Commit 7bd1590d authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Alexei Starovoitov
Browse files

bpf: selftests: Add kfunc_call test 



This patch adds a few kernel function bpf_kfunc_call_test*() 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*()
is also added in this patch.

Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210325015252.1551395-1-kafai@fb.com
parent 78e60bbb

include/linux/bpf.h

+6 −0
Original line number Diff line number Diff line
@@ -1532,6 +1532,7 @@ int bpf_prog_test_run_raw_tp(struct bpf_prog *prog, 
int bpf_prog_test_run_sk_lookup(struct bpf_prog *prog,

				const union bpf_attr *kattr,

				union bpf_attr __user *uattr);

bool bpf_prog_test_check_kfunc_call(u32 kfunc_id);

bool btf_ctx_access(int off, int size, enum bpf_access_type type,

		    const struct bpf_prog *prog,

		    struct bpf_insn_access_aux *info);
@@ -1731,6 +1732,11 @@ static inline int bpf_prog_test_run_sk_lookup(struct bpf_prog *prog, 
	return -ENOTSUPP;

}



static inline bool bpf_prog_test_check_kfunc_call(u32 kfunc_id)

{

	return false;

}



static inline void bpf_map_put(struct bpf_map *map)

{

}

net/bpf/test_run.c

+28 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
/* Copyright (c) 2017 Facebook

 */

#include <linux/bpf.h>

#include <linux/btf_ids.h>

#include <linux/slab.h>

#include <linux/vmalloc.h>

#include <linux/etherdevice.h>
@@ -213,10 +214,37 @@ 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;

}



struct sock * noinline bpf_kfunc_call_test3(struct sock *sk)

{

	return sk;

}



__diag_pop();



ALLOW_ERROR_INJECTION(bpf_modify_return_test, ERRNO);



BTF_SET_START(test_sk_kfunc_ids)

BTF_ID(func, bpf_kfunc_call_test1)

BTF_ID(func, bpf_kfunc_call_test2)

BTF_ID(func, bpf_kfunc_call_test3)

BTF_SET_END(test_sk_kfunc_ids)



bool bpf_prog_test_check_kfunc_call(u32 kfunc_id)

{

	return btf_id_set_contains(&test_sk_kfunc_ids, kfunc_id);

}



static void *bpf_test_init(const union bpf_attr *kattr, u32 size,

			   u32 headroom, u32 tailroom)

{

net/core/filter.c

+1 −0
Original line number Diff line number Diff line
@@ -9813,6 +9813,7 @@ const struct bpf_verifier_ops tc_cls_act_verifier_ops = { 
	.convert_ctx_access	= tc_cls_act_convert_ctx_access,

	.gen_prologue		= tc_cls_act_prologue,

	.gen_ld_abs		= bpf_gen_ld_abs,

	.check_kfunc_call	= bpf_prog_test_check_kfunc_call,

};



const struct bpf_prog_ops tc_cls_act_prog_ops = {

tools/testing/selftests/bpf/prog_tests/kfunc_call.c

0 → 100644
+59 −0
Original line number Diff line number Diff line 
// 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 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, NULL);

	ASSERT_OK(err, "bpf_prog_test_run(test1)");

	ASSERT_EQ(retval, 12, "test1-retval");



	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, NULL);

	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, NULL);

	ASSERT_OK(err, "bpf_prog_test_run(test1)");

	ASSERT_EQ(retval, 10, "test1-retval");

	ASSERT_NEQ(skel->data->active_res, -1, "active_res");

	ASSERT_EQ(skel->data->sk_state, BPF_TCP_CLOSE, "sk_state");



	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();

}

tools/testing/selftests/bpf/progs/kfunc_call_test.c

0 → 100644
+47 −0
Original line number Diff line number Diff line 
// 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 int bpf_kfunc_call_test2(struct sock *sk, __u32 a, __u32 b) __ksym;

extern __u64 bpf_kfunc_call_test1(struct sock *sk, __u32 a, __u64 b,

				  __u32 c, __u64 d) __ksym;



SEC("classifier")

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")

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";