Commit | Line | Data |
---|---|---|
2dccf128 | 1 | /* |
a90917c3 | 2 | * lttng-context.c |
2dccf128 | 3 | * |
2dccf128 | 4 | * LTTng trace/channel/event context management. |
17baffe2 | 5 | * |
886d51a3 MD |
6 | * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
7 | * | |
8 | * This library is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU Lesser General Public | |
10 | * License as published by the Free Software Foundation; only | |
11 | * version 2.1 of the License. | |
12 | * | |
13 | * This library is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | * Lesser General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU Lesser General Public | |
19 | * License along with this library; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
2dccf128 MD |
21 | */ |
22 | ||
23 | #include <linux/module.h> | |
24 | #include <linux/list.h> | |
25 | #include <linux/mutex.h> | |
26 | #include <linux/slab.h> | |
27 | #include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */ | |
a90917c3 MD |
28 | #include "lttng-events.h" |
29 | #include "lttng-tracer.h" | |
2dccf128 | 30 | |
44252f0f MD |
31 | int lttng_find_context(struct lttng_ctx *ctx, const char *name) |
32 | { | |
33 | unsigned int i; | |
34 | ||
35 | for (i = 0; i < ctx->nr_fields; i++) { | |
4b58a8e4 MD |
36 | /* Skip allocated (but non-initialized) contexts */ |
37 | if (!ctx->fields[i].event_field.name) | |
38 | continue; | |
44252f0f MD |
39 | if (!strcmp(ctx->fields[i].event_field.name, name)) |
40 | return 1; | |
41 | } | |
42 | return 0; | |
43 | } | |
44 | EXPORT_SYMBOL_GPL(lttng_find_context); | |
45 | ||
2001023e MD |
46 | /* |
47 | * Note: as we append context information, the pointer location may change. | |
48 | */ | |
2dccf128 MD |
49 | struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p) |
50 | { | |
51 | struct lttng_ctx_field *field; | |
52 | struct lttng_ctx *ctx; | |
53 | ||
54 | if (!*ctx_p) { | |
55 | *ctx_p = kzalloc(sizeof(struct lttng_ctx), GFP_KERNEL); | |
56 | if (!*ctx_p) | |
57 | return NULL; | |
ebfdc612 | 58 | (*ctx_p)->largest_align = 1; |
2dccf128 MD |
59 | } |
60 | ctx = *ctx_p; | |
61 | if (ctx->nr_fields + 1 > ctx->allocated_fields) { | |
62 | struct lttng_ctx_field *new_fields; | |
63 | ||
0f034e0f | 64 | ctx->allocated_fields = max_t(size_t, 1, 2 * ctx->allocated_fields); |
2dccf128 MD |
65 | new_fields = kzalloc(ctx->allocated_fields * sizeof(struct lttng_ctx_field), GFP_KERNEL); |
66 | if (!new_fields) | |
67 | return NULL; | |
68 | if (ctx->fields) | |
77aefe99 | 69 | memcpy(new_fields, ctx->fields, sizeof(*ctx->fields) * ctx->nr_fields); |
2dccf128 MD |
70 | kfree(ctx->fields); |
71 | ctx->fields = new_fields; | |
72 | } | |
73 | field = &ctx->fields[ctx->nr_fields]; | |
74 | ctx->nr_fields++; | |
75 | return field; | |
76 | } | |
77 | EXPORT_SYMBOL_GPL(lttng_append_context); | |
78 | ||
ebfdc612 MD |
79 | /* |
80 | * lttng_context_update() should be called at least once between context | |
81 | * modification and trace start. | |
82 | */ | |
83 | void lttng_context_update(struct lttng_ctx *ctx) | |
84 | { | |
85 | int i; | |
86 | size_t largest_align = 8; /* in bits */ | |
87 | ||
88 | for (i = 0; i < ctx->nr_fields; i++) { | |
89 | struct lttng_type *type; | |
90 | size_t field_align = 8; | |
91 | ||
92 | type = &ctx->fields[i].event_field.type; | |
93 | switch (type->atype) { | |
94 | case atype_integer: | |
95 | field_align = type->u.basic.integer.alignment; | |
96 | break; | |
97 | case atype_array: | |
98 | { | |
99 | struct lttng_basic_type *btype; | |
100 | ||
101 | btype = &type->u.array.elem_type; | |
102 | switch (btype->atype) { | |
103 | case atype_integer: | |
104 | field_align = btype->u.basic.integer.alignment; | |
105 | break; | |
106 | case atype_string: | |
107 | break; | |
108 | ||
109 | case atype_array: | |
110 | case atype_sequence: | |
111 | default: | |
112 | WARN_ON_ONCE(1); | |
113 | break; | |
114 | } | |
115 | break; | |
116 | } | |
117 | case atype_sequence: | |
118 | { | |
119 | struct lttng_basic_type *btype; | |
120 | ||
121 | btype = &type->u.sequence.length_type; | |
122 | switch (btype->atype) { | |
123 | case atype_integer: | |
124 | field_align = btype->u.basic.integer.alignment; | |
125 | break; | |
126 | ||
127 | case atype_string: | |
128 | case atype_array: | |
129 | case atype_sequence: | |
130 | default: | |
131 | WARN_ON_ONCE(1); | |
132 | break; | |
133 | } | |
134 | ||
135 | btype = &type->u.sequence.elem_type; | |
136 | switch (btype->atype) { | |
137 | case atype_integer: | |
138 | field_align = max_t(size_t, | |
139 | field_align, | |
140 | btype->u.basic.integer.alignment); | |
141 | break; | |
142 | ||
143 | case atype_string: | |
144 | break; | |
145 | ||
146 | case atype_array: | |
147 | case atype_sequence: | |
148 | default: | |
149 | WARN_ON_ONCE(1); | |
150 | break; | |
151 | } | |
152 | break; | |
153 | } | |
154 | case atype_string: | |
155 | break; | |
156 | ||
157 | case atype_enum: | |
158 | default: | |
159 | WARN_ON_ONCE(1); | |
160 | break; | |
161 | } | |
162 | largest_align = max_t(size_t, largest_align, field_align); | |
163 | } | |
164 | ctx->largest_align = largest_align >> 3; /* bits to bytes */ | |
165 | } | |
166 | ||
4cae220c MD |
167 | /* |
168 | * Remove last context field. | |
169 | */ | |
8289661d MD |
170 | void lttng_remove_context_field(struct lttng_ctx **ctx_p, |
171 | struct lttng_ctx_field *field) | |
172 | { | |
173 | struct lttng_ctx *ctx; | |
174 | ||
175 | ctx = *ctx_p; | |
176 | ctx->nr_fields--; | |
4cae220c | 177 | WARN_ON_ONCE(&ctx->fields[ctx->nr_fields] != field); |
8289661d MD |
178 | memset(&ctx->fields[ctx->nr_fields], 0, sizeof(struct lttng_ctx_field)); |
179 | } | |
180 | EXPORT_SYMBOL_GPL(lttng_remove_context_field); | |
181 | ||
2dccf128 MD |
182 | void lttng_destroy_context(struct lttng_ctx *ctx) |
183 | { | |
184 | int i; | |
185 | ||
8070f5c0 MD |
186 | if (!ctx) |
187 | return; | |
9e7e4892 MD |
188 | for (i = 0; i < ctx->nr_fields; i++) { |
189 | if (ctx->fields[i].destroy) | |
190 | ctx->fields[i].destroy(&ctx->fields[i]); | |
191 | } | |
2dccf128 MD |
192 | kfree(ctx->fields); |
193 | kfree(ctx); | |
194 | } |