+ switch (event->instrumentation) {
+ case LTTNG_KERNEL_TRACEPOINT:
+ ltt_event_put(event->desc);
+ break;
+ case LTTNG_KERNEL_KPROBE:
+ module_put(event->desc->owner);
+ lttng_kprobes_destroy_private(event);
+ break;
+ case LTTNG_KERNEL_FUNCTION:
+ module_put(event->desc->owner);
+ lttng_ftrace_destroy_private(event);
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ }
+ list_del(&event->list);
+ lttng_destroy_context(event->ctx);
+ kmem_cache_free(event_cache, event);
+}
+
+/*
+ * We have exclusive access to our metadata buffer (protected by the
+ * sessions_mutex), so we can do racy operations such as looking for
+ * remaining space left in packet and write, since mutual exclusion
+ * protects us from concurrent writes.
+ */
+int lttng_metadata_printf(struct ltt_session *session,
+ const char *fmt, ...)
+{
+ struct lib_ring_buffer_ctx ctx;
+ struct ltt_channel *chan = session->metadata;
+ char *str;
+ int ret = 0, waitret;
+ size_t len, reserve_len, pos;
+ va_list ap;
+
+ WARN_ON_ONCE(!ACCESS_ONCE(session->active));
+
+ va_start(ap, fmt);
+ str = kvasprintf(GFP_KERNEL, fmt, ap);
+ va_end(ap);
+ if (!str)
+ return -ENOMEM;
+
+ len = strlen(str);
+ pos = 0;
+
+ for (pos = 0; pos < len; pos += reserve_len) {
+ reserve_len = min_t(size_t,
+ chan->ops->packet_avail_size(chan->chan),
+ len - pos);
+ lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len,
+ sizeof(char), -1);
+ /*
+ * We don't care about metadata buffer's records lost
+ * count, because we always retry here. Report error if
+ * we need to bail out after timeout or being
+ * interrupted.
+ */
+ waitret = wait_event_interruptible_timeout(*chan->ops->get_reader_wait_queue(chan->chan),
+ ({
+ ret = chan->ops->event_reserve(&ctx, 0);
+ ret != -ENOBUFS || !ret;
+ }),
+ msecs_to_jiffies(LTTNG_METADATA_TIMEOUT_MSEC));
+ if (!waitret || waitret == -ERESTARTSYS || ret) {
+ printk(KERN_WARNING "LTTng: Failure to write metadata to buffers (%s)\n",
+ waitret == -ERESTARTSYS ? "interrupted" :
+ (ret == -ENOBUFS ? "timeout" : "I/O error"));
+ if (waitret == -ERESTARTSYS)
+ ret = waitret;
+ goto end;
+ }
+ chan->ops->event_write(&ctx, &str[pos], reserve_len);
+ chan->ops->event_commit(&ctx);
+ }
+end:
+ kfree(str);
+ return ret;
+}
+
+static
+int _ltt_field_statedump(struct ltt_session *session,
+ const struct lttng_event_field *field)
+{
+ int ret = 0;
+
+ switch (field->type.atype) {
+ case atype_integer:
+ ret = lttng_metadata_printf(session,
+ " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s;\n",
+ field->type.u.basic.integer.size,
+ field->type.u.basic.integer.alignment,
+ field->type.u.basic.integer.signedness,
+ (field->type.u.basic.integer.encoding == lttng_encode_none)
+ ? "none"
+ : (field->type.u.basic.integer.encoding == lttng_encode_UTF8)
+ ? "UTF8"
+ : "ASCII",
+ field->type.u.basic.integer.base,
+#ifdef __BIG_ENDIAN
+ field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
+#else
+ field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
+#endif
+ field->name);
+ break;
+ case atype_enum:
+ ret = lttng_metadata_printf(session,
+ " %s %s;\n",
+ field->type.u.basic.enumeration.name,
+ field->name);
+ break;
+ case atype_array:
+ {
+ const struct lttng_basic_type *elem_type;
+
+ elem_type = &field->type.u.array.elem_type;
+ ret = lttng_metadata_printf(session,
+ " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[%u];\n",
+ elem_type->u.basic.integer.size,
+ elem_type->u.basic.integer.alignment,
+ elem_type->u.basic.integer.signedness,
+ (elem_type->u.basic.integer.encoding == lttng_encode_none)
+ ? "none"
+ : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
+ ? "UTF8"
+ : "ASCII",
+ elem_type->u.basic.integer.base,
+#ifdef __BIG_ENDIAN
+ elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
+#else
+ elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
+#endif
+ field->name, field->type.u.array.length);
+ break;
+ }
+ case atype_sequence:
+ {
+ const struct lttng_basic_type *elem_type;
+ const struct lttng_basic_type *length_type;
+
+ elem_type = &field->type.u.sequence.elem_type;
+ length_type = &field->type.u.sequence.length_type;
+ ret = lttng_metadata_printf(session,
+ " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
+ length_type->u.basic.integer.size,
+ (unsigned int) length_type->u.basic.integer.alignment,
+ length_type->u.basic.integer.signedness,
+ (length_type->u.basic.integer.encoding == lttng_encode_none)
+ ? "none"
+ : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8)
+ ? "UTF8"
+ : "ASCII"),
+ length_type->u.basic.integer.base,
+#ifdef __BIG_ENDIAN
+ length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
+#else
+ length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
+#endif
+ field->name);
+ if (ret)
+ return ret;
+
+ ret = lttng_metadata_printf(session,
+ " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[ __%s_length ];\n",
+ elem_type->u.basic.integer.size,
+ (unsigned int) elem_type->u.basic.integer.alignment,
+ elem_type->u.basic.integer.signedness,
+ (elem_type->u.basic.integer.encoding == lttng_encode_none)
+ ? "none"
+ : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
+ ? "UTF8"
+ : "ASCII"),
+ elem_type->u.basic.integer.base,
+#ifdef __BIG_ENDIAN
+ elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
+#else
+ elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
+#endif
+ field->name,
+ field->name);
+ break;
+ }
+
+ case atype_string:
+ /* Default encoding is UTF8 */
+ ret = lttng_metadata_printf(session,
+ " string%s %s;\n",
+ field->type.u.basic.string.encoding == lttng_encode_ASCII ?
+ " { encoding = ASCII; }" : "",
+ field->name);