On Fri, Oct 22, 2021 at 03:55:10PM +0800, Hou Tao wrote:
> --- /dev/null
> +++ b/net/bpf/bpf_dummy_struct_ops.c
> @@ -0,0 +1,203 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021. Huawei Technologies Co., Ltd
> + */
> +#include <linux/kernel.h>
> +#include <linux/bpf_verifier.h>
> +#include <linux/bpf.h>
> +#include <linux/btf.h>
> +
> +extern struct bpf_struct_ops bpf_bpf_dummy_ops;
> +
> +/* A common type for test_N with return value in bpf_dummy_ops */
> +typedef int (*dummy_ops_test_ret_fn)(struct bpf_dummy_ops_state *state, ...);
> +
> +struct bpf_dummy_ops_test_args {
> + u64 args[MAX_BPF_FUNC_ARGS];
> + struct bpf_dummy_ops_state state;
> +};
> +
> +static struct bpf_dummy_ops_test_args *
> +dummy_ops_init_args(const union bpf_attr *kattr, unsigned int nr)
> +{
> + __u32 size_in;
> + struct bpf_dummy_ops_test_args *args;
> + void __user *ctx_in;
> + void __user *u_state;
> +
> + if (!nr || nr > MAX_BPF_FUNC_ARGS)
These checks are unnecessary and can be removed. They had already been
checked by the verifier during the bpf prog load time.
Others lgtm.
Acked-by: Martin KaFai Lau <kafai@xxxxxx>
> + return ERR_PTR(-EINVAL);
> +
> + size_in = kattr->test.ctx_size_in;
> + if (size_in != sizeof(u64) * nr)
> + return ERR_PTR(-EINVAL);
> +
> + args = kzalloc(sizeof(*args), GFP_KERNEL);
> + if (!args)
> + return ERR_PTR(-ENOMEM);
> +
> + ctx_in = u64_to_user_ptr(kattr->test.ctx_in);
> + if (copy_from_user(args->args, ctx_in, size_in))
> + goto out;
> +
> + /* args[0] is 0 means state argument of test_N will be NULL */
> + u_state = u64_to_user_ptr(args->args[0]);
> + if (u_state && copy_from_user(&args->state, u_state,
> + sizeof(args->state)))
> + goto out;
> +
> + return args;
> +out:
> + kfree(args);
> + return ERR_PTR(-EFAULT);
> +}
[ ... ]
> +int bpf_struct_ops_test_run(struct bpf_prog *prog, const union bpf_attr *kattr,
> + union bpf_attr __user *uattr)
> +{
> + const struct bpf_struct_ops *st_ops = &bpf_bpf_dummy_ops;
> + const struct btf_type *func_proto;
> + struct bpf_dummy_ops_test_args *args;
> + struct bpf_tramp_progs *tprogs;
> + void *image = NULL;
> + unsigned int op_idx;
> + int prog_ret;
> + int err;
> +
> + if (prog->aux->attach_btf_id != st_ops->type_id)
> + return -EOPNOTSUPP;
> +
> + func_proto = prog->aux->attach_func_proto;
> + args = dummy_ops_init_args(kattr, btf_type_vlen(func_proto));
> + if (IS_ERR(args))
> + return PTR_ERR(args);
