mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

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@huawei.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jeremie Galarneau <jgalar@efficios.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tom Zanussi <tzanussi@gmail.com>
Link: http://lkml.kernel.org/r/1429372220-6406-8-git-send-email-jolsa@kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
[ s/signess/signedness/g ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Wang Nan 2015-04-18 17:50:20 +02:00 committed by Arnaldo Carvalho de Melo
parent e0a7cce536
commit d4ae421392
1 changed files with 52 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

64
tools/perf/util/data-convert-bt.c
View File

@ -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;