| Message ID | 20220824134055.1328882-4-benjamin.tissoires@redhat.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | BPF |
| Headers | show |
| Series | Introduce eBPF support for HID devices | expand |
On Wed, 24 Aug 2022 at 15:41, Benjamin Tissoires <benjamin.tissoires@redhat.com> wrote: > > We need to also export the kfunc set to the syscall program type, > and then add a couple of eBPF programs that are testing those calls. > > The first one checks for valid access, and the second one is OK > from a static analysis point of view but fails at run time because > we are trying to access outside of the allocated memory. > > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> > > --- > > no changes in v9 > > no changes in v8 > > changes in v7: > - add 1 more case to ensure we can read the entire sizeof(ctx) > - add a test case for when the context is NULL > > new in v6 > --- > net/bpf/test_run.c | 1 + > .../selftests/bpf/prog_tests/kfunc_call.c | 28 +++++++++++++++ > .../selftests/bpf/progs/kfunc_call_test.c | 36 +++++++++++++++++++ > 3 files changed, 65 insertions(+) > > diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c > index 25d8ecf105aa..f16baf977a21 100644 > --- a/net/bpf/test_run.c > +++ b/net/bpf/test_run.c > @@ -1634,6 +1634,7 @@ static int __init bpf_prog_test_run_init(void) > > ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &bpf_prog_test_kfunc_set); > ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &bpf_prog_test_kfunc_set); > + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SYSCALL, &bpf_prog_test_kfunc_set); > return ret ?: register_btf_id_dtor_kfuncs(bpf_prog_test_dtor_kfunc, > ARRAY_SIZE(bpf_prog_test_dtor_kfunc), > THIS_MODULE); > diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c > index eede7c304f86..1edad012fe01 100644 > --- a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c > +++ b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c > @@ -9,10 +9,22 @@ > > #include "cap_helpers.h" > > +struct syscall_test_args { > + __u8 data[16]; > + size_t size; > +}; > + > static void test_main(void) > { > struct kfunc_call_test_lskel *skel; > int prog_fd, err; > + struct syscall_test_args args = { > + .size = 10, > + }; > + DECLARE_LIBBPF_OPTS(bpf_test_run_opts, syscall_topts, > + .ctx_in = &args, > + .ctx_size_in = sizeof(args), > + ); > LIBBPF_OPTS(bpf_test_run_opts, topts, > .data_in = &pkt_v4, > .data_size_in = sizeof(pkt_v4), > @@ -38,6 +50,22 @@ static void test_main(void) > ASSERT_OK(err, "bpf_prog_test_run(test_ref_btf_id)"); > ASSERT_EQ(topts.retval, 0, "test_ref_btf_id-retval"); > > + prog_fd = skel->progs.kfunc_syscall_test.prog_fd; > + err = bpf_prog_test_run_opts(prog_fd, &syscall_topts); > + ASSERT_OK(err, "bpf_prog_test_run(syscall_test)"); > + > + prog_fd = skel->progs.kfunc_syscall_test_fail.prog_fd; > + err = bpf_prog_test_run_opts(prog_fd, &syscall_topts); > + ASSERT_ERR(err, "bpf_prog_test_run(syscall_test_fail)"); It would be better to assert on the verifier error string, to make sure we continue actually testing the error we care about and not something else. > + > + syscall_topts.ctx_in = NULL; > + syscall_topts.ctx_size_in = 0; > + > + prog_fd = skel->progs.kfunc_syscall_test_null.prog_fd; > + err = bpf_prog_test_run_opts(prog_fd, &syscall_topts); > + ASSERT_OK(err, "bpf_prog_test_run(syscall_test_null)"); > + ASSERT_EQ(syscall_topts.retval, 0, "syscall_test_null-retval"); > + > kfunc_call_test_lskel__destroy(skel); > } > > diff --git a/tools/testing/selftests/bpf/progs/kfunc_call_test.c b/tools/testing/selftests/bpf/progs/kfunc_call_test.c > index 5aecbb9fdc68..da7ae0ef9100 100644 > --- a/tools/testing/selftests/bpf/progs/kfunc_call_test.c > +++ b/tools/testing/selftests/bpf/progs/kfunc_call_test.c > @@ -92,4 +92,40 @@ int kfunc_call_test_pass(struct __sk_buff *skb) > return 0; > } > > +struct syscall_test_args { > + __u8 data[16]; > + size_t size; > +}; > + > +SEC("syscall") > +int kfunc_syscall_test(struct syscall_test_args *args) > +{ > + const int size = args->size; > + > + if (size > sizeof(args->data)) > + return -7; /* -E2BIG */ > + > + bpf_kfunc_call_test_mem_len_pass1(&args->data, sizeof(args->data)); > + bpf_kfunc_call_test_mem_len_pass1(&args->data, sizeof(*args)); > + bpf_kfunc_call_test_mem_len_pass1(&args->data, size); > + > + return 0; > +} > + > +SEC("syscall") > +int kfunc_syscall_test_null(struct syscall_test_args *args) > +{ > + bpf_kfunc_call_test_mem_len_pass1(args, 0); > + Where is it testing 'NULL'? It is testing zero_size_allowed. > + return 0; > +} > + > +SEC("syscall") > +int kfunc_syscall_test_fail(struct syscall_test_args *args) > +{ > + bpf_kfunc_call_test_mem_len_pass1(&args->data, sizeof(*args) + 1); > + > + return 0; > +} > + > char _license[] SEC("license") = "GPL"; > -- > 2.36.1 >
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index 25d8ecf105aa..f16baf977a21 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -1634,6 +1634,7 @@ static int __init bpf_prog_test_run_init(void) ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &bpf_prog_test_kfunc_set); ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &bpf_prog_test_kfunc_set); + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SYSCALL, &bpf_prog_test_kfunc_set); return ret ?: register_btf_id_dtor_kfuncs(bpf_prog_test_dtor_kfunc, ARRAY_SIZE(bpf_prog_test_dtor_kfunc), THIS_MODULE); diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c index eede7c304f86..1edad012fe01 100644 --- a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c +++ b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c @@ -9,10 +9,22 @@ #include "cap_helpers.h" +struct syscall_test_args { + __u8 data[16]; + size_t size; +}; + static void test_main(void) { struct kfunc_call_test_lskel *skel; int prog_fd, err; + struct syscall_test_args args = { + .size = 10, + }; + DECLARE_LIBBPF_OPTS(bpf_test_run_opts, syscall_topts, + .ctx_in = &args, + .ctx_size_in = sizeof(args), + ); LIBBPF_OPTS(bpf_test_run_opts, topts, .data_in = &pkt_v4, .data_size_in = sizeof(pkt_v4), @@ -38,6 +50,22 @@ static void test_main(void) ASSERT_OK(err, "bpf_prog_test_run(test_ref_btf_id)"); ASSERT_EQ(topts.retval, 0, "test_ref_btf_id-retval"); + prog_fd = skel->progs.kfunc_syscall_test.prog_fd; + err = bpf_prog_test_run_opts(prog_fd, &syscall_topts); + ASSERT_OK(err, "bpf_prog_test_run(syscall_test)"); + + prog_fd = skel->progs.kfunc_syscall_test_fail.prog_fd; + err = bpf_prog_test_run_opts(prog_fd, &syscall_topts); + ASSERT_ERR(err, "bpf_prog_test_run(syscall_test_fail)"); + + syscall_topts.ctx_in = NULL; + syscall_topts.ctx_size_in = 0; + + prog_fd = skel->progs.kfunc_syscall_test_null.prog_fd; + err = bpf_prog_test_run_opts(prog_fd, &syscall_topts); + ASSERT_OK(err, "bpf_prog_test_run(syscall_test_null)"); + ASSERT_EQ(syscall_topts.retval, 0, "syscall_test_null-retval"); + kfunc_call_test_lskel__destroy(skel); } diff --git a/tools/testing/selftests/bpf/progs/kfunc_call_test.c b/tools/testing/selftests/bpf/progs/kfunc_call_test.c index 5aecbb9fdc68..da7ae0ef9100 100644 --- a/tools/testing/selftests/bpf/progs/kfunc_call_test.c +++ b/tools/testing/selftests/bpf/progs/kfunc_call_test.c @@ -92,4 +92,40 @@ int kfunc_call_test_pass(struct __sk_buff *skb) return 0; } +struct syscall_test_args { + __u8 data[16]; + size_t size; +}; + +SEC("syscall") +int kfunc_syscall_test(struct syscall_test_args *args) +{ + const int size = args->size; + + if (size > sizeof(args->data)) + return -7; /* -E2BIG */ + + bpf_kfunc_call_test_mem_len_pass1(&args->data, sizeof(args->data)); + bpf_kfunc_call_test_mem_len_pass1(&args->data, sizeof(*args)); + bpf_kfunc_call_test_mem_len_pass1(&args->data, size); + + return 0; +} + +SEC("syscall") +int kfunc_syscall_test_null(struct syscall_test_args *args) +{ + bpf_kfunc_call_test_mem_len_pass1(args, 0); + + return 0; +} + +SEC("syscall") +int kfunc_syscall_test_fail(struct syscall_test_args *args) +{ + bpf_kfunc_call_test_mem_len_pass1(&args->data, sizeof(*args) + 1); + + return 0; +} + char _license[] SEC("license") = "GPL";
We need to also export the kfunc set to the syscall program type, and then add a couple of eBPF programs that are testing those calls. The first one checks for valid access, and the second one is OK from a static analysis point of view but fails at run time because we are trying to access outside of the allocated memory. Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> --- no changes in v9 no changes in v8 changes in v7: - add 1 more case to ensure we can read the entire sizeof(ctx) - add a test case for when the context is NULL new in v6 --- net/bpf/test_run.c | 1 + .../selftests/bpf/prog_tests/kfunc_call.c | 28 +++++++++++++++ .../selftests/bpf/progs/kfunc_call_test.c | 36 +++++++++++++++++++ 3 files changed, 65 insertions(+)