+/*
+ * Copyright (C) 2010-2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#define _LGPL_SOURCE
+#include <stdint.h>
+#include <string.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <limits.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <common/common.h>
+#include <common/time.h>
+
+#include "ust-registry.h"
+#include "ust-clock.h"
+#include "ust-app.h"
+
+#ifndef max_t
+#define max_t(type, a, b) ((type) ((a) > (b) ? (a) : (b)))
+#endif
+
+#define NR_CLOCK_OFFSET_SAMPLES 10
+
+struct offset_sample {
+ int64_t offset; /* correlation offset */
+ uint64_t measure_delta; /* lower is better */
+};
+
+static
+int _lttng_field_statedump(struct ust_registry_session *session,
+ const struct lttng_ust_ctl_field *fields, size_t nr_fields,
+ size_t *iter_field, size_t nesting);
+
+static inline
+int get_count_order(unsigned int count)
+{
+ int order;
+
+ order = lttng_fls(count) - 1;
+ if (count & (count - 1)) {
+ order++;
+ }
+ LTTNG_ASSERT(order >= 0);
+ return order;
+}
+
+/*
+ * Returns offset where to write in metadata array, or negative error value on error.
+ */
+static
+ssize_t metadata_reserve(struct ust_registry_session *session, size_t len)
+{
+ size_t new_len = session->metadata_len + len;
+ size_t new_alloc_len = new_len;
+ size_t old_alloc_len = session->metadata_alloc_len;
+ ssize_t ret;
+
+ if (new_alloc_len > (UINT32_MAX >> 1))
+ return -EINVAL;
+ if ((old_alloc_len << 1) > (UINT32_MAX >> 1))
+ return -EINVAL;
+
+ if (new_alloc_len > old_alloc_len) {
+ char *newptr;
+
+ new_alloc_len =
+ max_t(size_t, 1U << get_count_order(new_alloc_len), old_alloc_len << 1);
+ newptr = (char *) realloc(session->metadata, new_alloc_len);
+ if (!newptr)
+ return -ENOMEM;
+ session->metadata = newptr;
+ /* We zero directly the memory from start of allocation. */
+ memset(&session->metadata[old_alloc_len], 0, new_alloc_len - old_alloc_len);
+ session->metadata_alloc_len = new_alloc_len;
+ }
+ ret = session->metadata_len;
+ session->metadata_len += len;
+ return ret;
+}
+
+static
+int metadata_file_append(struct ust_registry_session *session,
+ const char *str, size_t len)
+{
+ ssize_t written;
+
+ if (session->metadata_fd < 0) {
+ return 0;
+ }
+ /* Write to metadata file */
+ written = lttng_write(session->metadata_fd, str, len);
+ if (written != len) {
+ return -1;
+ }
+ return 0;
+}
+
+/*
+ * We have exclusive access to our metadata buffer (protected by the
+ * ust_lock), 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.
+ */
+static
+int lttng_metadata_printf(struct ust_registry_session *session,
+ const char *fmt, ...)
+{
+ char *str = NULL;
+ size_t len;
+ va_list ap;
+ ssize_t offset;
+ int ret;
+
+ va_start(ap, fmt);
+ ret = vasprintf(&str, fmt, ap);
+ va_end(ap);
+ if (ret < 0)
+ return -ENOMEM;
+
+ len = strlen(str);
+ offset = metadata_reserve(session, len);
+ if (offset < 0) {
+ ret = offset;
+ goto end;
+ }
+ memcpy(&session->metadata[offset], str, len);
+ ret = metadata_file_append(session, str, len);
+ if (ret) {
+ PERROR("Error appending to metadata file");
+ goto end;
+ }
+ DBG3("Append to metadata: \"%s\"", str);
+ ret = 0;
+
+end:
+ free(str);
+ return ret;
+}
+
+static
+int print_tabs(struct ust_registry_session *session, size_t nesting)
+{
+ size_t i;
+
+ for (i = 0; i < nesting; i++) {
+ int ret;
+
+ ret = lttng_metadata_printf(session, " ");
+ if (ret) {
+ return ret;
+ }
+ }
+ return 0;
+}
+
+static
+void sanitize_ctf_identifier(char *out, const char *in)
+{
+ size_t i;
+
+ for (i = 0; i < LTTNG_UST_ABI_SYM_NAME_LEN; i++) {
+ switch (in[i]) {
+ case '.':
+ case '$':
+ case ':':
+ out[i] = '_';
+ break;
+ default:
+ out[i] = in[i];
+ }
+ }
+}
+
+static
+int print_escaped_ctf_string(struct ust_registry_session *session, const char *string)
+{
+ int ret = 0;
+ size_t i;
+ char cur;
+
+ i = 0;
+ cur = string[i];
+ while (cur != '\0') {
+ switch (cur) {
+ case '\n':
+ ret = lttng_metadata_printf(session, "%s", "\\n");
+ break;
+ case '\\':
+ case '"':
+ ret = lttng_metadata_printf(session, "%c", '\\');
+ if (ret) {
+ goto error;
+ }
+ /* We still print the current char */
+ /* Fallthrough */
+ default:
+ ret = lttng_metadata_printf(session, "%c", cur);
+ break;
+ }
+
+ if (ret) {
+ goto error;
+ }
+
+ cur = string[++i];
+ }
+error:
+ return ret;
+}
+
+/* Called with session registry mutex held. */
+static
+int ust_metadata_enum_statedump(struct ust_registry_session *session,
+ const char *enum_name,
+ uint64_t enum_id,
+ const struct lttng_ust_ctl_integer_type *container_type,
+ const char *field_name, size_t *iter_field, size_t nesting)
+{
+ struct ust_registry_enum *reg_enum;
+ const struct lttng_ust_ctl_enum_entry *entries;
+ size_t nr_entries;
+ int ret = 0;
+ size_t i;
+ char identifier[LTTNG_UST_ABI_SYM_NAME_LEN];
+
+ rcu_read_lock();
+ reg_enum = ust_registry_lookup_enum_by_id(session, enum_name, enum_id);
+ rcu_read_unlock();
+ /* reg_enum can still be used because session registry mutex is held. */
+ if (!reg_enum) {
+ ret = -ENOENT;
+ goto end;
+ }
+ entries = reg_enum->entries;
+ nr_entries = reg_enum->nr_entries;
+
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+ ret = lttng_metadata_printf(session,
+ "enum : integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u; } {\n",
+ container_type->size,
+ container_type->alignment,
+ container_type->signedness,
+ (container_type->encoding == lttng_ust_ctl_encode_none)
+ ? "none"
+ : (container_type->encoding == lttng_ust_ctl_encode_UTF8)
+ ? "UTF8"
+ : "ASCII",
+ container_type->base);
+ if (ret) {
+ goto end;
+ }
+ nesting++;
+ /* Dump all entries */
+ for (i = 0; i < nr_entries; i++) {
+ const struct lttng_ust_ctl_enum_entry *entry = &entries[i];
+ int j, len;
+
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+ ret = lttng_metadata_printf(session,
+ "\"");
+ if (ret) {
+ goto end;
+ }
+ len = strlen(entry->string);
+ /* Escape the character '"' */
+ for (j = 0; j < len; j++) {
+ char c = entry->string[j];
+
+ switch (c) {
+ case '"':
+ ret = lttng_metadata_printf(session,
+ "\\\"");
+ break;
+ case '\\':
+ ret = lttng_metadata_printf(session,
+ "\\\\");
+ break;
+ default:
+ ret = lttng_metadata_printf(session,
+ "%c", c);
+ break;
+ }
+ if (ret) {
+ goto end;
+ }
+ }
+ ret = lttng_metadata_printf(session, "\"");
+ if (ret) {
+ goto end;
+ }
+
+ if (entry->u.extra.options &
+ LTTNG_UST_CTL_UST_ENUM_ENTRY_OPTION_IS_AUTO) {
+ ret = lttng_metadata_printf(session, ",\n");
+ if (ret) {
+ goto end;
+ }
+ } else {
+ ret = lttng_metadata_printf(session,
+ " = ");
+ if (ret) {
+ goto end;
+ }
+
+ if (entry->start.signedness) {
+ ret = lttng_metadata_printf(session,
+ "%lld", (long long) entry->start.value);
+ } else {
+ ret = lttng_metadata_printf(session,
+ "%llu", entry->start.value);
+ }
+ if (ret) {
+ goto end;
+ }
+
+ if (entry->start.signedness == entry->end.signedness &&
+ entry->start.value ==
+ entry->end.value) {
+ ret = lttng_metadata_printf(session, ",\n");
+ } else {
+ if (entry->end.signedness) {
+ ret = lttng_metadata_printf(session,
+ " ... %lld,\n",
+ (long long) entry->end.value);
+ } else {
+ ret = lttng_metadata_printf(session,
+ " ... %llu,\n",
+ entry->end.value);
+ }
+ }
+ if (ret) {
+ goto end;
+ }
+ }
+ }
+ nesting--;
+ sanitize_ctf_identifier(identifier, field_name);
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+ ret = lttng_metadata_printf(session, "} _%s;\n",
+ identifier);
+end:
+ (*iter_field)++;
+ return ret;
+}
+
+static
+int _lttng_variant_statedump(struct ust_registry_session *session,
+ uint32_t nr_choices, const char *tag_name,
+ uint32_t alignment,
+ const struct lttng_ust_ctl_field *fields, size_t nr_fields,
+ size_t *iter_field, size_t nesting)
+{
+ const struct lttng_ust_ctl_field *variant = &fields[*iter_field];
+ uint32_t i;
+ int ret;
+ char identifier[LTTNG_UST_ABI_SYM_NAME_LEN];
+
+ if (variant->type.atype != lttng_ust_ctl_atype_variant) {
+ ret = -EINVAL;
+ goto end;
+ }
+ (*iter_field)++;
+ sanitize_ctf_identifier(identifier, tag_name);
+ if (alignment) {
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+ ret = lttng_metadata_printf(session,
+ "struct { } align(%u) _%s_padding;\n",
+ alignment * CHAR_BIT,
+ variant->name);
+ if (ret) {
+ goto end;
+ }
+ }
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+ ret = lttng_metadata_printf(session,
+ "variant <_%s> {\n",
+ identifier);
+ if (ret) {
+ goto end;
+ }
+
+ for (i = 0; i < nr_choices; i++) {
+ if (*iter_field >= nr_fields) {
+ ret = -EOVERFLOW;
+ goto end;
+ }
+ ret = _lttng_field_statedump(session,
+ fields, nr_fields,
+ iter_field, nesting + 1);
+ if (ret) {
+ goto end;
+ }
+ }
+ sanitize_ctf_identifier(identifier, variant->name);
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+ ret = lttng_metadata_printf(session,
+ "} _%s;\n",
+ identifier);
+ if (ret) {
+ goto end;
+ }
+end:
+ return ret;
+}
+
+static
+int _lttng_field_statedump(struct ust_registry_session *session,
+ const struct lttng_ust_ctl_field *fields, size_t nr_fields,
+ size_t *iter_field, size_t nesting)
+{
+ int ret = 0;
+ const char *bo_be = " byte_order = be;";
+ const char *bo_le = " byte_order = le;";
+ const char *bo_native = "";
+ const char *bo_reverse;
+ const struct lttng_ust_ctl_field *field;
+
+ if (*iter_field >= nr_fields) {
+ ret = -EOVERFLOW;
+ goto end;
+ }
+ field = &fields[*iter_field];
+
+ if (session->byte_order == BIG_ENDIAN) {
+ bo_reverse = bo_le;
+ } else {
+ bo_reverse = bo_be;
+ }
+
+ switch (field->type.atype) {
+ case lttng_ust_ctl_atype_integer:
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+ ret = lttng_metadata_printf(session,
+ "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
+ field->type.u.integer.size,
+ field->type.u.integer.alignment,
+ field->type.u.integer.signedness,
+ (field->type.u.integer.encoding == lttng_ust_ctl_encode_none)
+ ? "none"
+ : (field->type.u.integer.encoding == lttng_ust_ctl_encode_UTF8)
+ ? "UTF8"
+ : "ASCII",
+ field->type.u.integer.base,
+ field->type.u.integer.reverse_byte_order ? bo_reverse : bo_native,
+ field->name);
+ (*iter_field)++;
+ break;
+ case lttng_ust_ctl_atype_enum:
+ ret = ust_metadata_enum_statedump(session,
+ field->type.u.legacy.basic.enumeration.name,
+ field->type.u.legacy.basic.enumeration.id,
+ &field->type.u.legacy.basic.enumeration.container_type,
+ field->name, iter_field, nesting);
+ break;
+ case lttng_ust_ctl_atype_float:
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+ ret = lttng_metadata_printf(session,
+ "floating_point { exp_dig = %u; mant_dig = %u; align = %u;%s } _%s;\n",
+ field->type.u._float.exp_dig,
+ field->type.u._float.mant_dig,
+ field->type.u._float.alignment,
+ field->type.u._float.reverse_byte_order ? bo_reverse : bo_native,
+ field->name);
+ (*iter_field)++;
+ break;
+ case lttng_ust_ctl_atype_array:
+ {
+ const struct lttng_ust_ctl_basic_type *elem_type;
+
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+ elem_type = &field->type.u.legacy.array.elem_type;
+ /* Only integers are currently supported in arrays. */
+ if (elem_type->atype != lttng_ust_ctl_atype_integer) {
+ ret = -EINVAL;
+ goto end;
+ }
+ 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_ust_ctl_encode_none)
+ ? "none"
+ : (elem_type->u.basic.integer.encoding == lttng_ust_ctl_encode_UTF8)
+ ? "UTF8"
+ : "ASCII",
+ elem_type->u.basic.integer.base,
+ elem_type->u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
+ field->name, field->type.u.legacy.array.length);
+ (*iter_field)++;
+ break;
+ }
+ case lttng_ust_ctl_atype_array_nestable:
+ {
+ uint32_t array_length;
+ const struct lttng_ust_ctl_field *array_nestable;
+ const struct lttng_ust_ctl_type *elem_type;
+
+ array_length = field->type.u.array_nestable.length;
+ (*iter_field)++;
+
+ if (*iter_field >= nr_fields) {
+ ret = -EOVERFLOW;
+ goto end;
+ }
+ array_nestable = &fields[*iter_field];
+ elem_type = &array_nestable->type;
+
+ /* Only integers are currently supported in arrays. */
+ if (elem_type->atype != lttng_ust_ctl_atype_integer) {
+ ret = -EINVAL;
+ goto end;
+ }
+
+ if (field->type.u.array_nestable.alignment) {
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+ ret = lttng_metadata_printf(session,
+ "struct { } align(%u) _%s_padding;\n",
+ field->type.u.array_nestable.alignment * CHAR_BIT,
+ field->name);
+ if (ret) {
+ goto end;
+ }
+ }
+
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+ ret = lttng_metadata_printf(session,
+ "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
+ elem_type->u.integer.size,
+ elem_type->u.integer.alignment,
+ elem_type->u.integer.signedness,
+ (elem_type->u.integer.encoding == lttng_ust_ctl_encode_none)
+ ? "none"
+ : (elem_type->u.integer.encoding == lttng_ust_ctl_encode_UTF8)
+ ? "UTF8"
+ : "ASCII",
+ elem_type->u.integer.base,
+ elem_type->u.integer.reverse_byte_order ? bo_reverse : bo_native,
+ field->name, array_length);
+ (*iter_field)++;
+ break;
+ }
+ case lttng_ust_ctl_atype_sequence:
+ {
+ const struct lttng_ust_ctl_basic_type *elem_type;
+ const struct lttng_ust_ctl_basic_type *length_type;
+
+ elem_type = &field->type.u.legacy.sequence.elem_type;
+ length_type = &field->type.u.legacy.sequence.length_type;
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+
+ /* Only integers are currently supported in sequences. */
+ if (elem_type->atype != lttng_ust_ctl_atype_integer) {
+ ret = -EINVAL;
+ goto end;
+ }
+
+ 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_ust_ctl_encode_none)
+ ? "none"
+ : ((length_type->u.basic.integer.encoding == lttng_ust_ctl_encode_UTF8)
+ ? "UTF8"
+ : "ASCII"),
+ length_type->u.basic.integer.base,
+ length_type->u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
+ field->name);
+ if (ret) {
+ goto end;
+ }
+
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+ 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_ust_ctl_encode_none)
+ ? "none"
+ : ((elem_type->u.basic.integer.encoding == lttng_ust_ctl_encode_UTF8)
+ ? "UTF8"
+ : "ASCII"),
+ elem_type->u.basic.integer.base,
+ elem_type->u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
+ field->name,
+ field->name);
+ (*iter_field)++;
+ break;
+ }
+ case lttng_ust_ctl_atype_sequence_nestable:
+ {
+ const struct lttng_ust_ctl_field *sequence_nestable;
+ const struct lttng_ust_ctl_type *elem_type;
+
+ (*iter_field)++;
+ if (*iter_field >= nr_fields) {
+ ret = -EOVERFLOW;
+ goto end;
+ }
+ sequence_nestable = &fields[*iter_field];
+ elem_type = &sequence_nestable->type;
+
+ /* Only integers are currently supported in sequences. */
+ if (elem_type->atype != lttng_ust_ctl_atype_integer) {
+ ret = -EINVAL;
+ goto end;
+ }
+
+ if (field->type.u.sequence_nestable.alignment) {
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+ ret = lttng_metadata_printf(session,
+ "struct { } align(%u) _%s_padding;\n",
+ field->type.u.sequence_nestable.alignment * CHAR_BIT,
+ field->name);
+ if (ret) {
+ goto end;
+ }
+ }
+
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+ ret = lttng_metadata_printf(session,
+ "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ _%s ];\n",
+ elem_type->u.integer.size,
+ (unsigned int) elem_type->u.integer.alignment,
+ elem_type->u.integer.signedness,
+ (elem_type->u.integer.encoding == lttng_ust_ctl_encode_none)
+ ? "none"
+ : ((elem_type->u.integer.encoding == lttng_ust_ctl_encode_UTF8)
+ ? "UTF8"
+ : "ASCII"),
+ elem_type->u.integer.base,
+ elem_type->u.integer.reverse_byte_order ? bo_reverse : bo_native,
+ field->name,
+ field->type.u.sequence_nestable.length_name);
+ (*iter_field)++;
+ break;
+ }
+ case lttng_ust_ctl_atype_string:
+ /* Default encoding is UTF8 */
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+ ret = lttng_metadata_printf(session,
+ "string%s _%s;\n",
+ field->type.u.string.encoding == lttng_ust_ctl_encode_ASCII ?
+ " { encoding = ASCII; }" : "",
+ field->name);
+ (*iter_field)++;
+ break;
+ case lttng_ust_ctl_atype_variant:
+ ret = _lttng_variant_statedump(session,
+ field->type.u.legacy.variant.nr_choices,
+ field->type.u.legacy.variant.tag_name,
+ 0,
+ fields, nr_fields, iter_field, nesting);
+ if (ret) {
+ goto end;
+ }
+ break;
+ case lttng_ust_ctl_atype_variant_nestable:
+ ret = _lttng_variant_statedump(session,
+ field->type.u.variant_nestable.nr_choices,
+ field->type.u.variant_nestable.tag_name,
+ field->type.u.variant_nestable.alignment,
+ fields, nr_fields, iter_field, nesting);
+ if (ret) {
+ goto end;
+ }
+ break;
+ case lttng_ust_ctl_atype_struct:
+ if (field->type.u.legacy._struct.nr_fields != 0) {
+ /* Currently only 0-length structures are supported. */
+ ret = -EINVAL;
+ goto end;
+ }
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+ ret = lttng_metadata_printf(session,
+ "struct {} _%s;\n",
+ field->name);
+ (*iter_field)++;
+ break;
+ case lttng_ust_ctl_atype_struct_nestable:
+ if (field->type.u.struct_nestable.nr_fields != 0) {
+ /* Currently only 0-length structures are supported. */
+ ret = -EINVAL;
+ goto end;
+ }
+ ret = print_tabs(session, nesting);
+ if (ret) {
+ goto end;
+ }
+ if (field->type.u.struct_nestable.alignment) {
+ ret = lttng_metadata_printf(session,
+ "struct {} align(%u) _%s;\n",
+ field->type.u.struct_nestable.alignment * CHAR_BIT,
+ field->name);
+ if (ret) {
+ goto end;
+ }
+ } else {
+ ret = lttng_metadata_printf(session,
+ "struct {} _%s;\n",
+ field->name);
+ }
+ (*iter_field)++;
+ break;
+ case lttng_ust_ctl_atype_enum_nestable:
+ {
+ const struct lttng_ust_ctl_field *container_field;
+ const struct lttng_ust_ctl_type *container_type;
+
+ (*iter_field)++;
+ if (*iter_field >= nr_fields) {
+ ret = -EOVERFLOW;
+ goto end;
+ }
+ container_field = &fields[*iter_field];
+ container_type = &container_field->type;
+
+ /* Only integers are supported as container types. */
+ if (container_type->atype != lttng_ust_ctl_atype_integer) {
+ ret = -EINVAL;
+ goto end;
+ }
+ ret = ust_metadata_enum_statedump(session,
+ field->type.u.enum_nestable.name,
+ field->type.u.enum_nestable.id,
+ &container_type->u.integer,
+ field->name, iter_field, nesting);
+ break;
+ }
+ default:
+ ret = -EINVAL;
+ }
+end:
+ return ret;
+}
+
+static
+int _lttng_context_metadata_statedump(struct ust_registry_session *session,
+ size_t nr_ctx_fields,
+ struct lttng_ust_ctl_field *ctx)
+{
+ int ret = 0;
+ size_t i = 0;
+
+ if (!ctx)
+ return 0;
+ for (;;) {
+ if (i >= nr_ctx_fields) {
+ break;
+ }
+ ret = _lttng_field_statedump(session, ctx,
+ nr_ctx_fields, &i, 2);
+ if (ret) {
+ break;
+ }
+ }
+ return ret;
+}
+
+static
+int _lttng_fields_metadata_statedump(struct ust_registry_session *session,
+ struct ust_registry_event *event)
+{
+ int ret = 0;
+ size_t i = 0;
+
+ for (;;) {
+ if (i >= event->nr_fields) {
+ break;
+ }
+ ret = _lttng_field_statedump(session, event->fields,
+ event->nr_fields, &i, 2);
+ if (ret) {
+ break;
+ }
+ }
+ return ret;
+}
+
+/*
+ * Should be called with session registry mutex held.
+ */
+int ust_metadata_event_statedump(struct ust_registry_session *session,
+ struct ust_registry_channel *chan,
+ struct ust_registry_event *event)
+{
+ int ret = 0;
+
+ /* Don't dump metadata events */
+ if (chan->chan_id == -1U)
+ return 0;
+
+ ret = lttng_metadata_printf(session,
+ "event {\n"
+ " name = \"%s\";\n"
+ " id = %u;\n"
+ " stream_id = %u;\n",
+ event->name,
+ event->id,
+ chan->chan_id);
+ if (ret) {
+ goto end;
+ }
+
+ ret = lttng_metadata_printf(session,
+ " loglevel = %d;\n",
+ event->loglevel_value);
+ if (ret) {
+ goto end;
+ }
+
+ if (event->model_emf_uri) {
+ ret = lttng_metadata_printf(session,
+ " model.emf.uri = \"%s\";\n",
+ event->model_emf_uri);
+ if (ret) {
+ goto end;
+ }
+ }
+
+ ret = lttng_metadata_printf(session,
+ " fields := struct {\n"
+ );
+ if (ret) {
+ goto end;
+ }
+
+ ret = _lttng_fields_metadata_statedump(session, event);
+ if (ret) {
+ goto end;
+ }
+
+ ret = lttng_metadata_printf(session,
+ " };\n"
+ "};\n\n");
+ if (ret) {
+ goto end;
+ }
+ event->metadata_dumped = 1;
+
+end:
+ return ret;
+}
+
+/*
+ * Should be called with session registry mutex held.
+ */
+int ust_metadata_channel_statedump(struct ust_registry_session *session,
+ struct ust_registry_channel *chan)
+{
+ int ret = 0;
+
+ /* Don't dump metadata events */
+ if (chan->chan_id == -1U)
+ return 0;
+
+ if (!chan->header_type)
+ return -EINVAL;
+
+ ret = lttng_metadata_printf(session,
+ "stream {\n"
+ " id = %u;\n"
+ " event.header := %s;\n"
+ " packet.context := struct packet_context;\n",
+ chan->chan_id,
+ chan->header_type == LTTNG_UST_CTL_CHANNEL_HEADER_COMPACT ?
+ "struct event_header_compact" :
+ "struct event_header_large");
+ if (ret) {
+ goto end;
+ }
+
+ if (chan->ctx_fields) {
+ ret = lttng_metadata_printf(session,
+ " event.context := struct {\n");
+ if (ret) {
+ goto end;
+ }
+ }
+ ret = _lttng_context_metadata_statedump(session,
+ chan->nr_ctx_fields,
+ chan->ctx_fields);
+ if (ret) {
+ goto end;
+ }
+ if (chan->ctx_fields) {
+ ret = lttng_metadata_printf(session,
+ " };\n");
+ if (ret) {
+ goto end;
+ }
+ }
+
+ ret = lttng_metadata_printf(session,
+ "};\n\n");
+ /* Flag success of metadata dump. */
+ chan->metadata_dumped = 1;
+
+end:
+ return ret;
+}
+
+static
+int _lttng_stream_packet_context_declare(struct ust_registry_session *session)
+{
+ return lttng_metadata_printf(session,
+ "struct packet_context {\n"
+ " uint64_clock_monotonic_t timestamp_begin;\n"
+ " uint64_clock_monotonic_t timestamp_end;\n"
+ " uint64_t content_size;\n"
+ " uint64_t packet_size;\n"
+ " uint64_t packet_seq_num;\n"
+ " unsigned long events_discarded;\n"
+ " uint32_t cpu_id;\n"
+ "};\n\n"
+ );
+}
+
+/*
+ * Compact header:
+ * id: range: 0 - 30.
+ * id 31 is reserved to indicate an extended header.
+ *
+ * Large header:
+ * id: range: 0 - 65534.
+ * id 65535 is reserved to indicate an extended header.
+ */
+static
+int _lttng_event_header_declare(struct ust_registry_session *session)
+{
+ return lttng_metadata_printf(session,
+ "struct event_header_compact {\n"
+ " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
+ " variant <id> {\n"
+ " struct {\n"
+ " uint27_clock_monotonic_t timestamp;\n"
+ " } compact;\n"
+ " struct {\n"
+ " uint32_t id;\n"
+ " uint64_clock_monotonic_t timestamp;\n"
+ " } extended;\n"
+ " } v;\n"
+ "} align(%u);\n"
+ "\n"
+ "struct event_header_large {\n"
+ " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
+ " variant <id> {\n"
+ " struct {\n"
+ " uint32_clock_monotonic_t timestamp;\n"
+ " } compact;\n"
+ " struct {\n"
+ " uint32_t id;\n"
+ " uint64_clock_monotonic_t timestamp;\n"
+ " } extended;\n"
+ " } v;\n"
+ "} align(%u);\n\n",
+ session->uint32_t_alignment,
+ session->uint16_t_alignment
+ );
+}
+
+/*
+ * The offset between monotonic and realtime clock can be negative if
+ * the system sets the REALTIME clock to 0 after boot.
+ */
+static
+int measure_single_clock_offset(struct offset_sample *sample)
+{
+ uint64_t monotonic_avg, monotonic[2], measure_delta, realtime;
+ uint64_t tcf = trace_clock_freq();
+ struct timespec rts = { 0, 0 };
+ int ret;
+
+ monotonic[0] = trace_clock_read64();
+ ret = lttng_clock_gettime(CLOCK_REALTIME, &rts);
+ if (ret < 0) {
+ return ret;
+ }
+ monotonic[1] = trace_clock_read64();
+ measure_delta = monotonic[1] - monotonic[0];
+ if (measure_delta > sample->measure_delta) {
+ /*
+ * Discard value if it took longer to read than the best
+ * sample so far.
+ */
+ return 0;
+ }
+ monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
+ realtime = (uint64_t) rts.tv_sec * tcf;
+ if (tcf == NSEC_PER_SEC) {
+ realtime += rts.tv_nsec;
+ } else {
+ realtime += (uint64_t) rts.tv_nsec * tcf / NSEC_PER_SEC;
+ }
+ sample->offset = (int64_t) realtime - monotonic_avg;
+ sample->measure_delta = measure_delta;
+ return 0;
+}
+
+/*
+ * Approximation of NTP time of day to clock monotonic correlation,
+ * taken at start of trace. Keep the measurement that took the less time
+ * to complete, thus removing imprecision caused by preemption.
+ * May return a negative offset.
+ */
+static
+int64_t measure_clock_offset(void)
+{
+ int i;
+ struct offset_sample offset_best_sample = {
+ .offset = 0,
+ .measure_delta = UINT64_MAX,
+ };
+
+ for (i = 0; i < NR_CLOCK_OFFSET_SAMPLES; i++) {
+ if (measure_single_clock_offset(&offset_best_sample)) {
+ return 0;
+ }
+ }
+ return offset_best_sample.offset;
+}
+
+static
+int print_metadata_session_information(struct ust_registry_session *registry)
+{
+ int ret;
+ struct ltt_session *session = NULL;
+ char creation_datetime[ISO8601_STR_LEN];
+
+ rcu_read_lock();
+ session = session_find_by_id(registry->tracing_id);
+ if (!session) {
+ ret = -1;
+ goto error;
+ }
+
+ /* Print the trace name */
+ ret = lttng_metadata_printf(registry, " trace_name = \"");
+ if (ret) {
+ goto error;
+ }
+
+ /*
+ * This is necessary since the creation time is present in the session
+ * name when it is generated.
+ */
+ if (session->has_auto_generated_name) {
+ ret = print_escaped_ctf_string(registry, DEFAULT_SESSION_NAME);
+ } else {
+ ret = print_escaped_ctf_string(registry, session->name);
+ }
+ if (ret) {
+ goto error;
+ }
+
+ ret = lttng_metadata_printf(registry, "\";\n");
+ if (ret) {
+ goto error;
+ }
+
+ /* Prepare creation time */
+ ret = time_to_iso8601_str(session->creation_time, creation_datetime,
+ sizeof(creation_datetime));
+ if (ret) {
+ goto error;
+ }
+
+ /* Output the reste of the information */
+ ret = lttng_metadata_printf(registry,
+ " trace_creation_datetime = \"%s\";\n"
+ " hostname = \"%s\";\n",
+ creation_datetime, session->hostname);
+ if (ret) {
+ goto error;
+ }
+
+error:
+ if (session) {
+ session_put(session);
+ }
+ rcu_read_unlock();
+ return ret;
+}
+
+static
+int print_metadata_app_information(struct ust_registry_session *registry,
+ struct ust_app *app)
+{
+ int ret;
+ char datetime[ISO8601_STR_LEN];
+
+ if (!app) {
+ ret = 0;
+ goto end;
+ }
+
+ ret = time_to_iso8601_str(
+ app->registration_time, datetime, sizeof(datetime));
+ if (ret) {
+ goto end;
+ }
+
+ ret = lttng_metadata_printf(registry,
+ " tracer_patchlevel = %u;\n"
+ " vpid = %d;\n"
+ " procname = \"%s\";\n"
+ " vpid_datetime = \"%s\";\n",
+ app->version.patchlevel, (int) app->pid, app->name,
+ datetime);
+
+end:
+ return ret;
+}
+
+/*
+ * Should be called with session registry mutex held.
+ */
+int ust_metadata_session_statedump(struct ust_registry_session *session,
+ struct ust_app *app,
+ uint32_t major,
+ uint32_t minor)
+{
+ char uuid_s[LTTNG_UUID_STR_LEN],
+ clock_uuid_s[LTTNG_UUID_STR_LEN];
+ int ret = 0;
+
+ LTTNG_ASSERT(session);
+
+ lttng_uuid_to_str(session->uuid, uuid_s);
+
+ /* For crash ABI */
+ ret = lttng_metadata_printf(session,
+ "/* CTF %u.%u */\n\n",
+ CTF_SPEC_MAJOR,
+ CTF_SPEC_MINOR);
+ if (ret) {
+ goto end;
+ }
+
+ ret = lttng_metadata_printf(session,
+ "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
+ "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
+ "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
+ "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
+ "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
+ "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
+ "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
+ "\n"
+ "trace {\n"
+ " major = %u;\n"
+ " minor = %u;\n"
+ " uuid = \"%s\";\n"
+ " byte_order = %s;\n"
+ " packet.header := struct {\n"
+ " uint32_t magic;\n"
+ " uint8_t uuid[16];\n"
+ " uint32_t stream_id;\n"
+ " uint64_t stream_instance_id;\n"
+ " };\n"
+ "};\n\n",
+ session->uint8_t_alignment,
+ session->uint16_t_alignment,
+ session->uint32_t_alignment,
+ session->uint64_t_alignment,
+ session->bits_per_long,
+ session->long_alignment,
+ CTF_SPEC_MAJOR,
+ CTF_SPEC_MINOR,
+ uuid_s,
+ session->byte_order == BIG_ENDIAN ? "be" : "le"
+ );
+ if (ret) {
+ goto end;
+ }
+
+ ret = lttng_metadata_printf(session,
+ "env {\n"
+ " domain = \"ust\";\n"
+ " tracer_name = \"lttng-ust\";\n"
+ " tracer_major = %u;\n"
+ " tracer_minor = %u;\n"
+ " tracer_buffering_scheme = \"%s\";\n"
+ " tracer_buffering_id = %u;\n"
+ " architecture_bit_width = %u;\n",
+ major,
+ minor,
+ app ? "pid" : "uid",
+ app ? (int) app->pid : (int) session->tracing_uid,
+ session->bits_per_long);
+ if (ret) {
+ goto end;
+ }
+
+ ret = print_metadata_session_information(session);
+ if (ret) {
+ goto end;
+ }
+
+ /*
+ * If per-application registry, we can output extra information
+ * about the application.
+ */
+ ret = print_metadata_app_information(session, app);
+ if (ret) {
+ goto end;
+ }
+
+ ret = lttng_metadata_printf(session,
+ "};\n\n"
+ );
+ if (ret) {
+ goto end;
+ }
+
+ ret = lttng_metadata_printf(session,
+ "clock {\n"
+ " name = \"%s\";\n",
+ trace_clock_name()
+ );
+ if (ret) {
+ goto end;
+ }
+
+ if (!trace_clock_uuid(clock_uuid_s)) {
+ ret = lttng_metadata_printf(session,
+ " uuid = \"%s\";\n",
+ clock_uuid_s
+ );
+ if (ret) {
+ goto end;
+ }
+ }
+
+ ret = lttng_metadata_printf(session,
+ " description = \"%s\";\n"
+ " freq = %" PRIu64 "; /* Frequency, in Hz */\n"
+ " /* clock value offset from Epoch is: offset * (1/freq) */\n"
+ " offset = %" PRId64 ";\n"
+ "};\n\n",
+ trace_clock_description(),
+ trace_clock_freq(),
+ measure_clock_offset()
+ );
+ if (ret) {
+ goto end;
+ }
+
+ ret = lttng_metadata_printf(session,
+ "typealias integer {\n"
+ " size = 27; align = 1; signed = false;\n"
+ " map = clock.%s.value;\n"
+ "} := uint27_clock_monotonic_t;\n"
+ "\n"
+ "typealias integer {\n"
+ " size = 32; align = %u; signed = false;\n"
+ " map = clock.%s.value;\n"
+ "} := uint32_clock_monotonic_t;\n"
+ "\n"
+ "typealias integer {\n"
+ " size = 64; align = %u; signed = false;\n"
+ " map = clock.%s.value;\n"
+ "} := uint64_clock_monotonic_t;\n\n",
+ trace_clock_name(),
+ session->uint32_t_alignment,
+ trace_clock_name(),
+ session->uint64_t_alignment,
+ trace_clock_name()
+ );
+ if (ret) {
+ goto end;
+ }
+
+ ret = _lttng_stream_packet_context_declare(session);
+ if (ret) {
+ goto end;
+ }
+
+ ret = _lttng_event_header_declare(session);
+ if (ret) {
+ goto end;
+ }
+
+end:
+ return ret;
+}