From 0497a9ebaf7ae4d573497b3e053ad4c3d5c9921d Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 11 Nov 2013 16:08:10 -0500 Subject: 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 Signed-off-by: Steven Rostedt Tested-by: Jiri Olsa Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Jiri Olsa Cc: Namhyung Kim Link: http://lkml.kernel.org/r/20131111160810.0ba9df7d@gandalf.local.home Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/traceevent/event-parse.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'tools') diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c index 8f450adaa9c2..0362d575de7d 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; } -- cgit v1.2.2