linux-kernel - Re: [PATCH] riscv, bpf: try RVC for reg move within BPF

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] [thread-next>] [day] [month] [year] [list]

Date: Tue, 21 May 2024 18:35:39 +0200
From: Björn Töpel <bjorn@...nel.org>
To: Xiao Wang <xiao.w.wang@...el.com>, paul.walmsley@...ive.com,
 palmer@...belt.com, aou@...s.berkeley.edu, luke.r.nels@...il.com,
 xi.wang@...il.com
Cc: ast@...nel.org, daniel@...earbox.net, andrii@...nel.org,
 martin.lau@...ux.dev, eddyz87@...il.com, song@...nel.org,
 yonghong.song@...ux.dev, john.fastabend@...il.com, kpsingh@...nel.org,
 sdf@...gle.com, haoluo@...gle.com, jolsa@...nel.org,
 linux-riscv@...ts.infradead.org, linux-kernel@...r.kernel.org,
 bpf@...r.kernel.org, pulehui@...wei.com, haicheng.li@...el.com, Xiao Wang
 <xiao.w.wang@...el.com>
Subject: Re: [PATCH] riscv, bpf: try RVC for reg move within BPF_CMPXCHG JIT

Xiao Wang <xiao.w.wang@...el.com> writes:

> We could try to emit compressed insn for reg move operation during CMPXCHG
> JIT, the instruction compression has no impact on the jump offsets of
> following forward and backward jump instructions.

..and at some point we should start supporting Zacas and friends,
instead of lr/sc.

> Signed-off-by: Xiao Wang <xiao.w.wang@...el.com>

Acked-by: Björn Töpel <bjorn@...nel.org>