2013-10-11 15:39:55

by Howard Cochran

Subject: [PATCH] trace-cmd: Handle __print_hex(__get_dynamic_array(fieldname), len)

The kernel has a few events with a format similar to this excerpt:
field:unsigned int len; offset:12; size:4; signed:0;
field:__data_loc unsigned char[] data_array; offset:16; size:4; signed:0;
print fmt: "%s", __print_hex(__get_dynamic_array(data_array), REC->len)

trace-cmd could already parse that arg correctly, but print_str_arg()
was unable to handle the first parameter being a dynamic array. (It
just printed a "field not found" warning).

Teach print_str_arg's PRINT_HEX case to handle the nested
PRINT_DYNAMIC_ARRAY correctly. The output now matches the kernel's own
formatting for this case.

Signed-off-by: Howard Cochran <[email protected]>
---
event-parse.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/event-parse.c b/event-parse.c
index e961553..fdb176e 100644
--- a/event-parse.c
+++ b/event-parse.c
@@ -3550,15 +3550,23 @@ static void print_str_arg(struct trace_seq *s, void *data, int size,
}
break;
case PRINT_HEX:
- field = arg->hex.field->field.field;
- if (!field) {
- str = arg->hex.field->field.name;
- field = pevent_find_any_field(event, str);
- if (!field)
- goto out_warning_field;
- arg->hex.field->field.field = field;
+ if (PRINT_DYNAMIC_ARRAY == arg->hex.field->type) {
+ unsigned long offset;
+ offset = pevent_read_number(pevent,
+ data + arg->hex.field->dynarray.field->offset,
+ arg->hex.field->dynarray.field->size);
+ hex = data + (offset & 0xffff);
+ } else {
+ field = arg->hex.field->field.field;
+ if (!field) {
+ str = arg->hex.field->field.name;
+ field = pevent_find_any_field(event, str);
+ if (!field)
+ goto out_warning_field;
+ arg->hex.field->field.field = field;
+ }
+ hex = data + field->offset;
}
- hex = data + field->offset;
len = eval_num_arg(data, size, event, arg->hex.size);
for (i = 0; i < len; i++) {
if (i)
--
1.7.10.2.4.g36f8dc1

2013-10-14 01:22:59

by Namhyung Kim

Subject: Re: [PATCH] trace-cmd: Handle __print_hex(__get_dynamic_array(fieldname), len)

Hi Howard,

On Fri, 11 Oct 2013 10:55:49 -0400, Howard Cochran wrote:
> The kernel has a few events with a format similar to this excerpt:
> field:unsigned int len; offset:12; size:4; signed:0;
> field:__data_loc unsigned char[] data_array; offset:16; size:4; signed:0;
> print fmt: "%s", __print_hex(__get_dynamic_array(data_array), REC->len)
>
> trace-cmd could already parse that arg correctly, but print_str_arg()
> was unable to handle the first parameter being a dynamic array. (It
> just printed a "field not found" warning).
>
> Teach print_str_arg's PRINT_HEX case to handle the nested
> PRINT_DYNAMIC_ARRAY correctly. The output now matches the kernel's own
> formatting for this case.

It seems that it needs to be added to libtraceevent also. Could you
also send a patch against tools/lib/traceevent/event-parse.c in the
Linux kernel source?

Thanks,
Namhyung

>
> Signed-off-by: Howard Cochran <[email protected]>
> ---
> event-parse.c | 24 ++++++++++++++++--------
> 1 file changed, 16 insertions(+), 8 deletions(-)
>
> diff --git a/event-parse.c b/event-parse.c
> index e961553..fdb176e 100644
> --- a/event-parse.c
> +++ b/event-parse.c
> @@ -3550,15 +3550,23 @@ static void print_str_arg(struct trace_seq *s, void *data, int size,
> }
> break;
> case PRINT_HEX:
> - field = arg->hex.field->field.field;
> - if (!field) {
> - str = arg->hex.field->field.name;
> - field = pevent_find_any_field(event, str);
> - if (!field)
> - goto out_warning_field;
> - arg->hex.field->field.field = field;
> + if (PRINT_DYNAMIC_ARRAY == arg->hex.field->type) {
> + unsigned long offset;
> + offset = pevent_read_number(pevent,
> + data + arg->hex.field->dynarray.field->offset,
> + arg->hex.field->dynarray.field->size);
> + hex = data + (offset & 0xffff);
> + } else {
> + field = arg->hex.field->field.field;
> + if (!field) {
> + str = arg->hex.field->field.name;
> + field = pevent_find_any_field(event, str);
> + if (!field)
> + goto out_warning_field;
> + arg->hex.field->field.field = field;
> + }
> + hex = data + field->offset;
> }
> - hex = data + field->offset;
> len = eval_num_arg(data, size, event, arg->hex.size);
> for (i = 0; i < len; i++) {
> if (i)

2013-10-14 18:46:07

by Howard Cochran

Subject: [PATCH] tools lib traceevent: Handle __print_hex(__get_dynamic_array(fld), len)

The kernel has a few events with a format similar to this excerpt:
field:unsigned int len; offset:12; size:4; signed:0;
field:__data_loc unsigned char[] data_array; offset:16; size:4; signed:0;
print fmt: "%s", __print_hex(__get_dynamic_array(data_array), REC->len)

event-parse could already parse that arg correctly, but print_str_arg()
was unable to handle the first parameter being a dynamic array. (It
just printed a "field not found" warning).

Teach print_str_arg's PRINT_HEX case to handle the nested
PRINT_DYNAMIC_ARRAY correctly. The output now matches the kernel's own
formatting for this case.

Signed-off-by: Howard Cochran <[email protected]>
---
tools/lib/traceevent/event-parse.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index d1c2a6a..bcfa6b7 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -3565,15 +3565,23 @@ static void print_str_arg(struct trace_seq *s, void *data, int size,
}
break;
case PRINT_HEX:
- field = arg->hex.field->field.field;
- if (!field) {
- str = arg->hex.field->field.name;
- field = pevent_find_any_field(event, str);
- if (!field)
- goto out_warning_field;
- arg->hex.field->field.field = field;
+ if (PRINT_DYNAMIC_ARRAY == arg->hex.field->type) {
+ unsigned long offset;
+ offset = pevent_read_number(pevent,
+ data + arg->hex.field->dynarray.field->offset,
+ arg->hex.field->dynarray.field->size);
+ hex = data + (offset & 0xffff);
+ } else {
+ field = arg->hex.field->field.field;
+ if (!field) {
+ str = arg->hex.field->field.name;
+ field = pevent_find_any_field(event, str);
+ if (!field)
+ goto out_warning_field;
+ arg->hex.field->field.field = field;
+ }
+ hex = data + field->offset;
}
- hex = data + field->offset;
len = eval_num_arg(data, size, event, arg->hex.size);
for (i = 0; i < len; i++) {
if (i)
--
1.7.10.2.4.g36f8dc1