diff options
| -rw-r--r-- | kernel/bpf/verifier.c | 20 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/summarization.c | 21 |
2 files changed, 25 insertions, 16 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 2c812a5f1da8..d738ce6e7428 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -22151,6 +22151,21 @@ static int check_unreliable_func_args(struct bpf_verifier_log *log, struct btf * return -EINVAL; } +/* + * An extension is verified as a program that runs under the RCU read lock. Does + * the function that it is to replace? + */ +static bool func_has_rcu_read_lock(const struct bpf_prog *prog, int subprog) +{ + const struct bpf_func_info_aux *sub_aux = &prog->aux->func_info_aux[subprog]; + + if (!subprog) + return !prog->sleepable; + + return !sub_aux->called[BPF_FUNC_CTX_SLEEPABLE] && + !sub_aux->called[BPF_FUNC_CTX_NO_RCU_LOCK]; +} + int bpf_check_attach_target(struct bpf_verifier_log *log, const struct bpf_prog *prog, const struct bpf_prog *tgt_prog, @@ -22247,6 +22262,11 @@ int bpf_check_attach_target(struct bpf_verifier_log *log, "Cannot extend a writable raw tracepoint program\n"); return -EINVAL; } + if (!func_has_rcu_read_lock(tgt_prog, subprog)) { + bpf_log(log, + "Cannot extend a function that runs without RCU read lock\n"); + return -EINVAL; + } tgt_changes_pkt_data = aux->func ? aux->func[subprog]->aux->changes_pkt_data : aux->changes_pkt_data; diff --git a/tools/testing/selftests/bpf/prog_tests/summarization.c b/tools/testing/selftests/bpf/prog_tests/summarization.c index 6951786044ca..3e4bcf071735 100644 --- a/tools/testing/selftests/bpf/prog_tests/summarization.c +++ b/tools/testing/selftests/bpf/prog_tests/summarization.c @@ -53,17 +53,6 @@ static void test_aux(const char *main_prog_name, err = summarization_freplace__load(freplace); print_verifier_log(log); - /* The might_sleep extension doesn't work yet as sleepable calls are not - * allowed, but preserve the check in case it's supported later and then - * this particular combination can be enabled. - */ - if (!strcmp("might_sleep", replacement) && err) { - ASSERT_HAS_SUBSTR(log, "sleepable helper bpf_copy_from_user#", "error log"); - ASSERT_EQ(err, -EINVAL, "err"); - test__skip(); - goto out; - } - if (expect_load) { ASSERT_OK(err, "summarization_freplace__load"); } else { @@ -86,9 +75,8 @@ out: * Also test a case when main subprogram itself is replaced and is a single * subprogram in a program. * - * This holds for might_sleep programs. It is ok to replace might_sleep with - * might_sleep and with does_not_sleep, but does_not_sleep cannot be replaced - * with might_sleep. + * An extension is verified as a non-sleepable program, hence nothing that runs + * sleepable can be replaced. */ void test_summarization_freplace(void) { @@ -111,7 +99,7 @@ void test_summarization_freplace(void) }, }; const char *pkt_err = "Extension program changes packet data"; - const char *slp_err = "Extension program may sleep"; + const char *slp_err = "Cannot extend a function that runs without RCU read lock"; struct { const char *func; bool has_side_effect; @@ -136,7 +124,8 @@ void test_summarization_freplace(void) if (!test__start_subtest(buf)) continue; test_aux(mains[t][i].main, mains[t][i].to_be_replaced, replacements[t][j].func, - mains[t][i].has_side_effect || !replacements[t][j].has_side_effect, + t == 0 && + (mains[t][i].has_side_effect || !replacements[t][j].has_side_effect), replacements[t][j].err_msg); } } |