From: Andrii Nakryiko <andrii.nakryiko@gmail.com>
To: Pedro Tammela <pctammela@gmail.com>
Cc: Pedro Tammela <pctammela@mojatatu.com>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>, Shuah Khan <shuah@kernel.org>,
Joe Stringer <joe@cilium.io>,
Quentin Monnet <quentin@isovalent.com>,
Yang Li <yang.lee@linux.alibaba.com>,
Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
open list <linux-kernel@vger.kernel.org>,
"open list:KERNEL SELFTEST FRAMEWORK"
<linux-kselftest@vger.kernel.org>
Subject: Re: [PATCH bpf-next] bpf: check flags in 'bpf_ringbuf_discard()' and 'bpf_ringbuf_submit()'
Date: Tue, 30 Mar 2021 23:58:16 -0700 [thread overview]
Message-ID: <CAEf4BzZ5hZ+ca-S3cBWmkEtsB4nvQhzR5EA5+Q6En0m+N8um4w@mail.gmail.com> (raw)
In-Reply-To: <20210328161055.257504-2-pctammela@mojatatu.com>
On Sun, Mar 28, 2021 at 9:12 AM Pedro Tammela <pctammela@gmail.com> wrote:
>
> The current code only checks flags in 'bpf_ringbuf_output()'.
>
> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
> ---
> include/uapi/linux/bpf.h | 8 ++++----
> kernel/bpf/ringbuf.c | 13 +++++++++++--
> tools/include/uapi/linux/bpf.h | 8 ++++----
> 3 files changed, 19 insertions(+), 10 deletions(-)
>
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index 100cb2e4c104..232b5e5dd045 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -4073,7 +4073,7 @@ union bpf_attr {
> * Valid pointer with *size* bytes of memory available; NULL,
> * otherwise.
> *
> - * void bpf_ringbuf_submit(void *data, u64 flags)
> + * int bpf_ringbuf_submit(void *data, u64 flags)
> * Description
> * Submit reserved ring buffer sample, pointed to by *data*.
> * If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
> @@ -4083,9 +4083,9 @@ union bpf_attr {
> * If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
> * of new data availability is sent unconditionally.
> * Return
> - * Nothing. Always succeeds.
bpf_ringbuf_submit/bpf_ringbuf_commit has to alway succeed. That's an
explicit and strict rule, which BPF verifier relies on. We cannot bail
out due to unknown flags, because then ringbuf sample won't ever be
submitted and will block all the subsequent samples.
> + * 0 on success, or a negative error in case of failure.
> *
[...]
next prev parent reply other threads:[~2021-03-31 6:59 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-28 16:10 [PATCH bpf-next] bpf: add 'BPF_RB_MAY_WAKEUP' flag Pedro Tammela
2021-03-28 16:10 ` [PATCH bpf-next] bpf: check flags in 'bpf_ringbuf_discard()' and 'bpf_ringbuf_submit()' Pedro Tammela
2021-03-29 16:10 ` Song Liu
2021-03-30 14:22 ` Pedro Tammela
2021-03-30 18:12 ` Song Liu
2021-03-31 6:58 ` Andrii Nakryiko [this message]
2021-03-28 16:10 ` [PATCH bpf-next] libbpf: Add '_wait()' and '_nowait()' macros for 'bpf_ring_buffer__poll()' Pedro Tammela
2021-03-29 16:28 ` Song Liu
2021-03-31 18:59 ` Andrii Nakryiko
2021-03-29 16:05 ` [PATCH bpf-next] bpf: add 'BPF_RB_MAY_WAKEUP' flag Song Liu
2021-03-31 6:53 ` Andrii Nakryiko
2021-04-03 13:34 ` Pedro Tammela
2021-04-03 15:51 ` 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=CAEf4BzZ5hZ+ca-S3cBWmkEtsB4nvQhzR5EA5+Q6En0m+N8um4w@mail.gmail.com \
--to=andrii.nakryiko@gmail.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=joe@cilium.io \
--cc=john.fastabend@gmail.com \
--cc=kafai@fb.com \
--cc=kpsingh@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=pctammela@gmail.com \
--cc=pctammela@mojatatu.com \
--cc=quentin@isovalent.com \
--cc=shuah@kernel.org \
--cc=songliubraving@fb.com \
--cc=yang.lee@linux.alibaba.com \
--cc=yhs@fb.com \
/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).