From: Simon Horman <horms@kernel.org>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Andrii Nakryiko <andrii@kernel.org>,
bpf@vger.kernel.org, netdev@vger.kernel.org, paul@paul-moore.com,
brauner@kernel.org, linux-fsdevel@vger.kernel.org,
linux-security-module@vger.kernel.org, keescook@chromium.org,
kernel-team@meta.com, sargun@sargun.me
Subject: Re: [PATCH v11 bpf-next 02/17] bpf: add BPF token delegation mount options to BPF FS
Date: Tue, 5 Dec 2023 09:13:44 +0000 [thread overview]
Message-ID: <20231205091344.GR50400@kernel.org> (raw)
In-Reply-To: <CAEf4BzbN2xovoTyQeK1sHZdB-YMeiC=U7oOmUcpcb5_ZHEcFgA@mail.gmail.com>
On Thu, Nov 30, 2023 at 10:13:41AM -0800, Andrii Nakryiko wrote:
> On Thu, Nov 30, 2023 at 10:03 AM Andrii Nakryiko
> <andrii.nakryiko@gmail.com> wrote:
> >
> > On Thu, Nov 30, 2023 at 8:37 AM Simon Horman <horms@kernel.org> wrote:
> > >
> > > On Mon, Nov 27, 2023 at 11:03:54AM -0800, Andrii Nakryiko wrote:
> > >
> > > ...
> > >
> > > > @@ -764,7 +817,10 @@ static int bpf_get_tree(struct fs_context *fc)
> > > >
> > > > static void bpf_free_fc(struct fs_context *fc)
> > > > {
> > > > - kfree(fc->fs_private);
> > > > + struct bpf_mount_opts *opts = fc->s_fs_info;
> > > > +
> > > > + if (opts)
> > > > + kfree(opts);
> > > > }
> > >
> > > Hi Andrii,
> > >
> > > as it looks like there will be a v12, I have a minor nit to report: There
> > > is no need to check if opts is non-NULL because kfree() is basically a
> > > no-op if it's argument is NULL.
> > >
> > > So perhaps this can become (completely untested!):
> > >
> > > static void bpf_free_fc(struct fs_context *fc)
> > > {
> > > kfree(fc->s_fs_info);
> > > }
> > >
> >
> > sure, I can drop the check, I wasn't sure if it's canonical or not to
> > check the argument for NULL before calling kfree(). For user-space
> > it's definitely quite expected to not have to check for null before
> > calling free().
>
> Heh, turns out I already simplified this, but it's in the next patch.
> I'll move it into patch #2, though, where it actually belongs.
Thanks. I do believe that for kernel code not checking for NULL here
is preferred.
next prev parent reply other threads:[~2023-12-05 9:13 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-27 19:03 [PATCH v11 bpf-next 00/17] BPF token and BPF FS-based delegation Andrii Nakryiko
2023-11-27 19:03 ` [PATCH v11 bpf-next 01/17] bpf: align CAP_NET_ADMIN checks with bpf_capable() approach Andrii Nakryiko
2023-11-27 19:03 ` [PATCH v11 bpf-next 02/17] bpf: add BPF token delegation mount options to BPF FS Andrii Nakryiko
2023-11-30 14:18 ` Christian Brauner
2023-11-30 18:02 ` Andrii Nakryiko
2023-11-30 16:36 ` Simon Horman
2023-11-30 18:03 ` Andrii Nakryiko
2023-11-30 18:13 ` Andrii Nakryiko
2023-12-05 9:13 ` Simon Horman [this message]
2023-11-27 19:03 ` [PATCH v11 bpf-next 03/17] bpf: introduce BPF token object Andrii Nakryiko
2023-11-29 0:05 ` Andrii Nakryiko
2023-11-30 14:05 ` Christian Brauner
2023-11-30 14:27 ` Christian Brauner
2023-11-30 17:57 ` Andrii Nakryiko
2023-11-27 19:03 ` [PATCH v11 bpf-next 04/17] bpf: add BPF token support to BPF_MAP_CREATE command Andrii Nakryiko
2023-11-27 19:03 ` [PATCH v11 bpf-next 05/17] bpf: add BPF token support to BPF_BTF_LOAD command Andrii Nakryiko
2023-11-27 19:03 ` [PATCH v11 bpf-next 06/17] bpf: add BPF token support to BPF_PROG_LOAD command Andrii Nakryiko
2023-11-27 19:03 ` [PATCH v11 bpf-next 07/17] bpf: take into account BPF token when fetching helper protos Andrii Nakryiko
2023-11-27 19:04 ` [PATCH v11 bpf-next 08/17] bpf: consistently use BPF token throughout BPF verifier logic Andrii Nakryiko
2023-11-27 19:04 ` [PATCH v11 bpf-next 09/17] bpf,lsm: refactor bpf_prog_alloc/bpf_prog_free LSM hooks Andrii Nakryiko
2023-11-27 19:04 ` [PATCH v11 bpf-next 10/17] bpf,lsm: refactor bpf_map_alloc/bpf_map_free " Andrii Nakryiko
2023-11-27 19:04 ` [PATCH v11 bpf-next 11/17] bpf,lsm: add BPF token " Andrii Nakryiko
2023-11-27 19:04 ` [PATCH v11 bpf-next 12/17] libbpf: add bpf_token_create() API Andrii Nakryiko
2023-11-27 19:04 ` [PATCH v11 bpf-next 13/17] libbpf: add BPF token support to bpf_map_create() API Andrii Nakryiko
2023-11-27 19:04 ` [PATCH v11 bpf-next 14/17] libbpf: add BPF token support to bpf_btf_load() API Andrii Nakryiko
2023-11-27 19:04 ` [PATCH v11 bpf-next 15/17] libbpf: add BPF token support to bpf_prog_load() API Andrii Nakryiko
2023-11-27 19:04 ` [PATCH v11 bpf-next 16/17] selftests/bpf: add BPF token-enabled tests Andrii Nakryiko
2023-11-27 19:04 ` [PATCH v11 bpf-next 17/17] bpf,selinux: allocate bpf_security_struct per BPF token Andrii Nakryiko
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=20231205091344.GR50400@kernel.org \
--to=horms@kernel.org \
--cc=andrii.nakryiko@gmail.com \
--cc=andrii@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=brauner@kernel.org \
--cc=keescook@chromium.org \
--cc=kernel-team@meta.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=paul@paul-moore.com \
--cc=sargun@sargun.me \
/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).