diff options
| -rw-r--r-- | kernel/bpf/verifier.c | 32 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/fexit_noreturns.c | 9 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/fexit_noreturns.c | 15 |
3 files changed, 56 insertions, 0 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 3303a3605ee8..19ece8893d38 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -23215,6 +23215,33 @@ BTF_ID(func, __rcu_read_unlock) #endif BTF_SET_END(btf_id_deny) +/* fexit and fmod_ret can't be used to attach to __noreturn functions. + * Currently, we must manually list all __noreturn functions here. Once a more + * robust solution is implemented, this workaround can be removed. + */ +BTF_SET_START(noreturn_deny) +#ifdef CONFIG_IA32_EMULATION +BTF_ID(func, __ia32_sys_exit) +BTF_ID(func, __ia32_sys_exit_group) +#endif +#ifdef CONFIG_KUNIT +BTF_ID(func, __kunit_abort) +BTF_ID(func, kunit_try_catch_throw) +#endif +#ifdef CONFIG_MODULES +BTF_ID(func, __module_put_and_kthread_exit) +#endif +#ifdef CONFIG_X86_64 +BTF_ID(func, __x64_sys_exit) +BTF_ID(func, __x64_sys_exit_group) +#endif +BTF_ID(func, do_exit) +BTF_ID(func, do_group_exit) +BTF_ID(func, kthread_complete_and_exit) +BTF_ID(func, kthread_exit) +BTF_ID(func, make_task_dead) +BTF_SET_END(noreturn_deny) + static bool can_be_sleepable(struct bpf_prog *prog) { if (prog->type == BPF_PROG_TYPE_TRACING) { @@ -23301,6 +23328,11 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) } else if (prog->type == BPF_PROG_TYPE_TRACING && btf_id_set_contains(&btf_id_deny, btf_id)) { return -EINVAL; + } else if ((prog->expected_attach_type == BPF_TRACE_FEXIT || + prog->expected_attach_type == BPF_MODIFY_RETURN) && + btf_id_set_contains(&noreturn_deny, btf_id)) { + verbose(env, "Attaching fexit/fmod_ret to __noreturn functions is rejected.\n"); + return -EINVAL; } key = bpf_trampoline_compute_key(tgt_prog, prog->aux->attach_btf, btf_id); diff --git a/tools/testing/selftests/bpf/prog_tests/fexit_noreturns.c b/tools/testing/selftests/bpf/prog_tests/fexit_noreturns.c new file mode 100644 index 000000000000..568d3aa48a78 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/fexit_noreturns.c @@ -0,0 +1,9 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <test_progs.h> +#include "fexit_noreturns.skel.h" + +void test_fexit_noreturns(void) +{ + RUN_TESTS(fexit_noreturns); +} diff --git a/tools/testing/selftests/bpf/progs/fexit_noreturns.c b/tools/testing/selftests/bpf/progs/fexit_noreturns.c new file mode 100644 index 000000000000..54654539f550 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/fexit_noreturns.c @@ -0,0 +1,15 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> +#include "bpf_misc.h" + +char _license[] SEC("license") = "GPL"; + +SEC("fexit/do_exit") +__failure __msg("Attaching fexit/fmod_ret to __noreturn functions is rejected.") +int BPF_PROG(noreturns) +{ + return 0; +} |