_user_unknown (void);
168
169/*
170 * Evaluating arguments X, PTR, SIZE, and SEGMENT may involve subroutine-calls, which
171 * could clobber r8 (among others). Thus, be careful not to evaluate them while using r8.
172 */
173#define __do_put_user(check, x, ptr, size) \
174({ \
175 __typeof__ (x) __pu_x = (x); \
176 __typeof__ (*(ptr)) __user *__pu_ptr = (ptr); \
177 __typeof__ (size) __pu_size = (size); \
178 long __pu_err = -EFAULT; \
179 \
180 if (!check || __access_ok(__pu_ptr, __pu_size)) \
181 switch (__pu_size) { \
182 case 1: __put_user_size(__pu_x, __pu_ptr, 1, __pu_err); break; \
183 case 2: __put_user_size(__pu_x, __pu_ptr, 2, __pu_err); break; \
184 case 4: __put_user_size(__pu_x, __pu_ptr, 4, __pu_err); break; \
185 case 8: __put_user_size(__pu_x, __pu_ptr, 8, __pu_err); break; \
186 default: __put_user_unknown(); break; \
187 } \
188 __pu_err; \
189})
190
191#define __put_user_nocheck(x, ptr, size) __do_put_user(0, x, ptr, size)
192#define __put_user_check(x, ptr, size) __do_put_user(1, x, ptr, size)
193
194/*
195 * Complex access routines
196 */
197extern unsigned long __must_check __copy_user (void __user *to, const void __user *from,
198 unsigned long count);
199
200static inline unsigned long
201raw_copy_to_user(void __user *to, const void *from, unsigned long count)
202{
203 return __copy_user(to, (__force void __user *) from, count);
204}
205
206static inline unsigned long
207raw_copy_from_user(void *to, const void __user *from, unsigned long count)
208{
209 return __copy_user((__force void __user *) to, from, count);
210}
211
212#define INLINE_COPY_FROM_USER
213#define INLINE_COPY_TO_USER
214
215extern unsigned long __do_clear_user (void __user *, unsigned long);
216
217#define __clear_user(to, n) __do_clear_user(to, n)
218
219#define clear_user(to, n) \
220({ \
221 unsigned long __cu_len = (n); \
222 if (__access_ok(to, __cu_len)) \
223 __cu_len = __do_clear_user(to, __cu_len); \
224 __cu_len; \
225})
226
227
228/*
229 * Returns: -EFAULT if exception before terminator, N if the entire buffer filled, else
230 * strlen.
231 */
232extern long __must_check __strncpy_from_user (char *to, const char __user *from, long to_len);
233
234#define strncpy_from_user(to, from, n) \
235({ \
236 const char __user * __sfu_from = (from); \
237 long __sfu_ret = -EFAULT; \
238 if (__access_ok(__sfu_from, 0)) \
239 __sfu_ret = __strncpy_from_user((to), __sfu_from, (n)); \
240 __sfu_ret; \
241})
242
243/*
244 * Returns: 0 if exception before NUL or reaching the supplied limit
245 * (N), a value greater than N if the limit would be exceeded, else
246 * strlen.
247 */
248extern unsigned long __strnlen_user (const char __user *, long);
249
250#define strnlen_user(str, len) \
251({ \
252 const char __user *__su_str = (str); \
253 unsigned long __su_ret = 0; \
254 if (__access_ok(__su_str, 0)) \
255 __su_ret = __strnlen_user(__su_str, len); \
256 __su_ret; \
257})
258
259#define ARCH_HAS_TRANSLATE_MEM_PTR 1
260static __inline__ void *
261xlate_dev_mem_ptr(phys_addr_t p)
262{
263 struct page *page;
264 void *ptr;
265
266 page = pfn_to_page(p >> PAGE_SHIFT);
267 if (PageUncached(page))
268 ptr = (void *)p + __IA64_UNCACHED_OFFSET;
269 else
270 ptr = __va(p);
271
272 return ptr;
273}
274
275/*
276 * Convert a virtual cached kernel memory pointer to an uncached pointer
277 */
278static __inline__ void *
279xlate_dev_kmem_ptr(void *p)
280{
281 struct page *page;
282 void *ptr;
283
284 page = virt_to_page((unsigned long)p);
285 if (PageUncached(page))
286 ptr = (void *)__pa(p) + __IA64_UNCACHED_OFFSET;
287 else
288 ptr = p;
289
290 return ptr;
291}
292
293#endif /* _ASM_IA64_UACCESS_H */
1#ifndef _ASM_IA64_UACCESS_H
2#define _ASM_IA64_UACCESS_H
3
4/*
5 * This file defines various macros to transfer memory areas across
6 * the user/kernel boundary. This needs to be done carefully because
7 * this code is executed in kernel mode and uses user-specified
8 * addresses. Thus, we need to be careful not to let the user to
9 * trick us into accessing kernel memory that would normally be
10 * inaccessible. This code is also fairly performance sensitive,
11 * so we want to spend as little time doing safety checks as
12 * possible.
13 *
14 * To make matters a bit more interesting, these macros sometimes also
15 * called from within the kernel itself, in which case the address
16 * validity check must be skipped. The get_fs() macro tells us what
17 * to do: if get_fs()==USER_DS, checking is performed, if
18 * get_fs()==KERNEL_DS, checking is bypassed.
19 *
20 * Note that even if the memory area specified by the user is in a
21 * valid address range, it is still possible that we'll get a page
22 * fault while accessing it. This is handled by filling out an
23 * exception handler fixup entry for each instruction that has the
24 * potential to fault. When such a fault occurs, the page fault
25 * handler checks to see whether the faulting instruction has a fixup
26 * associated and, if so, sets r8 to -EFAULT and clears r9 to 0 and
27 * then resumes execution at the continuation point.
28 *
29 * Based on <asm-alpha/uaccess.h>.
30 *
31 * Copyright (C) 1998, 1999, 2001-2004 Hewlett-Packard Co
32 * David Mosberger-Tang <davidm@hpl.hp.com>
33 */
34
35#include <linux/compiler.h>
36#include <linux/errno.h>
37#include <linux/sched.h>
38#include <linux/page-flags.h>
39#include <linux/mm.h>
40
41#include <asm/intrinsics.h>
42#include <asm/pgtable.h>
43#include <asm/io.h>
44
45/*
46 * For historical reasons, the following macros are grossly misnamed:
47 */
48#define KERNEL_DS ((mm_segment_t) { ~0UL }) /* cf. access_ok() */
49#define USER_DS ((mm_segment_t) { TASK_SIZE-1 }) /* cf. access_ok() */
50
51#define VERIFY_READ 0
52#define VERIFY_WRITE 1
53
54#define get_ds() (KERNEL_DS)
55#define get_fs() (current_thread_info()->addr_limit)
56#define set_fs(x) (current_thread_info()->addr_limit = (x))
57
58#define segment_eq(a, b) ((a).seg == (b).seg)
59
60/*
61 * When accessing user memory, we need to make sure the entire area really is in
62 * user-level space. In order to do this efficiently, we make sure that the page at
63 * address TASK_SIZE is never valid. We also need to make sure that the address doesn't
64 * point inside the virtually mapped linear page table.
65 */
66#define __access_ok(addr, size, segment) \
67({ \
68 __chk_user_ptr(addr); \
69 (likely((unsigned long) (addr) <= (segment).seg) \
70 && ((segment).seg == KERNEL_DS.seg \
71 || likely(REGION_OFFSET((unsigned long) (addr)) < RGN_MAP_LIMIT))); \
72})
73#define access_ok(type, addr, size) __access_ok((addr), (size), get_fs())
74
75/*
76 * These are the main single-value transfer routines. They automatically
77 * use the right size if we just have the right pointer type.
78 *
79 * Careful to not
80 * (a) re-use the arguments for side effects (sizeof/typeof is ok)
81 * (b) require any knowledge of processes at this stage
82 */
83#define put_user(x, ptr) __put_user_check((__typeof__(*(ptr))) (x), (ptr), sizeof(*(ptr)), get_fs())
84#define get_user(x, ptr) __get_user_check((x), (ptr), sizeof(*(ptr)), get_fs())
85
86/*
87 * The "__xxx" versions do not do address space checking, useful when
88 * doing multiple accesses to the same area (the programmer has to do the
89 * checks by hand with "access_ok()")
90 */
91#define __put_user(x, ptr) __put_user_nocheck((__typeof__(*(ptr))) (x), (ptr), sizeof(*(ptr)))
92#define __get_user(x, ptr) __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
93
94extern long __put_user_unaligned_unknown (void);
95
96#define __put_user_unaligned(x, ptr) \
97({ \
98 long __ret; \
99 switch (sizeof(*(ptr))) { \
100 case 1: __ret = __put_user((x), (ptr)); break; \
101 case 2: __ret = (__put_user((x), (u8 __user *)(ptr))) \
102 | (__put_user((x) >> 8, ((u8 __user *)(ptr) + 1))); break; \
103 case 4: __ret = (__put_user((x), (u16 __user *)(ptr))) \
104 | (__put_user((x) >> 16, ((u16 __user *)(ptr) + 1))); break; \
105 case 8: __ret = (__put_user((x), (u32 __user *)(ptr))) \
106 | (__put_user((x) >> 32, ((u32 __user *)(ptr) + 1))); break; \
107 default: __ret = __put_user_unaligned_unknown(); \
108 } \
109 __ret; \
110})
111
112extern long __get_user_unaligned_unknown (void);
113
114#define __get_user_unaligned(x, ptr) \
115({ \
116 long __ret; \
117 switch (sizeof(*(ptr))) { \
118 case 1: __ret = __get_user((x), (ptr)); break; \
119 case 2: __ret = (__get_user((x), (u8 __user *)(ptr))) \
120 | (__get_user((x) >> 8, ((u8 __user *)(ptr) + 1))); break; \
121 case 4: __ret = (__get_user((x), (u16 __user *)(ptr))) \
122 | (__get_user((x) >> 16, ((u16 __user *)(ptr) + 1))); break; \
123 case 8: __ret = (__get_user((x), (u32 __user *)(ptr))) \
124 | (__get_user((x) >> 32, ((u32 __user *)(ptr) + 1))); break; \
125 default: __ret = __get_user_unaligned_unknown(); \
126 } \
127 __ret; \
128})
129
130#ifdef ASM_SUPPORTED
131 struct __large_struct { unsigned long buf[100]; };
132# define __m(x) (*(struct __large_struct __user *)(x))
133
134/* We need to declare the __ex_table section before we can use it in .xdata. */
135asm (".section \"__ex_table\", \"a\"\n\t.previous");
136
137# define __get_user_size(val, addr, n, err) \
138do { \
139 register long __gu_r8 asm ("r8") = 0; \
140 register long __gu_r9 asm ("r9"); \
141 asm ("\n[1:]\tld"#n" %0=%2%P2\t// %0 and %1 get overwritten by exception handler\n" \
142 "\t.xdata4 \"__ex_table\", 1b-., 1f-.+4\n" \
143 "[1:]" \
144 : "=r"(__gu_r9), "=r"(__gu_r8) : "m"(__m(addr)), "1"(__gu_r8)); \
145 (err) = __gu_r8; \
146 (val) = __gu_r9; \
147} while (0)
148
149/*
150 * The "__put_user_size()" macro tells gcc it reads from memory instead of writing it. This
151 * is because they do not write to any memory gcc knows about, so there are no aliasing
152 * issues.
153 */
154# define __put_user_size(val, addr, n, err) \
155do { \
156 register long __pu_r8 asm ("r8") = 0; \
157 asm volatile ("\n[1:]\tst"#n" %1=%r2%P1\t// %0 gets overwritten by exception handler\n" \
158 "\t.xdata4 \"__ex_table\", 1b-., 1f-.\n" \
159 "[1:]" \
160 : "=r"(__pu_r8) : "m"(__m(addr)), "rO"(val), "0"(__pu_r8)); \
161 (err) = __pu_r8; \
162} while (0)
163
164#else /* !ASM_SUPPORTED */
165# define RELOC_TYPE 2 /* ip-rel */
166# define __get_user_size(val, addr, n, err) \
167do { \
168 __ld_user("__ex_table", (unsigned long) addr, n, RELOC_TYPE); \
169 (err) = ia64_getreg(_IA64_REG_R8); \
170 (val) = ia64_getreg(_IA64_REG_R9); \
171} while (0)
172# define __put_user_size(val, addr, n, err) \
173do { \
174 __st_user("__ex_table", (unsigned long) addr, n, RELOC_TYPE, \
175 (__force unsigned long) (val)); \
176 (err) = ia64_getreg(_IA64_REG_R8); \
177} while (0)
178#endif /* !ASM_SUPPORTED */
179
180extern void __get_user_unknown (void);
181
182/*
183 * Evaluating arguments X, PTR, SIZE, and SEGMENT may involve subroutine-calls, which
184 * could clobber r8 and r9 (among others). Thus, be careful not to evaluate it while
185 * using r8/r9.
186 */
187#define __do_get_user(check, x, ptr, size, segment) \
188({ \
189 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
190 __typeof__ (size) __gu_size = (size); \
191 long __gu_err = -EFAULT; \
192 unsigned long __gu_val = 0; \
193 if (!check || __access_ok(__gu_ptr, size, segment)) \
194 switch (__gu_size) { \
195 case 1: __get_user_size(__gu_val, __gu_ptr, 1, __gu_err); break; \
196 case 2: __get_user_size(__gu_val, __gu_ptr, 2, __gu_err); break; \
197 case 4: __get_user_size(__gu_val, __gu_ptr, 4, __gu_err); break; \
198 case 8: __get_user_size(__gu_val, __gu_ptr, 8, __gu_err); break; \
199 default: __get_user_unknown(); break; \
200 } \
201 (x) = (__force __typeof__(*(__gu_ptr))) __gu_val; \
202 __gu_err; \
203})
204
205#define __get_user_nocheck(x, ptr, size) __do_get_user(0, x, ptr, size, KERNEL_DS)
206#define __get_user_check(x, ptr, size, segment) __do_get_user(1, x, ptr, size, segment)
207
208extern void __put_user_unknown (void);
209
210/*
211 * Evaluating arguments X, PTR, SIZE, and SEGMENT may involve subroutine-calls, which
212 * could clobber r8 (among others). Thus, be careful not to evaluate them while using r8.
213 */
214#define __do_put_user(check, x, ptr, size, segment) \
215({ \
216 __typeof__ (x) __pu_x = (x); \
217 __typeof__ (*(ptr)) __user *__pu_ptr = (ptr); \
218 __typeof__ (size) __pu_size = (size); \
219 long __pu_err = -EFAULT; \
220 \
221 if (!check || __access_ok(__pu_ptr, __pu_size, segment)) \
222 switch (__pu_size) { \
223 case 1: __put_user_size(__pu_x, __pu_ptr, 1, __pu_err); break; \
224 case 2: __put_user_size(__pu_x, __pu_ptr, 2, __pu_err); break; \
225 case 4: __put_user_size(__pu_x, __pu_ptr, 4, __pu_err); break; \
226 case 8: __put_user_size(__pu_x, __pu_ptr, 8, __pu_err); break; \
227 default: __put_user_unknown(); break; \
228 } \
229 __pu_err; \
230})
231
232#define __put_user_nocheck(x, ptr, size) __do_put_user(0, x, ptr, size, KERNEL_DS)
233#define __put_user_check(x, ptr, size, segment) __do_put_user(1, x, ptr, size, segment)
234
235/*
236 * Complex access routines
237 */
238extern unsigned long __must_check __copy_user (void __user *to, const void __user *from,
239 unsigned long count);
240
241static inline unsigned long
242__copy_to_user (void __user *to, const void *from, unsigned long count)
243{
244 return __copy_user(to, (__force void __user *) from, count);
245}
246
247static inline unsigned long
248__copy_from_user (void *to, const void __user *from, unsigned long count)
249{
250 return __copy_user((__force void __user *) to, from, count);
251}
252
253#define __copy_to_user_inatomic __copy_to_user
254#define __copy_from_user_inatomic __copy_from_user
255#define copy_to_user(to, from, n) \
256({ \
257 void __user *__cu_to = (to); \
258 const void *__cu_from = (from); \
259 long __cu_len = (n); \
260 \
261 if (__access_ok(__cu_to, __cu_len, get_fs())) \
262 __cu_len = __copy_user(__cu_to, (__force void __user *) __cu_from, __cu_len); \
263 __cu_len; \
264})
265
266#define copy_from_user(to, from, n) \
267({ \
268 void *__cu_to = (to); \
269 const void __user *__cu_from = (from); \
270 long __cu_len = (n); \
271 \
272 __chk_user_ptr(__cu_from); \
273 if (__access_ok(__cu_from, __cu_len, get_fs())) \
274 __cu_len = __copy_user((__force void __user *) __cu_to, __cu_from, __cu_len); \
275 __cu_len; \
276})
277
278#define __copy_in_user(to, from, size) __copy_user((to), (from), (size))
279
280static inline unsigned long
281copy_in_user (void __user *to, const void __user *from, unsigned long n)
282{
283 if (likely(access_ok(VERIFY_READ, from, n) && access_ok(VERIFY_WRITE, to, n)))
284 n = __copy_user(to, from, n);
285 return n;
286}
287
288extern unsigned long __do_clear_user (void __user *, unsigned long);
289
290#define __clear_user(to, n) __do_clear_user(to, n)
291
292#define clear_user(to, n) \
293({ \
294 unsigned long __cu_len = (n); \
295 if (__access_ok(to, __cu_len, get_fs())) \
296 __cu_len = __do_clear_user(to, __cu_len); \
297 __cu_len; \
298})
299
300
301/*
302 * Returns: -EFAULT if exception before terminator, N if the entire buffer filled, else
303 * strlen.
304 */
305extern long __must_check __strncpy_from_user (char *to, const char __user *from, long to_len);
306
307#define strncpy_from_user(to, from, n) \
308({ \
309 const char __user * __sfu_from = (from); \
310 long __sfu_ret = -EFAULT; \
311 if (__access_ok(__sfu_from, 0, get_fs())) \
312 __sfu_ret = __strncpy_from_user((to), __sfu_from, (n)); \
313 __sfu_ret; \
314})
315
316/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
317extern unsigned long __strlen_user (const char __user *);
318
319#define strlen_user(str) \
320({ \
321 const char __user *__su_str = (str); \
322 unsigned long __su_ret = 0; \
323 if (__access_ok(__su_str, 0, get_fs())) \
324 __su_ret = __strlen_user(__su_str); \
325 __su_ret; \
326})
327
328/*
329 * Returns: 0 if exception before NUL or reaching the supplied limit
330 * (N), a value greater than N if the limit would be exceeded, else
331 * strlen.
332 */
333extern unsigned long __strnlen_user (const char __user *, long);
334
335#define strnlen_user(str, len) \
336({ \
337 const char __user *__su_str = (str); \
338 unsigned long __su_ret = 0; \
339 if (__access_ok(__su_str, 0, get_fs())) \
340 __su_ret = __strnlen_user(__su_str, len); \
341 __su_ret; \
342})
343
344#define ARCH_HAS_RELATIVE_EXTABLE
345
346struct exception_table_entry {
347 int insn; /* location-relative address of insn this fixup is for */
348 int fixup; /* location-relative continuation addr.; if bit 2 is set, r9 is set to 0 */
349};
350
351extern void ia64_handle_exception (struct pt_regs *regs, const struct exception_table_entry *e);
352extern const struct exception_table_entry *search_exception_tables (unsigned long addr);
353
354static inline int
355ia64_done_with_exception (struct pt_regs *regs)
356{
357 const struct exception_table_entry *e;
358 e = search_exception_tables(regs->cr_iip + ia64_psr(regs)->ri);
359 if (e) {
360 ia64_handle_exception(regs, e);
361 return 1;
362 }
363 return 0;
364}
365
366#define ARCH_HAS_TRANSLATE_MEM_PTR 1
367static __inline__ void *
368xlate_dev_mem_ptr(phys_addr_t p)
369{
370 struct page *page;
371 void *ptr;
372
373 page = pfn_to_page(p >> PAGE_SHIFT);
374 if (PageUncached(page))
375 ptr = (void *)p + __IA64_UNCACHED_OFFSET;
376 else
377 ptr = __va(p);
378
379 return ptr;
380}
381
382/*
383 * Convert a virtual cached kernel memory pointer to an uncached pointer
384 */
385static __inline__ void *
386xlate_dev_kmem_ptr(void *p)
387{
388 struct page *page;
389 void *ptr;
390
391 page = virt_to_page((unsigned long)p);
392 if (PageUncached(page))
393 ptr = (void *)__pa(p) + __IA64_UNCACHED_OFFSET;
394 else
395 ptr = p;
396
397 return ptr;
398}
399
400#endif /* _ASM_IA64_UACCESS_H */