On Fri, Dec 15, 2023 at 6:42 AM Yonghong Song <yonghong.song@xxxxxxxxx> wrote: > > > On 12/15/23 6:24 AM, Jiri Olsa wrote: > > On Fri, Dec 15, 2023 at 10:16:27AM +0100, Jiri Olsa wrote: > >> hi, > >> The bpf CI is broken due to clang emitting 2 functions for > >> bpf_fentry_test7: > >> > >> # cat available_filter_functions | grep bpf_fentry_test7 > >> bpf_fentry_test7 > >> bpf_fentry_test7.specialized.1 > >> > >> The tests attach to 'bpf_fentry_test7' while the function with > >> '.specialized.1' suffix is executed in bpf_prog_test_run_tracing. > >> > >> It looks like clang optimalization that comes from passing 0 > >> as argument and returning it directly in bpf_fentry_test7. > >> > >> I'm not sure there's a way to disable this, so far I came > >> up with solution below that passes real pointer, but I think > >> that was not the original intention for the test. > >> > >> We had issue with this function back in august: > >> 32337c0a2824 bpf: Prevent inlining of bpf_fentry_test7() > >> > >> I'm not sure why it started to show now? was clang updated for CI? > >> > >> I'll try to find out more, but any clang ideas are welcome ;-) > >> > >> thanks, > >> jirka > > > > hm, there seems to be fix in bpf-next for this one: > > > > b16904fd9f01 bpf: Fix a few selftest failures due to llvm18 change > > Maybe submit a patch to https://github.com/kernel-patches/vmtest/tree/master/ci/diffs? > That is typically the place to have temporary patches to workaround ci failures. > To get bpf/master back to green CI I did it meanwhile ([0]). Jiri, please check the PR to be familiar with the process for the future similar mitigations, thanks. [0] https://github.com/kernel-patches/vmtest/pull/258 > > > > jirka > > > >> > >> --- > >> diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c > >> index c9fdcc5cdce1..33208eec9361 100644 > >> --- a/net/bpf/test_run.c > >> +++ b/net/bpf/test_run.c > >> @@ -543,7 +543,7 @@ struct bpf_fentry_test_t { > >> int noinline bpf_fentry_test7(struct bpf_fentry_test_t *arg) > >> { > >> asm volatile (""); > >> - return (long)arg; > >> + return 0; > >> } > >> > >> int noinline bpf_fentry_test8(struct bpf_fentry_test_t *arg) > >> @@ -668,7 +668,7 @@ int bpf_prog_test_run_tracing(struct bpf_prog *prog, > >> bpf_fentry_test4((void *)7, 8, 9, 10) != 34 || > >> bpf_fentry_test5(11, (void *)12, 13, 14, 15) != 65 || > >> bpf_fentry_test6(16, (void *)17, 18, 19, (void *)20, 21) != 111 || > >> - bpf_fentry_test7((struct bpf_fentry_test_t *)0) != 0 || > >> + bpf_fentry_test7(&arg) != 0 || > >> bpf_fentry_test8(&arg) != 0 || > >> bpf_fentry_test9(&retval) != 0) > >> goto out; > >> diff --git a/tools/testing/selftests/bpf/progs/fentry_test.c b/tools/testing/selftests/bpf/progs/fentry_test.c > >> index 52a550d281d9..95c5c34ccaa8 100644 > >> --- a/tools/testing/selftests/bpf/progs/fentry_test.c > >> +++ b/tools/testing/selftests/bpf/progs/fentry_test.c > >> @@ -64,7 +64,7 @@ __u64 test7_result = 0; > >> SEC("fentry/bpf_fentry_test7") > >> int BPF_PROG(test7, struct bpf_fentry_test_t *arg) > >> { > >> - if (!arg) > >> + if (arg) > >> test7_result = 1; > >> return 0; > >> } > >> diff --git a/tools/testing/selftests/bpf/progs/fexit_test.c b/tools/testing/selftests/bpf/progs/fexit_test.c > >> index 8f1ccb7302e1..ffb30236ca02 100644 > >> --- a/tools/testing/selftests/bpf/progs/fexit_test.c > >> +++ b/tools/testing/selftests/bpf/progs/fexit_test.c > >> @@ -65,7 +65,7 @@ __u64 test7_result = 0; > >> SEC("fexit/bpf_fentry_test7") > >> int BPF_PROG(test7, struct bpf_fentry_test_t *arg) > >> { > >> - if (!arg) > >> + if (arg) > >> test7_result = 1; > >> return 0; > >> }
