From 2b506f20af2b9dcfb3cb2d19e4c804eb20565841 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 16 Nov 2022 11:02:27 +0100 Subject: selftests/bpf: Filter out default_idle from kprobe_multi bench Alexei hit following rcu warning when running prog_test -j. [ 128.049567] WARNING: suspicious RCU usage [ 128.049569] 6.1.0-rc2 #912 Tainted: G O ... [ 128.050944] kprobe_multi_link_handler+0x6c/0x1d0 [ 128.050947] ? kprobe_multi_link_handler+0x42/0x1d0 [ 128.050950] ? __cpuidle_text_start+0x8/0x8 [ 128.050952] ? __cpuidle_text_start+0x8/0x8 [ 128.050958] fprobe_handler.part.1+0xac/0x150 [ 128.050964] 0xffffffffa02130c8 [ 128.050991] ? default_idle+0x5/0x20 [ 128.050998] default_idle+0x5/0x20 It's caused by bench test attaching kprobe_multi link to default_idle function, which is not executed in rcu safe context so the kprobe handler on top of it will trigger the rcu warning. Filtering out default_idle function from the bench test. Reported-by: Alexei Starovoitov Signed-off-by: Jiri Olsa Link: https://lore.kernel.org/r/20221116100228.2064612-1-jolsa@kernel.org Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c') diff --git a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c index d457a55ff408..b43928967515 100644 --- a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c +++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c @@ -358,10 +358,12 @@ static int get_syms(char ***symsp, size_t *cntp) * We attach to almost all kernel functions and some of them * will cause 'suspicious RCU usage' when fprobe is attached * to them. Filter out the current culprits - arch_cpu_idle - * and rcu_* functions. + * default_idle and rcu_* functions. */ if (!strcmp(name, "arch_cpu_idle")) continue; + if (!strcmp(name, "default_idle")) + continue; if (!strncmp(name, "rcu_", 4)) continue; if (!strcmp(name, "bpf_dispatcher_xdp_func")) -- cgit v1.2.3 From 8be602dadb2febb5e4cb367bff1162205bcf9905 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 16 Nov 2022 11:02:28 +0100 Subject: selftests/bpf: Make test_bench_attach serial Alexei hit another rcu warnings because of this test. Making test_bench_attach serial so it does not disrupts other tests during parallel tests run. While this change is not the fix, it should be less likely to hit it with this test being executed serially. Reported-by: Alexei Starovoitov Signed-off-by: Jiri Olsa Link: https://lore.kernel.org/r/20221116100228.2064612-2-jolsa@kernel.org Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c') diff --git a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c index b43928967515..a4b4133d39e9 100644 --- a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c +++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c @@ -402,7 +402,7 @@ error: return err; } -static void test_bench_attach(void) +void serial_test_kprobe_multi_bench_attach(void) { LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); struct kprobe_multi_empty *skel = NULL; @@ -470,6 +470,4 @@ void test_kprobe_multi_test(void) test_attach_api_syms(); if (test__start_subtest("attach_api_fails")) test_attach_api_fails(); - if (test__start_subtest("bench_attach")) - test_bench_attach(); } -- cgit v1.2.3