samples/bpf: Extend RLIMIT_MEMLOCK for xdp_{sample_pkts, router_ipv4}

There is a common problem with xdp samples that happens when user wants
to run a particular sample and some bpf program is already loaded. The
default 64kb RLIMIT_MEMLOCK resource limit will cause a following error
(assuming that xdp sample that is failing was converted to libbpf
usage):

libbpf: Error in bpf_object__probe_name():Operation not permitted(1).
Couldn't load basic 'r0 = 0' BPF program.
libbpf: failed to load object './xdp_sample_pkts_kern.o'

Fix it in xdp_sample_pkts and xdp_router_ipv4 by setting RLIMIT_MEMLOCK
to RLIM_INFINITY.

Signed-off-by: Maciej Fijalkowski <[email protected]>
Reviewed-by: Jakub Kicinski <[email protected]>
Acked-by: Jesper Dangaard Brouer <[email protected]>
Acked-by: John Fastabend <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>

1 files changed, 7 insertions, 0 deletions

diff --git a/samples/bpf/xdp_router_ipv4_user.c b/samples/bpf/xdp_router_ipv4_user.c
index cea2306f5ab7..c63c6beec7d6 100644
--- a/samples/bpf/xdp_router_ipv4_user.c
+++ b/samples/bpf/xdp_router_ipv4_user.c
@@ -25,6 +25,7 @@
 #include <sys/syscall.h>
 #include "bpf_util.h"
 #include "bpf/libbpf.h"
+#include <sys/resource.h>
 
 int sock, sock_arp, flags = 0;
 static int total_ifindex;
@@ -609,6 +610,7 @@ cleanup:
 
 int main(int ac, char **argv)
 {
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 	struct bpf_prog_load_attr prog_load_attr = {
 		.prog_type	= BPF_PROG_TYPE_XDP,
 	};
@@ -635,6 +637,11 @@ int main(int ac, char **argv)
 		ifname_list = (argv + 1);
 	}
 
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK)");
+		return 1;
+	}
+
 	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
 		return 1;