+/*
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * LTTng lib ring buffer client template.
+ */
+
+#include <limits.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include <ust-events-internal.h>
+#include <lttng/urcu/pointer.h>
+#include "ust-bitfield.h"
+#include "ust-compat.h"
+#include "clock.h"
+#include "context-internal.h"
+#include "lttng-tracer.h"
+#include "../libringbuffer/frontend_types.h"
+#include <urcu/tls-compat.h>
+
+#define LTTNG_COMPACT_EVENT_BITS 5
+#define LTTNG_COMPACT_TSC_BITS 27
+
+enum app_ctx_mode {
+ APP_CTX_DISABLED,
+ APP_CTX_ENABLED,
+};
+
+/*
+ * Keep the natural field alignment for _each field_ within this structure if
+ * you ever add/remove a field from this header. Packed attribute is not used
+ * because gcc generates poor code on at least powerpc and mips. Don't ever
+ * let gcc add padding between the structure elements.
+ */
+
+struct packet_header {
+ /* Trace packet header */
+ uint32_t magic; /*
+ * Trace magic number.
+ * contains endianness information.
+ */
+ uint8_t uuid[LTTNG_UST_UUID_LEN];
+ uint32_t stream_id;
+ uint64_t stream_instance_id;
+
+ struct {
+ /* Stream packet context */
+ uint64_t timestamp_begin; /* Cycle count at subbuffer start */
+ uint64_t timestamp_end; /* Cycle count at subbuffer end */
+ uint64_t content_size; /* Size of data in subbuffer */
+ uint64_t packet_size; /* Subbuffer size (include padding) */
+ uint64_t packet_seq_num; /* Packet sequence number */
+ unsigned long events_discarded; /*
+ * Events lost in this subbuffer since
+ * the beginning of the trace.
+ * (may overflow)
+ */
+ uint32_t cpu_id; /* CPU id associated with stream */
+ uint8_t header_end; /* End of header */
+ } ctx;
+};
+
+struct lttng_client_ctx {
+ size_t packet_context_len;
+ size_t event_context_len;
+ struct lttng_ust_ctx *chan_ctx;
+ struct lttng_ust_ctx *event_ctx;
+};
+
+/*
+ * Indexed by lib_ring_buffer_nesting_count().
+ */
+typedef struct lttng_ust_lib_ring_buffer_ctx_private private_ctx_stack_t[LIB_RING_BUFFER_MAX_NESTING];
+static DEFINE_URCU_TLS(private_ctx_stack_t, private_ctx_stack);
+
+/*
+ * Force a read (imply TLS fixup for dlopen) of TLS variables.
+ */
+void RING_BUFFER_MODE_TEMPLATE_TLS_FIXUP(void)
+{
+ asm volatile ("" : : "m" (URCU_TLS(private_ctx_stack)));
+}
+
+static inline uint64_t lib_ring_buffer_clock_read(struct lttng_ust_lib_ring_buffer_channel *chan)
+{
+ return trace_clock_read64();
+}
+
+static inline
+size_t ctx_get_aligned_size(size_t offset, struct lttng_ust_ctx *ctx,
+ size_t ctx_len)
+{
+ size_t orig_offset = offset;
+
+ if (caa_likely(!ctx))
+ return 0;
+ offset += lttng_ust_lib_ring_buffer_align(offset, ctx->largest_align);
+ offset += ctx_len;
+ return offset - orig_offset;
+}
+
+static inline
+void ctx_get_struct_size(struct lttng_ust_ctx *ctx, size_t *ctx_len,
+ enum app_ctx_mode mode)
+{
+ int i;
+ size_t offset = 0;
+
+ if (caa_likely(!ctx)) {
+ *ctx_len = 0;
+ return;
+ }
+ for (i = 0; i < ctx->nr_fields; i++) {
+ if (mode == APP_CTX_ENABLED) {
+ offset += ctx->fields[i]->get_size(ctx->fields[i], offset);
+ } else {
+ if (lttng_context_is_app(ctx->fields[i]->event_field->name)) {
+ /*
+ * Before UST 2.8, we cannot use the
+ * application context, because we
+ * cannot trust that the handler used
+ * for get_size is the same used for
+ * ctx_record, which would result in
+ * corrupted traces when tracing
+ * concurrently with application context
+ * register/unregister.
+ */
+ offset += lttng_ust_dummy_get_size(ctx->fields[i], offset);
+ } else {
+ offset += ctx->fields[i]->get_size(ctx->fields[i], offset);
+ }
+ }
+ }
+ *ctx_len = offset;
+}
+
+static inline
+void ctx_record(struct lttng_ust_lib_ring_buffer_ctx *bufctx,
+ struct lttng_ust_channel_buffer *chan,
+ struct lttng_ust_ctx *ctx,
+ enum app_ctx_mode mode)
+{
+ int i;
+
+ if (caa_likely(!ctx))
+ return;
+ lttng_ust_lib_ring_buffer_align_ctx(bufctx, ctx->largest_align);
+ for (i = 0; i < ctx->nr_fields; i++) {
+ if (mode == APP_CTX_ENABLED) {
+ ctx->fields[i]->record(ctx->fields[i], bufctx, chan);
+ } else {
+ if (lttng_context_is_app(ctx->fields[i]->event_field->name)) {
+ /*
+ * Before UST 2.8, we cannot use the
+ * application context, because we
+ * cannot trust that the handler used
+ * for get_size is the same used for
+ * ctx_record, which would result in
+ * corrupted traces when tracing
+ * concurrently with application context
+ * register/unregister.
+ */
+ lttng_ust_dummy_record(ctx->fields[i], bufctx, chan);
+ } else {
+ ctx->fields[i]->record(ctx->fields[i], bufctx, chan);
+ }
+ }
+ }
+}
+
+/*
+ * record_header_size - Calculate the header size and padding necessary.
+ * @config: ring buffer instance configuration
+ * @chan: channel
+ * @offset: offset in the write buffer
+ * @pre_header_padding: padding to add before the header (output)
+ * @ctx: reservation context
+ *
+ * Returns the event header size (including padding).
+ *
+ * The payload must itself determine its own alignment from the biggest type it
+ * contains.
+ */
+static __inline__
+size_t record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
+ struct lttng_ust_lib_ring_buffer_channel *chan,
+ size_t offset,
+ size_t *pre_header_padding,
+ struct lttng_ust_lib_ring_buffer_ctx *ctx,
+ struct lttng_client_ctx *client_ctx)
+{
+ struct lttng_ust_channel_buffer *lttng_chan = channel_get_private(chan);
+ size_t orig_offset = offset;
+ size_t padding;
+
+ switch (lttng_chan->priv->header_type) {
+ case 1: /* compact */
+ padding = lttng_ust_lib_ring_buffer_align(offset, lttng_ust_rb_alignof(uint32_t));
+ offset += padding;
+ if (!(ctx->priv->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTTNG_RFLAG_EXTENDED))) {
+ offset += sizeof(uint32_t); /* id and timestamp */
+ } else {
+ /* Minimum space taken by LTTNG_COMPACT_EVENT_BITS id */
+ offset += (LTTNG_COMPACT_EVENT_BITS + CHAR_BIT - 1) / CHAR_BIT;
+ /* Align extended struct on largest member */
+ offset += lttng_ust_lib_ring_buffer_align(offset, lttng_ust_rb_alignof(uint64_t));
+ offset += sizeof(uint32_t); /* id */
+ offset += lttng_ust_lib_ring_buffer_align(offset, lttng_ust_rb_alignof(uint64_t));
+ offset += sizeof(uint64_t); /* timestamp */
+ }
+ break;
+ case 2: /* large */
+ padding = lttng_ust_lib_ring_buffer_align(offset, lttng_ust_rb_alignof(uint16_t));
+ offset += padding;
+ offset += sizeof(uint16_t);
+ if (!(ctx->priv->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTTNG_RFLAG_EXTENDED))) {
+ offset += lttng_ust_lib_ring_buffer_align(offset, lttng_ust_rb_alignof(uint32_t));
+ offset += sizeof(uint32_t); /* timestamp */
+ } else {
+ /* Align extended struct on largest member */
+ offset += lttng_ust_lib_ring_buffer_align(offset, lttng_ust_rb_alignof(uint64_t));
+ offset += sizeof(uint32_t); /* id */
+ offset += lttng_ust_lib_ring_buffer_align(offset, lttng_ust_rb_alignof(uint64_t));
+ offset += sizeof(uint64_t); /* timestamp */
+ }
+ break;
+ default:
+ padding = 0;
+ WARN_ON_ONCE(1);
+ }
+ offset += ctx_get_aligned_size(offset, client_ctx->chan_ctx,
+ client_ctx->packet_context_len);
+ offset += ctx_get_aligned_size(offset, client_ctx->event_ctx,
+ client_ctx->event_context_len);
+ *pre_header_padding = padding;
+ return offset - orig_offset;
+}
+
+#include "../libringbuffer/api.h"
+#include "lttng-rb-clients.h"
+
+static
+void lttng_write_event_header_slow(const struct lttng_ust_lib_ring_buffer_config *config,
+ struct lttng_ust_lib_ring_buffer_ctx *ctx,
+ struct lttng_client_ctx *client_ctx,
+ uint32_t event_id);
+
+/*
+ * lttng_write_event_header
+ *
+ * Writes the event header to the offset (already aligned on 32-bits).
+ *
+ * @config: ring buffer instance configuration
+ * @ctx: reservation context
+ * @event_id: event ID
+ */
+static __inline__
+void lttng_write_event_header(const struct lttng_ust_lib_ring_buffer_config *config,
+ struct lttng_ust_lib_ring_buffer_ctx *ctx,
+ struct lttng_client_ctx *client_ctx,
+ uint32_t event_id)
+{
+ struct lttng_ust_channel_buffer *lttng_chan = channel_get_private(ctx->priv->chan);
+
+ if (caa_unlikely(ctx->priv->rflags))
+ goto slow_path;
+
+ switch (lttng_chan->priv->header_type) {
+ case 1: /* compact */
+ {
+ uint32_t id_time = 0;
+
+ bt_bitfield_write(&id_time, uint32_t,
+ 0,
+ LTTNG_COMPACT_EVENT_BITS,
+ event_id);
+ bt_bitfield_write(&id_time, uint32_t,
+ LTTNG_COMPACT_EVENT_BITS,
+ LTTNG_COMPACT_TSC_BITS,
+ ctx->priv->tsc);
+ lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
+ break;
+ }
+ case 2: /* large */
+ {
+ uint32_t timestamp = (uint32_t) ctx->priv->tsc;
+ uint16_t id = event_id;
+
+ lib_ring_buffer_write(config, ctx, &id, sizeof(id));
+ lttng_ust_lib_ring_buffer_align_ctx(ctx, lttng_ust_rb_alignof(uint32_t));
+ lib_ring_buffer_write(config, ctx, ×tamp, sizeof(timestamp));
+ break;
+ }
+ default:
+ WARN_ON_ONCE(1);
+ }
+
+ ctx_record(ctx, lttng_chan, client_ctx->chan_ctx, APP_CTX_ENABLED);
+ ctx_record(ctx, lttng_chan, client_ctx->event_ctx, APP_CTX_ENABLED);
+ lttng_ust_lib_ring_buffer_align_ctx(ctx, ctx->largest_align);
+
+ return;
+
+slow_path:
+ lttng_write_event_header_slow(config, ctx, client_ctx, event_id);
+}
+
+static
+void lttng_write_event_header_slow(const struct lttng_ust_lib_ring_buffer_config *config,
+ struct lttng_ust_lib_ring_buffer_ctx *ctx,
+ struct lttng_client_ctx *client_ctx,
+ uint32_t event_id)
+{
+ struct lttng_ust_lib_ring_buffer_ctx_private *ctx_private = ctx->priv;
+ struct lttng_ust_channel_buffer *lttng_chan = channel_get_private(ctx->priv->chan);
+
+ switch (lttng_chan->priv->header_type) {
+ case 1: /* compact */
+ if (!(ctx_private->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTTNG_RFLAG_EXTENDED))) {
+ uint32_t id_time = 0;
+
+ bt_bitfield_write(&id_time, uint32_t,
+ 0,
+ LTTNG_COMPACT_EVENT_BITS,
+ event_id);
+ bt_bitfield_write(&id_time, uint32_t,
+ LTTNG_COMPACT_EVENT_BITS,
+ LTTNG_COMPACT_TSC_BITS,
+ ctx_private->tsc);
+ lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
+ } else {
+ uint8_t id = 0;
+ uint64_t timestamp = ctx_private->tsc;
+
+ bt_bitfield_write(&id, uint8_t,
+ 0,
+ LTTNG_COMPACT_EVENT_BITS,
+ 31);
+ lib_ring_buffer_write(config, ctx, &id, sizeof(id));
+ /* Align extended struct on largest member */
+ lttng_ust_lib_ring_buffer_align_ctx(ctx, lttng_ust_rb_alignof(uint64_t));
+ lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
+ lttng_ust_lib_ring_buffer_align_ctx(ctx, lttng_ust_rb_alignof(uint64_t));
+ lib_ring_buffer_write(config, ctx, ×tamp, sizeof(timestamp));
+ }
+ break;
+ case 2: /* large */
+ {
+ if (!(ctx_private->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTTNG_RFLAG_EXTENDED))) {
+ uint32_t timestamp = (uint32_t) ctx_private->tsc;
+ uint16_t id = event_id;
+
+ lib_ring_buffer_write(config, ctx, &id, sizeof(id));
+ lttng_ust_lib_ring_buffer_align_ctx(ctx, lttng_ust_rb_alignof(uint32_t));
+ lib_ring_buffer_write(config, ctx, ×tamp, sizeof(timestamp));
+ } else {
+ uint16_t id = 65535;
+ uint64_t timestamp = ctx_private->tsc;
+
+ lib_ring_buffer_write(config, ctx, &id, sizeof(id));
+ /* Align extended struct on largest member */
+ lttng_ust_lib_ring_buffer_align_ctx(ctx, lttng_ust_rb_alignof(uint64_t));
+ lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
+ lttng_ust_lib_ring_buffer_align_ctx(ctx, lttng_ust_rb_alignof(uint64_t));
+ lib_ring_buffer_write(config, ctx, ×tamp, sizeof(timestamp));
+ }
+ break;
+ }
+ default:
+ WARN_ON_ONCE(1);
+ }
+ ctx_record(ctx, lttng_chan, client_ctx->chan_ctx, APP_CTX_ENABLED);
+ ctx_record(ctx, lttng_chan, client_ctx->event_ctx, APP_CTX_ENABLED);
+ lttng_ust_lib_ring_buffer_align_ctx(ctx, ctx->largest_align);
+}
+
+static const struct lttng_ust_lib_ring_buffer_config client_config;
+
+static uint64_t client_ring_buffer_clock_read(struct lttng_ust_lib_ring_buffer_channel *chan)
+{
+ return lib_ring_buffer_clock_read(chan);
+}
+
+static
+size_t client_record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
+ struct lttng_ust_lib_ring_buffer_channel *chan,
+ size_t offset,
+ size_t *pre_header_padding,
+ struct lttng_ust_lib_ring_buffer_ctx *ctx,
+ void *client_ctx)
+{
+ return record_header_size(config, chan, offset,
+ pre_header_padding, ctx, client_ctx);
+}
+
+/**
+ * client_packet_header_size - called on buffer-switch to a new sub-buffer
+ *
+ * Return header size without padding after the structure. Don't use packed
+ * structure because gcc generates inefficient code on some architectures
+ * (powerpc, mips..)
+ */
+static size_t client_packet_header_size(void)
+{
+ return offsetof(struct packet_header, ctx.header_end);
+}
+
+static void client_buffer_begin(struct lttng_ust_lib_ring_buffer *buf, uint64_t tsc,
+ unsigned int subbuf_idx,
+ struct lttng_ust_shm_handle *handle)
+{
+ struct lttng_ust_lib_ring_buffer_channel *chan = shmp(handle, buf->backend.chan);
+ struct packet_header *header =
+ (struct packet_header *)
+ lib_ring_buffer_offset_address(&buf->backend,
+ subbuf_idx * chan->backend.subbuf_size,
+ handle);
+ struct lttng_ust_channel_buffer *lttng_chan = channel_get_private(chan);
+ uint64_t cnt = shmp_index(handle, buf->backend.buf_cnt, subbuf_idx)->seq_cnt;
+
+ assert(header);
+ if (!header)
+ return;
+ header->magic = CTF_MAGIC_NUMBER;
+ memcpy(header->uuid, lttng_chan->priv->uuid, sizeof(lttng_chan->priv->uuid));
+ header->stream_id = lttng_chan->priv->id;
+ header->stream_instance_id = buf->backend.cpu;
+ header->ctx.timestamp_begin = tsc;
+ header->ctx.timestamp_end = 0;
+ header->ctx.content_size = ~0ULL; /* for debugging */
+ header->ctx.packet_size = ~0ULL;
+ header->ctx.packet_seq_num = chan->backend.num_subbuf * cnt + subbuf_idx;
+ header->ctx.events_discarded = 0;
+ header->ctx.cpu_id = buf->backend.cpu;
+}
+
+/*
+ * offset is assumed to never be 0 here : never deliver a completely empty
+ * subbuffer. data_size is between 1 and subbuf_size.
+ */
+static void client_buffer_end(struct lttng_ust_lib_ring_buffer *buf, uint64_t tsc,
+ unsigned int subbuf_idx, unsigned long data_size,
+ struct lttng_ust_shm_handle *handle)
+{
+ struct lttng_ust_lib_ring_buffer_channel *chan = shmp(handle, buf->backend.chan);
+ struct packet_header *header =
+ (struct packet_header *)
+ lib_ring_buffer_offset_address(&buf->backend,
+ subbuf_idx * chan->backend.subbuf_size,
+ handle);
+ unsigned long records_lost = 0;
+
+ assert(header);
+ if (!header)
+ return;
+ header->ctx.timestamp_end = tsc;
+ header->ctx.content_size =
+ (uint64_t) data_size * CHAR_BIT; /* in bits */
+ header->ctx.packet_size =
+ (uint64_t) LTTNG_UST_PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
+
+ records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf);
+ records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
+ records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
+ header->ctx.events_discarded = records_lost;
+}
+
+static int client_buffer_create(struct lttng_ust_lib_ring_buffer *buf, void *priv,
+ int cpu, const char *name, struct lttng_ust_shm_handle *handle)
+{
+ return 0;
+}
+
+static void client_buffer_finalize(struct lttng_ust_lib_ring_buffer *buf, void *priv, int cpu, struct lttng_ust_shm_handle *handle)
+{
+}
+
+static void client_content_size_field(const struct lttng_ust_lib_ring_buffer_config *config,
+ size_t *offset, size_t *length)
+{
+ *offset = offsetof(struct packet_header, ctx.content_size);
+ *length = sizeof(((struct packet_header *) NULL)->ctx.content_size);
+}
+
+static void client_packet_size_field(const struct lttng_ust_lib_ring_buffer_config *config,
+ size_t *offset, size_t *length)
+{
+ *offset = offsetof(struct packet_header, ctx.packet_size);
+ *length = sizeof(((struct packet_header *) NULL)->ctx.packet_size);
+}
+
+static struct packet_header *client_packet_header(struct lttng_ust_lib_ring_buffer *buf,
+ struct lttng_ust_shm_handle *handle)
+{
+ return lib_ring_buffer_read_offset_address(&buf->backend, 0, handle);
+}
+
+static int client_timestamp_begin(struct lttng_ust_lib_ring_buffer *buf,
+ struct lttng_ust_lib_ring_buffer_channel *chan,
+ uint64_t *timestamp_begin)
+{
+ struct lttng_ust_shm_handle *handle = chan->handle;
+ struct packet_header *header;
+
+ header = client_packet_header(buf, handle);
+ if (!header)
+ return -1;
+ *timestamp_begin = header->ctx.timestamp_begin;
+ return 0;
+}
+
+static int client_timestamp_end(struct lttng_ust_lib_ring_buffer *buf,
+ struct lttng_ust_lib_ring_buffer_channel *chan,
+ uint64_t *timestamp_end)
+{
+ struct lttng_ust_shm_handle *handle = chan->handle;
+ struct packet_header *header;
+
+ header = client_packet_header(buf, handle);
+ if (!header)
+ return -1;
+ *timestamp_end = header->ctx.timestamp_end;
+ return 0;
+}
+
+static int client_events_discarded(struct lttng_ust_lib_ring_buffer *buf,
+ struct lttng_ust_lib_ring_buffer_channel *chan,
+ uint64_t *events_discarded)
+{
+ struct lttng_ust_shm_handle *handle = chan->handle;
+ struct packet_header *header;
+
+ header = client_packet_header(buf, handle);
+ if (!header)
+ return -1;
+ *events_discarded = header->ctx.events_discarded;
+ return 0;
+}
+
+static int client_content_size(struct lttng_ust_lib_ring_buffer *buf,
+ struct lttng_ust_lib_ring_buffer_channel *chan,
+ uint64_t *content_size)
+{
+ struct lttng_ust_shm_handle *handle = chan->handle;
+ struct packet_header *header;
+
+ header = client_packet_header(buf, handle);
+ if (!header)
+ return -1;
+ *content_size = header->ctx.content_size;
+ return 0;
+}
+
+static int client_packet_size(struct lttng_ust_lib_ring_buffer *buf,
+ struct lttng_ust_lib_ring_buffer_channel *chan,
+ uint64_t *packet_size)
+{
+ struct lttng_ust_shm_handle *handle = chan->handle;
+ struct packet_header *header;
+
+ header = client_packet_header(buf, handle);
+ if (!header)
+ return -1;
+ *packet_size = header->ctx.packet_size;
+ return 0;
+}
+
+static int client_stream_id(struct lttng_ust_lib_ring_buffer *buf,
+ struct lttng_ust_lib_ring_buffer_channel *chan,
+ uint64_t *stream_id)
+{
+ struct lttng_ust_channel_buffer *lttng_chan = channel_get_private(chan);
+
+ *stream_id = lttng_chan->priv->id;
+
+ return 0;
+}
+
+static int client_current_timestamp(struct lttng_ust_lib_ring_buffer *buf,
+ struct lttng_ust_lib_ring_buffer_channel *chan,
+ uint64_t *ts)
+{
+ *ts = client_ring_buffer_clock_read(chan);
+
+ return 0;
+}
+
+static int client_sequence_number(struct lttng_ust_lib_ring_buffer *buf,
+ struct lttng_ust_lib_ring_buffer_channel *chan,
+ uint64_t *seq)
+{
+ struct lttng_ust_shm_handle *handle = chan->handle;
+ struct packet_header *header;
+
+ header = client_packet_header(buf, handle);
+ if (!header)
+ return -1;
+ *seq = header->ctx.packet_seq_num;
+ return 0;
+}
+
+static int client_instance_id(struct lttng_ust_lib_ring_buffer *buf,
+ struct lttng_ust_lib_ring_buffer_channel *chan,
+ uint64_t *id)
+{
+ *id = buf->backend.cpu;
+
+ return 0;
+}
+
+static const
+struct lttng_ust_client_lib_ring_buffer_client_cb client_cb = {
+ .parent = {
+ .ring_buffer_clock_read = client_ring_buffer_clock_read,
+ .record_header_size = client_record_header_size,
+ .subbuffer_header_size = client_packet_header_size,
+ .buffer_begin = client_buffer_begin,
+ .buffer_end = client_buffer_end,
+ .buffer_create = client_buffer_create,
+ .buffer_finalize = client_buffer_finalize,
+ .content_size_field = client_content_size_field,
+ .packet_size_field = client_packet_size_field,
+ },
+ .timestamp_begin = client_timestamp_begin,
+ .timestamp_end = client_timestamp_end,
+ .events_discarded = client_events_discarded,
+ .content_size = client_content_size,
+ .packet_size = client_packet_size,
+ .stream_id = client_stream_id,
+ .current_timestamp = client_current_timestamp,
+ .sequence_number = client_sequence_number,
+ .instance_id = client_instance_id,
+};
+
+static const struct lttng_ust_lib_ring_buffer_config client_config = {
+ .cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
+ .cb.record_header_size = client_record_header_size,
+ .cb.subbuffer_header_size = client_packet_header_size,
+ .cb.buffer_begin = client_buffer_begin,
+ .cb.buffer_end = client_buffer_end,
+ .cb.buffer_create = client_buffer_create,
+ .cb.buffer_finalize = client_buffer_finalize,
+ .cb.content_size_field = client_content_size_field,
+ .cb.packet_size_field = client_packet_size_field,
+
+ .tsc_bits = LTTNG_COMPACT_TSC_BITS,
+ .alloc = RING_BUFFER_ALLOC_PER_CPU,
+ .sync = RING_BUFFER_SYNC_GLOBAL,
+ .mode = RING_BUFFER_MODE_TEMPLATE,
+ .backend = RING_BUFFER_PAGE,
+ .output = RING_BUFFER_MMAP,
+ .oops = RING_BUFFER_OOPS_CONSISTENCY,
+ .ipi = RING_BUFFER_NO_IPI_BARRIER,
+ .wakeup = LTTNG_CLIENT_WAKEUP,
+ .client_type = LTTNG_CLIENT_TYPE,
+
+ .cb_ptr = &client_cb.parent,
+};
+
+static
+struct lttng_ust_channel_buffer *_channel_create(const char *name,
+ void *buf_addr,
+ size_t subbuf_size, size_t num_subbuf,
+ unsigned int switch_timer_interval,
+ unsigned int read_timer_interval,
+ unsigned char *uuid,
+ uint32_t chan_id,
+ const int *stream_fds, int nr_stream_fds,
+ int64_t blocking_timeout)
+{
+ struct lttng_ust_abi_channel_config chan_priv_init;
+ struct lttng_ust_shm_handle *handle;
+ struct lttng_ust_channel_buffer *lttng_chan_buf;
+
+ lttng_chan_buf = lttng_ust_alloc_channel_buffer();
+ if (!lttng_chan_buf)
+ return NULL;
+ memcpy(lttng_chan_buf->priv->uuid, uuid, LTTNG_UST_UUID_LEN);
+ lttng_chan_buf->priv->id = chan_id;
+
+ memset(&chan_priv_init, 0, sizeof(chan_priv_init));
+ memcpy(chan_priv_init.uuid, uuid, LTTNG_UST_UUID_LEN);
+ chan_priv_init.id = chan_id;
+
+ handle = channel_create(&client_config, name,
+ __alignof__(struct lttng_ust_abi_channel_config),
+ sizeof(struct lttng_ust_abi_channel_config),
+ &chan_priv_init,
+ lttng_chan_buf, buf_addr, subbuf_size, num_subbuf,
+ switch_timer_interval, read_timer_interval,
+ stream_fds, nr_stream_fds, blocking_timeout);
+ if (!handle)
+ goto error;
+ lttng_chan_buf->priv->rb_chan = shmp(handle, handle->chan);
+ return lttng_chan_buf;
+
+error:
+ lttng_ust_free_channel_common(lttng_chan_buf->parent);
+ return NULL;
+}
+
+static
+void lttng_channel_destroy(struct lttng_ust_channel_buffer *lttng_chan_buf)
+{
+ channel_destroy(lttng_chan_buf->priv->rb_chan, lttng_chan_buf->priv->rb_chan->handle, 1);
+ lttng_ust_free_channel_common(lttng_chan_buf->parent);
+}
+
+static
+int lttng_event_reserve(struct lttng_ust_lib_ring_buffer_ctx *ctx)
+{
+ struct lttng_ust_event_recorder *event_recorder = ctx->client_priv;
+ struct lttng_ust_channel_buffer *lttng_chan = event_recorder->chan;
+ struct lttng_client_ctx client_ctx;
+ int ret, nesting;
+ struct lttng_ust_lib_ring_buffer_ctx_private *private_ctx;
+ uint32_t event_id;
+
+ event_id = event_recorder->priv->id;
+ client_ctx.chan_ctx = lttng_ust_rcu_dereference(lttng_chan->priv->ctx);
+ client_ctx.event_ctx = lttng_ust_rcu_dereference(event_recorder->priv->ctx);
+ /* Compute internal size of context structures. */
+ ctx_get_struct_size(client_ctx.chan_ctx, &client_ctx.packet_context_len,
+ APP_CTX_ENABLED);
+ ctx_get_struct_size(client_ctx.event_ctx, &client_ctx.event_context_len,
+ APP_CTX_ENABLED);
+
+ nesting = lib_ring_buffer_nesting_inc(&client_config);
+ if (nesting < 0)
+ return -EPERM;
+
+ private_ctx = &URCU_TLS(private_ctx_stack)[nesting];
+ memset(private_ctx, 0, sizeof(*private_ctx));
+ private_ctx->pub = ctx;
+ private_ctx->chan = lttng_chan->priv->rb_chan;
+
+ ctx->priv = private_ctx;
+
+ switch (lttng_chan->priv->header_type) {
+ case 1: /* compact */
+ if (event_id > 30)
+ private_ctx->rflags |= LTTNG_RFLAG_EXTENDED;
+ break;
+ case 2: /* large */
+ if (event_id > 65534)
+ private_ctx->rflags |= LTTNG_RFLAG_EXTENDED;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ }
+
+ ret = lib_ring_buffer_reserve(&client_config, ctx, &client_ctx);
+ if (caa_unlikely(ret))
+ goto put;
+ if (lib_ring_buffer_backend_get_pages(&client_config, ctx,
+ &private_ctx->backend_pages)) {
+ ret = -EPERM;
+ goto put;
+ }
+ lttng_write_event_header(&client_config, ctx, &client_ctx, event_id);
+ return 0;
+put:
+ lib_ring_buffer_nesting_dec(&client_config);
+ return ret;
+}
+
+static
+void lttng_event_commit(struct lttng_ust_lib_ring_buffer_ctx *ctx)
+{
+ lib_ring_buffer_commit(&client_config, ctx);
+ lib_ring_buffer_nesting_dec(&client_config);
+}
+
+static
+void lttng_event_write(struct lttng_ust_lib_ring_buffer_ctx *ctx,
+ const void *src, size_t len, size_t alignment)
+{
+ lttng_ust_lib_ring_buffer_align_ctx(ctx, alignment);
+ lib_ring_buffer_write(&client_config, ctx, src, len);
+}
+
+static
+void lttng_event_strcpy(struct lttng_ust_lib_ring_buffer_ctx *ctx,
+ const char *src, size_t len)
+{
+ lib_ring_buffer_strcpy(&client_config, ctx, src, len, '#');
+}
+
+static
+void lttng_event_pstrcpy_pad(struct lttng_ust_lib_ring_buffer_ctx *ctx,
+ const char *src, size_t len)
+{
+ lib_ring_buffer_pstrcpy(&client_config, ctx, src, len, '\0');
+}
+
+static
+int lttng_is_finalized(struct lttng_ust_channel_buffer *chan)
+{
+ struct lttng_ust_lib_ring_buffer_channel *rb_chan = chan->priv->rb_chan;
+
+ return lib_ring_buffer_channel_is_finalized(rb_chan);
+}
+
+static
+int lttng_is_disabled(struct lttng_ust_channel_buffer *chan)
+{
+ struct lttng_ust_lib_ring_buffer_channel *rb_chan = chan->priv->rb_chan;
+
+ return lib_ring_buffer_channel_is_disabled(rb_chan);
+}
+
+static
+int lttng_flush_buffer(struct lttng_ust_channel_buffer *chan)
+{
+ struct lttng_ust_lib_ring_buffer_channel *rb_chan = chan->priv->rb_chan;
+ struct lttng_ust_lib_ring_buffer *buf;
+ int cpu;
+
+ for_each_channel_cpu(cpu, rb_chan) {
+ int shm_fd, wait_fd, wakeup_fd;
+ uint64_t memory_map_size;
+
+ buf = channel_get_ring_buffer(&client_config, rb_chan,
+ cpu, rb_chan->handle, &shm_fd, &wait_fd,
+ &wakeup_fd, &memory_map_size);
+ lib_ring_buffer_switch(&client_config, buf,
+ SWITCH_ACTIVE, rb_chan->handle);
+ }
+ return 0;
+}
+
+static struct lttng_transport lttng_relay_transport = {
+ .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap",
+ .ops = {
+ .struct_size = sizeof(struct lttng_ust_channel_buffer_ops),
+ .priv = __LTTNG_COMPOUND_LITERAL(struct lttng_ust_channel_buffer_ops_private, {
+ .pub = <tng_relay_transport.ops,
+ .channel_create = _channel_create,
+ .channel_destroy = lttng_channel_destroy,
+ .packet_avail_size = NULL, /* Would be racy anyway */
+ .is_finalized = lttng_is_finalized,
+ .is_disabled = lttng_is_disabled,
+ .flush_buffer = lttng_flush_buffer,
+ }),
+ .event_reserve = lttng_event_reserve,
+ .event_commit = lttng_event_commit,
+ .event_write = lttng_event_write,
+ .event_strcpy = lttng_event_strcpy,
+ .event_pstrcpy_pad = lttng_event_pstrcpy_pad,
+ },
+ .client_config = &client_config,
+};
+
+void RING_BUFFER_MODE_TEMPLATE_INIT(void)
+{
+ DBG("LTT : ltt ring buffer client \"%s\" init\n",
+ "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap");
+ lttng_transport_register(<tng_relay_transport);
+}
+
+void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
+{
+ DBG("LTT : ltt ring buffer client \"%s\" exit\n",
+ "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap");
+ lttng_transport_unregister(<tng_relay_transport);
+}