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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> |
607ca46e | 13 | #include <uapi/linux/uio.h> |
1da177e4 | 14 | |
92236878 | 15 | struct page; |
241699cd | 16 | struct pipe_inode_info; |
812ed032 JS |
17 | |
18 | struct kvec { | |
19 | void *iov_base; /* and that should *never* hold a userland pointer */ | |
20 | size_t iov_len; | |
21 | }; | |
22 | ||
62a8067a AV |
23 | enum { |
24 | ITER_IOVEC = 0, | |
25 | ITER_KVEC = 2, | |
26 | ITER_BVEC = 4, | |
241699cd | 27 | ITER_PIPE = 8, |
62a8067a AV |
28 | }; |
29 | ||
92236878 | 30 | struct iov_iter { |
71d8e532 | 31 | int type; |
92236878 KO |
32 | size_t iov_offset; |
33 | size_t count; | |
62a8067a AV |
34 | union { |
35 | const struct iovec *iov; | |
a280455f | 36 | const struct kvec *kvec; |
62a8067a | 37 | const struct bio_vec *bvec; |
241699cd AV |
38 | struct pipe_inode_info *pipe; |
39 | }; | |
40 | union { | |
41 | unsigned long nr_segs; | |
42 | int idx; | |
62a8067a | 43 | }; |
92236878 KO |
44 | }; |
45 | ||
1da177e4 LT |
46 | /* |
47 | * Total number of bytes covered by an iovec. | |
48 | * | |
49 | * NOTE that it is not safe to use this function until all the iovec's | |
50 | * segment lengths have been validated. Because the individual lengths can | |
51 | * overflow a size_t when added together. | |
52 | */ | |
53 | static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs) | |
54 | { | |
55 | unsigned long seg; | |
56 | size_t ret = 0; | |
57 | ||
58 | for (seg = 0; seg < nr_segs; seg++) | |
59 | ret += iov[seg].iov_len; | |
60 | return ret; | |
61 | } | |
62 | ||
92236878 KO |
63 | static inline struct iovec iov_iter_iovec(const struct iov_iter *iter) |
64 | { | |
65 | return (struct iovec) { | |
66 | .iov_base = iter->iov->iov_base + iter->iov_offset, | |
67 | .iov_len = min(iter->count, | |
68 | iter->iov->iov_len - iter->iov_offset), | |
69 | }; | |
70 | } | |
71 | ||
72 | #define iov_for_each(iov, iter, start) \ | |
241699cd | 73 | if (!((start).type & (ITER_BVEC | ITER_PIPE))) \ |
92236878 KO |
74 | for (iter = (start); \ |
75 | (iter).count && \ | |
76 | ((iov = iov_iter_iovec(&(iter))), 1); \ | |
77 | iov_iter_advance(&(iter), (iov).iov_len)) | |
78 | ||
1da177e4 | 79 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to); |
d2f83e90 | 80 | |
92236878 KO |
81 | size_t iov_iter_copy_from_user_atomic(struct page *page, |
82 | struct iov_iter *i, unsigned long offset, size_t bytes); | |
92236878 KO |
83 | void iov_iter_advance(struct iov_iter *i, size_t bytes); |
84 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes); | |
85 | size_t iov_iter_single_seg_count(const struct iov_iter *i); | |
6e58e79d AV |
86 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
87 | struct iov_iter *i); | |
f0d1bec9 AV |
88 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, |
89 | struct iov_iter *i); | |
36f7a8a4 | 90 | size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i); |
c35e0248 | 91 | size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i); |
cbbd26b8 | 92 | bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i); |
aa583096 | 93 | size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i); |
cbbd26b8 | 94 | bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i); |
c35e0248 | 95 | size_t iov_iter_zero(size_t bytes, struct iov_iter *); |
886a3911 | 96 | unsigned long iov_iter_alignment(const struct iov_iter *i); |
357f435d | 97 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i); |
71d8e532 AV |
98 | void iov_iter_init(struct iov_iter *i, int direction, const struct iovec *iov, |
99 | unsigned long nr_segs, size_t count); | |
05afcb77 AV |
100 | void iov_iter_kvec(struct iov_iter *i, int direction, const struct kvec *kvec, |
101 | unsigned long nr_segs, size_t count); | |
102 | void iov_iter_bvec(struct iov_iter *i, int direction, const struct bio_vec *bvec, | |
abb78f87 | 103 | unsigned long nr_segs, size_t count); |
241699cd AV |
104 | void iov_iter_pipe(struct iov_iter *i, int direction, struct pipe_inode_info *pipe, |
105 | size_t count); | |
7b2c99d1 | 106 | ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages, |
2c80929c | 107 | size_t maxsize, unsigned maxpages, size_t *start); |
91f79c43 AV |
108 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages, |
109 | size_t maxsize, size_t *start); | |
f67da30c | 110 | int iov_iter_npages(const struct iov_iter *i, int maxpages); |
92236878 | 111 | |
4b8164b9 AV |
112 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags); |
113 | ||
b57332b4 | 114 | static inline size_t iov_iter_count(const struct iov_iter *i) |
92236878 KO |
115 | { |
116 | return i->count; | |
117 | } | |
118 | ||
b57332b4 | 119 | static inline bool iter_is_iovec(const struct iov_iter *i) |
777eda2c | 120 | { |
241699cd | 121 | return !(i->type & (ITER_BVEC | ITER_KVEC | ITER_PIPE)); |
777eda2c AV |
122 | } |
123 | ||
bd8e0ff9 OS |
124 | /* |
125 | * Get one of READ or WRITE out of iter->type without any other flags OR'd in | |
126 | * with it. | |
127 | * | |
128 | * The ?: is just for type safety. | |
129 | */ | |
d3849953 | 130 | #define iov_iter_rw(i) ((0 ? (struct iov_iter *)0 : (i))->type & (READ | WRITE)) |
bd8e0ff9 | 131 | |
0b86dbf6 AV |
132 | /* |
133 | * Cap the iov_iter by given limit; note that the second argument is | |
134 | * *not* the new size - it's upper limit for such. Passing it a value | |
135 | * greater than the amount of data in iov_iter is fine - it'll just do | |
136 | * nothing in that case. | |
137 | */ | |
138 | static inline void iov_iter_truncate(struct iov_iter *i, u64 count) | |
0c949334 | 139 | { |
0b86dbf6 AV |
140 | /* |
141 | * count doesn't have to fit in size_t - comparison extends both | |
142 | * operands to u64 here and any value that would be truncated by | |
143 | * conversion in assignement is by definition greater than all | |
144 | * values of size_t, including old i->count. | |
145 | */ | |
0c949334 AV |
146 | if (i->count > count) |
147 | i->count = count; | |
148 | } | |
149 | ||
b42b15fd AV |
150 | /* |
151 | * reexpand a previously truncated iterator; count must be no more than how much | |
152 | * we had shrunk it. | |
153 | */ | |
154 | static inline void iov_iter_reexpand(struct iov_iter *i, size_t count) | |
155 | { | |
156 | i->count = count; | |
157 | } | |
36f7a8a4 | 158 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, struct iov_iter *i); |
a604ec7e | 159 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i); |
cbbd26b8 | 160 | bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i); |
b42b15fd | 161 | |
bc917be8 AV |
162 | int import_iovec(int type, const struct iovec __user * uvector, |
163 | unsigned nr_segs, unsigned fast_segs, | |
164 | struct iovec **iov, struct iov_iter *i); | |
165 | ||
166 | #ifdef CONFIG_COMPAT | |
167 | struct compat_iovec; | |
168 | int compat_import_iovec(int type, const struct compat_iovec __user * uvector, | |
169 | unsigned nr_segs, unsigned fast_segs, | |
170 | struct iovec **iov, struct iov_iter *i); | |
171 | #endif | |
172 | ||
173 | int import_single_range(int type, void __user *buf, size_t len, | |
174 | struct iovec *iov, struct iov_iter *i); | |
175 | ||
812ed032 | 176 | #endif |