From: Eric Biggers <ebiggers@kernel.org>
To: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org, fsverity@lists.linux.dev, ast@kernel.org,
daniel@iogearbox.net, andrii@kernel.org, martin.lau@kernel.org,
kernel-team@meta.com, tytso@mit.edu,
roberto.sassu@huaweicloud.com
Subject: Re: [PATCH bpf-next 2/5] bpf, fsverity: Add kfunc bpf_get_fsverity_digest
Date: Mon, 16 Oct 2023 22:46:37 -0700 [thread overview]
Message-ID: <20231017054637.GH1907@sol.localdomain> (raw)
In-Reply-To: <CAPhsuW4u2GNL8BmEPPtYjc1KtP4Dx+wqtX1fc2eMPYB_6LmrRA@mail.gmail.com>
On Mon, Oct 16, 2023 at 10:35:16PM -0700, Song Liu wrote:
> On Mon, Oct 16, 2023 at 8:12 PM Eric Biggers <ebiggers@kernel.org> wrote:
> >
> > On Mon, Oct 16, 2023 at 01:10:40PM -0700, Song Liu wrote:
> > > On Sun, Oct 15, 2023 at 12:07 AM Eric Biggers <ebiggers@kernel.org> wrote:
> > > >
> > > [...]
> > > > > + */
> > > > > +__bpf_kfunc int bpf_get_fsverity_digest(struct file *file, struct bpf_dynptr_kern *digest_ptr)
> > > > > +{
> > > > > + const struct inode *inode = file_inode(file);
> > > > > + struct fsverity_digest *arg = digest_ptr->data;
> > > >
> > > > What alignment is guaranteed here?
> > >
> > > drnptr doesn't not provide alignment guarantee for digest_ptr->data.
> > > If we need alignment guarantee, we need to add it here.
> >
> > So technically it's wrong to cast it to struct fsverity_digest, then.
>
> We can enforce alignment here. Would __aligned(2) be sufficient?
>
Do you mean something like the following:
if (!IS_ALIGNED((uintptr_t)digest_ptr->data, __alignof__(*arg)))
return -EINVAL;
next prev parent reply other threads:[~2023-10-17 5:46 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20231013182644.2346458-1-song@kernel.org>
[not found] ` <20231013182644.2346458-3-song@kernel.org>
2023-10-15 7:07 ` [PATCH bpf-next 2/5] bpf, fsverity: Add kfunc bpf_get_fsverity_digest Eric Biggers
2023-10-16 20:10 ` Song Liu
2023-10-17 3:12 ` Eric Biggers
2023-10-17 5:35 ` Song Liu
2023-10-17 5:46 ` Eric Biggers [this message]
2023-10-17 14:16 ` Song Liu
2023-10-17 19:50 ` Andrii Nakryiko
[not found] ` <20231013182644.2346458-6-song@kernel.org>
2023-10-17 19:08 ` [PATCH bpf-next 5/5] selftests/bpf: Add test that use fsverity and xattr to sign a file Alexei Starovoitov
2023-10-17 20:36 ` Song Liu
[not found] ` <20231013182644.2346458-2-song@kernel.org>
2023-10-17 18:58 ` [PATCH bpf-next 1/5] bpf: Add kfunc bpf_get_file_xattr Andrii Nakryiko
2023-10-17 20:31 ` Song Liu
2023-10-17 21:52 ` Andrii Nakryiko
2023-10-17 22:16 ` Song Liu
2023-10-17 22:40 ` Andrii Nakryiko
2023-10-17 22:46 ` Song Liu
2023-10-18 1:42 ` Hou Tao
2023-10-17 19:10 ` Alexei Starovoitov
2023-11-02 1:19 ` KP Singh
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=20231017054637.GH1907@sol.localdomain \
--to=ebiggers@kernel.org \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=fsverity@lists.linux.dev \
--cc=kernel-team@meta.com \
--cc=martin.lau@kernel.org \
--cc=roberto.sassu@huaweicloud.com \
--cc=song@kernel.org \
--cc=tytso@mit.edu \
/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).