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