[PATCH bpf-next v6 04/23] selftests/bpf: add test for accessing ctx from syscall program type
From: Benjamin Tissoires <hidden>
Date: 2022-07-12 15:00:52
Also in:
bpf, linux-doc, linux-input, linux-kselftest, lkml
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [selftests] (test runners & infrastructure), kernel selftest framework, networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Shuah Khan, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <redacted> --- new in v6 --- net/bpf/test_run.c | 1 + .../selftests/bpf/prog_tests/kfunc_call.c | 20 ++++++++++++++ .../selftests/bpf/progs/kfunc_call_test.c | 27 +++++++++++++++++++ 3 files changed, 48 insertions(+)
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 2ca96acbc50a..9da2a42811e8 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c@@ -1646,6 +1646,7 @@ static int __init bpf_prog_test_run_init(void) int ret; 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_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 c00eb974eb85..22547aafdd60 100644
--- a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c
+++ b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c@@ -6,10 +6,22 @@ #include "kfunc_call_test_subprog.skel.h" #include "kfunc_call_test_subprog.lskel.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),
@@ -35,6 +47,14 @@ 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)"); + 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..0978834e22ad 100644
--- a/tools/testing/selftests/bpf/progs/kfunc_call_test.c
+++ b/tools/testing/selftests/bpf/progs/kfunc_call_test.c@@ -92,4 +92,31 @@ 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, size); + + 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";
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2.36.1