[PATCH 4.19 30/79] selftests/bpf: fix "bind{4, 6} deny specific IP & port" on s390

Greg Kroah-Hartman
2019-09-19T22:32:33Z

From: Ilya Leoshkevich <iii@linux.ibm.com>

[ Upstream commit 27df5c7068bf23cab282dc64b1c9894429b3b8a0 ]

"bind4 allow specific IP & port" and "bind6 deny specific IP & port"
fail on s390 because of endianness issue: the 4 IP address bytes are
loaded as a word and compared with a constant, but the value of this
constant should be different on big- and little- endian machines, which
is not the case right now.

Use __bpf_constant_ntohl to generate proper value based on machine
endianness.

Fixes: 1d436885b23b ("selftests/bpf: Selftest for sys_bind post-hooks.")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/testing/selftests/bpf/test_sock.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_sock.c b/tools/testing/selftests/bpf/test_sock.c
index b8ebe2f580741..e9567122070a3 100644
--- a/tools/testing/selftests/bpf/test_sock.c
+++ b/tools/testing/selftests/bpf/test_sock.c
@@ -13,6 +13,7 @@
#include <bpf/bpf.h>

#include "cgroup_helpers.h"
+#include "bpf_endian.h"
#include "bpf_rlimit.h"
#include "bpf_util.h"

@@ -231,7 +232,8 @@ static struct sock_test tests[] = {
/* if (ip == expected && port == expected) */
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock, src_ip6[3])),
- BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x01000000, 4),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_7,
+ __bpf_constant_ntohl(0x00000001), 4),
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock, src_port)),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x2001, 2),
@@ -260,7 +262,8 @@ static struct sock_test tests[] = {
/* if (ip == expected && port == expected) */
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock, src_ip4)),
- BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x0100007F, 4),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_7,
+ __bpf_constant_ntohl(0x7F000001), 4),
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock, src_port)),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2),
--
2.20.1