Commit | Line | Data |
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a6352fd4 | 1 | /* |
c0c0989a | 2 | * SPDX-License-Identifier: LGPL-2.1-only |
a6352fd4 | 3 | * |
e92f3e28 | 4 | * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
a6352fd4 MD |
5 | */ |
6 | ||
c0c0989a MJ |
7 | #ifndef _LIBRINGBUFFER_SHM_H |
8 | #define _LIBRINGBUFFER_SHM_H | |
9 | ||
b4051ad8 | 10 | #include <stddef.h> |
a6352fd4 | 11 | #include <stdint.h> |
4e79769f | 12 | #include <unistd.h> |
9d315d6d | 13 | #include "common/logging.h" |
35897f8b | 14 | #include <urcu/compiler.h> |
1d498196 | 15 | #include "shm_types.h" |
a6352fd4 | 16 | |
74d81a6c MD |
17 | /* channel_handle_create - for UST. */ |
18 | extern | |
19 | struct lttng_ust_shm_handle *channel_handle_create(void *data, | |
1d18d519 MJ |
20 | uint64_t memory_map_size, int wakeup_fd) |
21 | __attribute__((visibility("hidden"))); | |
ddabe860 | 22 | |
74d81a6c MD |
23 | /* channel_handle_add_stream - for UST. */ |
24 | extern | |
25 | int channel_handle_add_stream(struct lttng_ust_shm_handle *handle, | |
26 | int shm_fd, int wakeup_fd, uint32_t stream_nr, | |
1d18d519 MJ |
27 | uint64_t memory_map_size) |
28 | __attribute__((visibility("hidden"))); | |
ddabe860 | 29 | |
1d18d519 MJ |
30 | unsigned int channel_handle_get_nr_streams(struct lttng_ust_shm_handle *handle) |
31 | __attribute__((visibility("hidden"))); | |
ddabe860 | 32 | |
a6352fd4 | 33 | /* |
1d498196 MD |
34 | * Pointer dereferencing. We don't trust the shm_ref, so we validate |
35 | * both the index and offset with known boundaries. | |
ed5426d3 MD |
36 | * |
37 | * "shmp" and "shmp_index" guarantee that it's safe to use the pointer | |
38 | * target type, even in the occurrence of shm_ref modification by an | |
39 | * untrusted process having write access to the shm_ref. We return a | |
40 | * NULL pointer if the ranges are invalid. | |
a6352fd4 | 41 | */ |
a6352fd4 | 42 | static inline |
4746ae29 | 43 | char *_shmp_offset(struct shm_object_table *table, struct shm_ref *ref, |
cba4b7a3 | 44 | size_t idx, size_t elem_size) |
a6352fd4 | 45 | { |
1d498196 | 46 | struct shm_object *obj; |
cba4b7a3 | 47 | size_t objindex, ref_offset; |
a6352fd4 | 48 | |
cba4b7a3 | 49 | objindex = (size_t) ref->index; |
b5a3dfa5 | 50 | if (caa_unlikely(objindex >= table->allocated_len)) |
1d498196 | 51 | return NULL; |
cba4b7a3 | 52 | obj = &table->objects[objindex]; |
4746ae29 | 53 | ref_offset = (size_t) ref->offset; |
cba4b7a3 MD |
54 | ref_offset += idx * elem_size; |
55 | /* Check if part of the element returned would exceed the limits. */ | |
b5a3dfa5 | 56 | if (caa_unlikely(ref_offset + elem_size > obj->memory_map_size)) |
a6352fd4 | 57 | return NULL; |
4746ae29 | 58 | return &obj->memory_map[ref_offset]; |
a6352fd4 MD |
59 | } |
60 | ||
4041a8a7 MJ |
61 | #define shmp_index(handle, ref, index) \ |
62 | ((__typeof__((ref)._type)) _shmp_offset((handle)->table, &(ref)._ref, index, sizeof(*((ref)._type)))) | |
1d498196 | 63 | |
4746ae29 MD |
64 | #define shmp(handle, ref) shmp_index(handle, ref, 0) |
65 | ||
431d5cf0 | 66 | static inline |
1d498196 | 67 | void _set_shmp(struct shm_ref *ref, struct shm_ref src) |
431d5cf0 | 68 | { |
1d498196 | 69 | *ref = src; |
431d5cf0 MD |
70 | } |
71 | ||
1d498196 MD |
72 | #define set_shmp(ref, src) _set_shmp(&(ref)._ref, src) |
73 | ||
97572c04 | 74 | struct shm_object_table *shm_object_table_create(size_t max_nb_obj, bool populate) |
1d18d519 | 75 | __attribute__((visibility("hidden"))); |
ddabe860 | 76 | |
74d81a6c MD |
77 | struct shm_object *shm_object_table_alloc(struct shm_object_table *table, |
78 | size_t memory_map_size, | |
a9ff648c | 79 | enum shm_object_type type, |
4b68c31f | 80 | const int stream_fd, |
97572c04 | 81 | int cpu, bool populate) |
1d18d519 | 82 | __attribute__((visibility("hidden"))); |
ddabe860 | 83 | |
74d81a6c MD |
84 | struct shm_object *shm_object_table_append_shm(struct shm_object_table *table, |
85 | int shm_fd, int wakeup_fd, uint32_t stream_nr, | |
97572c04 | 86 | size_t memory_map_size, bool populate) |
1d18d519 | 87 | __attribute__((visibility("hidden"))); |
ddabe860 | 88 | |
74d81a6c MD |
89 | /* mem ownership is passed to shm_object_table_append_mem(). */ |
90 | struct shm_object *shm_object_table_append_mem(struct shm_object_table *table, | |
1d18d519 MJ |
91 | void *mem, size_t memory_map_size, int wakeup_fd) |
92 | __attribute__((visibility("hidden"))); | |
ddabe860 | 93 | |
1d18d519 MJ |
94 | void shm_object_table_destroy(struct shm_object_table *table, int consumer) |
95 | __attribute__((visibility("hidden"))); | |
1d498196 MD |
96 | |
97 | /* | |
98 | * zalloc_shm - allocate memory within a shm object. | |
99 | * | |
100 | * Shared memory is already zeroed by shmget. | |
101 | * *NOT* multithread-safe (should be protected by mutex). | |
102 | * Returns a -1, -1 tuple on error. | |
103 | */ | |
1d18d519 MJ |
104 | struct shm_ref zalloc_shm(struct shm_object *obj, size_t len) |
105 | __attribute__((visibility("hidden"))); | |
ddabe860 | 106 | |
1d18d519 MJ |
107 | void align_shm(struct shm_object *obj, size_t align) |
108 | __attribute__((visibility("hidden"))); | |
1d498196 | 109 | |
74d81a6c MD |
110 | static inline |
111 | int shm_get_wait_fd(struct lttng_ust_shm_handle *handle, struct shm_ref *ref) | |
112 | { | |
113 | struct shm_object_table *table = handle->table; | |
114 | struct shm_object *obj; | |
115 | size_t index; | |
116 | ||
117 | index = (size_t) ref->index; | |
118 | if (caa_unlikely(index >= table->allocated_len)) | |
119 | return -EPERM; | |
120 | obj = &table->objects[index]; | |
121 | return obj->wait_fd[0]; | |
122 | } | |
123 | ||
5d61a504 | 124 | static inline |
38fae1d3 | 125 | int shm_get_wakeup_fd(struct lttng_ust_shm_handle *handle, struct shm_ref *ref) |
5d61a504 MD |
126 | { |
127 | struct shm_object_table *table = handle->table; | |
128 | struct shm_object *obj; | |
129 | size_t index; | |
130 | ||
131 | index = (size_t) ref->index; | |
b5a3dfa5 | 132 | if (caa_unlikely(index >= table->allocated_len)) |
5d61a504 MD |
133 | return -EPERM; |
134 | obj = &table->objects[index]; | |
135 | return obj->wait_fd[1]; | |
74d81a6c MD |
136 | } |
137 | ||
138 | static inline | |
139 | int shm_close_wait_fd(struct lttng_ust_shm_handle *handle, | |
140 | struct shm_ref *ref) | |
141 | { | |
142 | struct shm_object_table *table = handle->table; | |
143 | struct shm_object *obj; | |
c33ceb02 | 144 | int wait_fd; |
74d81a6c MD |
145 | size_t index; |
146 | int ret; | |
5d61a504 | 147 | |
74d81a6c MD |
148 | index = (size_t) ref->index; |
149 | if (caa_unlikely(index >= table->allocated_len)) | |
150 | return -EPERM; | |
151 | obj = &table->objects[index]; | |
c33ceb02 MD |
152 | wait_fd = obj->wait_fd[0]; |
153 | if (wait_fd < 0) | |
74d81a6c | 154 | return -ENOENT; |
c33ceb02 MD |
155 | obj->wait_fd[0] = -1; |
156 | ret = close(wait_fd); | |
74d81a6c MD |
157 | if (ret) { |
158 | ret = -errno; | |
159 | return ret; | |
160 | } | |
74d81a6c | 161 | return 0; |
5d61a504 MD |
162 | } |
163 | ||
164 | static inline | |
74d81a6c MD |
165 | int shm_close_wakeup_fd(struct lttng_ust_shm_handle *handle, |
166 | struct shm_ref *ref) | |
5d61a504 MD |
167 | { |
168 | struct shm_object_table *table = handle->table; | |
169 | struct shm_object *obj; | |
c33ceb02 | 170 | int wakeup_fd; |
5d61a504 | 171 | size_t index; |
74d81a6c | 172 | int ret; |
5d61a504 MD |
173 | |
174 | index = (size_t) ref->index; | |
b5a3dfa5 | 175 | if (caa_unlikely(index >= table->allocated_len)) |
5d61a504 MD |
176 | return -EPERM; |
177 | obj = &table->objects[index]; | |
c33ceb02 MD |
178 | wakeup_fd = obj->wait_fd[1]; |
179 | if (wakeup_fd < 0) | |
74d81a6c | 180 | return -ENOENT; |
c33ceb02 MD |
181 | obj->wait_fd[1] = -1; |
182 | ret = close(wakeup_fd); | |
74d81a6c MD |
183 | if (ret) { |
184 | ret = -errno; | |
185 | return ret; | |
186 | } | |
74d81a6c | 187 | return 0; |
5d61a504 MD |
188 | } |
189 | ||
381c0f1e | 190 | static inline |
74d81a6c MD |
191 | int shm_get_shm_fd(struct lttng_ust_shm_handle *handle, struct shm_ref *ref) |
192 | { | |
193 | struct shm_object_table *table = handle->table; | |
194 | struct shm_object *obj; | |
195 | size_t index; | |
196 | ||
197 | index = (size_t) ref->index; | |
198 | if (caa_unlikely(index >= table->allocated_len)) | |
199 | return -EPERM; | |
200 | obj = &table->objects[index]; | |
201 | return obj->shm_fd; | |
202 | } | |
203 | ||
204 | ||
205 | static inline | |
206 | int shm_get_shm_size(struct lttng_ust_shm_handle *handle, struct shm_ref *ref, | |
207 | uint64_t *size) | |
381c0f1e MD |
208 | { |
209 | struct shm_object_table *table = handle->table; | |
210 | struct shm_object *obj; | |
211 | size_t index; | |
212 | ||
213 | index = (size_t) ref->index; | |
b5a3dfa5 | 214 | if (caa_unlikely(index >= table->allocated_len)) |
381c0f1e MD |
215 | return -EPERM; |
216 | obj = &table->objects[index]; | |
74d81a6c | 217 | *size = obj->memory_map_size; |
381c0f1e MD |
218 | return 0; |
219 | } | |
220 | ||
a6352fd4 | 221 | #endif /* _LIBRINGBUFFER_SHM_H */ |