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

[Howard Cochran]

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 <hcoc...@lexmark.com>
---
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

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[Namhyung Kim]

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

[Howard Cochran]

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 <hcoc...@lexmark.com>
---

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,

1.7.10.2.4.g36f8dc1

[tip-bot for Howard Cochran]

Commit-ID: b30f75eba27a9ab0704cbc501e9be3b025ce56fe
Gitweb: http://git.kernel.org/tip/b30f75eba27a9ab0704cbc501e9be3b025ce56fe
Author: Howard Cochran <hcoc...@lexmark.com>
AuthorDate: Fri, 1 Nov 2013 17:53:56 -0400
Committer: Arnaldo Carvalho de Melo <ac...@redhat.com>
CommitDate: Mon, 4 Nov 2013 14:34:43 -0300

tools lib traceevent: 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 <hcoc...@lexmark.com>

Cc: Andrew Morton <ak...@linux-foundation.org>
Cc: Frederic Weisbecker <fwei...@gmail.com>
Cc: Ingo Molnar <mi...@kernel.org>
Cc: Namhyung Kim <namh...@kernel.org>
Link: http://lkml.kernel.org/r/1381503349-12271-1-gi...@lexmark.com
[ Removed "polish compare", we don't do that here ]
Signed-off-by: Steven Rostedt <ros...@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <ac...@redhat.com>
---
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 013c8d3..0a1ffe0 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -3588,15 +3588,23 @@ 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 (arg->hex.field->type == PRINT_DYNAMIC_ARRAY) {

+ 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)
--