b5d1343ac4d783369ea50c10708062910f89c2b0
1 #ifndef _LIBRINGBUFFER_SHM_H
2 #define _LIBRINGBUFFER_SHM_H
7 * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
9 * This library is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; only
12 * version 2.1 of the License.
14 * This library is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with this library; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26 #include <usterr-signal-safe.h>
27 #include <urcu/compiler.h>
28 #include "shm_types.h"
30 /* channel_handle_create - for UST. */
32 struct lttng_ust_shm_handle
*channel_handle_create(void *data
,
33 uint64_t memory_map_size
, int wakeup_fd
);
34 /* channel_handle_add_stream - for UST. */
36 int channel_handle_add_stream(struct lttng_ust_shm_handle
*handle
,
37 int shm_fd
, int wakeup_fd
, uint32_t stream_nr
,
38 uint64_t memory_map_size
);
39 unsigned int channel_handle_get_nr_streams(struct lttng_ust_shm_handle
*handle
);
41 void channel_destroy(struct channel
*chan
, struct lttng_ust_shm_handle
*handle
,
45 * Pointer dereferencing. We don't trust the shm_ref, so we validate
46 * both the index and offset with known boundaries.
48 * "shmp" and "shmp_index" guarantee that it's safe to use the pointer
49 * target type, even in the occurrence of shm_ref modification by an
50 * untrusted process having write access to the shm_ref. We return a
51 * NULL pointer if the ranges are invalid.
54 char *_shmp_offset(struct shm_object_table
*table
, struct shm_ref
*ref
,
55 size_t idx
, size_t elem_size
)
57 struct shm_object
*obj
;
58 size_t objindex
, ref_offset
;
60 objindex
= (size_t) ref
->index
;
61 if (caa_unlikely(objindex
>= table
->allocated_len
))
63 obj
= &table
->objects
[objindex
];
64 ref_offset
= (size_t) ref
->offset
;
65 ref_offset
+= idx
* elem_size
;
66 /* Check if part of the element returned would exceed the limits. */
67 if (caa_unlikely(ref_offset
+ elem_size
> obj
->memory_map_size
))
69 return &obj
->memory_map
[ref_offset
];
72 #define shmp_index(handle, ref, index) \
74 __typeof__((ref)._type) ____ptr_ret; \
75 ____ptr_ret = (__typeof__(____ptr_ret)) _shmp_offset((handle)->table, &(ref)._ref, index, sizeof(*____ptr_ret)); \
79 #define shmp(handle, ref) shmp_index(handle, ref, 0)
82 void _set_shmp(struct shm_ref
*ref
, struct shm_ref src
)
87 #define set_shmp(ref, src) _set_shmp(&(ref)._ref, src)
89 struct shm_object_table
*shm_object_table_create(size_t max_nb_obj
);
90 struct shm_object
*shm_object_table_alloc(struct shm_object_table
*table
,
91 size_t memory_map_size
,
92 enum shm_object_type type
,
95 struct shm_object
*shm_object_table_append_shm(struct shm_object_table
*table
,
96 int shm_fd
, int wakeup_fd
, uint32_t stream_nr
,
97 size_t memory_map_size
);
98 /* mem ownership is passed to shm_object_table_append_mem(). */
99 struct shm_object
*shm_object_table_append_mem(struct shm_object_table
*table
,
100 void *mem
, size_t memory_map_size
, int wakeup_fd
);
101 void shm_object_table_destroy(struct shm_object_table
*table
, int consumer
);
104 * zalloc_shm - allocate memory within a shm object.
106 * Shared memory is already zeroed by shmget.
107 * *NOT* multithread-safe (should be protected by mutex).
108 * Returns a -1, -1 tuple on error.
110 struct shm_ref
zalloc_shm(struct shm_object
*obj
, size_t len
);
111 void align_shm(struct shm_object
*obj
, size_t align
);
114 int shm_get_wait_fd(struct lttng_ust_shm_handle
*handle
, struct shm_ref
*ref
)
116 struct shm_object_table
*table
= handle
->table
;
117 struct shm_object
*obj
;
120 index
= (size_t) ref
->index
;
121 if (caa_unlikely(index
>= table
->allocated_len
))
123 obj
= &table
->objects
[index
];
124 return obj
->wait_fd
[0];
128 int shm_get_wakeup_fd(struct lttng_ust_shm_handle
*handle
, struct shm_ref
*ref
)
130 struct shm_object_table
*table
= handle
->table
;
131 struct shm_object
*obj
;
134 index
= (size_t) ref
->index
;
135 if (caa_unlikely(index
>= table
->allocated_len
))
137 obj
= &table
->objects
[index
];
138 return obj
->wait_fd
[1];
142 int shm_close_wait_fd(struct lttng_ust_shm_handle
*handle
,
145 struct shm_object_table
*table
= handle
->table
;
146 struct shm_object
*obj
;
151 index
= (size_t) ref
->index
;
152 if (caa_unlikely(index
>= table
->allocated_len
))
154 obj
= &table
->objects
[index
];
155 wait_fd
= obj
->wait_fd
[0];
158 obj
->wait_fd
[0] = -1;
159 ret
= close(wait_fd
);
168 int shm_close_wakeup_fd(struct lttng_ust_shm_handle
*handle
,
171 struct shm_object_table
*table
= handle
->table
;
172 struct shm_object
*obj
;
177 index
= (size_t) ref
->index
;
178 if (caa_unlikely(index
>= table
->allocated_len
))
180 obj
= &table
->objects
[index
];
181 wakeup_fd
= obj
->wait_fd
[1];
184 obj
->wait_fd
[1] = -1;
185 ret
= close(wakeup_fd
);
194 int shm_get_shm_fd(struct lttng_ust_shm_handle
*handle
, struct shm_ref
*ref
)
196 struct shm_object_table
*table
= handle
->table
;
197 struct shm_object
*obj
;
200 index
= (size_t) ref
->index
;
201 if (caa_unlikely(index
>= table
->allocated_len
))
203 obj
= &table
->objects
[index
];
209 int shm_get_shm_size(struct lttng_ust_shm_handle
*handle
, struct shm_ref
*ref
,
212 struct shm_object_table
*table
= handle
->table
;
213 struct shm_object
*obj
;
216 index
= (size_t) ref
->index
;
217 if (caa_unlikely(index
>= table
->allocated_len
))
219 obj
= &table
->objects
[index
];
220 *size
= obj
->memory_map_size
;
224 #endif /* _LIBRINGBUFFER_SHM_H */
This page took 0.03812 seconds and 4 git commands to generate.