ksym_tracer: Support read accesses independent of read/write.

All of the infrastructure already exists to support read accesses
for platforms that support a read access independently of read/write
(such as in the case of the SuperH UBC). This just trivially hooks
up the read case by itself.

Signed-off-by: Paul Mundt <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Li Zefan <[e-mail]>
Cc: Prasad <[e-mail]>
Cc: Alan Stern <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Arnaldo Carvalho de Melo <[e-mail]>
Cc: Steven Rostedt <[e-mail]>
Cc: Jan Kiszka <[e-mail]>
Cc: Jiri Slaby <[e-mail]>
Cc: Avi Kivity <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Mike Galbraith <[e-mail]>
Cc: Masami Hiramatsu <[e-mail]>
Cc: Arjan van de Ven <[e-mail]>
LKML-Reference: <[e-mail]>
Signed-off-by: Frederic Weisbecker <[e-mail]>

kernel/trace/trace_ksym.c

···
 		access |= HW_BREAKPOINT_X;
 
 	switch (access) {
+	case HW_BREAKPOINT_R:
 	case HW_BREAKPOINT_W:
 	case HW_BREAKPOINT_W | HW_BREAKPOINT_R:
 		return access;
···
 
 	hlist_for_each_entry(entry, node, &ksym_filter_head, ksym_hlist) {
 		ret = trace_seq_printf(s, "%pS:", (void *)entry->ksym_addr);
-		if (entry->type == HW_BREAKPOINT_W)
+		if (entry->type == HW_BREAKPOINT_R)
+			ret = trace_seq_puts(s, "r--\n");
+		else if (entry->type == HW_BREAKPOINT_W)
 			ret = trace_seq_puts(s, "-w-\n");
 		else if (entry->type == (HW_BREAKPOINT_W | HW_BREAKPOINT_R))
 			ret = trace_seq_puts(s, "rw-\n");
···
 		return TRACE_TYPE_PARTIAL_LINE;
 
 	switch (field->type) {
+	case HW_BREAKPOINT_R:
+		ret = trace_seq_printf(s, " R  ");
+		break;
 	case HW_BREAKPOINT_W:
 		ret = trace_seq_printf(s, " W  ");
 		break;
···
 	access_type = entry->type;
 
 	switch (access_type) {
+	case HW_BREAKPOINT_R:
+		seq_puts(m, "  R           ");
+		break;
 	case HW_BREAKPOINT_W:
 		seq_puts(m, "  W           ");
 		break;