--- /dev/null
+/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
+ *
+ * lttng-ring-buffer-event-notifier-client.h
+ *
+ * LTTng lib ring buffer event notifier client template.
+ *
+ * Copyright (C) 2010-2020 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_mappings() */
+#include <lttng/events.h>
+#include <lttng/tracer.h>
+
+static struct lttng_transport lttng_relay_transport;
+
+struct event_notifier_packet_header {
+ uint8_t header_end[0];
+};
+
+struct event_notifier_record_header {
+ uint8_t header_end[0]; /* End of header */
+};
+
+static const struct lib_ring_buffer_config client_config;
+
+static inline
+u64 lib_ring_buffer_clock_read(struct channel *chan)
+{
+ return 0;
+}
+
+static inline
+size_t record_header_size(const struct lib_ring_buffer_config *config,
+ struct channel *chan, size_t offset,
+ size_t *pre_header_padding,
+ struct lib_ring_buffer_ctx *ctx,
+ void *client_ctx)
+{
+ return 0;
+}
+
+#include <ringbuffer/api.h>
+
+static u64 client_ring_buffer_clock_read(struct channel *chan)
+{
+ return 0;
+}
+
+static
+size_t client_record_header_size(const struct lib_ring_buffer_config *config,
+ struct channel *chan, size_t offset,
+ size_t *pre_header_padding,
+ struct lib_ring_buffer_ctx *ctx,
+ void *client_ctx)
+{
+ return 0;
+}
+
+/**
+ * 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 event_notifier_packet_header, header_end);
+}
+
+static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
+ unsigned int subbuf_idx)
+{
+}
+
+/*
+ * 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 lib_ring_buffer *buf, u64 tsc,
+ unsigned int subbuf_idx, unsigned long data_size)
+{
+}
+
+static int client_buffer_create(struct lib_ring_buffer *buf, void *priv,
+ int cpu, const char *name)
+{
+ return 0;
+}
+
+static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu)
+{
+}
+
+static int client_timestamp_begin(const struct lib_ring_buffer_config *config,
+ struct lib_ring_buffer *buf, uint64_t *timestamp_begin)
+{
+ return -ENOSYS;
+}
+
+static int client_timestamp_end(const struct lib_ring_buffer_config *config,
+ struct lib_ring_buffer *bufb,
+ uint64_t *timestamp_end)
+{
+ return -ENOSYS;
+}
+
+static int client_events_discarded(const struct lib_ring_buffer_config *config,
+ struct lib_ring_buffer *bufb,
+ uint64_t *events_discarded)
+{
+ return -ENOSYS;
+}
+
+static int client_current_timestamp(const struct lib_ring_buffer_config *config,
+ struct lib_ring_buffer *bufb,
+ uint64_t *ts)
+{
+ return -ENOSYS;
+}
+
+static int client_content_size(const struct lib_ring_buffer_config *config,
+ struct lib_ring_buffer *bufb,
+ uint64_t *content_size)
+{
+ return -ENOSYS;
+}
+
+static int client_packet_size(const struct lib_ring_buffer_config *config,
+ struct lib_ring_buffer *bufb,
+ uint64_t *packet_size)
+{
+ return -ENOSYS;
+}
+
+static int client_stream_id(const struct lib_ring_buffer_config *config,
+ struct lib_ring_buffer *bufb,
+ uint64_t *stream_id)
+{
+ return -ENOSYS;
+}
+
+static int client_sequence_number(const struct lib_ring_buffer_config *config,
+ struct lib_ring_buffer *bufb,
+ uint64_t *seq)
+{
+ return -ENOSYS;
+}
+
+static
+int client_instance_id(const struct lib_ring_buffer_config *config,
+ struct lib_ring_buffer *bufb,
+ uint64_t *id)
+{
+ return -ENOSYS;
+}
+
+static void client_record_get(const struct lib_ring_buffer_config *config,
+ struct channel *chan, struct lib_ring_buffer *buf,
+ size_t offset, size_t *header_len,
+ size_t *payload_len, u64 *timestamp)
+{
+ struct event_notifier_record_header header;
+ int ret;
+
+ ret = lib_ring_buffer_read(&buf->backend, offset, &header,
+ offsetof(struct event_notifier_record_header, header_end));
+ CHAN_WARN_ON(chan, ret != offsetof(struct event_notifier_record_header, header_end));
+ *header_len = offsetof(struct event_notifier_record_header, header_end);
+ /*
+ * Currently, only 64-bit event notifier ID.
+ */
+ *payload_len = sizeof(uint64_t);
+ *timestamp = 0;
+}
+
+static const struct 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.record_get = client_record_get,
+
+ .tsc_bits = 0,
+ .alloc = RING_BUFFER_ALLOC_GLOBAL,
+ .sync = RING_BUFFER_SYNC_GLOBAL,
+ .mode = RING_BUFFER_MODE_TEMPLATE,
+ .backend = RING_BUFFER_PAGE,
+ .output = RING_BUFFER_OUTPUT_TEMPLATE,
+ .oops = RING_BUFFER_OOPS_CONSISTENCY,
+ .ipi = RING_BUFFER_NO_IPI_BARRIER,
+ .wakeup = RING_BUFFER_WAKEUP_BY_WRITER,
+};
+
+static
+void release_priv_ops(void *priv_ops)
+{
+ module_put(THIS_MODULE);
+}
+
+static
+void lttng_channel_destroy(struct channel *chan)
+{
+ channel_destroy(chan);
+}
+
+static
+struct channel *_channel_create(const char *name,
+ void *priv, void *buf_addr,
+ size_t subbuf_size, size_t num_subbuf,
+ unsigned int switch_timer_interval,
+ unsigned int read_timer_interval)
+{
+ struct lttng_event_notifier_group *event_notifier_group = priv;
+ struct channel *chan;
+
+ chan = channel_create(&client_config, name,
+ event_notifier_group, buf_addr,
+ subbuf_size, num_subbuf, switch_timer_interval,
+ read_timer_interval);
+ if (chan) {
+ /*
+ * Ensure this module is not unloaded before we finish
+ * using lttng_relay_transport.ops.
+ */
+ if (!try_module_get(THIS_MODULE)) {
+ printk(KERN_WARNING "LTTng: Can't lock event_notifier transport module.\n");
+ goto error;
+ }
+ chan->backend.priv_ops = <tng_relay_transport.ops;
+ chan->backend.release_priv_ops = release_priv_ops;
+ }
+ return chan;
+
+error:
+ lttng_channel_destroy(chan);
+ return NULL;
+}
+
+static
+struct lib_ring_buffer *lttng_buffer_read_open(struct channel *chan)
+{
+ struct lib_ring_buffer *buf;
+
+ buf = channel_get_ring_buffer(&client_config, chan, 0);
+ if (!lib_ring_buffer_open_read(buf))
+ return buf;
+ return NULL;
+}
+
+static
+int lttng_buffer_has_read_closed_stream(struct channel *chan)
+{
+ struct lib_ring_buffer *buf;
+ int cpu;
+
+ for_each_channel_cpu(cpu, chan) {
+ buf = channel_get_ring_buffer(&client_config, chan, cpu);
+ if (!atomic_long_read(&buf->active_readers))
+ return 1;
+ }
+ return 0;
+}
+
+static
+void lttng_buffer_read_close(struct lib_ring_buffer *buf)
+{
+ lib_ring_buffer_release_read(buf);
+}
+
+static
+int lttng_event_reserve(struct lib_ring_buffer_ctx *ctx, uint32_t event_id)
+{
+ int ret;
+
+ ret = lib_ring_buffer_reserve(&client_config, ctx, NULL);
+ if (ret)
+ return ret;
+ lib_ring_buffer_backend_get_pages(&client_config, ctx,
+ &ctx->backend_pages);
+ return 0;
+}
+
+static
+void lttng_event_commit(struct lib_ring_buffer_ctx *ctx)
+{
+ lib_ring_buffer_commit(&client_config, ctx);
+}
+
+static
+void lttng_event_write(struct lib_ring_buffer_ctx *ctx, const void *src,
+ size_t len)
+{
+ lib_ring_buffer_write(&client_config, ctx, src, len);
+}
+
+static
+void lttng_event_write_from_user(struct lib_ring_buffer_ctx *ctx,
+ const void __user *src, size_t len)
+{
+ lib_ring_buffer_copy_from_user_inatomic(&client_config, ctx, src, len);
+}
+
+static
+void lttng_event_memset(struct lib_ring_buffer_ctx *ctx,
+ int c, size_t len)
+{
+ lib_ring_buffer_memset(&client_config, ctx, c, len);
+}
+
+static
+void lttng_event_strcpy(struct lib_ring_buffer_ctx *ctx, const char *src,
+ size_t len)
+{
+ lib_ring_buffer_strcpy(&client_config, ctx, src, len, '#');
+}
+
+static
+size_t lttng_packet_avail_size(struct channel *chan)
+{
+ unsigned long o_begin;
+ struct lib_ring_buffer *buf;
+
+ buf = chan->backend.buf; /* Only for global buffer ! */
+ o_begin = v_read(&client_config, &buf->offset);
+ if (subbuf_offset(o_begin, chan) != 0) {
+ return chan->backend.subbuf_size - subbuf_offset(o_begin, chan);
+ } else {
+ return chan->backend.subbuf_size - subbuf_offset(o_begin, chan)
+ - sizeof(struct event_notifier_packet_header);
+ }
+}
+
+static
+wait_queue_head_t *lttng_get_writer_buf_wait_queue(struct channel *chan, int cpu)
+{
+ struct lib_ring_buffer *buf = channel_get_ring_buffer(&client_config,
+ chan, cpu);
+ return &buf->write_wait;
+}
+
+static
+wait_queue_head_t *lttng_get_hp_wait_queue(struct channel *chan)
+{
+ return &chan->hp_wait;
+}
+
+static
+int lttng_is_finalized(struct channel *chan)
+{
+ return lib_ring_buffer_channel_is_finalized(chan);
+}
+
+static
+int lttng_is_disabled(struct channel *chan)
+{
+ return lib_ring_buffer_channel_is_disabled(chan);
+}
+
+static struct lttng_transport lttng_relay_transport = {
+ .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING,
+ .owner = THIS_MODULE,
+ .ops = {
+ .channel_create = _channel_create,
+ .channel_destroy = lttng_channel_destroy,
+ .buffer_read_open = lttng_buffer_read_open,
+ .buffer_has_read_closed_stream =
+ lttng_buffer_has_read_closed_stream,
+ .buffer_read_close = lttng_buffer_read_close,
+ .event_reserve = lttng_event_reserve,
+ .event_commit = lttng_event_commit,
+ .event_write_from_user = lttng_event_write_from_user,
+ .event_memset = lttng_event_memset,
+ .event_write = lttng_event_write,
+ .event_strcpy = lttng_event_strcpy,
+ .packet_avail_size = lttng_packet_avail_size,
+ .get_writer_buf_wait_queue = lttng_get_writer_buf_wait_queue,
+ .get_hp_wait_queue = lttng_get_hp_wait_queue,
+ .is_finalized = lttng_is_finalized,
+ .is_disabled = lttng_is_disabled,
+ .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 int __init lttng_ring_buffer_event_notifier_client_init(void)
+{
+ /*
+ * This vmalloc sync all also takes care of the lib ring buffer
+ * vmalloc'd module pages when it is built as a module into LTTng.
+ */
+ wrapper_vmalloc_sync_mappings();
+ lttng_transport_register(<tng_relay_transport);
+ return 0;
+}
+
+module_init(lttng_ring_buffer_event_notifier_client_init);
+
+static void __exit lttng_ring_buffer_event_notifier_client_exit(void)
+{
+ lttng_transport_unregister(<tng_relay_transport);
+}
+
+module_exit(lttng_ring_buffer_event_notifier_client_exit);
+
+MODULE_LICENSE("GPL and additional rights");
+MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
+MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
+ " client");
+MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
+ __stringify(LTTNG_MODULES_MINOR_VERSION) "."
+ __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
+ LTTNG_MODULES_EXTRAVERSION);
projects / lttng-modules.git / commitdiff
