diff options
| author | David Vernet <void@manifault.com> | 2023-02-01 11:30:16 -0600 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2023-02-02 00:25:14 +0100 |
| commit | 6aed15e330bfec6a423f40582b2a8b53d9ce1757 (patch) | |
| tree | 7ba09ec45bc7c8865844287480a39f8f5984dd3d | |
| parent | 400031e05adfcef9e80eca80bdfc3f4b63658be4 (diff) | |
selftests/bpf: Add testcase for static kfunc with unused arg
kfuncs are allowed to be static, or not use one or more of their
arguments. For example, bpf_xdp_metadata_rx_hash() in net/core/xdp.c is
meant to be implemented by drivers, with the default implementation just
returning -EOPNOTSUPP. As described in [0], such kfuncs can have their
arguments elided, which can cause BTF encoding to be skipped. The new
__bpf_kfunc macro should address this, and this patch adds a selftest
which verifies that a static kfunc with at least one unused argument can
still be encoded and invoked by a BPF program.
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230201173016.342758-5-void@manifault.com
| -rw-r--r-- | net/bpf/test_run.c | 6 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/kfunc_call.c | 1 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/kfunc_call_test.c | 11 |
3 files changed, 18 insertions, 0 deletions
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index af9827c4b351..e6f773d12045 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -741,6 +741,11 @@ __bpf_kfunc void bpf_kfunc_call_test_destructive(void) { } +__bpf_kfunc static u32 bpf_kfunc_call_test_static_unused_arg(u32 arg, u32 unused) +{ + return arg; +} + __diag_pop(); BTF_SET8_START(bpf_test_modify_return_ids) @@ -779,6 +784,7 @@ BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_fail1) BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_fail2) BTF_ID_FLAGS(func, bpf_kfunc_call_test_ref, KF_TRUSTED_ARGS) BTF_ID_FLAGS(func, bpf_kfunc_call_test_destructive, KF_DESTRUCTIVE) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_static_unused_arg) BTF_SET8_END(test_sk_check_kfunc_ids) static void *bpf_test_init(const union bpf_attr *kattr, u32 user_size, diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c index bb4cd82a788a..a543742cd7bd 100644 --- a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c +++ b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c @@ -77,6 +77,7 @@ static struct kfunc_test_params kfunc_tests[] = { TC_TEST(kfunc_call_test_get_mem, 42), SYSCALL_TEST(kfunc_syscall_test, 0), SYSCALL_NULL_CTX_TEST(kfunc_syscall_test_null, 0), + TC_TEST(kfunc_call_test_static_unused_arg, 0), }; struct syscall_test_args { diff --git a/tools/testing/selftests/bpf/progs/kfunc_call_test.c b/tools/testing/selftests/bpf/progs/kfunc_call_test.c index d91c58d06d38..7daa8f5720b9 100644 --- a/tools/testing/selftests/bpf/progs/kfunc_call_test.c +++ b/tools/testing/selftests/bpf/progs/kfunc_call_test.c @@ -17,6 +17,7 @@ extern void bpf_kfunc_call_test_mem_len_pass1(void *mem, int len) __ksym; extern void bpf_kfunc_call_test_mem_len_fail2(__u64 *mem, int len) __ksym; extern int *bpf_kfunc_call_test_get_rdwr_mem(struct prog_test_ref_kfunc *p, const int rdwr_buf_size) __ksym; extern int *bpf_kfunc_call_test_get_rdonly_mem(struct prog_test_ref_kfunc *p, const int rdonly_buf_size) __ksym; +extern u32 bpf_kfunc_call_test_static_unused_arg(u32 arg, u32 unused) __ksym; SEC("tc") int kfunc_call_test4(struct __sk_buff *skb) @@ -181,4 +182,14 @@ int kfunc_call_test_get_mem(struct __sk_buff *skb) return ret; } +SEC("tc") +int kfunc_call_test_static_unused_arg(struct __sk_buff *skb) +{ + + u32 expected = 5, actual; + + actual = bpf_kfunc_call_test_static_unused_arg(expected, 0xdeadbeef); + return actual != expected ? -1 : 0; +} + char _license[] SEC("license") = "GPL"; |