perf probe: Finder fails to resolve function name to address

If DIE entries corresponding to declarations appear before definition
entry, probe finder returns error instead of continuing to look further
for a definition entry.

This patch ensures we reach to the DIE entry corresponding to the
definition and get the function address.

V2: A simpler solution based on Masami's suggestion.

Signed-off-by: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/4F703FB9.9020407@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/probe-finder.c

@@ -972,10 +972,12 @@ static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
 	struct dwarf_callback_param *param = data;
 	struct probe_finder *pf = param->data;
 	struct perf_probe_point *pp = &pf->pev->point;
+	Dwarf_Attribute attr;
 
 	/* Check tag and diename */
 	if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
-	    !die_compare_name(sp_die, pp->function))
+	    !die_compare_name(sp_die, pp->function) ||
+	    dwarf_attr(sp_die, DW_AT_declaration, &attr))
 		return DWARF_CB_OK;
 
 	/* Check declared file */