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b7cdc182 | 1 | /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) |
9f36eaed | 2 | * |
a90917c3 | 3 | * lttng-context.c |
2dccf128 | 4 | * |
2dccf128 | 5 | * LTTng trace/channel/event context management. |
17baffe2 | 6 | * |
886d51a3 | 7 | * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
2dccf128 MD |
8 | */ |
9 | ||
10 | #include <linux/module.h> | |
11 | #include <linux/list.h> | |
12 | #include <linux/mutex.h> | |
13 | #include <linux/slab.h> | |
263b6c88 | 14 | #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_mappings() */ |
2df37e95 | 15 | #include <lttng/events.h> |
437d5aa5 | 16 | #include <lttng/events-internal.h> |
2df37e95 | 17 | #include <lttng/tracer.h> |
2dccf128 | 18 | |
07dfc1d0 MD |
19 | /* |
20 | * The filter implementation requires that two consecutive "get" for the | |
21 | * same context performed by the same thread return the same result. | |
22 | */ | |
23 | ||
24 | /* | |
25 | * Static array of contexts, for $ctx filters. | |
26 | */ | |
437d5aa5 | 27 | struct lttng_kernel_ctx *lttng_static_ctx; |
07dfc1d0 | 28 | |
437d5aa5 | 29 | int lttng_kernel_find_context(struct lttng_kernel_ctx *ctx, const char *name) |
44252f0f MD |
30 | { |
31 | unsigned int i; | |
437d5aa5 | 32 | const char *subname; |
44252f0f | 33 | |
c02eb859 MD |
34 | if (!ctx) |
35 | return 0; | |
437d5aa5 MD |
36 | if (strncmp(name, "$ctx.", strlen("$ctx.")) == 0) { |
37 | subname = name + strlen("$ctx."); | |
38 | } else { | |
39 | subname = name; | |
40 | } | |
44252f0f | 41 | for (i = 0; i < ctx->nr_fields; i++) { |
4b58a8e4 | 42 | /* Skip allocated (but non-initialized) contexts */ |
437d5aa5 | 43 | if (!ctx->fields[i].event_field->name) |
4b58a8e4 | 44 | continue; |
437d5aa5 | 45 | if (!strcmp(ctx->fields[i].event_field->name, subname)) |
44252f0f MD |
46 | return 1; |
47 | } | |
48 | return 0; | |
49 | } | |
437d5aa5 | 50 | EXPORT_SYMBOL_GPL(lttng_kernel_find_context); |
44252f0f | 51 | |
437d5aa5 | 52 | int lttng_kernel_get_context_index(struct lttng_kernel_ctx *ctx, const char *name) |
07dfc1d0 MD |
53 | { |
54 | unsigned int i; | |
0451bcec | 55 | const char *subname; |
07dfc1d0 MD |
56 | |
57 | if (!ctx) | |
58 | return -1; | |
0451bcec MD |
59 | if (strncmp(name, "$ctx.", strlen("$ctx.")) == 0) { |
60 | subname = name + strlen("$ctx."); | |
61 | } else { | |
62 | subname = name; | |
63 | } | |
07dfc1d0 MD |
64 | for (i = 0; i < ctx->nr_fields; i++) { |
65 | /* Skip allocated (but non-initialized) contexts */ | |
437d5aa5 | 66 | if (!ctx->fields[i].event_field->name) |
07dfc1d0 | 67 | continue; |
437d5aa5 | 68 | if (!strcmp(ctx->fields[i].event_field->name, subname)) |
07dfc1d0 MD |
69 | return i; |
70 | } | |
71 | return -1; | |
72 | } | |
437d5aa5 | 73 | EXPORT_SYMBOL_GPL(lttng_kernel_get_context_index); |
07dfc1d0 | 74 | |
437d5aa5 | 75 | struct lttng_kernel_ctx_field *lttng_kernel_get_context_field_from_index(struct lttng_kernel_ctx *ctx, |
c02eb859 MD |
76 | size_t index) |
77 | { | |
78 | if (index >= ctx->nr_fields) | |
79 | return NULL; | |
80 | return &ctx->fields[index]; | |
81 | } | |
437d5aa5 | 82 | EXPORT_SYMBOL_GPL(lttng_kernel_get_context_field_from_index); |
c02eb859 | 83 | |
2001023e MD |
84 | /* |
85 | * Note: as we append context information, the pointer location may change. | |
437d5aa5 | 86 | * lttng_kernel_context_add_field leaves the new last context initialized to NULL. |
2001023e | 87 | */ |
437d5aa5 MD |
88 | static |
89 | int lttng_kernel_context_add_field(struct lttng_kernel_ctx **ctx_p) | |
2dccf128 | 90 | { |
437d5aa5 | 91 | struct lttng_kernel_ctx *ctx; |
2dccf128 MD |
92 | |
93 | if (!*ctx_p) { | |
437d5aa5 | 94 | *ctx_p = kzalloc(sizeof(struct lttng_kernel_ctx), GFP_KERNEL); |
2dccf128 | 95 | if (!*ctx_p) |
437d5aa5 | 96 | return -ENOMEM; |
a9dd15da | 97 | (*ctx_p)->largest_align = 1; |
2dccf128 MD |
98 | } |
99 | ctx = *ctx_p; | |
100 | if (ctx->nr_fields + 1 > ctx->allocated_fields) { | |
437d5aa5 | 101 | struct lttng_kernel_ctx_field *new_fields; |
2dccf128 | 102 | |
0f034e0f | 103 | ctx->allocated_fields = max_t(size_t, 1, 2 * ctx->allocated_fields); |
437d5aa5 | 104 | new_fields = lttng_kvzalloc(ctx->allocated_fields * sizeof(*new_fields), GFP_KERNEL); |
2dccf128 | 105 | if (!new_fields) |
437d5aa5 | 106 | return -ENOMEM; |
2dccf128 | 107 | if (ctx->fields) |
77aefe99 | 108 | memcpy(new_fields, ctx->fields, sizeof(*ctx->fields) * ctx->nr_fields); |
48f5e0b5 | 109 | lttng_kvfree(ctx->fields); |
2dccf128 MD |
110 | ctx->fields = new_fields; |
111 | } | |
437d5aa5 MD |
112 | ctx->nr_fields++; |
113 | return 0; | |
c02eb859 | 114 | } |
c02eb859 | 115 | |
437d5aa5 | 116 | static size_t get_type_max_align(const struct lttng_kernel_type_common *type) |
c02eb859 | 117 | { |
437d5aa5 MD |
118 | switch (type->type) { |
119 | case lttng_kernel_type_integer: | |
120 | return lttng_kernel_get_type_integer(type)->alignment; | |
121 | case lttng_kernel_type_string: | |
122 | return CHAR_BIT; | |
123 | case lttng_kernel_type_enum: | |
124 | return get_type_max_align(lttng_kernel_get_type_enum(type)->container_type); | |
125 | case lttng_kernel_type_array: | |
126 | return max_t(size_t, get_type_max_align(lttng_kernel_get_type_array(type)->elem_type), | |
127 | lttng_kernel_get_type_array(type)->alignment); | |
128 | case lttng_kernel_type_sequence: | |
129 | return max_t(size_t, get_type_max_align(lttng_kernel_get_type_sequence(type)->elem_type), | |
130 | lttng_kernel_get_type_sequence(type)->alignment); | |
131 | case lttng_kernel_type_struct: | |
132 | { | |
133 | unsigned int i; | |
134 | size_t field_align = 0; | |
135 | const struct lttng_kernel_type_struct *struct_type = lttng_kernel_get_type_struct(type); | |
136 | ||
137 | for (i = 0; i < struct_type->nr_fields; i++) { | |
138 | field_align = max_t(size_t, | |
139 | get_type_max_align(struct_type->fields[i]->type), | |
140 | field_align); | |
141 | } | |
142 | return field_align; | |
143 | } | |
144 | case lttng_kernel_type_variant: | |
145 | /* Variants are not accounted in the overall alignment of the type they are embedded in. */ | |
146 | return 0; | |
147 | default: | |
148 | WARN_ON_ONCE(1); | |
149 | return 0; | |
150 | } | |
2dccf128 | 151 | } |
2dccf128 | 152 | |
a9dd15da MD |
153 | /* |
154 | * lttng_context_update() should be called at least once between context | |
155 | * modification and trace start. | |
156 | */ | |
437d5aa5 MD |
157 | static |
158 | void lttng_context_update(struct lttng_kernel_ctx *ctx) | |
a9dd15da MD |
159 | { |
160 | int i; | |
161 | size_t largest_align = 8; /* in bits */ | |
162 | ||
163 | for (i = 0; i < ctx->nr_fields; i++) { | |
a9dd15da MD |
164 | size_t field_align = 8; |
165 | ||
437d5aa5 | 166 | field_align = get_type_max_align(ctx->fields[i].event_field->type); |
a9dd15da MD |
167 | largest_align = max_t(size_t, largest_align, field_align); |
168 | } | |
169 | ctx->largest_align = largest_align >> 3; /* bits to bytes */ | |
170 | } | |
171 | ||
437d5aa5 MD |
172 | int lttng_kernel_context_append(struct lttng_kernel_ctx **ctx_p, |
173 | const struct lttng_kernel_ctx_field *f) | |
c02eb859 | 174 | { |
437d5aa5 | 175 | int ret; |
c02eb859 | 176 | |
437d5aa5 MD |
177 | ret = lttng_kernel_context_add_field(ctx_p); |
178 | if (ret) | |
179 | return ret; | |
180 | (*ctx_p)->fields[(*ctx_p)->nr_fields - 1] = *f; | |
181 | lttng_context_update(*ctx_p); | |
182 | return 0; | |
c02eb859 | 183 | } |
c02eb859 | 184 | |
437d5aa5 | 185 | void lttng_kernel_context_remove_last(struct lttng_kernel_ctx **ctx_p) |
8289661d | 186 | { |
437d5aa5 | 187 | struct lttng_kernel_ctx *ctx = *ctx_p; |
8289661d | 188 | |
437d5aa5 MD |
189 | if (!ctx->nr_fields) |
190 | return; | |
191 | memset(&ctx->fields[ctx->nr_fields - 1], 0, sizeof(struct lttng_kernel_ctx_field)); | |
8289661d | 192 | ctx->nr_fields--; |
437d5aa5 | 193 | lttng_context_update(ctx); |
8289661d | 194 | } |
8289661d | 195 | |
437d5aa5 | 196 | void lttng_kernel_destroy_context(struct lttng_kernel_ctx *ctx) |
2dccf128 MD |
197 | { |
198 | int i; | |
199 | ||
8070f5c0 MD |
200 | if (!ctx) |
201 | return; | |
9e7e4892 MD |
202 | for (i = 0; i < ctx->nr_fields; i++) { |
203 | if (ctx->fields[i].destroy) | |
2dc781e0 | 204 | ctx->fields[i].destroy(ctx->fields[i].priv); |
9e7e4892 | 205 | } |
48f5e0b5 | 206 | lttng_kvfree(ctx->fields); |
2dccf128 MD |
207 | kfree(ctx); |
208 | } | |
07dfc1d0 MD |
209 | |
210 | int lttng_context_init(void) | |
211 | { | |
212 | int ret; | |
213 | ||
f127e61e MD |
214 | ret = lttng_add_hostname_to_ctx(<tng_static_ctx); |
215 | if (ret) { | |
5a15f70c | 216 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_hostname_to_ctx"); |
f127e61e MD |
217 | } |
218 | ret = lttng_add_nice_to_ctx(<tng_static_ctx); | |
07dfc1d0 | 219 | if (ret) { |
5a15f70c | 220 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_nice_to_ctx"); |
07dfc1d0 | 221 | } |
07dfc1d0 MD |
222 | ret = lttng_add_pid_to_ctx(<tng_static_ctx); |
223 | if (ret) { | |
5a15f70c | 224 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_pid_to_ctx"); |
07dfc1d0 | 225 | } |
f127e61e | 226 | ret = lttng_add_ppid_to_ctx(<tng_static_ctx); |
07dfc1d0 | 227 | if (ret) { |
5a15f70c | 228 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_ppid_to_ctx"); |
07dfc1d0 MD |
229 | } |
230 | ret = lttng_add_prio_to_ctx(<tng_static_ctx); | |
231 | if (ret) { | |
5a15f70c | 232 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_prio_to_ctx"); |
07dfc1d0 | 233 | } |
f127e61e | 234 | ret = lttng_add_procname_to_ctx(<tng_static_ctx); |
07dfc1d0 | 235 | if (ret) { |
5a15f70c | 236 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_procname_to_ctx"); |
07dfc1d0 MD |
237 | } |
238 | ret = lttng_add_tid_to_ctx(<tng_static_ctx); | |
239 | if (ret) { | |
5a15f70c | 240 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_tid_to_ctx"); |
07dfc1d0 | 241 | } |
f127e61e | 242 | ret = lttng_add_vppid_to_ctx(<tng_static_ctx); |
07dfc1d0 | 243 | if (ret) { |
5a15f70c | 244 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_vppid_to_ctx"); |
07dfc1d0 | 245 | } |
f127e61e | 246 | ret = lttng_add_vtid_to_ctx(<tng_static_ctx); |
07dfc1d0 | 247 | if (ret) { |
5a15f70c | 248 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_vtid_to_ctx"); |
07dfc1d0 | 249 | } |
f127e61e | 250 | ret = lttng_add_vpid_to_ctx(<tng_static_ctx); |
07dfc1d0 | 251 | if (ret) { |
5a15f70c | 252 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_vpid_to_ctx"); |
07dfc1d0 | 253 | } |
b3699d90 MD |
254 | ret = lttng_add_cpu_id_to_ctx(<tng_static_ctx); |
255 | if (ret) { | |
5a15f70c | 256 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_cpu_id_to_ctx"); |
b3699d90 | 257 | } |
79150a49 JD |
258 | ret = lttng_add_interruptible_to_ctx(<tng_static_ctx); |
259 | if (ret) { | |
5a15f70c | 260 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_interruptible_to_ctx"); |
79150a49 JD |
261 | } |
262 | ret = lttng_add_need_reschedule_to_ctx(<tng_static_ctx); | |
263 | if (ret) { | |
5a15f70c | 264 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_need_reschedule_to_ctx"); |
79150a49 | 265 | } |
79150a49 | 266 | ret = lttng_add_preemptible_to_ctx(<tng_static_ctx); |
d0e59d6f | 267 | if (ret && ret != -ENOSYS) { |
5a15f70c | 268 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_preemptible_to_ctx"); |
79150a49 | 269 | } |
79150a49 | 270 | ret = lttng_add_migratable_to_ctx(<tng_static_ctx); |
d0e59d6f | 271 | if (ret && ret != -ENOSYS) { |
5a15f70c | 272 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_migratable_to_ctx"); |
79150a49 | 273 | } |
a6cf40a4 MJ |
274 | ret = lttng_add_cgroup_ns_to_ctx(<tng_static_ctx); |
275 | if (ret && ret != -ENOSYS) { | |
5a15f70c | 276 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_cgroup_ns_to_ctx"); |
a6cf40a4 MJ |
277 | } |
278 | ret = lttng_add_ipc_ns_to_ctx(<tng_static_ctx); | |
279 | if (ret && ret != -ENOSYS) { | |
5a15f70c | 280 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_ipc_ns_to_ctx"); |
a6cf40a4 MJ |
281 | } |
282 | ret = lttng_add_mnt_ns_to_ctx(<tng_static_ctx); | |
283 | if (ret && ret != -ENOSYS) { | |
5a15f70c | 284 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_mnt_ns_to_ctx"); |
a6cf40a4 MJ |
285 | } |
286 | ret = lttng_add_net_ns_to_ctx(<tng_static_ctx); | |
287 | if (ret && ret != -ENOSYS) { | |
5a15f70c | 288 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_net_ns_to_ctx"); |
a6cf40a4 MJ |
289 | } |
290 | ret = lttng_add_pid_ns_to_ctx(<tng_static_ctx); | |
291 | if (ret && ret != -ENOSYS) { | |
5a15f70c | 292 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_pid_ns_to_ctx"); |
a6cf40a4 MJ |
293 | } |
294 | ret = lttng_add_user_ns_to_ctx(<tng_static_ctx); | |
295 | if (ret && ret != -ENOSYS) { | |
5a15f70c | 296 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_user_ns_to_ctx"); |
a6cf40a4 MJ |
297 | } |
298 | ret = lttng_add_uts_ns_to_ctx(<tng_static_ctx); | |
299 | if (ret && ret != -ENOSYS) { | |
5a15f70c | 300 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_uts_ns_to_ctx"); |
a6cf40a4 | 301 | } |
876e2e92 MJ |
302 | ret = lttng_add_time_ns_to_ctx(<tng_static_ctx); |
303 | if (ret && ret != -ENOSYS) { | |
5a15f70c | 304 | printk(KERN_WARNING "LTTng: Cannot add context lttng_add_time_ns_to_ctx"); |
876e2e92 | 305 | } |
f127e61e | 306 | /* TODO: perf counters for filtering */ |
07dfc1d0 MD |
307 | return 0; |
308 | } | |
309 | ||
310 | void lttng_context_exit(void) | |
311 | { | |
437d5aa5 | 312 | lttng_kernel_destroy_context(lttng_static_ctx); |
07dfc1d0 MD |
313 | lttng_static_ctx = NULL; |
314 | } |