netdev - Re: [PATCH v2 1/2] bpf: remove struct bpf_prog_type

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20170409.182236.865920818973965236.davem@davemloft.net>
Date:   Sun, 09 Apr 2017 18:22:36 -0700 (PDT)
From:   David Miller <davem@...emloft.net>
To:     johannes@...solutions.net
Cc:     netdev@...r.kernel.org, alexei.starovoitov@...il.com,
        johannes.berg@...el.com
Subject: Re: [PATCH v2 1/2] bpf: remove struct bpf_prog_type_list

From: Johannes Berg <johannes@...solutions.net>
Date: Fri,  7 Apr 2017 21:00:07 +0200

> From: Johannes Berg <johannes.berg@...el.com>
> 
> There's no need to have struct bpf_prog_type_list since
> it just contains a list_head, the type, and the ops
> pointer. Since the types are densely packed and not
> actually dynamically registered, it's much easier and
> smaller to have an array of type->ops pointer. Also
> initialize this array statically to remove code needed
> to initialize it.
> 
> Signed-off-by: Johannes Berg <johannes.berg@...el.com>

If you just don't want to list things multiple times how about:

linux/bpf_verifiers.h:
BPF_VERIFIER(BPF_PROG_TYPE_SOCKET_FILTER, sk_filter_prog_ops)
BPF_VERIFIER(BPF_PROG_TYPE_SCHED_CLS, tc_cls_prog_ops)
 ...

Then in bpf.h:

#define BPF_VERIFIER(TYPE_VAL, SYM) extern const struct bpf_verifier_ops SYM;
#include <linux/bpf_verifiers.h"

and in kernel/bpf/syscall.c:

#define BPF_VERIFIER(TYPE_VAL, SYM) [TYPE_VAL] = &SYM,
#include <linux/bpf_verifiers.h"

or something like that.

Maybe there is some even more straightforward way to do this without
using sections or anything like that, which we can't see right now :)