On 09/07/2024 11:45, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@xxxxxxxxxx>
>
> Run bpf_tcp_ca selftests (./test_progs -t bpf_tcp_ca) on a Loongarch
> platform, some "Segmentation fault" errors occur:
>
> '''
> test_dctcp:PASS:bpf_dctcp__open_and_load 0 nsec
> test_dctcp:FAIL:bpf_map__attach_struct_ops unexpected error: -524
> #29/1 bpf_tcp_ca/dctcp:FAIL
> test_cubic:PASS:bpf_cubic__open_and_load 0 nsec
> test_cubic:FAIL:bpf_map__attach_struct_ops unexpected error: -524
> #29/2 bpf_tcp_ca/cubic:FAIL
> test_dctcp_fallback:PASS:dctcp_skel 0 nsec
> test_dctcp_fallback:PASS:bpf_dctcp__load 0 nsec
> test_dctcp_fallback:FAIL:dctcp link unexpected error: -524
> #29/4 bpf_tcp_ca/dctcp_fallback:FAIL
> test_write_sk_pacing:PASS:open_and_load 0 nsec
> test_write_sk_pacing:FAIL:attach_struct_ops unexpected error: -524
> #29/6 bpf_tcp_ca/write_sk_pacing:FAIL
> test_update_ca:PASS:open 0 nsec
> test_update_ca:FAIL:attach_struct_ops unexpected error: -524
> settcpca:FAIL:setsockopt unexpected setsockopt: \
> actual -1 == expected -1
> (network_helpers.c:99: errno: No such file or directory) \
> Failed to call post_socket_cb
> start_test:FAIL:start_server_str unexpected start_server_str: \
> actual -1 == expected -1
> test_update_ca:FAIL:ca1_ca1_cnt unexpected ca1_ca1_cnt: \
> actual 0 <= expected 0
> #29/9 bpf_tcp_ca/update_ca:FAIL
> #29 bpf_tcp_ca:FAIL
> Caught signal #11!
> Stack trace:
> ./test_progs(crash_handler+0x28)[0x5555567ed91c]
> linux-vdso.so.1(__vdso_rt_sigreturn+0x0)[0x7ffffee408b0]
> ./test_progs(bpf_link__update_map+0x80)[0x555556824a78]
> ./test_progs(+0x94d68)[0x5555564c4d68]
> ./test_progs(test_bpf_tcp_ca+0xe8)[0x5555564c6a88]
> ./test_progs(+0x3bde54)[0x5555567ede54]
> ./test_progs(main+0x61c)[0x5555567efd54]
> /usr/lib64/libc.so.6(+0x22208)[0x7ffff2aaa208]
> /usr/lib64/libc.so.6(__libc_start_main+0xac)[0x7ffff2aaa30c]
> ./test_progs(_start+0x48)[0x55555646bca8]
> Segmentation fault
> '''
>
> This is because BPF trampoline is not implemented on Loongarch yet,
> "link" returned by bpf_map__attach_struct_ops() is NULL. test_progs
> crashs when this NULL link passes to bpf_link__update_map(). This
> patch adds NULL checks for all links in bpf_tcp_ca to fix these errors.
> If "link" is NULL, goto the newly added label "out" to destroy the skel.
>
> v2:
> - use "goto out" instead of "return" as Eduard suggested.
>
> Signed-off-by: Geliang Tang <tanggeliang@xxxxxxxxxx>
Reviewed-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
Maybe I'm missing it, but I'm not seeing this series on
patchwork.kernel.org/project/netdevbpf, so we don't have an associated
CI run (the series is in the kselftest patchwork however). Is there some
patchwork bot magic that will do this?
> ---
> .../selftests/bpf/prog_tests/bpf_tcp_ca.c | 21 +++++++++++++------
> 1 file changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c b/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c
> index d842ff64bc2a..efc1bf2ff7de 100644
> --- a/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c
> +++ b/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c
> @@ -411,7 +411,8 @@ static void test_update_ca(void)
> return;
>
> link = bpf_map__attach_struct_ops(skel->maps.ca_update_1);
> - ASSERT_OK_PTR(link, "attach_struct_ops");
> + if (!ASSERT_OK_PTR(link, "attach_struct_ops"))
> + goto out;
>
> do_test(&opts);
> saved_ca1_cnt = skel->bss->ca1_cnt;
> @@ -425,6 +426,7 @@ static void test_update_ca(void)
> ASSERT_GT(skel->bss->ca2_cnt, 0, "ca2_ca2_cnt");
>
> bpf_link__destroy(link);
> +out:
> tcp_ca_update__destroy(skel);
> }
>
> @@ -447,7 +449,8 @@ static void test_update_wrong(void)
> return;
>
> link = bpf_map__attach_struct_ops(skel->maps.ca_update_1);
> - ASSERT_OK_PTR(link, "attach_struct_ops");
> + if (!ASSERT_OK_PTR(link, "attach_struct_ops"))
> + goto out;
>
> do_test(&opts);
> saved_ca1_cnt = skel->bss->ca1_cnt;
> @@ -460,11 +463,13 @@ static void test_update_wrong(void)
> ASSERT_GT(skel->bss->ca1_cnt, saved_ca1_cnt, "ca2_ca1_cnt");
>
> bpf_link__destroy(link);
> +out:
> tcp_ca_update__destroy(skel);
> }
>
> static void test_mixed_links(void)
> {
> + struct bpf_link *link = NULL, *link_nl = NULL;
> struct cb_opts cb_opts = {
> .cc = "tcp_ca_update",
> };
> @@ -473,7 +478,6 @@ static void test_mixed_links(void)
> .cb_opts = &cb_opts,
> };
> struct tcp_ca_update *skel;
> - struct bpf_link *link, *link_nl;
> int err;
>
> skel = tcp_ca_update__open_and_load();
> @@ -481,10 +485,12 @@ static void test_mixed_links(void)
> return;
>
> link_nl = bpf_map__attach_struct_ops(skel->maps.ca_no_link);
> - ASSERT_OK_PTR(link_nl, "attach_struct_ops_nl");
> + if (!ASSERT_OK_PTR(link_nl, "attach_struct_ops_nl"))
> + goto out;
>
> link = bpf_map__attach_struct_ops(skel->maps.ca_update_1);
> - ASSERT_OK_PTR(link, "attach_struct_ops");
> + if (!ASSERT_OK_PTR(link, "attach_struct_ops"))
> + goto out;
>
> do_test(&opts);
> ASSERT_GT(skel->bss->ca1_cnt, 0, "ca1_ca1_cnt");
> @@ -492,6 +498,7 @@ static void test_mixed_links(void)
> err = bpf_link__update_map(link, skel->maps.ca_no_link);
> ASSERT_ERR(err, "update_map");
>
> +out:
> bpf_link__destroy(link);
> bpf_link__destroy(link_nl);
> tcp_ca_update__destroy(skel);
> @@ -536,7 +543,8 @@ static void test_link_replace(void)
> bpf_link__destroy(link);
>
> link = bpf_map__attach_struct_ops(skel->maps.ca_update_2);
> - ASSERT_OK_PTR(link, "attach_struct_ops_2nd");
> + if (!ASSERT_OK_PTR(link, "attach_struct_ops_2nd"))
> + goto out;
>
> /* BPF_F_REPLACE with a wrong old map Fd. It should fail!
> *
> @@ -559,6 +567,7 @@ static void test_link_replace(void)
>
> bpf_link__destroy(link);
>
> +out:
> tcp_ca_update__destroy(skel);
> }
>
