[lttng-dev] [RFC-patch] Add support of struct metadata in tracepoints
Geneviève Bastien
gbastien+lttng at versatic.net
Thu Apr 18 14:20:57 EDT 2013
Introduce the new macro TRACEPOINT_STRUCT to define ctf struct metadata
that can be used by tracepoints using _struct as entry and tp_memcpy_struct
to copy a struct field.
Struct metadata can contain nested structs.
This extra metadata is added to the metadata file only if events use it.
Signed-off-by: Geneviève Bastien <gbastien+lttng at versatic.net>
---
lttng-events.c | 166 ++++++++++++++++++++++++++++++++++-
lttng-events.h | 44 ++++++++++
probes/lttng-events-reset.h | 15 ++++
probes/lttng-events.h | 206 ++++++++++++++++++++++++++++++++++++++++++--
4 files changed, 421 insertions(+), 10 deletions(-)
diff --git a/lttng-events.c b/lttng-events.c
index 4f30904..b332c29 100644
--- a/lttng-events.c
+++ b/lttng-events.c
@@ -61,6 +61,7 @@ void synchronize_trace(void)
struct lttng_session *lttng_session_create(void)
{
struct lttng_session *session;
+ int i;
mutex_lock(&sessions_mutex);
session = kzalloc(sizeof(struct lttng_session), GFP_KERNEL);
@@ -70,6 +71,11 @@ struct lttng_session *lttng_session_create(void)
INIT_LIST_HEAD(&session->events);
uuid_le_gen(&session->uuid);
list_add(&session->list, &sessions);
+ /* Initialize dumped metadata */
+ for (i = 0; i < NR_METADATA_TYPES; i++) {
+ session->dumped_metadata[i].nr_metadata = 0;
+ session->dumped_metadata[i].next = 0;
+ }
mutex_unlock(&sessions_mutex);
return session;
}
@@ -78,7 +84,8 @@ void lttng_session_destroy(struct lttng_session *session)
{
struct lttng_channel *chan, *tmpchan;
struct lttng_event *event, *tmpevent;
- int ret;
+ struct lttng_metadata_dumped_data *dumped;
+ int ret, i, j;
mutex_lock(&sessions_mutex);
ACCESS_ONCE(session->active) = 0;
@@ -96,6 +103,15 @@ void lttng_session_destroy(struct lttng_session *session)
list_for_each_entry_safe(chan, tmpchan, &session->chan, list)
_lttng_channel_destroy(chan);
list_del(&session->list);
+ /* Destroy dumped metadata */
+ for (i = 0; i < NR_METADATA_TYPES; i++) {
+ dumped = session->dumped_metadata[i].next;
+ for (j = 0; j < session->dumped_metadata[i].nr_metadata; j++) {
+ dumped = dumped->next;
+ kfree(dumped);
+ }
+
+ }
mutex_unlock(&sessions_mutex);
kfree(session);
}
@@ -654,6 +670,13 @@ int _lttng_field_statedump(struct lttng_session *session,
" { encoding = ASCII; }" : "",
field->name);
break;
+ case atype_struct:
+ ret = lttng_metadata_printf(session,
+ " struct %s_%s _%s;\n",
+ field->type.u.ctf_struct.provider,
+ field->type.u.ctf_struct.name,
+ field->name);
+ break;
default:
WARN_ON_ONCE(1);
return -EINVAL;
@@ -662,6 +685,141 @@ int _lttng_field_statedump(struct lttng_session *session,
}
static
+int _lttng_is_type_metadata_dumped(struct lttng_session *session,
+ const struct lttng_metadata *metadata)
+{
+ /* Is the metadata dumped yet ? */
+ struct lttng_metadata_dumped_data *dumped;
+ int is_dumped = 0, i;
+
+ dumped = session->dumped_metadata[metadata->mtype].next;
+ switch (metadata->mtype) {
+ case mtype_struct:
+ for (i = 0; i < session->dumped_metadata[metadata->mtype].nr_metadata; i++) {
+ if (metadata->m.ctf_st.struct_desc ==
+ dumped->dumped_ptr.struct_desc) {
+ is_dumped = 1;
+ break;
+ }
+ dumped = dumped->next;
+ }
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+ return is_dumped;
+}
+
+static int _lttng_type_metadata_mark_dumped(struct lttng_session *session,
+ const struct lttng_metadata *metadata)
+{
+ /* mark this metadata as dumped */
+ struct lttng_metadata_dumped_data *dumped;
+
+ dumped = kzalloc(sizeof(struct lttng_metadata_dumped_data),
+ GFP_KERNEL);
+ if (!dumped)
+ return -ENOMEM;
+
+ switch (metadata->mtype) {
+ case mtype_struct:
+ dumped->dumped_ptr.struct_desc = metadata->m.ctf_st.struct_desc;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+
+ dumped->next = session->dumped_metadata[metadata->mtype].next;
+ session->dumped_metadata[metadata->mtype].next = dumped;
+ session->dumped_metadata[metadata->mtype].nr_metadata++;
+ return 0;
+}
+
+static
+int _lttng_type_metadata_statedump(struct lttng_session *session,
+ const struct lttng_metadata *metadata, unsigned int nr_metadata);
+
+static
+int _lttng_type_metadata_do_statedump(struct lttng_session *session,
+ const struct lttng_metadata *meta)
+{
+ int i, ret = 0;
+
+ switch (meta->mtype) {
+ case mtype_struct:
+ ret = _lttng_type_metadata_statedump(session,
+ meta->m.ctf_st.type_metadata,
+ meta->m.ctf_st.nr_metadata);
+ if (ret)
+ return ret;
+
+ ret = lttng_metadata_printf(session,
+ "struct %s_%s {\n",
+ meta->m.ctf_st.struct_desc->provider,
+ meta->m.ctf_st.struct_desc->name
+ );
+ if (ret)
+ return ret;
+
+ /* Print fields */
+ for (i = 0; i < meta->m.ctf_st.struct_desc->nr_fields; i++) {
+ const struct lttng_event_field *field;
+
+ field = &meta->m.ctf_st.struct_desc->fields[i];
+ ret = _lttng_field_statedump(session, field);
+ if (ret)
+ return ret;
+ }
+ ret = lttng_metadata_printf(session,
+ "};\n\n");
+ if (ret)
+ return ret;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+ if (ret)
+ return ret;
+
+ ret = _lttng_type_metadata_mark_dumped(session, meta);
+ return ret;
+}
+
+static
+int _lttng_type_metadata_statedump(struct lttng_session *session,
+ const struct lttng_metadata *metadata, unsigned int nr_metadata)
+{
+ int i, ret = 0;
+
+ for (i = 0; i < nr_metadata; i++) {
+ const struct lttng_metadata *meta = &metadata[i];
+
+ if (_lttng_is_type_metadata_dumped(session, meta))
+ continue;
+
+ ret = _lttng_type_metadata_do_statedump(session, meta);
+ if (ret)
+ return ret;
+ }
+ return ret;
+}
+
+static
+int _lttng_event_type_metadata_statedump(struct lttng_session *session,
+ struct lttng_event *event)
+{
+ int ret = 0;
+ const struct lttng_event_desc *desc = event->desc;
+
+ ret = _lttng_type_metadata_statedump(session,
+ desc->type_metadata, desc->nr_metadata);
+ return ret;
+}
+
+static
int _lttng_context_metadata_statedump(struct lttng_session *session,
struct lttng_ctx *ctx)
{
@@ -710,6 +868,11 @@ int _lttng_event_metadata_statedump(struct lttng_session *session,
if (chan == session->metadata)
return 0;
+ /* Dump the type metadata for this event */
+ ret = _lttng_event_type_metadata_statedump(session, event);
+ if (ret)
+ goto end;
+
ret = lttng_metadata_printf(session,
"event {\n"
" name = %s;\n"
@@ -746,7 +909,6 @@ int _lttng_event_metadata_statedump(struct lttng_session *session,
ret = _lttng_fields_metadata_statedump(session, event);
if (ret)
goto end;
-
/*
* LTTng space reservation can only reserve multiples of the
* byte size.
diff --git a/lttng-events.h b/lttng-events.h
index 37a5db7..67c49f1 100644
--- a/lttng-events.h
+++ b/lttng-events.h
@@ -47,9 +47,16 @@ enum abstract_types {
atype_array,
atype_sequence,
atype_string,
+ atype_struct,
NR_ABSTRACT_TYPES,
};
+/* Metadata types */
+enum metadata_types {
+ mtype_struct,
+ NR_METADATA_TYPES,
+};
+
/* Update the string_encodings name table in lttng-types.c along with this enum */
enum lttng_string_encodings {
lttng_encode_none = 0,
@@ -115,6 +122,9 @@ struct lttng_type {
struct lttng_basic_type length_type;
struct lttng_basic_type elem_type;
} sequence;
+ struct {
+ const char *name, *provider;
+ } ctf_struct;
} u;
};
@@ -161,12 +171,45 @@ struct lttng_ctx {
unsigned int allocated_fields;
};
+struct lttng_struct_desc {
+ const char *provider, *name;
+ const struct lttng_event_field *fields; /* fields */
+ unsigned int nr_fields;
+ struct module *owner;
+};
+
+struct lttng_metadata {
+ enum metadata_types mtype;
+ union {
+ struct {
+ const struct lttng_struct_desc *struct_desc;
+ const struct lttng_metadata *type_metadata;
+ unsigned int nr_metadata;
+ } ctf_st;
+ } m;
+};
+
+struct lttng_metadata_dumped_data {
+ union {
+ const struct lttng_struct_desc *struct_desc;
+ } dumped_ptr;
+ struct lttng_metadata_dumped_data *next;
+};
+
+struct lttng_metadata_dumped {
+ unsigned int nr_metadata;
+ struct lttng_metadata_dumped_data *next;
+};
+
struct lttng_event_desc {
const char *name;
void *probe_callback;
const struct lttng_event_ctx *ctx; /* context */
const struct lttng_event_field *fields; /* event payload */
+ /* type metadata added by events */
+ const struct lttng_metadata *type_metadata;
unsigned int nr_fields;
+ unsigned int nr_metadata;
struct module *owner;
};
@@ -277,6 +320,7 @@ struct lttng_session {
struct list_head list; /* Session list */
unsigned int free_chan_id; /* Next chan ID to allocate */
uuid_le uuid; /* Trace session unique ID */
+ struct lttng_metadata_dumped dumped_metadata[NR_METADATA_TYPES];
unsigned int metadata_dumped:1;
};
diff --git a/probes/lttng-events-reset.h b/probes/lttng-events-reset.h
index 44e8ba5..dd60ca6 100644
--- a/probes/lttng-events-reset.h
+++ b/probes/lttng-events-reset.h
@@ -20,6 +20,9 @@
/* Reset macros used within TRACE_EVENT to "nothing" */
+#undef TRACE_METADATA
+#define TRACE_METADATA 1
+
#undef __field_full
#define __field_full(_type, _item, _order, _base)
@@ -35,6 +38,9 @@
#undef __string
#define __string(_item, _src)
+#undef __struct
+#define __struct(_provider, _type, _item, _params)
+
#undef tp_assign
#define tp_assign(dest, src)
@@ -47,6 +53,9 @@
#undef tp_strcpy
#define tp_strcpy(dest, src)
+#undef tp_memcpy_struct
+#define tp_memcpy_struct(provider, name, dest, src)
+
#undef __get_str
#define __get_str(field)
@@ -65,6 +74,9 @@
#undef TP_STRUCT__entry
#define TP_STRUCT__entry(args...)
+#undef TP_FIELDS
+#define TP_FIELDS(args...)
+
#undef TP_fast_assign
#define TP_fast_assign(args...)
@@ -94,3 +106,6 @@
#undef TRACE_EVENT_FLAGS
#define TRACE_EVENT_FLAGS(name, value)
+
+#undef TRACEPOINT_STRUCT
+#define TRACEPOINT_STRUCT(_provider, _name, _proto, _args, _fields)
diff --git a/probes/lttng-events.h b/probes/lttng-events.h
index 8a3a886..93f4abc 100644
--- a/probes/lttng-events.h
+++ b/probes/lttng-events.h
@@ -263,9 +263,31 @@ void trace_##_name(void *__data);
#define __string_from_user(_item, _src) \
__string(_item, _src)
+#undef __struct
+#define __struct(_provider, _type, _item, _params) \
+ { \
+ .name = #_item, \
+ .type = \
+ { \
+ .atype = atype_struct, \
+ .u.ctf_struct.provider = #_provider, \
+ .u.ctf_struct.name = #_type, \
+ }, \
+ },
+
#undef TP_STRUCT__entry
#define TP_STRUCT__entry(args...) args /* Only one used in this phase */
+#undef TP_FIELDS
+#define TP_FIELDS(args...) args /* Only one used in this phase */
+
+#undef TRACEPOINT_STRUCT
+#define TRACEPOINT_STRUCT(_provider, _name, _proto, _args, _fields) \
+ static const struct lttng_event_field \
+ __struct_fields___##_provider##_##_name[] = { \
+ _fields \
+ };
+
#undef DECLARE_EVENT_CLASS_NOARGS
#define DECLARE_EVENT_CLASS_NOARGS(_name, _tstruct, _assign, _print) \
static const struct lttng_event_field __event_fields___##_name[] = { \
@@ -301,6 +323,74 @@ static void __event_probe__##_name(void *__data);
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
/*
+ * Stage 3.2 of the trace events.
+ *
+ * Create type metadata description
+ */
+
+#include "lttng-events-reset.h" /* Reset all macros within TRACE_EVENT */
+
+#undef TRACEPOINT_STRUCT
+#define TRACEPOINT_STRUCT(_provider, _name, _proto, _args, _fields) \
+static struct lttng_struct_desc __struct_desc___##_provider##_##_name = {\
+ .fields = __struct_fields___##_provider##_##_name, \
+ .nr_fields = ARRAY_SIZE(__struct_fields___##_provider##_##_name),\
+ .provider = #_provider, \
+ .name = #_name, \
+ .owner = THIS_MODULE, \
+ };
+
+#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
+
+/*
+ * Stage 3.3 of the trace events.
+ *
+ * Associate metadata description to event or event template or other struct
+ */
+
+/* Named field types must be defined in lttng-types.h */
+
+#include "lttng-events-reset.h" /* Reset all macros within TRACE_EVENT */
+
+#undef __struct
+#define __struct(_provider, _type, _item, _params) \
+ { \
+ .mtype = mtype_struct, \
+ .m.ctf_st.struct_desc = &__struct_desc___##_provider##_##_type,\
+ .m.ctf_st.type_metadata = __type_metadata_for__##_provider##_##_type,\
+ .m.ctf_st.nr_metadata = ARRAY_SIZE(__type_metadata_for__##_provider##_##_type),\
+ },
+
+
+#undef TP_STRUCT__entry
+#define TP_STRUCT__entry(args...) args /* Only one used in this phase */
+
+#undef TP_FIELDS
+#define TP_FIELDS(args...) args
+
+#undef TRACEPOINT_STRUCT
+#define TRACEPOINT_STRUCT(_provider, _name, _proto, _args, _fields) \
+static const struct lttng_metadata __type_metadata_for__##_provider##_##_name[] = {\
+ _fields \
+};
+
+
+
+#undef DECLARE_EVENT_CLASS_NOARGS
+#define DECLARE_EVENT_CLASS_NOARGS(_name, _tstruct, _assign, _print) \
+static const struct lttng_metadata __type_metadata_for__##_name[] = { \
+ _tstruct \
+};
+
+#undef DECLARE_EVENT_CLASS
+#define DECLARE_EVENT_CLASS(_name, _proto, _args, _tstruct, _assign, _print) \
+ DECLARE_EVENT_CLASS_NOARGS(_name, PARAMS(_tstruct), PARAMS(_assign), \
+ PARAMS(_print))
+
+#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
+
+
+/*
* Stage 3.9 of the trace events.
*
* Create event descriptions.
@@ -318,9 +408,11 @@ static void __event_probe__##_name(void *__data);
#define DEFINE_EVENT_MAP_NOARGS(_template, _name, _map) \
static const struct lttng_event_desc __event_desc___##_map = { \
.fields = __event_fields___##_template, \
+ .type_metadata = __type_metadata_for__##_template, \
.name = #_map, \
.probe_callback = (void *) TP_PROBE_CB(_template), \
.nr_fields = ARRAY_SIZE(__event_fields___##_template), \
+ .nr_metadata = ARRAY_SIZE(__type_metadata_for__##_template), \
.owner = THIS_MODULE, \
};
@@ -379,9 +471,12 @@ static __used struct lttng_probe_desc TP_ID(__probe_desc___, TRACE_SYSTEM) = {
#undef TP_ID
/*
- * Stage 6 of the trace events.
+ * Stage 6.0 of the trace events.
*
* Create static inline function that calculates event size.
+ *
+ * First stage creates function to calculate sizes of sub-metadata
+ * (with no effect on the dynamic length values)
*/
#include "lttng-events-reset.h" /* Reset all macros within TRACE_EVENT */
@@ -403,6 +498,57 @@ static __used struct lttng_probe_desc TP_ID(__probe_desc___, TRACE_SYSTEM) = {
__event_len += lib_ring_buffer_align(__event_len, lttng_alignof(u32)); \
__event_len += sizeof(u32); \
__event_len += lib_ring_buffer_align(__event_len, lttng_alignof(_type)); \
+ __event_len += sizeof(_type) * (_length); \
+
+#undef __string
+#define __string(_item, _src) \
+ __event_len += strlen(_src) + 1;
+
+/*
+ * strlen_user includes \0. If returns 0, it faulted, so we set size to
+ * 1 (\0 only).
+ */
+#undef __string_from_user
+#define __string_from_user(_item, _src) \
+ __event_len += max_t(size_t, lttng_strlen_user_inatomic(_src), 1);
+
+#undef __struct
+#define __struct(_provider, _type, _item, _params) \
+ __event_len += __struct_get_size__##_provider##_##_type(_params);\
+
+#undef TP_PROTO
+#define TP_PROTO(args...) args
+
+#undef TP_STRUCT__entry
+#define TP_STRUCT__entry(args...) args
+
+#undef TP_FIELDS
+#define TP_FIELDS(args...) args
+
+#undef TRACEPOINT_STRUCT
+#define TRACEPOINT_STRUCT(_provider, _name, _proto, _args, _fields) \
+static inline size_t __struct_get_size__##_provider##_##_name(_proto) \
+ { \
+ size_t __event_len = 0; \
+ \
+ _fields \
+ return __event_len; \
+}
+
+#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
+
+/*
+ * Stage 6.1 of the trace events.
+ *
+ * Create static inline function that calculates event size, this time adding
+ * the size to the dynamic_len array
+ */
+
+#undef __dynamic_array_enc_ext
+#define __dynamic_array_enc_ext(_type, _item, _length, _order, _base, _encoding)\
+ __event_len += lib_ring_buffer_align(__event_len, lttng_alignof(u32)); \
+ __event_len += sizeof(u32); \
+ __event_len += lib_ring_buffer_align(__event_len, lttng_alignof(_type));\
__dynamic_len[__dynamic_len_idx] = (_length); \
__event_len += sizeof(_type) * __dynamic_len[__dynamic_len_idx]; \
__dynamic_len_idx++;
@@ -420,11 +566,13 @@ static __used struct lttng_probe_desc TP_ID(__probe_desc___, TRACE_SYSTEM) = {
__event_len += __dynamic_len[__dynamic_len_idx++] = \
max_t(size_t, lttng_strlen_user_inatomic(_src), 1);
-#undef TP_PROTO
-#define TP_PROTO(args...) args
+#undef __struct
+#define __struct(_provider, _type, _item, _params) \
+ __event_len += __dynamic_len[__dynamic_len_idx++] = \
+ __struct_get_size__##_provider##_##_type(_params);
-#undef TP_STRUCT__entry
-#define TP_STRUCT__entry(args...) args
+#undef TRACEPOINT_STRUCT
+#define TRACEPOINT_STRUCT(_provider, _name, _proto, _args, _fields)
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(_name, _proto, _args, _tstruct, _assign, _print) \
@@ -470,12 +618,36 @@ static inline size_t __event_get_size__##_name(size_t *__dynamic_len, _proto) \
#undef __string_from_user
#define __string_from_user(_item, _src)
+#undef __struct
+#define __struct(_provider, _type, _item, _params) \
+ __event_align = max_t(size_t, __event_align, \
+ __instruct_get_align__##_provider##_##_type(_params));
+
#undef TP_PROTO
#define TP_PROTO(args...) args
+#undef TP_ARGS
+#define TP_ARGS(args...) args
+
#undef TP_STRUCT__entry
#define TP_STRUCT__entry(args...) args
+#undef TP_FIELDS
+#define TP_FIELDS(args...) args
+
+#undef TRACEPOINT_STRUCT
+#define TRACEPOINT_STRUCT(_provider, _name, _proto, _args, _fields) \
+static inline size_t __struct_get_align__##_provider##_##_name(_proto) \
+{ \
+ size_t __event_align = 1; \
+ _fields \
+ return __event_align; \
+} \
+static inline size_t __instruct_get_align__##_provider##_##_name(_proto)\
+{ \
+ return __struct_get_align__##_provider##_##_name(_args); \
+}
+
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(_name, _proto, _args, _tstruct, _assign, _print) \
static inline size_t __event_get_align__##_name(_proto) \
@@ -487,7 +659,6 @@ static inline size_t __event_get_align__##_name(_proto) \
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
-
/*
* Stage 8 of the trace events.
*
@@ -517,6 +688,9 @@ static inline size_t __event_get_align__##_name(_proto) \
#define __string_from_user(_item, _src) \
__string(_item, _src)
+#undef __struct
+#define __struct(_provider, _type, _item, _params) char _item;
+
#undef TP_STRUCT__entry
#define TP_STRUCT__entry(args...) args
@@ -528,7 +702,6 @@ struct __event_typemap__##_name { \
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
-
/*
* Stage 9 of the trace events.
*
@@ -568,6 +741,11 @@ __end_field_##_item:
#define __string_from_user(_item, _src) \
__string(_item, _src)
+#undef __struct
+#define __struct(_provider, _type, _item, _params) \
+ goto __assign_##_item; \
+__end_field_##_item:
+
/*
* Macros mapping tp_assign() to "=", tp_memcpy() to memcpy() and tp_strcpy() to
* strcpy().
@@ -624,12 +802,24 @@ __assign_##dest##_2: \
#define tp_memcpy_dyn_from_user(dest, src) \
tp_memcpy_dyn_gen(event_write_from_user, dest, src)
+#undef tp_memcpy_struct_gen
+#define tp_memcpy_struct_gen(write_ops, provider, name, dest, src) \
+__assign_##dest: \
+ lib_ring_buffer_align_ctx(&__ctx, __struct_get_align__##provider##_##name(src));\
+ __chan->ops->write_ops(&__ctx, src, \
+ sizeof(__typemap.dest) * __get_dynamic_array_len(dest));\
+ goto __end_field_##dest;
+
+#undef tp_memcpy_struct
+#define tp_memcpy_struct(provider, name, dest, src) \
+ tp_memcpy_struct_gen(event_write, provider, name, dest, src)
+
/*
* The string length including the final \0.
*/
#undef tp_copy_string_from_user
#define tp_copy_string_from_user(dest, src) \
- __assign_##dest: \
+__assign_##dest: \
{ \
size_t __ustrlen; \
\
--
1.8.2.1
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