Merge tag 'perf-urgent-for-mingo-4.13-20170712' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fix from Arnaldo Carvalho de Melo:

 - Accept zero as the kernel base address, to resolve symbols on
   architectures that don't partition the virtual address space in
   kernel/user, S/390, is one of such architectures and was where
   this problem was noticed. (Arnaldo Carvalho de Melo)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

tools/perf/util/machine.c

@@ -2209,7 +2209,7 @@ int machine__get_kernel_start(struct machine *machine)
 	machine->kernel_start = 1ULL << 63;
 	if (map) {
 		err = map__load(map);
-		if (map->start)
+		if (!err)
 			machine->kernel_start = map->start;
 	}
 	return err;