| Message ID | 160051619397.58048.16822043567956571063.stgit@toke.dk |
|---|---|
| State | Superseded |
| Headers | show |
| Series | None | expand |
On Sat, Sep 19, 2020 at 4:50 AM Toke Høiland-Jørgensen <toke@redhat.com> wrote: > > From: Toke Høiland-Jørgensen <toke@redhat.com> > > This adds a selftest that ensures that modify_return tracing programs > cannot be attached to freplace programs. The security_ prefix is added to > the freplace program because that would otherwise let it pass the check for > modify_return. > > Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> > --- Acked-by: Andrii Nakryiko <andriin@fb.com> > .../selftests/bpf/prog_tests/fexit_bpf2bpf.c | 68 ++++++++++++++++++++ > .../selftests/bpf/progs/fmod_ret_freplace.c | 14 ++++ > .../selftests/bpf/progs/freplace_get_constant.c | 2 - > 3 files changed, 83 insertions(+), 1 deletion(-) > create mode 100644 tools/testing/selftests/bpf/progs/fmod_ret_freplace.c > > diff --git a/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c b/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c > index 27677e015730..6339d125ef9a 100644 > --- a/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c > +++ b/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c > @@ -233,6 +233,72 @@ static void test_func_replace_multi(void) > prog_name, true, test_second_attach); > } > > +static void test_fmod_ret_freplace(void) > +{ > + const char *tgt_name = "./test_pkt_access.o"; > + const char *freplace_name = "./freplace_get_constant.o"; > + const char *fmod_ret_name = "./fmod_ret_freplace.o"; > + struct bpf_link *freplace_link = NULL, *fmod_link = NULL; > + struct bpf_object *freplace_obj = NULL, *pkt_obj, *fmod_obj = NULL; > + struct bpf_program *prog; > + __u32 duration = 0; > + int err, pkt_fd; > + > + err = bpf_prog_load(tgt_name, BPF_PROG_TYPE_UNSPEC, > + &pkt_obj, &pkt_fd); > + /* the target prog should load fine */ > + if (CHECK(err, "tgt_prog_load", "file %s err %d errno %d\n", > + tgt_name, err, errno)) > + return; > + DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts, > + .attach_prog_fd = pkt_fd, > + ); this is variable declaration, it has to be together with all the variables above > + > + freplace_obj = bpf_object__open_file(freplace_name, &opts); > + if (CHECK(IS_ERR_OR_NULL(freplace_obj), "freplace_obj_open", > + "failed to open %s: %ld\n", freplace_name, > + PTR_ERR(freplace_obj))) > + goto out; > + > + err = bpf_object__load(freplace_obj); > + if (CHECK(err, "freplace_obj_load", "err %d\n", err)) > + goto out; > + > + prog = bpf_program__next(NULL, freplace_obj); > + freplace_link = bpf_program__attach_trace(prog); > + if (CHECK(IS_ERR(freplace_link), "freplace_attach_trace", "failed to link\n")) > + goto out; > + > + opts.attach_prog_fd = bpf_program__fd(prog); > + fmod_obj = bpf_object__open_file(fmod_ret_name, &opts); > + if (CHECK(IS_ERR_OR_NULL(fmod_obj), "fmod_obj_open", > + "failed to open %s: %ld\n", fmod_ret_name, > + PTR_ERR(fmod_obj))) > + goto out; > + > + err = bpf_object__load(fmod_obj); > + if (CHECK(err, "fmod_obj_load", "err %d\n", err)) > + goto out; > + > + prog = bpf_program__next(NULL, fmod_obj); > + fmod_link = bpf_program__attach_trace(prog); > + if (CHECK(!IS_ERR(fmod_link), "fmod_attach_trace", > + "linking fmod_ret to freplace should fail\n")) > + goto out; > + > +out: > + if (!IS_ERR_OR_NULL(freplace_link)) > + bpf_link__destroy(freplace_link); > + if (!IS_ERR_OR_NULL(fmod_link)) > + bpf_link__destroy(fmod_link); > + if (!IS_ERR_OR_NULL(freplace_obj)) > + bpf_object__close(freplace_obj); > + if (!IS_ERR_OR_NULL(fmod_obj)) > + bpf_object__close(fmod_obj); no need for all IS_ERR_OR_NULL checks > + bpf_object__close(pkt_obj); > +} > + > + [...]
diff --git a/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c b/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c index 27677e015730..6339d125ef9a 100644 --- a/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c +++ b/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c @@ -233,6 +233,72 @@ static void test_func_replace_multi(void) prog_name, true, test_second_attach); } +static void test_fmod_ret_freplace(void) +{ + const char *tgt_name = "./test_pkt_access.o"; + const char *freplace_name = "./freplace_get_constant.o"; + const char *fmod_ret_name = "./fmod_ret_freplace.o"; + struct bpf_link *freplace_link = NULL, *fmod_link = NULL; + struct bpf_object *freplace_obj = NULL, *pkt_obj, *fmod_obj = NULL; + struct bpf_program *prog; + __u32 duration = 0; + int err, pkt_fd; + + err = bpf_prog_load(tgt_name, BPF_PROG_TYPE_UNSPEC, + &pkt_obj, &pkt_fd); + /* the target prog should load fine */ + if (CHECK(err, "tgt_prog_load", "file %s err %d errno %d\n", + tgt_name, err, errno)) + return; + DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts, + .attach_prog_fd = pkt_fd, + ); + + freplace_obj = bpf_object__open_file(freplace_name, &opts); + if (CHECK(IS_ERR_OR_NULL(freplace_obj), "freplace_obj_open", + "failed to open %s: %ld\n", freplace_name, + PTR_ERR(freplace_obj))) + goto out; + + err = bpf_object__load(freplace_obj); + if (CHECK(err, "freplace_obj_load", "err %d\n", err)) + goto out; + + prog = bpf_program__next(NULL, freplace_obj); + freplace_link = bpf_program__attach_trace(prog); + if (CHECK(IS_ERR(freplace_link), "freplace_attach_trace", "failed to link\n")) + goto out; + + opts.attach_prog_fd = bpf_program__fd(prog); + fmod_obj = bpf_object__open_file(fmod_ret_name, &opts); + if (CHECK(IS_ERR_OR_NULL(fmod_obj), "fmod_obj_open", + "failed to open %s: %ld\n", fmod_ret_name, + PTR_ERR(fmod_obj))) + goto out; + + err = bpf_object__load(fmod_obj); + if (CHECK(err, "fmod_obj_load", "err %d\n", err)) + goto out; + + prog = bpf_program__next(NULL, fmod_obj); + fmod_link = bpf_program__attach_trace(prog); + if (CHECK(!IS_ERR(fmod_link), "fmod_attach_trace", + "linking fmod_ret to freplace should fail\n")) + goto out; + +out: + if (!IS_ERR_OR_NULL(freplace_link)) + bpf_link__destroy(freplace_link); + if (!IS_ERR_OR_NULL(fmod_link)) + bpf_link__destroy(fmod_link); + if (!IS_ERR_OR_NULL(freplace_obj)) + bpf_object__close(freplace_obj); + if (!IS_ERR_OR_NULL(fmod_obj)) + bpf_object__close(fmod_obj); + bpf_object__close(pkt_obj); +} + + static void test_func_sockmap_update(void) { const char *prog_name[] = { @@ -315,4 +381,6 @@ void test_fexit_bpf2bpf(void) test_func_map_prog_compatibility(); if (test__start_subtest("func_replace_multi")) test_func_replace_multi(); + if (test__start_subtest("fmod_ret_freplace")) + test_fmod_ret_freplace(); } diff --git a/tools/testing/selftests/bpf/progs/fmod_ret_freplace.c b/tools/testing/selftests/bpf/progs/fmod_ret_freplace.c new file mode 100644 index 000000000000..c8943ccee6c0 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/fmod_ret_freplace.c @@ -0,0 +1,14 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +volatile __u64 test_fmod_ret = 0; +SEC("fmod_ret/security_new_get_constant") +int BPF_PROG(fmod_ret_test, long val, int ret) +{ + test_fmod_ret = 1; + return 120; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/freplace_get_constant.c b/tools/testing/selftests/bpf/progs/freplace_get_constant.c index 8f0ecf94e533..705e4b64dfc2 100644 --- a/tools/testing/selftests/bpf/progs/freplace_get_constant.c +++ b/tools/testing/selftests/bpf/progs/freplace_get_constant.c @@ -5,7 +5,7 @@ volatile __u64 test_get_constant = 0; SEC("freplace/get_constant") -int new_get_constant(long val) +int security_new_get_constant(long val) { if (val != 123) return 0;