samples/bpf: adjust rlimit RLIMIT_MEMLOCK for traceex2, tracex3 and tracex4

Needed to adjust max locked memory RLIMIT_MEMLOCK for testing these bpf samples
as these are using more and larger maps than can fit in distro default 64Kbytes limit.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/samples/bpf/tracex4_user.c b/samples/bpf/tracex4_user.c
index 03449f77..22c644f 100644
--- a/samples/bpf/tracex4_user.c
+++ b/samples/bpf/tracex4_user.c
@@ -12,6 +12,8 @@
 #include <string.h>
 #include <time.h>
 #include <linux/bpf.h>
+#include <sys/resource.h>
+
 #include "libbpf.h"
 #include "bpf_load.h"
 
@@ -50,11 +52,17 @@ static void print_old_objects(int fd)
 
 int main(int ac, char **argv)
 {
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 	char filename[256];
 	int i;
 
 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK, RLIM_INFINITY)");
+		return 1;
+	}
+
 	if (load_bpf_file(filename)) {
 		printf("%s", bpf_log_buf);
 		return 1;