perf probe: Fix use of kernel image path given by 'k' option

Users were not being able to have the explicitely specified vmlinux
pathname used, instead a search on the vmlinux path was always being
made.

Reported-by: Francis Moreau <[e-mail]>
Acked-by: Masami Hiramatsu <[e-mail]>
Cc: [e-mail]
Cc: Francis Moreau <[e-mail]>
Cc: Franck Bui-Huu <[e-mail]>
Cc: Masami Hiramatsu <[e-mail]>
LPU-Reference: <[e-mail]>
Signed-off-by: Franck Bui-Huu <[e-mail]>
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/builtin-probe.c

···
 	     !params.show_lines))
 		usage_with_options(probe_usage, options);
 
+	/*
+	 * Only consider the user's kernel image path if given.
+	 */
+	symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
+
 	if (params.list_events) {
 		if (params.mod_events) {
 			pr_err("  Error: Don't use --list with --add/--del.\n");

tools/perf/util/probe-event.c

···
 const char *kernel_get_module_path(const char *module)
 {
 	struct dso *dso;
+	struct map *map;
+	const char *vmlinux_name;
 
 	if (module) {
 		list_for_each_entry(dso, &machine.kernel_dsos, node) {
···
 		}
 		pr_debug("Failed to find module %s.\n", module);
 		return NULL;
+	}
+
+	map = machine.vmlinux_maps[MAP__FUNCTION];
+	dso = map->dso;
+
+	vmlinux_name = symbol_conf.vmlinux_name;
+	if (vmlinux_name) {
+		if (dso__load_vmlinux(dso, map, vmlinux_name, NULL) <= 0)
+			return NULL;
 	} else {
-		dso = machine.vmlinux_maps[MAP__FUNCTION]->dso;
-		if (dso__load_vmlinux_path(dso,
-			 machine.vmlinux_maps[MAP__FUNCTION], NULL) < 0) {
+		if (dso__load_vmlinux_path(dso, map, NULL) < 0) {
 			pr_debug("Failed to load kernel map.\n");
 			return NULL;
 		}

tools/perf/util/symbol.c

···
 	return -1;
 }
 
-static int dso__load_vmlinux(struct dso *self, struct map *map,
-			     const char *vmlinux, symbol_filter_t filter)
+int dso__load_vmlinux(struct dso *self, struct map *map,
+		      const char *vmlinux, symbol_filter_t filter)
 {
 	int err = -1, fd;
 

tools/perf/util/symbol.h

···
 struct dso *__dsos__findnew(struct list_head *head, const char *name);
 
 int dso__load(struct dso *self, struct map *map, symbol_filter_t filter);
+int dso__load_vmlinux(struct dso *self, struct map *map,
+		      const char *vmlinux, symbol_filter_t filter);
 int dso__load_vmlinux_path(struct dso *self, struct map *map,
 			   symbol_filter_t filter);
 int dso__load_kallsyms(struct dso *self, const char *filename, struct map *map,