On 09/07/2024 11:45, Geliang Tang wrote:
From: Geliang Tang tanggeliang@kylinos.cn
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@kylinos.cn
Reviewed-by: Alan Maguire alan.maguire@oracle.com
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); }