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2
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4
5#ifndef __LINUX_UIO_H
6#define __LINUX_UIO_H
7
8#include <linux/kernel.h>
9#include <linux/thread_info.h>
10#include <crypto/hash.h>
11#include <uapi/linux/uio.h>
12
13struct page;
14struct pipe_inode_info;
15
16struct kvec {
17 void *iov_base;
18 size_t iov_len;
19};
20
21enum iter_type {
22
23 ITER_BVEC_FLAG_NO_REF = 2,
24
25
26 ITER_IOVEC = 4,
27 ITER_KVEC = 8,
28 ITER_BVEC = 16,
29 ITER_PIPE = 32,
30 ITER_DISCARD = 64,
31};
32
33struct iov_iter {
34
35
36
37
38
39 unsigned int type;
40 size_t iov_offset;
41 size_t count;
42 union {
43 const struct iovec *iov;
44 const struct kvec *kvec;
45 const struct bio_vec *bvec;
46 struct pipe_inode_info *pipe;
47 };
48 union {
49 unsigned long nr_segs;
50 struct {
51 int idx;
52 int start_idx;
53 };
54 };
55};
56
57static inline enum iter_type iov_iter_type(const struct iov_iter *i)
58{
59 return i->type & ~(READ | WRITE | ITER_BVEC_FLAG_NO_REF);
60}
61
62static inline bool iter_is_iovec(const struct iov_iter *i)
63{
64 return iov_iter_type(i) == ITER_IOVEC;
65}
66
67static inline bool iov_iter_is_kvec(const struct iov_iter *i)
68{
69 return iov_iter_type(i) == ITER_KVEC;
70}
71
72static inline bool iov_iter_is_bvec(const struct iov_iter *i)
73{
74 return iov_iter_type(i) == ITER_BVEC;
75}
76
77static inline bool iov_iter_is_pipe(const struct iov_iter *i)
78{
79 return iov_iter_type(i) == ITER_PIPE;
80}
81
82static inline bool iov_iter_is_discard(const struct iov_iter *i)
83{
84 return iov_iter_type(i) == ITER_DISCARD;
85}
86
87static inline unsigned char iov_iter_rw(const struct iov_iter *i)
88{
89 return i->type & (READ | WRITE);
90}
91
92static inline bool iov_iter_bvec_no_ref(const struct iov_iter *i)
93{
94 return (i->type & ITER_BVEC_FLAG_NO_REF) != 0;
95}
96
97
98
99
100
101
102
103
104static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs)
105{
106 unsigned long seg;
107 size_t ret = 0;
108
109 for (seg = 0; seg < nr_segs; seg++)
110 ret += iov[seg].iov_len;
111 return ret;
112}
113
114static inline struct iovec iov_iter_iovec(const struct iov_iter *iter)
115{
116 return (struct iovec) {
117 .iov_base = iter->iov->iov_base + iter->iov_offset,
118 .iov_len = min(iter->count,
119 iter->iov->iov_len - iter->iov_offset),
120 };
121}
122
123size_t iov_iter_copy_from_user_atomic(struct page *page,
124 struct iov_iter *i, unsigned long offset, size_t bytes);
125void iov_iter_advance(struct iov_iter *i, size_t bytes);
126void iov_iter_revert(struct iov_iter *i, size_t bytes);
127int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes);
128size_t iov_iter_single_seg_count(const struct iov_iter *i);
129size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
130 struct iov_iter *i);
131size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
132 struct iov_iter *i);
133
134size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
135size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i);
136bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i);
137size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i);
138bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i);
139
140static __always_inline __must_check
141size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
142{
143 if (unlikely(!check_copy_size(addr, bytes, true)))
144 return 0;
145 else
146 return _copy_to_iter(addr, bytes, i);
147}
148
149static __always_inline __must_check
150size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
151{
152 if (unlikely(!check_copy_size(addr, bytes, false)))
153 return 0;
154 else
155 return _copy_from_iter(addr, bytes, i);
156}
157
158static __always_inline __must_check
159bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
160{
161 if (unlikely(!check_copy_size(addr, bytes, false)))
162 return false;
163 else
164 return _copy_from_iter_full(addr, bytes, i);
165}
166
167static __always_inline __must_check
168size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
169{
170 if (unlikely(!check_copy_size(addr, bytes, false)))
171 return 0;
172 else
173 return _copy_from_iter_nocache(addr, bytes, i);
174}
175
176static __always_inline __must_check
177bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i)
178{
179 if (unlikely(!check_copy_size(addr, bytes, false)))
180 return false;
181 else
182 return _copy_from_iter_full_nocache(addr, bytes, i);
183}
184
185#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
186
187
188
189
190
191
192size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i);
193#else
194#define _copy_from_iter_flushcache _copy_from_iter_nocache
195#endif
196
197#ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE
198size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i);
199#else
200#define _copy_to_iter_mcsafe _copy_to_iter
201#endif
202
203static __always_inline __must_check
204size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
205{
206 if (unlikely(!check_copy_size(addr, bytes, false)))
207 return 0;
208 else
209 return _copy_from_iter_flushcache(addr, bytes, i);
210}
211
212static __always_inline __must_check
213size_t copy_to_iter_mcsafe(void *addr, size_t bytes, struct iov_iter *i)
214{
215 if (unlikely(!check_copy_size(addr, bytes, true)))
216 return 0;
217 else
218 return _copy_to_iter_mcsafe(addr, bytes, i);
219}
220
221size_t iov_iter_zero(size_t bytes, struct iov_iter *);
222unsigned long iov_iter_alignment(const struct iov_iter *i);
223unsigned long iov_iter_gap_alignment(const struct iov_iter *i);
224void iov_iter_init(struct iov_iter *i, unsigned int direction, const struct iovec *iov,
225 unsigned long nr_segs, size_t count);
226void iov_iter_kvec(struct iov_iter *i, unsigned int direction, const struct kvec *kvec,
227 unsigned long nr_segs, size_t count);
228void iov_iter_bvec(struct iov_iter *i, unsigned int direction, const struct bio_vec *bvec,
229 unsigned long nr_segs, size_t count);
230void iov_iter_pipe(struct iov_iter *i, unsigned int direction, struct pipe_inode_info *pipe,
231 size_t count);
232void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count);
233ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages,
234 size_t maxsize, unsigned maxpages, size_t *start);
235ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages,
236 size_t maxsize, size_t *start);
237int iov_iter_npages(const struct iov_iter *i, int maxpages);
238
239const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags);
240
241static inline size_t iov_iter_count(const struct iov_iter *i)
242{
243 return i->count;
244}
245
246
247
248
249
250
251
252static inline void iov_iter_truncate(struct iov_iter *i, u64 count)
253{
254
255
256
257
258
259
260 if (i->count > count)
261 i->count = count;
262}
263
264
265
266
267
268static inline void iov_iter_reexpand(struct iov_iter *i, size_t count)
269{
270 i->count = count;
271}
272size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, struct iov_iter *i);
273size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
274bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
275size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp,
276 struct iov_iter *i);
277
278int import_iovec(int type, const struct iovec __user * uvector,
279 unsigned nr_segs, unsigned fast_segs,
280 struct iovec **iov, struct iov_iter *i);
281
282#ifdef CONFIG_COMPAT
283struct compat_iovec;
284int compat_import_iovec(int type, const struct compat_iovec __user * uvector,
285 unsigned nr_segs, unsigned fast_segs,
286 struct iovec **iov, struct iov_iter *i);
287#endif
288
289int import_single_range(int type, void __user *buf, size_t len,
290 struct iovec *iov, struct iov_iter *i);
291
292int iov_iter_for_each_range(struct iov_iter *i, size_t bytes,
293 int (*f)(struct kvec *vec, void *context),
294 void *context);
295
296#endif
297