On Tue, Mar 16, 2021 at 12:02 AM Martin KaFai Lau <kafai@xxxxxx> wrote:
>
> This patch adds two kernel function bpf_kfunc_call_test[12]() for the
> selftest's test_run purpose. They will be allowed for tc_cls prog.
>
> The selftest calling the kernel function bpf_kfunc_call_test[12]()
> is also added in this patch.
>
> Signed-off-by: Martin KaFai Lau <kafai@xxxxxx>
> ---
> net/bpf/test_run.c | 11 ++++
> net/core/filter.c | 11 ++++
> .../selftests/bpf/prog_tests/kfunc_call.c | 61 +++++++++++++++++++
> .../selftests/bpf/progs/kfunc_call_test.c | 48 +++++++++++++++
> .../bpf/progs/kfunc_call_test_subprog.c | 31 ++++++++++
> 5 files changed, 162 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/prog_tests/kfunc_call.c
> create mode 100644 tools/testing/selftests/bpf/progs/kfunc_call_test.c
> create mode 100644 tools/testing/selftests/bpf/progs/kfunc_call_test_subprog.c
>
> diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
> index 0abdd67f44b1..c1baab0c7d96 100644
> --- a/net/bpf/test_run.c
> +++ b/net/bpf/test_run.c
> @@ -209,6 +209,17 @@ int noinline bpf_modify_return_test(int a, int *b)
> *b += 1;
> return a + *b;
> }
> +
> +u64 noinline bpf_kfunc_call_test1(struct sock *sk, u32 a, u64 b, u32 c, u64 d)
> +{
> + return a + b + c + d;
> +}
> +
> +int noinline bpf_kfunc_call_test2(struct sock *sk, u32 a, u32 b)
> +{
> + return a + b;
> +}
> +
> __diag_pop();
>
> ALLOW_ERROR_INJECTION(bpf_modify_return_test, ERRNO);
> diff --git a/net/core/filter.c b/net/core/filter.c
> index 10dac9dd5086..605fbbdd694b 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -9799,12 +9799,23 @@ const struct bpf_prog_ops sk_filter_prog_ops = {
> .test_run = bpf_prog_test_run_skb,
> };
>
> +BTF_SET_START(bpf_tc_cls_kfunc_ids)
> +BTF_ID(func, bpf_kfunc_call_test1)
> +BTF_ID(func, bpf_kfunc_call_test2)
> +BTF_SET_END(bpf_tc_cls_kfunc_ids)
> +
> +static bool tc_cls_check_kern_func_call(u32 kfunc_id)
> +{
> + return btf_id_set_contains(&bpf_tc_cls_kfunc_ids, kfunc_id);
> +}
> +
> const struct bpf_verifier_ops tc_cls_act_verifier_ops = {
> .get_func_proto = tc_cls_act_func_proto,
> .is_valid_access = tc_cls_act_is_valid_access,
> .convert_ctx_access = tc_cls_act_convert_ctx_access,
> .gen_prologue = tc_cls_act_prologue,
> .gen_ld_abs = bpf_gen_ld_abs,
> + .check_kern_func_call = tc_cls_check_kern_func_call,
> };
>
> const struct bpf_prog_ops tc_cls_act_prog_ops = {
> diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c
> new file mode 100644
> index 000000000000..3850e6cc0a7d
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c
> @@ -0,0 +1,61 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2021 Facebook */
> +#include <test_progs.h>
> +#include <network_helpers.h>
> +#include "kfunc_call_test.skel.h"
> +#include "kfunc_call_test_subprog.skel.h"
> +
> +static __u32 duration;
> +
you shouldn't need it, you don't use CHECK()s
> +static void test_main(void)
> +{
> + struct kfunc_call_test *skel;
> + int prog_fd, retval, err;
> +
> + skel = kfunc_call_test__open_and_load();
> + if (!ASSERT_OK_PTR(skel, "skel"))
> + return;
> +
> + prog_fd = bpf_program__fd(skel->progs.kfunc_call_test1);
> + err = bpf_prog_test_run(prog_fd, 1, &pkt_v4, sizeof(pkt_v4),
> + NULL, NULL, (__u32 *)&retval, &duration);
> +
> + if (ASSERT_OK(err, "bpf_prog_test_run(test1)"))
> + ASSERT_EQ(retval, 12, "test1-retval");
there is no harm in doing retval check unconditionally. If something
goes wrong, you'll both know that err != 0 and what retval you got (if
you ever care, but if not, it doesn't hurt either). Same below.
> +
> + prog_fd = bpf_program__fd(skel->progs.kfunc_call_test2);
> + err = bpf_prog_test_run(prog_fd, 1, &pkt_v4, sizeof(pkt_v4),
> + NULL, NULL, (__u32 *)&retval, &duration);
> + if (ASSERT_OK(err, "bpf_prog_test_run(test2)"))
> + ASSERT_EQ(retval, 3, "test2-retval");
> +
> + kfunc_call_test__destroy(skel);
> +}
> +
> +static void test_subprog(void)
> +{
> + struct kfunc_call_test_subprog *skel;
> + int prog_fd, retval, err;
> +
> + skel = kfunc_call_test_subprog__open_and_load();
> + if (!ASSERT_OK_PTR(skel, "skel"))
> + return;
> +
> + prog_fd = bpf_program__fd(skel->progs.kfunc_call_test1);
> + err = bpf_prog_test_run(prog_fd, 1, &pkt_v4, sizeof(pkt_v4),
> + NULL, NULL, (__u32 *)&retval, &duration);
> +
> + if (ASSERT_OK(err, "bpf_prog_test_run(test1)"))
> + ASSERT_EQ(retval, 10, "test1-retval");
> +
> + kfunc_call_test_subprog__destroy(skel);
> +}
> +
> +void test_kfunc_call(void)
> +{
> + if (test__start_subtest("main"))
> + test_main();
> +
> + if (test__start_subtest("subprog"))
> + test_subprog();
> +}
> diff --git a/tools/testing/selftests/bpf/progs/kfunc_call_test.c b/tools/testing/selftests/bpf/progs/kfunc_call_test.c
> new file mode 100644
> index 000000000000..ea8c5266efd8
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/kfunc_call_test.c
> @@ -0,0 +1,48 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2021 Facebook */
> +#include <linux/bpf.h>
> +#include <bpf/bpf_helpers.h>
> +#include "bpf_tcp_helpers.h"
> +
> +extern __u64 bpf_kfunc_call_test1(struct sock *sk, __u32 a, __u64 b,
> + __u32 c, __u64 d) __ksym;
> +extern int bpf_kfunc_call_test2(struct sock *sk, __u32 a, __u32 b) __ksym;
> +
> +SEC("classifier/test2")
> +int kfunc_call_test2(struct __sk_buff *skb)
> +{
> + struct bpf_sock *sk = skb->sk;
> +
> + if (!sk)
> + return -1;
> +
> + sk = bpf_sk_fullsock(sk);
> + if (!sk)
> + return -1;
> +
> + return bpf_kfunc_call_test2((struct sock *)sk, 1, 2);
> +}
> +
> +SEC("classifier/test1")
please use just SEC("classifier") here and above, libbpf will handle
that properly
> +int kfunc_call_test1(struct __sk_buff *skb)
> +{
> + struct bpf_sock *sk = skb->sk;
> + __u64 a = 1ULL << 32;
> + __u32 ret;
> +
> + if (!sk)
> + return -1;
> +
> + sk = bpf_sk_fullsock(sk);
> + if (!sk)
> + return -1;
> +
> + a = bpf_kfunc_call_test1((struct sock *)sk, 1, a | 2, 3, a | 4);
> +
> + ret = a >> 32; /* ret should be 2 */
> + ret += (__u32)a; /* ret should be 12 */
> +
> + return ret;
> +}
> +
> +char _license[] SEC("license") = "GPL";
> diff --git a/tools/testing/selftests/bpf/progs/kfunc_call_test_subprog.c b/tools/testing/selftests/bpf/progs/kfunc_call_test_subprog.c
> new file mode 100644
> index 000000000000..9bf66f8c826e
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/kfunc_call_test_subprog.c
> @@ -0,0 +1,31 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2021 Facebook */
> +#include <linux/bpf.h>
> +#include <bpf/bpf_helpers.h>
> +#include "bpf_tcp_helpers.h"
> +
> +extern __u64 bpf_kfunc_call_test1(struct sock *sk, __u32 a, __u64 b,
> + __u32 c, __u64 d) __ksym;
> +
> +__attribute__ ((noinline))
__noinline
> +int f1(struct __sk_buff *skb)
> +{
> + struct bpf_sock *sk = skb->sk;
> +
> + if (!sk)
> + return -1;
> +
> + sk = bpf_sk_fullsock(sk);
> + if (!sk)
> + return -1;
> +
> + return (__u32)bpf_kfunc_call_test1((struct sock *)sk, 1, 2, 3, 4);
> +}
> +
> +SEC("classifier/test1_subprog")
same, just "classifier"
> +int kfunc_call_test1(struct __sk_buff *skb)
> +{
> + return f1(skb);
> +}
> +
> +char _license[] SEC("license") = "GPL";
> --
> 2.30.2
>
