On 1/26/24 6:50 PM, Martin KaFai Lau wrote:
From: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
In s390, CI reported that the sock_iter_batch selftest
hits this error very often:
2024-01-26T16:56:49.3091804Z Bind /proc/self/ns/net -> /run/netns/sock_iter_batch_netns failed: No such file or directory
2024-01-26T16:56:49.3149524Z Cannot remove namespace file "/run/netns/sock_iter_batch_netns": No such file or directory
2024-01-26T16:56:49.3772213Z test_sock_iter_batch:FAIL:ip netns add sock_iter_batch_netns unexpected error: 256 (errno 0)
It happens very often in s390 but Manu also noticed it happens very
sparsely in other arch also.
It turns out the default dash shell does not recognize "&>"
Not sure whether it is feasible or not. But is it possible
for all our test VMs we run '/bin/bash' before everyting else
so we have a uniform bash environment so we do not need to
worry about other shells?
as a redirection operator, so the command went to the background.
In the sock_iter_batch selftest, the "ip netns delete" went
into background and then race with the following "ip netns add"
command.
This patch replaces the "&> /dev/null" usage with ">/dev/null 2>&1"
and does this redirection in the SYS_NOFAIL macro instead of doing
it individually by its caller. The SYS_NOFAIL callers do not care
about failure, so it is no harm to do this redirection even if
some of the existing callers do not redirect to /dev/null now.
It touches different test files, so I skipped the Fixes tags
in this patch. Some of the changed tests do not use "&>"
but they use the SYS_NOFAIL, so these tests are also
changed to avoid doing its own redirection because
SYS_NOFAIL does it internally now.
Signed-off-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
---
.../selftests/bpf/prog_tests/decap_sanity.c | 2 +-
.../selftests/bpf/prog_tests/fib_lookup.c | 2 +-
.../selftests/bpf/prog_tests/ip_check_defrag.c | 4 ++--
.../selftests/bpf/prog_tests/lwt_redirect.c | 2 +-
.../selftests/bpf/prog_tests/lwt_reroute.c | 2 +-
tools/testing/selftests/bpf/prog_tests/mptcp.c | 2 +-
.../selftests/bpf/prog_tests/sock_destroy.c | 2 +-
.../selftests/bpf/prog_tests/sock_iter_batch.c | 4 ++--
.../selftests/bpf/prog_tests/test_tunnel.c | 18 +++++++++---------
tools/testing/selftests/bpf/test_progs.h | 7 ++++++-
10 files changed, 25 insertions(+), 20 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/decap_sanity.c b/tools/testing/selftests/bpf/prog_tests/decap_sanity.c
index 5c0ebe6ba866..dcb9e5070cc3 100644
--- a/tools/testing/selftests/bpf/prog_tests/decap_sanity.c
+++ b/tools/testing/selftests/bpf/prog_tests/decap_sanity.c
@@ -72,6 +72,6 @@ void test_decap_sanity(void)
bpf_tc_hook_destroy(&qdisc_hook);
close_netns(nstoken);
}
- SYS_NOFAIL("ip netns del " NS_TEST " &> /dev/null");
+ SYS_NOFAIL("ip netns del " NS_TEST);
decap_sanity__destroy(skel);
}
[...]
diff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h
index 2f9f6f250f17..80df51244886 100644
--- a/tools/testing/selftests/bpf/test_progs.h
+++ b/tools/testing/selftests/bpf/test_progs.h
@@ -385,10 +385,15 @@ int test__join_cgroup(const char *path);
goto goto_label; \
})
+#define ALL_TO_DEV_NULL " >/dev/null 2>&1"
+
#define SYS_NOFAIL(fmt, ...) \
({ \
char cmd[1024]; \
- snprintf(cmd, sizeof(cmd), fmt, ##__VA_ARGS__); \
+ int n; \
+ n = snprintf(cmd, sizeof(cmd), fmt, ##__VA_ARGS__); \
+ if (n < sizeof(cmd) && sizeof(cmd) - n >= sizeof(ALL_TO_DEV_NULL)) \
+ strcat(cmd, ALL_TO_DEV_NULL); \
system(cmd); \
})
