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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Berkeley style UIO structures - Alan Cox 1994. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version | |
7 | * 2 of the License, or (at your option) any later version. | |
8 | */ | |
607ca46e DH |
9 | #ifndef __LINUX_UIO_H |
10 | #define __LINUX_UIO_H | |
1da177e4 | 11 | |
92236878 | 12 | #include <linux/kernel.h> |
aa28de27 | 13 | #include <linux/thread_info.h> |
d05f4435 | 14 | #include <crypto/hash.h> |
607ca46e | 15 | #include <uapi/linux/uio.h> |
1da177e4 | 16 | |
92236878 | 17 | struct page; |
241699cd | 18 | struct pipe_inode_info; |
812ed032 JS |
19 | |
20 | struct kvec { | |
21 | void *iov_base; /* and that should *never* hold a userland pointer */ | |
22 | size_t iov_len; | |
23 | }; | |
24 | ||
00e23707 | 25 | enum iter_type { |
875f1d07 JA |
26 | /* set if ITER_BVEC doesn't hold a bv_page ref */ |
27 | ITER_BVEC_FLAG_NO_REF = 2, | |
28 | ||
29 | /* iter types */ | |
30 | ITER_IOVEC = 4, | |
31 | ITER_KVEC = 8, | |
32 | ITER_BVEC = 16, | |
33 | ITER_PIPE = 32, | |
34 | ITER_DISCARD = 64, | |
62a8067a AV |
35 | }; |
36 | ||
92236878 | 37 | struct iov_iter { |
875f1d07 JA |
38 | /* |
39 | * Bit 0 is the read/write bit, set if we're writing. | |
40 | * Bit 1 is the BVEC_FLAG_NO_REF bit, set if type is a bvec and | |
41 | * the caller isn't expecting to drop a page reference when done. | |
42 | */ | |
aa563d7b | 43 | unsigned int type; |
92236878 KO |
44 | size_t iov_offset; |
45 | size_t count; | |
62a8067a AV |
46 | union { |
47 | const struct iovec *iov; | |
a280455f | 48 | const struct kvec *kvec; |
62a8067a | 49 | const struct bio_vec *bvec; |
241699cd AV |
50 | struct pipe_inode_info *pipe; |
51 | }; | |
52 | union { | |
53 | unsigned long nr_segs; | |
27c0e374 AV |
54 | struct { |
55 | int idx; | |
56 | int start_idx; | |
57 | }; | |
62a8067a | 58 | }; |
92236878 KO |
59 | }; |
60 | ||
00e23707 DH |
61 | static inline enum iter_type iov_iter_type(const struct iov_iter *i) |
62 | { | |
f5eb4d3b | 63 | return i->type & ~(READ | WRITE | ITER_BVEC_FLAG_NO_REF); |
00e23707 DH |
64 | } |
65 | ||
66 | static inline bool iter_is_iovec(const struct iov_iter *i) | |
67 | { | |
68 | return iov_iter_type(i) == ITER_IOVEC; | |
69 | } | |
70 | ||
71 | static inline bool iov_iter_is_kvec(const struct iov_iter *i) | |
72 | { | |
73 | return iov_iter_type(i) == ITER_KVEC; | |
74 | } | |
75 | ||
76 | static inline bool iov_iter_is_bvec(const struct iov_iter *i) | |
77 | { | |
78 | return iov_iter_type(i) == ITER_BVEC; | |
79 | } | |
80 | ||
81 | static inline bool iov_iter_is_pipe(const struct iov_iter *i) | |
82 | { | |
83 | return iov_iter_type(i) == ITER_PIPE; | |
84 | } | |
85 | ||
9ea9ce04 DH |
86 | static inline bool iov_iter_is_discard(const struct iov_iter *i) |
87 | { | |
88 | return iov_iter_type(i) == ITER_DISCARD; | |
89 | } | |
90 | ||
00e23707 DH |
91 | static inline unsigned char iov_iter_rw(const struct iov_iter *i) |
92 | { | |
93 | return i->type & (READ | WRITE); | |
94 | } | |
95 | ||
875f1d07 JA |
96 | static inline bool iov_iter_bvec_no_ref(const struct iov_iter *i) |
97 | { | |
98 | return (i->type & ITER_BVEC_FLAG_NO_REF) != 0; | |
99 | } | |
100 | ||
1da177e4 LT |
101 | /* |
102 | * Total number of bytes covered by an iovec. | |
103 | * | |
104 | * NOTE that it is not safe to use this function until all the iovec's | |
105 | * segment lengths have been validated. Because the individual lengths can | |
106 | * overflow a size_t when added together. | |
107 | */ | |
108 | static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs) | |
109 | { | |
110 | unsigned long seg; | |
111 | size_t ret = 0; | |
112 | ||
113 | for (seg = 0; seg < nr_segs; seg++) | |
114 | ret += iov[seg].iov_len; | |
115 | return ret; | |
116 | } | |
117 | ||
92236878 KO |
118 | static inline struct iovec iov_iter_iovec(const struct iov_iter *iter) |
119 | { | |
120 | return (struct iovec) { | |
121 | .iov_base = iter->iov->iov_base + iter->iov_offset, | |
122 | .iov_len = min(iter->count, | |
123 | iter->iov->iov_len - iter->iov_offset), | |
124 | }; | |
125 | } | |
126 | ||
92236878 KO |
127 | size_t iov_iter_copy_from_user_atomic(struct page *page, |
128 | struct iov_iter *i, unsigned long offset, size_t bytes); | |
92236878 | 129 | void iov_iter_advance(struct iov_iter *i, size_t bytes); |
27c0e374 | 130 | void iov_iter_revert(struct iov_iter *i, size_t bytes); |
92236878 KO |
131 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes); |
132 | size_t iov_iter_single_seg_count(const struct iov_iter *i); | |
6e58e79d AV |
133 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
134 | struct iov_iter *i); | |
f0d1bec9 AV |
135 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, |
136 | struct iov_iter *i); | |
aa28de27 AV |
137 | |
138 | size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i); | |
139 | size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i); | |
140 | bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i); | |
141 | size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i); | |
142 | bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i); | |
143 | ||
144 | static __always_inline __must_check | |
145 | size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) | |
146 | { | |
147 | if (unlikely(!check_copy_size(addr, bytes, true))) | |
c43aeb19 | 148 | return 0; |
aa28de27 AV |
149 | else |
150 | return _copy_to_iter(addr, bytes, i); | |
151 | } | |
152 | ||
153 | static __always_inline __must_check | |
154 | size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) | |
155 | { | |
156 | if (unlikely(!check_copy_size(addr, bytes, false))) | |
c43aeb19 | 157 | return 0; |
aa28de27 AV |
158 | else |
159 | return _copy_from_iter(addr, bytes, i); | |
160 | } | |
161 | ||
162 | static __always_inline __must_check | |
163 | bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) | |
164 | { | |
165 | if (unlikely(!check_copy_size(addr, bytes, false))) | |
166 | return false; | |
167 | else | |
168 | return _copy_from_iter_full(addr, bytes, i); | |
169 | } | |
170 | ||
171 | static __always_inline __must_check | |
172 | size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) | |
173 | { | |
174 | if (unlikely(!check_copy_size(addr, bytes, false))) | |
c43aeb19 | 175 | return 0; |
aa28de27 AV |
176 | else |
177 | return _copy_from_iter_nocache(addr, bytes, i); | |
178 | } | |
179 | ||
180 | static __always_inline __must_check | |
181 | bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) | |
182 | { | |
183 | if (unlikely(!check_copy_size(addr, bytes, false))) | |
184 | return false; | |
185 | else | |
186 | return _copy_from_iter_full_nocache(addr, bytes, i); | |
187 | } | |
188 | ||
0aed55af DW |
189 | #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE |
190 | /* | |
191 | * Note, users like pmem that depend on the stricter semantics of | |
192 | * copy_from_iter_flushcache() than copy_from_iter_nocache() must check for | |
193 | * IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) before assuming that the | |
194 | * destination is flushed from the cache on return. | |
195 | */ | |
6a37e940 | 196 | size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i); |
0aed55af | 197 | #else |
6a37e940 LT |
198 | #define _copy_from_iter_flushcache _copy_from_iter_nocache |
199 | #endif | |
200 | ||
8780356e | 201 | #ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE |
522239b4 | 202 | size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i); |
8780356e DW |
203 | #else |
204 | #define _copy_to_iter_mcsafe _copy_to_iter | |
205 | #endif | |
206 | ||
6a37e940 LT |
207 | static __always_inline __must_check |
208 | size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) | |
0aed55af | 209 | { |
6a37e940 | 210 | if (unlikely(!check_copy_size(addr, bytes, false))) |
c43aeb19 | 211 | return 0; |
6a37e940 LT |
212 | else |
213 | return _copy_from_iter_flushcache(addr, bytes, i); | |
0aed55af | 214 | } |
6a37e940 | 215 | |
8780356e DW |
216 | static __always_inline __must_check |
217 | size_t copy_to_iter_mcsafe(void *addr, size_t bytes, struct iov_iter *i) | |
218 | { | |
dfb06cba | 219 | if (unlikely(!check_copy_size(addr, bytes, true))) |
8780356e DW |
220 | return 0; |
221 | else | |
222 | return _copy_to_iter_mcsafe(addr, bytes, i); | |
223 | } | |
224 | ||
c35e0248 | 225 | size_t iov_iter_zero(size_t bytes, struct iov_iter *); |
886a3911 | 226 | unsigned long iov_iter_alignment(const struct iov_iter *i); |
357f435d | 227 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i); |
aa563d7b | 228 | void iov_iter_init(struct iov_iter *i, unsigned int direction, const struct iovec *iov, |
71d8e532 | 229 | unsigned long nr_segs, size_t count); |
aa563d7b | 230 | void iov_iter_kvec(struct iov_iter *i, unsigned int direction, const struct kvec *kvec, |
05afcb77 | 231 | unsigned long nr_segs, size_t count); |
aa563d7b | 232 | void iov_iter_bvec(struct iov_iter *i, unsigned int direction, const struct bio_vec *bvec, |
abb78f87 | 233 | unsigned long nr_segs, size_t count); |
aa563d7b | 234 | void iov_iter_pipe(struct iov_iter *i, unsigned int direction, struct pipe_inode_info *pipe, |
241699cd | 235 | size_t count); |
9ea9ce04 | 236 | void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count); |
7b2c99d1 | 237 | ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages, |
2c80929c | 238 | size_t maxsize, unsigned maxpages, size_t *start); |
91f79c43 AV |
239 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages, |
240 | size_t maxsize, size_t *start); | |
f67da30c | 241 | int iov_iter_npages(const struct iov_iter *i, int maxpages); |
92236878 | 242 | |
4b8164b9 AV |
243 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags); |
244 | ||
b57332b4 | 245 | static inline size_t iov_iter_count(const struct iov_iter *i) |
92236878 KO |
246 | { |
247 | return i->count; | |
248 | } | |
249 | ||
0b86dbf6 AV |
250 | /* |
251 | * Cap the iov_iter by given limit; note that the second argument is | |
252 | * *not* the new size - it's upper limit for such. Passing it a value | |
253 | * greater than the amount of data in iov_iter is fine - it'll just do | |
254 | * nothing in that case. | |
255 | */ | |
256 | static inline void iov_iter_truncate(struct iov_iter *i, u64 count) | |
0c949334 | 257 | { |
0b86dbf6 AV |
258 | /* |
259 | * count doesn't have to fit in size_t - comparison extends both | |
260 | * operands to u64 here and any value that would be truncated by | |
261 | * conversion in assignement is by definition greater than all | |
262 | * values of size_t, including old i->count. | |
263 | */ | |
0c949334 AV |
264 | if (i->count > count) |
265 | i->count = count; | |
266 | } | |
267 | ||
b42b15fd AV |
268 | /* |
269 | * reexpand a previously truncated iterator; count must be no more than how much | |
270 | * we had shrunk it. | |
271 | */ | |
272 | static inline void iov_iter_reexpand(struct iov_iter *i, size_t count) | |
273 | { | |
274 | i->count = count; | |
275 | } | |
cb002d07 | 276 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, struct iov_iter *i); |
a604ec7e | 277 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i); |
cbbd26b8 | 278 | bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i); |
d05f4435 SG |
279 | size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, |
280 | struct iov_iter *i); | |
b42b15fd | 281 | |
bc917be8 AV |
282 | int import_iovec(int type, const struct iovec __user * uvector, |
283 | unsigned nr_segs, unsigned fast_segs, | |
284 | struct iovec **iov, struct iov_iter *i); | |
285 | ||
286 | #ifdef CONFIG_COMPAT | |
287 | struct compat_iovec; | |
288 | int compat_import_iovec(int type, const struct compat_iovec __user * uvector, | |
289 | unsigned nr_segs, unsigned fast_segs, | |
290 | struct iovec **iov, struct iov_iter *i); | |
291 | #endif | |
292 | ||
293 | int import_single_range(int type, void __user *buf, size_t len, | |
294 | struct iovec *iov, struct iov_iter *i); | |
295 | ||
09cf698a AV |
296 | int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, |
297 | int (*f)(struct kvec *vec, void *context), | |
298 | void *context); | |
299 | ||
812ed032 | 300 | #endif |