[PATCH 31/32] tools lib traceevent: Support function __get_dynamic_array_len

From: Wang Nan
Date: Fri Aug 28 2015 - 03:09:44 EST


From: He Kuang <hekuang@xxxxxxxxxx>

Support helper function __get_dynamic_array_len() in libtraceevent,
this function is used accompany with __print_array() or __print_hex(),
but currently it is not an available function in the function list of
process_function().

The total allocated length of the dynamic array is embedded in the top
half of __data_loc_##item field. This patch adds new arg type
PRINT_DYNAMIC_ARRAY_LEN to return the length to eval_num_arg(),

Signed-off-by: He Kuang <hekuang@xxxxxxxxxx>
Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: pi3orama@xxxxxxx
Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/1437448130-134621-2-git-send-email-hekuang@xxxxxxxxxx
---
tools/lib/traceevent/event-parse.c | 56 +++++++++++++++++++++-
tools/lib/traceevent/event-parse.h | 1 +
.../perf/util/scripting-engines/trace-event-perl.c | 1 +
.../util/scripting-engines/trace-event-python.c | 1 +
4 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index 4d88593..1244797 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -848,6 +848,7 @@ static void free_arg(struct print_arg *arg)
free(arg->bitmask.bitmask);
break;
case PRINT_DYNAMIC_ARRAY:
+ case PRINT_DYNAMIC_ARRAY_LEN:
free(arg->dynarray.index);
break;
case PRINT_OP:
@@ -2729,6 +2730,42 @@ process_dynamic_array(struct event_format *event, struct print_arg *arg, char **
}

static enum event_type
+process_dynamic_array_len(struct event_format *event, struct print_arg *arg,
+ char **tok)
+{
+ struct format_field *field;
+ enum event_type type;
+ char *token;
+
+ if (read_expect_type(EVENT_ITEM, &token) < 0)
+ goto out_free;
+
+ arg->type = PRINT_DYNAMIC_ARRAY_LEN;
+
+ /* Find the field */
+ field = pevent_find_field(event, token);
+ if (!field)
+ goto out_free;
+
+ arg->dynarray.field = field;
+ arg->dynarray.index = 0;
+
+ if (read_expected(EVENT_DELIM, ")") < 0)
+ goto out_err;
+
+ type = read_token(&token);
+ *tok = token;
+
+ return type;
+
+ out_free:
+ free_token(token);
+ out_err:
+ *tok = NULL;
+ return EVENT_ERROR;
+}
+
+static enum event_type
process_paren(struct event_format *event, struct print_arg *arg, char **tok)
{
struct print_arg *item_arg;
@@ -2975,6 +3012,10 @@ process_function(struct event_format *event, struct print_arg *arg,
free_token(token);
return process_dynamic_array(event, arg, tok);
}
+ if (strcmp(token, "__get_dynamic_array_len") == 0) {
+ free_token(token);
+ return process_dynamic_array_len(event, arg, tok);
+ }

func = find_func_handler(event->pevent, token);
if (func) {
@@ -3655,14 +3696,25 @@ eval_num_arg(void *data, int size, struct event_format *event, struct print_arg
goto out_warning_op;
}
break;
+ case PRINT_DYNAMIC_ARRAY_LEN:
+ offset = pevent_read_number(pevent,
+ data + arg->dynarray.field->offset,
+ arg->dynarray.field->size);
+ /*
+ * The total allocated length of the dynamic array is
+ * stored in the top half of the field, and the offset
+ * is in the bottom half of the 32 bit field.
+ */
+ val = (unsigned long long)(offset >> 16);
+ break;
case PRINT_DYNAMIC_ARRAY:
/* Without [], we pass the address to the dynamic data */
offset = pevent_read_number(pevent,
data + arg->dynarray.field->offset,
arg->dynarray.field->size);
/*
- * The actual length of the dynamic array is stored
- * in the top half of the field, and the offset
+ * The total allocated length of the dynamic array is
+ * stored in the top half of the field, and the offset
* is in the bottom half of the 32 bit field.
*/
offset &= 0xffff;
diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
index 204befb..6fc83c7 100644
--- a/tools/lib/traceevent/event-parse.h
+++ b/tools/lib/traceevent/event-parse.h
@@ -294,6 +294,7 @@ enum print_arg_type {
PRINT_OP,
PRINT_FUNC,
PRINT_BITMASK,
+ PRINT_DYNAMIC_ARRAY_LEN,
};

struct print_arg {
diff --git a/tools/perf/util/scripting-engines/trace-event-perl.c b/tools/perf/util/scripting-engines/trace-event-perl.c
index 1bd593b..544509c 100644
--- a/tools/perf/util/scripting-engines/trace-event-perl.c
+++ b/tools/perf/util/scripting-engines/trace-event-perl.c
@@ -221,6 +221,7 @@ static void define_event_symbols(struct event_format *event,
break;
case PRINT_BSTRING:
case PRINT_DYNAMIC_ARRAY:
+ case PRINT_DYNAMIC_ARRAY_LEN:
case PRINT_STRING:
case PRINT_BITMASK:
break;
diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
index ace2484..aa9e125 100644
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -251,6 +251,7 @@ static void define_event_symbols(struct event_format *event,
/* gcc warns for these? */
case PRINT_BSTRING:
case PRINT_DYNAMIC_ARRAY:
+ case PRINT_DYNAMIC_ARRAY_LEN:
case PRINT_FUNC:
case PRINT_BITMASK:
/* we should warn... */
--
2.1.0

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