From c196906d50e360d82ed9aa5596a9d0ce89b7ab78 Mon Sep 17 00:00:00 2001 From: Hou Tao Date: Mon, 25 Oct 2021 14:40:24 +0800 Subject: bpf: Add dummy BPF STRUCT_OPS for test purpose Currently the test of BPF STRUCT_OPS depends on the specific bpf implementation of tcp_congestion_ops, but it can not cover all basic functionalities (e.g, return value handling), so introduce a dummy BPF STRUCT_OPS for test purpose. Loading a bpf_dummy_ops implementation from userspace is prohibited, and its only purpose is to run BPF_PROG_TYPE_STRUCT_OPS program through bpf(BPF_PROG_TEST_RUN). Now programs for test_1() & test_2() are supported. The following three cases are exercised in bpf_dummy_struct_ops_test_run(): (1) test and check the value returned from state arg in test_1(state) The content of state is copied from userspace pointer and copied back after calling test_1(state). The user pointer is saved in an u64 array and the array address is passed through ctx_in. (2) test and check the return value of test_1(NULL) Just simulate the case in which an invalid input argument is passed in. (3) test multiple arguments passing in test_2(state, ...) 5 arguments are passed through ctx_in in form of u64 array. The first element of array is userspace pointer of state and others 4 arguments follow. Signed-off-by: Hou Tao Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20211025064025.2567443-4-houtao1@huawei.com --- include/linux/bpf.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'include') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 67f71e7def56..c098089c1b54 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1018,6 +1018,22 @@ static inline void bpf_module_put(const void *data, struct module *owner) else module_put(owner); } + +#ifdef CONFIG_NET +/* Define it here to avoid the use of forward declaration */ +struct bpf_dummy_ops_state { + int val; +}; + +struct bpf_dummy_ops { + int (*test_1)(struct bpf_dummy_ops_state *cb); + int (*test_2)(struct bpf_dummy_ops_state *cb, int a1, unsigned short a2, + char a3, unsigned long a4); +}; + +int bpf_struct_ops_test_run(struct bpf_prog *prog, const union bpf_attr *kattr, + union bpf_attr __user *uattr); +#endif #else static inline const struct bpf_struct_ops *bpf_struct_ops_find(u32 type_id) { -- cgit v1.2.3