Messages in this thread Patch in this message | | | Date | Mon, 11 Nov 2013 16:08:10 -0500 | From | Steven Rostedt <> | Subject | [PATCH] tools lib traceevent: Add direct access to dynamic arrays |
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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
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