linux-kernel - Re: [PATCH bpf-next v3 0/6] bpf trampoline support "jmp" mode

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] [day] [month] [year] [list]

Message-ID: <97c8e49c-ca27-40ec-8ff6-18b1b9061240@linux.dev>
Date: Wed, 19 Nov 2025 10:55:19 +0800
From: Leon Hwang <leon.hwang@...ux.dev>
To: Menglong Dong <menglong.dong@...ux.dev>,
 Menglong Dong <menglong8.dong@...il.com>,
 Alexei Starovoitov <alexei.starovoitov@...il.com>,
 Leon Hwang <leon.hwang@...ux.dev>
Cc: Alexei Starovoitov <ast@...nel.org>, Steven Rostedt
 <rostedt@...dmis.org>, Daniel Borkmann <daniel@...earbox.net>,
 John Fastabend <john.fastabend@...il.com>,
 Andrii Nakryiko <andrii@...nel.org>, Martin KaFai Lau
 <martin.lau@...ux.dev>, Eduard <eddyz87@...il.com>,
 Song Liu <song@...nel.org>, Yonghong Song <yonghong.song@...ux.dev>,
 KP Singh <kpsingh@...nel.org>, Stanislav Fomichev <sdf@...ichev.me>,
 Hao Luo <haoluo@...gle.com>, Jiri Olsa <jolsa@...nel.org>,
 Masami Hiramatsu <mhiramat@...nel.org>, Mark Rutland <mark.rutland@....com>,
 Mathieu Desnoyers <mathieu.desnoyers@...icios.com>, jiang.biao@...ux.dev,
 bpf <bpf@...r.kernel.org>, LKML <linux-kernel@...r.kernel.org>,
 linux-trace-kernel <linux-trace-kernel@...r.kernel.org>
Subject: Re: [PATCH bpf-next v3 0/6] bpf trampoline support "jmp" mode



On 19/11/25 10:47, Menglong Dong wrote:
> On 2025/11/19 08:28, Alexei Starovoitov wrote:
>> On Tue, Nov 18, 2025 at 4:36 AM Menglong Dong <menglong8.dong@...il.com> wrote:
>>>
>>> As we can see above, the performance of fexit increase from 80.544M/s to
>>> 136.540M/s, and the "fmodret" increase from 78.301M/s to 159.248M/s.
>>
>> Nice! Now we're talking.
>>
>> I think arm64 CPUs have a similar RSB-like return address predictor.
>> Do we need to do something similar there?
>> The question is not targeted to you, Menglong,
>> just wondering.
> 
> I did some research before, and I find that most arch
> have such RSB-like stuff. I'll have a look at the loongarch
> later(maybe after the LPC, as I'm forcing on the English practice),
> and Leon is following the arm64.

Yep, happy to take this on.

I'm reviewing the arm64 JIT code now and will experiment with possible
approaches to handle this as well.

Thanks,
Leon

> 
> For the other arch, we don't have the machine, and I think
> it needs some else help.
> 
> Thanks!
> Menglong Dong