From: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx>
Date: Wed, 15 Mar 2023 10:56:25 +0100
> From: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx>
> Date: Tue, 14 Mar 2023 16:54:25 -0700
>
>> On Tue, Mar 14, 2023 at 11:52 AM Alexei Starovoitov
>> <alexei.starovoitov@xxxxxxxxx> wrote:
>
> [...]
>
>> test_xdp_do_redirect:PASS:prog_run 0 nsec
>> test_xdp_do_redirect:PASS:pkt_count_xdp 0 nsec
>> test_xdp_do_redirect:PASS:pkt_count_zero 0 nsec
>> test_xdp_do_redirect:FAIL:pkt_count_tc unexpected pkt_count_tc: actual
>> 220 != expected 9998
>> test_max_pkt_size:PASS:prog_run_max_size 0 nsec
>> test_max_pkt_size:PASS:prog_run_too_big 0 nsec
>> close_netns:PASS:setns 0 nsec
>> #289 xdp_do_redirect:FAIL
>> Summary: 270/1674 PASSED, 30 SKIPPED, 1 FAILED
>>
>> Alex,
>> could you please take a look at why it's happening?
>>
>> I suspect it's an endianness issue in:
>> if (*metadata != 0x42)
>> return XDP_ABORTED;
>> but your patch didn't change that,
>> so I'm not sure why it worked before.
>
> Sure, lemme fix it real quick.
Hi Ilya,
Do you have s390 testing setups? Maybe you could take a look, since I
don't have one and can't debug it? Doesn't seem to be Endianness issue.
I mean, I have this (the below patch), but not sure it will fix
anything -- IIRC eBPF arch always matches the host arch ._.
I can't figure out from the code what does happen wrongly :s And it
happens only on s390.
Thanks,
Olek
---
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c b/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c
index 662b6c6c5ed7..b21371668447 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c
@@ -107,7 +107,7 @@ void test_xdp_do_redirect(void)
.attach_point = BPF_TC_INGRESS);
memcpy(&data[sizeof(__u32)], &pkt_udp, sizeof(pkt_udp));
- *((__u32 *)data) = 0x42; /* metadata test value */
+ *((__u32 *)data) = htonl(0x42); /* metadata test value */
skel = test_xdp_do_redirect__open();
if (!ASSERT_OK_PTR(skel, "skel"))
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_do_redirect.c b/tools/testing/selftests/bpf/progs/test_xdp_do_redirect.c
index cd2d4e3258b8..2475bc30ced2 100644
--- a/tools/testing/selftests/bpf/progs/test_xdp_do_redirect.c
+++ b/tools/testing/selftests/bpf/progs/test_xdp_do_redirect.c
@@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
#include <vmlinux.h>
+#include <bpf/bpf_endian.h>
#include <bpf/bpf_helpers.h>
#define ETH_ALEN 6
@@ -28,7 +29,7 @@ volatile int retcode = XDP_REDIRECT;
SEC("xdp")
int xdp_redirect(struct xdp_md *xdp)
{
- __u32 *metadata = (void *)(long)xdp->data_meta;
+ __be32 *metadata = (void *)(long)xdp->data_meta;
void *data_end = (void *)(long)xdp->data_end;
void *data = (void *)(long)xdp->data;
@@ -44,7 +45,7 @@ int xdp_redirect(struct xdp_md *xdp)
if (metadata + 1 > data)
return XDP_ABORTED;
- if (*metadata != 0x42)
+ if (*metadata != __bpf_htonl(0x42))
return XDP_ABORTED;
if (*payload == MARK_XMIT)
