linux-kernel - Re: [PATCH v5 net-next 06/29] bpf: add lookup/update/delete/iterate methods to BPF maps

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: <CAHA+R7MTJcsDpw=5P7hOsVf_pEOEZX_=cLrcw4ep4xntUxk=3Q@mail.gmail.com>
Date:	Mon, 25 Aug 2014 14:33:48 -0700
From:	Cong Wang <cwang@...pensource.com>
To:	Alexei Starovoitov <ast@...mgrid.com>
Cc:	"David S. Miller" <davem@...emloft.net>,
	Ingo Molnar <mingo@...nel.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Andy Lutomirski <luto@...capital.net>,
	Steven Rostedt <rostedt@...dmis.org>,
	Daniel Borkmann <dborkman@...hat.com>,
	Chema Gonzalez <chema@...gle.com>,
	Eric Dumazet <edumazet@...gle.com>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Brendan Gregg <brendan.d.gregg@...il.com>,
	Namhyung Kim <namhyung@...nel.org>,
	"H. Peter Anvin" <hpa@...or.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Kees Cook <keescook@...omium.org>, linux-api@...r.kernel.org,
	netdev <netdev@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v5 net-next 06/29] bpf: add lookup/update/delete/iterate
 methods to BPF maps

On Sun, Aug 24, 2014 at 1:21 PM, Alexei Starovoitov <ast@...mgrid.com> wrote:
> 'maps' is a generic storage of different types for sharing data between kernel
> and userspace.
>
> The maps are accessed from user space via BPF syscall, which has commands:
>
> - create a map with given type and attributes
>   fd = bpf_map_create(map_type, struct nlattr *attr, int len)
>   returns fd or negative error
>
> - lookup key in a given map referenced by fd
>   err = bpf_map_lookup_elem(int fd, void *key, void *value)
>   returns zero and stores found elem into value or negative error
>
> - create or update key/value pair in a given map
>   err = bpf_map_update_elem(int fd, void *key, void *value)
>   returns zero or negative error
>
> - find and delete element by key in a given map
>   err = bpf_map_delete_elem(int fd, void *key)
>
> - iterate map elements (based on input key return next_key)
>   err = bpf_map_get_next_key(int fd, void *key, void *next_key)


I think you need to document the bpf() syscall instead of wrappers on it,
from a developer's point of view. You will anyway need to document a new
syscall with a man page as a general rule.

In the changelog I mean something like:

err = bpf(BPF_MAP_LOOKUP_ELEM, ...);
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/