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