lkml.org 
[lkml]   [2013]   [Nov]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] tools lib traceevent: Add direct access to dynamic arrays

Jiri Olsa was writing a plugin for the cfg80211_tx_mlme_mgmt trace
event, and was not able to get the implemented function working.
The event's print fmt looks like:

"netdev:%s(%d), ftype:0x%.2x", REC->name, REC->ifindex,
__le16_to_cpup((__le16 *)__get_dynamic_array(frame))

As there's no helper function for __le16_to_cpup(), Jiri was creating one
with a plugin. But unfortunately, it would not work even though he set
up the plugin correctly.

The problem is that the function parameters do not handle the helper
function "__get_dynamic_array()", and that passes in a NULL pointer.

Adding PRINT_DYNAMIC_ARRAY direct support to eval_num_arg() allows the
use of __get_dynamic_array() in function parameters.

Reported-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
tools/lib/traceevent/event-parse.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index 8f450ad..0362d57 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -3435,6 +3435,19 @@ eval_num_arg(void *data, int size, struct event_format *event, struct print_arg
goto out_warning_op;
}
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
+ * is in the bottom half of the 32 bit field.
+ */
+ offset &= 0xffff;
+ val = (unsigned long long)(data + offset);
+ break;
default: /* not sure what to do there */
return 0;
}
--
1.8.4.rc3


\
 
 \ /
  Last update: 2013-11-11 22:41    [W:0.056 / U:1.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site