netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Alexei Starovoitov <ast@kernel.org>
Cc: "David S . Miller" <davem@davemloft.net>,
	daniel@iogearbox.net, luto@amacapital.net,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	kernel-team@fb.com
Subject: Re: [PATCH bpf-next 1/6] bpf: introduce BPF_PROG_TYPE_FILE_FILTER
Date: Fri, 5 Oct 2018 05:46:59 +0100	[thread overview]
Message-ID: <20181005044659.GU32577@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20181004025750.498303-2-ast@kernel.org>

On Wed, Oct 03, 2018 at 07:57:45PM -0700, Alexei Starovoitov wrote:
 
> @@ -15,6 +15,7 @@
>  #include <linux/bpf.h>
>  #include <linux/bpf-cgroup.h>
>  #include <net/sock.h>
> +#include <../fs/mount.h>

No.

> +	struct file *file = NULL;
> +	struct inode *inode;
> +	struct super_block *sb;
> +	struct mount *mnt;

Fuck, no.

> +	case offsetof(struct bpf_file_info, mnt_id):
> +		/* dst = real_mount(file->f_path.mnt)->mnt_id */
> +		mnt = real_mount(LD_1(file->f_path.mnt));
> +		LD_n(mnt->mnt_id);

NAK.  Anything in struct mount is private to just a couple of
files in fs/*.c.  Don't do that.  And keep in mind that internal
details can and will be changed at zero notice, so be careful
with adding such stuff.

Another problem is your direct poking in ->i_ino.  It's not
something directly exposed to userland at the moment and it should
not become such.  Filesystem has every right to have ->getattr()
set ->ino (== ->st_ino value) in whichever way it likes; the same
goes for ->dev.

  parent reply	other threads:[~2018-10-05  4:46 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-04  2:57 [PATCH bpf-next 0/6] bpf: introduce BPF_CGROUP_FILE_OPEN Alexei Starovoitov
2018-10-04  2:57 ` [PATCH bpf-next 1/6] bpf: introduce BPF_PROG_TYPE_FILE_FILTER Alexei Starovoitov
2018-10-04 19:41   ` Roman Gushchin
2018-10-04 19:51     ` Andy Lutomirski
2018-10-04 22:23       ` Alexei Starovoitov
2018-10-05  4:46   ` Al Viro [this message]
2018-10-05 22:05     ` Alexei Starovoitov
2018-10-05 22:09       ` Andy Lutomirski
2018-10-05 22:27         ` Alexei Starovoitov
2018-10-05 23:47           ` Al Viro
2018-10-06  0:22             ` Alexei Starovoitov
2018-10-08  0:56   ` Jann Horn
2018-10-08  2:22     ` Alexei Starovoitov
2018-10-08  9:06       ` Mickaël Salaün
2018-10-04  2:57 ` [PATCH bpf-next 2/6] fs: wire in BPF_CGROUP_FILE_OPEN hook Alexei Starovoitov
2018-10-04  2:57 ` [PATCH bpf-next 3/6] tools/bpf: sync uapi/bpf.h Alexei Starovoitov
2018-10-04  2:57 ` [PATCH bpf-next 4/6] trace/bpf: allow %o modifier in bpf_trace_printk Alexei Starovoitov
2018-10-04  2:57 ` [PATCH bpf-next 5/6] libbpf: support BPF_CGROUP_FILE_OPEN in libbpf Alexei Starovoitov
2018-10-04  2:57 ` [PATCH bpf-next 6/6] selftests/bpf: add a test for BPF_CGROUP_FILE_OPEN Alexei Starovoitov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20181005044659.GU32577@ZenIV.linux.org.uk \
    --to=viro@zeniv.linux.org.uk \
    --cc=ast@kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=davem@davemloft.net \
    --cc=kernel-team@fb.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@amacapital.net \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).