Fix: don't dereference NULL pointers
[lttng-ust.git] / liblttng-ust / lttng-ring-buffer-metadata-client.h
CommitLineData
3d1fc7fd 1/*
7dd08bec 2 * lttng-ring-buffer-client.h
3d1fc7fd 3 *
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4 * LTTng lib ring buffer client template.
5 *
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6 * Copyright (C) 2010-2012 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
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21 */
22
9f3fdbc6 23#include <stdint.h>
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24#include <lttng/ust-events.h>
25#include "lttng/bitfield.h"
7dd08bec 26#include "lttng-tracer.h"
9f3fdbc6 27#include "../libringbuffer/frontend_types.h"
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28
29struct metadata_packet_header {
30 uint32_t magic; /* 0x75D11D57 */
19d8b1b3 31 uint8_t uuid[LTTNG_UST_UUID_LEN]; /* Unique Universal Identifier */
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32 uint32_t checksum; /* 0 if unused */
33 uint32_t content_size; /* in bits */
34 uint32_t packet_size; /* in bits */
35 uint8_t compression_scheme; /* 0 if unused */
36 uint8_t encryption_scheme; /* 0 if unused */
37 uint8_t checksum_scheme; /* 0 if unused */
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38 uint8_t major; /* CTF spec major version number */
39 uint8_t minor; /* CTF spec minor version number */
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40 uint8_t header_end[0];
41};
42
43struct metadata_record_header {
44 uint8_t header_end[0]; /* End of header */
45};
46
4cfec15c 47static const struct lttng_ust_lib_ring_buffer_config client_config;
3d1fc7fd 48
23c8854a 49static inline uint64_t lib_ring_buffer_clock_read(struct channel *chan)
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50{
51 return 0;
52}
53
54static inline
4cfec15c 55unsigned char record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
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56 struct channel *chan, size_t offset,
57 size_t *pre_header_padding,
4cfec15c 58 struct lttng_ust_lib_ring_buffer_ctx *ctx)
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59{
60 return 0;
61}
62
9f3fdbc6 63#include "../libringbuffer/api.h"
82b9bde8 64#include "lttng-rb-clients.h"
3d1fc7fd 65
23c8854a 66static uint64_t client_ring_buffer_clock_read(struct channel *chan)
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67{
68 return 0;
69}
70
71static
4cfec15c 72size_t client_record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
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73 struct channel *chan, size_t offset,
74 size_t *pre_header_padding,
4cfec15c 75 struct lttng_ust_lib_ring_buffer_ctx *ctx)
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76{
77 return 0;
78}
79
80/**
81 * client_packet_header_size - called on buffer-switch to a new sub-buffer
82 *
83 * Return header size without padding after the structure. Don't use packed
84 * structure because gcc generates inefficient code on some architectures
85 * (powerpc, mips..)
86 */
87static size_t client_packet_header_size(void)
88{
89 return offsetof(struct metadata_packet_header, header_end);
90}
91
23c8854a 92static void client_buffer_begin(struct lttng_ust_lib_ring_buffer *buf, uint64_t tsc,
1d498196 93 unsigned int subbuf_idx,
38fae1d3 94 struct lttng_ust_shm_handle *handle)
3d1fc7fd 95{
1d498196 96 struct channel *chan = shmp(handle, buf->backend.chan);
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97 struct metadata_packet_header *header =
98 (struct metadata_packet_header *)
99 lib_ring_buffer_offset_address(&buf->backend,
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100 subbuf_idx * chan->backend.subbuf_size,
101 handle);
7dd08bec 102 struct lttng_channel *lttng_chan = channel_get_private(chan);
3d1fc7fd 103
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104 assert(header);
105 if (!header)
106 return;
3d1fc7fd 107 header->magic = TSDL_MAGIC_NUMBER;
7dd08bec 108 memcpy(header->uuid, lttng_chan->uuid, sizeof(lttng_chan->uuid));
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109 header->checksum = 0; /* 0 if unused */
110 header->content_size = 0xFFFFFFFF; /* in bits, for debugging */
111 header->packet_size = 0xFFFFFFFF; /* in bits, for debugging */
112 header->compression_scheme = 0; /* 0 if unused */
113 header->encryption_scheme = 0; /* 0 if unused */
114 header->checksum_scheme = 0; /* 0 if unused */
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115 header->major = CTF_SPEC_MAJOR;
116 header->minor = CTF_SPEC_MINOR;
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117}
118
119/*
120 * offset is assumed to never be 0 here : never deliver a completely empty
121 * subbuffer. data_size is between 1 and subbuf_size.
122 */
23c8854a 123static void client_buffer_end(struct lttng_ust_lib_ring_buffer *buf, uint64_t tsc,
1d498196 124 unsigned int subbuf_idx, unsigned long data_size,
38fae1d3 125 struct lttng_ust_shm_handle *handle)
3d1fc7fd 126{
1d498196 127 struct channel *chan = shmp(handle, buf->backend.chan);
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128 struct metadata_packet_header *header =
129 (struct metadata_packet_header *)
130 lib_ring_buffer_offset_address(&buf->backend,
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131 subbuf_idx * chan->backend.subbuf_size,
132 handle);
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133 unsigned long records_lost = 0;
134
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135 assert(header);
136 if (!header)
137 return;
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138 header->content_size = data_size * CHAR_BIT; /* in bits */
139 header->packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
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140 /*
141 * We do not care about the records lost count, because the metadata
142 * channel waits and retry.
143 */
144 (void) lib_ring_buffer_get_records_lost_full(&client_config, buf);
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145 records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
146 records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
147 WARN_ON_ONCE(records_lost != 0);
148}
149
4cfec15c 150static int client_buffer_create(struct lttng_ust_lib_ring_buffer *buf, void *priv,
1d498196 151 int cpu, const char *name,
38fae1d3 152 struct lttng_ust_shm_handle *handle)
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153{
154 return 0;
155}
156
4cfec15c 157static void client_buffer_finalize(struct lttng_ust_lib_ring_buffer *buf,
1d498196 158 void *priv, int cpu,
38fae1d3 159 struct lttng_ust_shm_handle *handle)
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160{
161}
162
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163static const
164struct lttng_ust_client_lib_ring_buffer_client_cb client_cb = {
165 .parent = {
166 .ring_buffer_clock_read = client_ring_buffer_clock_read,
167 .record_header_size = client_record_header_size,
168 .subbuffer_header_size = client_packet_header_size,
169 .buffer_begin = client_buffer_begin,
170 .buffer_end = client_buffer_end,
171 .buffer_create = client_buffer_create,
172 .buffer_finalize = client_buffer_finalize,
173 },
174};
175
4cfec15c 176static const struct lttng_ust_lib_ring_buffer_config client_config = {
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177 .cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
178 .cb.record_header_size = client_record_header_size,
179 .cb.subbuffer_header_size = client_packet_header_size,
180 .cb.buffer_begin = client_buffer_begin,
181 .cb.buffer_end = client_buffer_end,
182 .cb.buffer_create = client_buffer_create,
183 .cb.buffer_finalize = client_buffer_finalize,
184
185 .tsc_bits = 0,
186 .alloc = RING_BUFFER_ALLOC_GLOBAL,
187 .sync = RING_BUFFER_SYNC_GLOBAL,
188 .mode = RING_BUFFER_MODE_TEMPLATE,
189 .backend = RING_BUFFER_PAGE,
5d61a504 190 .output = RING_BUFFER_MMAP,
3d1fc7fd 191 .oops = RING_BUFFER_OOPS_CONSISTENCY,
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192 .ipi = RING_BUFFER_NO_IPI_BARRIER,
193 .wakeup = RING_BUFFER_WAKEUP_BY_WRITER,
c1fca457 194 .client_type = LTTNG_CLIENT_TYPE,
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195
196 .cb_ptr = &client_cb.parent,
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197};
198
82b9bde8 199const struct lttng_ust_client_lib_ring_buffer_client_cb *LTTNG_CLIENT_CALLBACKS = &client_cb;
c1fca457 200
3d1fc7fd 201static
7dd08bec 202struct lttng_channel *_channel_create(const char *name,
a3f61e7f 203 void *buf_addr,
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204 size_t subbuf_size, size_t num_subbuf,
205 unsigned int switch_timer_interval,
193183fb 206 unsigned int read_timer_interval,
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207 unsigned char *uuid,
208 uint32_t chan_id)
3d1fc7fd 209{
74d81a6c 210 struct lttng_channel chan_priv_init;
a3f61e7f 211 struct lttng_ust_shm_handle *handle;
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212 struct lttng_channel *lttng_chan;
213 void *priv;
a3f61e7f 214
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215 memset(&chan_priv_init, 0, sizeof(chan_priv_init));
216 memcpy(chan_priv_init.uuid, uuid, LTTNG_UST_UUID_LEN);
6ca18e66 217 chan_priv_init.id = chan_id;
a3f61e7f 218 handle = channel_create(&client_config, name,
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219 &priv, __alignof__(struct lttng_channel),
220 sizeof(struct lttng_channel),
74d81a6c 221 &chan_priv_init,
a3f61e7f 222 buf_addr, subbuf_size, num_subbuf,
74d81a6c 223 switch_timer_interval, read_timer_interval);
a3f61e7f 224 if (!handle)
1b2c2540 225 return NULL;
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226 lttng_chan = priv;
227 lttng_chan->handle = handle;
74d81a6c 228 lttng_chan->chan = shmp(handle, handle->chan);
7dd08bec 229 return lttng_chan;
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230}
231
232static
74d81a6c 233void lttng_channel_destroy(struct lttng_channel *chan)
3d1fc7fd 234{
74d81a6c 235 channel_destroy(chan->chan, chan->handle, 1);
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236}
237
238static
7dd08bec 239int lttng_event_reserve(struct lttng_ust_lib_ring_buffer_ctx *ctx, uint32_t event_id)
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240{
241 return lib_ring_buffer_reserve(&client_config, ctx);
242}
243
244static
7dd08bec 245void lttng_event_commit(struct lttng_ust_lib_ring_buffer_ctx *ctx)
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246{
247 lib_ring_buffer_commit(&client_config, ctx);
248}
249
250static
7dd08bec 251void lttng_event_write(struct lttng_ust_lib_ring_buffer_ctx *ctx, const void *src,
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252 size_t len)
253{
254 lib_ring_buffer_write(&client_config, ctx, src, len);
255}
256
257static
7dd08bec 258size_t lttng_packet_avail_size(struct channel *chan, struct lttng_ust_shm_handle *handle)
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259
260{
261 unsigned long o_begin;
4cfec15c 262 struct lttng_ust_lib_ring_buffer *buf;
3d1fc7fd 263
1d498196 264 buf = shmp(handle, chan->backend.buf[0].shmp); /* Only for global buffer ! */
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265 o_begin = v_read(&client_config, &buf->offset);
266 if (subbuf_offset(o_begin, chan) != 0) {
267 return chan->backend.subbuf_size - subbuf_offset(o_begin, chan);
268 } else {
269 return chan->backend.subbuf_size - subbuf_offset(o_begin, chan)
270 - sizeof(struct metadata_packet_header);
271 }
272}
273
9f3fdbc6 274#if 0
3d1fc7fd 275static
7dd08bec 276wait_queue_head_t *lttng_get_reader_wait_queue(struct channel *chan)
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277{
278 return &chan->read_wait;
279}
280
281static
7dd08bec 282wait_queue_head_t *lttng_get_hp_wait_queue(struct channel *chan)
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283{
284 return &chan->hp_wait;
285}
9f3fdbc6 286#endif //0
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287
288static
7dd08bec 289int lttng_is_finalized(struct channel *chan)
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290{
291 return lib_ring_buffer_channel_is_finalized(chan);
292}
293
294static
7dd08bec 295int lttng_is_disabled(struct channel *chan)
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296{
297 return lib_ring_buffer_channel_is_disabled(chan);
298}
299
43861eab 300static
7dd08bec 301int lttng_flush_buffer(struct channel *chan, struct lttng_ust_shm_handle *handle)
43861eab 302{
4cfec15c 303 struct lttng_ust_lib_ring_buffer *buf;
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304 int shm_fd, wait_fd, wakeup_fd;
305 uint64_t memory_map_size;
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306
307 buf = channel_get_ring_buffer(&client_config, chan,
74d81a6c 308 0, handle, &shm_fd, &wait_fd, &wakeup_fd,
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309 &memory_map_size);
310 lib_ring_buffer_switch(&client_config, buf,
311 SWITCH_ACTIVE, handle);
312 return 0;
313}
314
7dd08bec 315static struct lttng_transport lttng_relay_transport = {
818173b9 316 .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap",
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317 .ops = {
318 .channel_create = _channel_create,
7dd08bec 319 .channel_destroy = lttng_channel_destroy,
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320 .event_reserve = lttng_event_reserve,
321 .event_commit = lttng_event_commit,
322 .event_write = lttng_event_write,
323 .packet_avail_size = lttng_packet_avail_size,
324 //.get_reader_wait_queue = lttng_get_reader_wait_queue,
325 //.get_hp_wait_queue = lttng_get_hp_wait_queue,
326 .is_finalized = lttng_is_finalized,
327 .is_disabled = lttng_is_disabled,
328 .flush_buffer = lttng_flush_buffer,
3d1fc7fd 329 },
74d81a6c 330 .client_config = &client_config,
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331};
332
edaa1431 333void RING_BUFFER_MODE_TEMPLATE_INIT(void)
3d1fc7fd 334{
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335 DBG("LTT : ltt ring buffer client \"%s\" init\n",
336 "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap");
7dd08bec 337 lttng_transport_register(&lttng_relay_transport);
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338}
339
edaa1431 340void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
3d1fc7fd 341{
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342 DBG("LTT : ltt ring buffer client \"%s\" exit\n",
343 "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap");
7dd08bec 344 lttng_transport_unregister(&lttng_relay_transport);
3d1fc7fd 345}
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