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ebabbf58 | 1 | /* |
c0c0989a | 2 | * SPDX-License-Identifier: LGPL-2.1-only |
ebabbf58 MD |
3 | * |
4 | * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
ebabbf58 MD |
5 | */ |
6 | ||
c0c0989a MJ |
7 | #ifndef _LIBCOUNTER_SHM_H |
8 | #define _LIBCOUNTER_SHM_H | |
9 | ||
ebabbf58 MD |
10 | #include <stddef.h> |
11 | #include <stdint.h> | |
12 | #include <unistd.h> | |
13 | #include <usterr-signal-safe.h> | |
14 | #include <urcu/compiler.h> | |
15 | #include "shm_types.h" | |
3b098ac1 | 16 | #include "helper.h" |
ebabbf58 MD |
17 | |
18 | /* lttng_counter_handle_create - for UST. */ | |
19 | extern | |
20 | struct lttng_counter_shm_handle *lttng_counter_handle_create(void *data, | |
21 | uint64_t memory_map_size, int wakeup_fd); | |
22 | /* lttng_counter_handle_add_cpu - for UST. */ | |
23 | extern | |
24 | int lttng_counter_handle_add_cpu(struct lttng_counter_shm_handle *handle, | |
25 | int shm_fd, uint32_t cpu_nr, | |
26 | uint64_t memory_map_size); | |
3b098ac1 | 27 | LTTNG_HIDDEN |
ebabbf58 MD |
28 | unsigned int lttng_counter_handle_get_nr_cpus(struct lttng_counter_shm_handle *handle); |
29 | ||
30 | /* | |
31 | * Pointer dereferencing. We don't trust the shm_ref, so we validate | |
32 | * both the index and offset with known boundaries. | |
33 | * | |
34 | * "shmp" and "shmp_index" guarantee that it's safe to use the pointer | |
35 | * target type, even in the occurrence of shm_ref modification by an | |
36 | * untrusted process having write access to the shm_ref. We return a | |
37 | * NULL pointer if the ranges are invalid. | |
38 | */ | |
39 | static inline | |
40 | char *_lttng_counter_shmp_offset(struct lttng_counter_shm_object_table *table, | |
41 | struct lttng_counter_shm_ref *ref, | |
42 | size_t idx, size_t elem_size) | |
43 | { | |
44 | struct lttng_counter_shm_object *obj; | |
45 | size_t objindex, ref_offset; | |
46 | ||
47 | objindex = (size_t) ref->index; | |
48 | if (caa_unlikely(objindex >= table->allocated_len)) | |
49 | return NULL; | |
50 | obj = &table->objects[objindex]; | |
51 | ref_offset = (size_t) ref->offset; | |
52 | ref_offset += idx * elem_size; | |
53 | /* Check if part of the element returned would exceed the limits. */ | |
54 | if (caa_unlikely(ref_offset + elem_size > obj->memory_map_size)) | |
55 | return NULL; | |
56 | return &obj->memory_map[ref_offset]; | |
57 | } | |
58 | ||
59 | #define lttng_counter_shmp_index(handle, ref, index) \ | |
60 | ({ \ | |
61 | __typeof__((ref)._type) ____ptr_ret; \ | |
62 | ____ptr_ret = (__typeof__(____ptr_ret)) _lttng_counter_shmp_offset((handle)->table, &(ref)._ref, index, sizeof(*____ptr_ret)); \ | |
63 | ____ptr_ret; \ | |
64 | }) | |
65 | ||
66 | #define lttng_counter_shmp(handle, ref) lttng_counter_shmp_index(handle, ref, 0) | |
67 | ||
68 | static inline | |
69 | void _lttng_counter_set_shmp(struct lttng_counter_shm_ref *ref, struct lttng_counter_shm_ref src) | |
70 | { | |
71 | *ref = src; | |
72 | } | |
73 | ||
74 | #define lttng_counter_set_shmp(ref, src) _lttng_counter_set_shmp(&(ref)._ref, src) | |
75 | ||
3b098ac1 | 76 | LTTNG_HIDDEN |
ebabbf58 | 77 | struct lttng_counter_shm_object_table *lttng_counter_shm_object_table_create(size_t max_nb_obj); |
3b098ac1 | 78 | LTTNG_HIDDEN |
ebabbf58 MD |
79 | struct lttng_counter_shm_object *lttng_counter_shm_object_table_alloc(struct lttng_counter_shm_object_table *table, |
80 | size_t memory_map_size, | |
81 | enum lttng_counter_shm_object_type type, | |
82 | const int cpu_fd, | |
83 | int cpu); | |
3b098ac1 | 84 | LTTNG_HIDDEN |
ebabbf58 MD |
85 | struct lttng_counter_shm_object *lttng_counter_shm_object_table_append_shm(struct lttng_counter_shm_object_table *table, |
86 | int shm_fd, size_t memory_map_size); | |
87 | /* mem ownership is passed to lttng_counter_shm_object_table_append_mem(). */ | |
3b098ac1 | 88 | LTTNG_HIDDEN |
ebabbf58 MD |
89 | struct lttng_counter_shm_object *lttng_counter_shm_object_table_append_mem(struct lttng_counter_shm_object_table *table, |
90 | void *mem, size_t memory_map_size); | |
3b098ac1 | 91 | LTTNG_HIDDEN |
ebabbf58 MD |
92 | void lttng_counter_shm_object_table_destroy(struct lttng_counter_shm_object_table *table, int consumer); |
93 | ||
94 | /* | |
95 | * lttng_counter_zalloc_shm - allocate memory within a shm object. | |
96 | * | |
97 | * Shared memory is already zeroed by shmget. | |
98 | * *NOT* multithread-safe (should be protected by mutex). | |
99 | * Returns a -1, -1 tuple on error. | |
100 | */ | |
3b098ac1 | 101 | LTTNG_HIDDEN |
ebabbf58 | 102 | struct lttng_counter_shm_ref lttng_counter_zalloc_shm(struct lttng_counter_shm_object *obj, size_t len); |
3b098ac1 | 103 | LTTNG_HIDDEN |
ebabbf58 MD |
104 | void lttng_counter_align_shm(struct lttng_counter_shm_object *obj, size_t align); |
105 | ||
106 | static inline | |
107 | int lttng_counter_shm_get_shm_fd(struct lttng_counter_shm_handle *handle, struct lttng_counter_shm_ref *ref) | |
108 | { | |
109 | struct lttng_counter_shm_object_table *table = handle->table; | |
110 | struct lttng_counter_shm_object *obj; | |
111 | size_t index; | |
112 | ||
113 | index = (size_t) ref->index; | |
114 | if (caa_unlikely(index >= table->allocated_len)) | |
115 | return -EPERM; | |
116 | obj = &table->objects[index]; | |
117 | return obj->shm_fd; | |
118 | } | |
119 | ||
120 | ||
121 | static inline | |
122 | int lttng_counter_shm_get_shm_size(struct lttng_counter_shm_handle *handle, struct lttng_counter_shm_ref *ref, | |
123 | uint64_t *size) | |
124 | { | |
125 | struct lttng_counter_shm_object_table *table = handle->table; | |
126 | struct lttng_counter_shm_object *obj; | |
127 | size_t index; | |
128 | ||
129 | index = (size_t) ref->index; | |
130 | if (caa_unlikely(index >= table->allocated_len)) | |
131 | return -EPERM; | |
132 | obj = &table->objects[index]; | |
133 | *size = obj->memory_map_size; | |
134 | return 0; | |
135 | } | |
136 | ||
137 | #endif /* _LIBCOUNTER_SHM_H */ |