Re: event filtering with trace-cmd

[Steven Rostedt]

On Wed, 2013-06-12 at 12:22 -0400, Steven Rostedt wrote:

> > # sudo trace-cmd record -e brcmfmac:brcmf_dbg -f 'level & 0x40000'
> > disable all
> > enable brcmfmac:brcmf_dbg
> > path = /sys/kernel/debug/tracing/events/brcmfmac/brcmf_dbg/enable
> > (level & 0x40000)
> > ^
> > parse_error: Invalid operator
> > 
> 
> The record -f command passes the filter into the kernel
> file /sys/kerne/debug/tracing/events/brcmfmac/brcmf_dbg/filter, and the
> error is actually coming from the kernel itself. Looking at the code, we
> do not currently accept binary operations. Although, it shouldn't be too
> hard to add. I may go and implement it for 3.11.
> 

Here, can you apply this patch and see if it does what you expect?

Thanks,

-- Steve

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index e1b653f..111eddf 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -35,6 +35,7 @@
 
 enum filter_op_ids
 {
+	OP_BAND,
 	OP_OR,
 	OP_AND,
 	OP_GLOB,
@@ -64,6 +65,7 @@ static struct filter_op filter_ops[] = {
 	{ OP_LE,	"<=",		5 },
 	{ OP_GT,	">",		5 },
 	{ OP_GE,	">=",		5 },
+	{ OP_BAND,	"&",		6 },
 	{ OP_NONE,	"OP_NONE",	0 },
 	{ OP_OPEN_PAREN, "(",		0 },
 };
@@ -156,6 +158,9 @@ static int filter_pred_##type(struct filter_pred *pred, void *event)	\
 	case OP_GE:							\
 		match = (*addr >= val);					\
 		break;							\
+	case OP_BAND:							\
+		match = (*addr & val);					\
+		break;							\
 	default:							\
 		break;							\
 	}								\


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