Commit-ID: d4ae42139289cbe38d5b84fa1558161d330d6e54
Gitweb: http://git.kernel.org/tip/d4ae42139289cbe38d5b84fa1558161d330d6e54
Author: Wang Nan <wangnan0@xxxxxxxxxx>
AuthorDate: Sat, 18 Apr 2015 17:50:20 +0200
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 29 Apr 2015 10:37:49 -0300
perf data: Fix signedness of value
When converting int values, perf first extractes it to a ulonglong, then
feeds it to babeltrace as a signed value.
For negative 32 bit values (for example, return values of failed
syscalls), the extracted data should be something like 0xfffffffe (-2).
It becomes a large int64 value.
Babeltrace denies to insert it with bt_ctf_field_signed_integer_set_value()
because it is larger than 0x7fffffff, the largest positive value a
32 bit int can be.
This patch introduces adjust_signedness(), which fills high bits of
ulonglong with 1 if the value is negative.
Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: He Kuang <hekuang@xxxxxxxxxx>
Cc: Jeremie Galarneau <jgalar@xxxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Tom Zanussi <tzanussi@xxxxxxxxx>
Link: http://lkml.kernel.org/r/1429372220-6406-8-git-send-email-jolsa@xxxxxxxxxx
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
[ s/signess/signedness/g ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/data-convert-bt.c | 64 +++++++++++++++++++++++++++++++--------
1 file changed, 52 insertions(+), 12 deletions(-)
diff --git a/tools/perf/util/data-convert-bt.c b/tools/perf/util/data-convert-bt.c
index 8eda4ed..5bfc119 100644
--- a/tools/perf/util/data-convert-bt.c
+++ b/tools/perf/util/data-convert-bt.c
@@ -166,6 +166,43 @@ get_tracepoint_field_type(struct ctf_writer *cw, struct format_field *field)
return cw->data.u32;
}
+static unsigned long long adjust_signedness(unsigned long long value_int, int size)
+{
+ unsigned long long value_mask;
+
+ /*
+ * value_mask = (1 << (size * 8 - 1)) - 1.
+ * Directly set value_mask for code readers.
+ */
+ switch (size) {
+ case 1:
+ value_mask = 0x7fULL;
+ break;
+ case 2:
+ value_mask = 0x7fffULL;
+ break;
+ case 4:
+ value_mask = 0x7fffffffULL;
+ break;
+ case 8:
+ /*
+ * For 64 bit value, return it self. There is no need
+ * to fill high bit.
+ */
+ /* Fall through */
+ default:
+ /* BUG! */
+ return value_int;
+ }
+
+ /* If it is a positive value, don't adjust. */
+ if ((value_int & (~0ULL - value_mask)) == 0)
+ return value_int;
+
+ /* Fill upper part of value_int with 1 to make it a negative long long. */
+ return (value_int & value_mask) | ~value_mask;
+}
+
static int add_tracepoint_field_value(struct ctf_writer *cw,
struct bt_ctf_event_class *event_class,
struct bt_ctf_event *event,
@@ -177,7 +214,6 @@ static int add_tracepoint_field_value(struct ctf_writer *cw,
struct bt_ctf_field *field;
const char *name = fmtf->name;
void *data = sample->raw_data;
- unsigned long long value_int;
unsigned long flags = fmtf->flags;
unsigned int n_items;
unsigned int i;
@@ -222,11 +258,6 @@ static int add_tracepoint_field_value(struct ctf_writer *cw,
type = get_tracepoint_field_type(cw, fmtf);
for (i = 0; i < n_items; i++) {
- if (!(flags & FIELD_IS_STRING))
- value_int = pevent_read_number(
- fmtf->event->pevent,
- data + offset + i * len, len);
-
if (flags & FIELD_IS_ARRAY)
field = bt_ctf_field_array_get_field(array_field, i);
else
@@ -240,12 +271,21 @@ static int add_tracepoint_field_value(struct ctf_writer *cw,
if (flags & FIELD_IS_STRING)
ret = bt_ctf_field_string_set_value(field,
data + offset + i * len);
- else if (!(flags & FIELD_IS_SIGNED))
- ret = bt_ctf_field_unsigned_integer_set_value(
- field, value_int);
- else
- ret = bt_ctf_field_signed_integer_set_value(
- field, value_int);
+ else {
+ unsigned long long value_int;
+
+ value_int = pevent_read_number(
+ fmtf->event->pevent,
+ data + offset + i * len, len);
+
+ if (!(flags & FIELD_IS_SIGNED))
+ ret = bt_ctf_field_unsigned_integer_set_value(
+ field, value_int);
+ else
+ ret = bt_ctf_field_signed_integer_set_value(
+ field, adjust_signedness(value_int, len));
+ }
+
if (ret) {
pr_err("failed to set file value %s\n", name);
goto err_put_field;
--
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