linux-kernel - Re: [PATCH 1/2] watchdog: refactor watchdog

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]

Message-ID: <CAD=FV=WiZ5=4Ck3G2gme=ey6uYQhi-3Wo32DpLj9P53wxGCojw@mail.gmail.com>
Date: Fri, 29 Aug 2025 14:33:57 -0700
From: Doug Anderson <dianders@...omium.org>
To: Yunhui Cui <cuiyunhui@...edance.com>
Cc: paul.walmsley@...ive.com, palmer@...belt.com, aou@...s.berkeley.edu, 
	alex@...ti.fr, atish.patra@...ux.dev, anup@...infault.org, will@...nel.org, 
	mark.rutland@....com, linux-riscv@...ts.infradead.org, 
	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org, 
	linux-perf-users@...r.kernel.org, catalin.marinas@....com, 
	masahiroy@...nel.org, suzuki.poulose@....com, maz@...nel.org, 
	zhanjie9@...ilicon.com, yangyicong@...ilicon.com, mingo@...nel.org, 
	lihuafei1@...wei.com, akpm@...ux-foundation.org, jpoimboe@...nel.org, 
	rppt@...nel.org, kees@...nel.org, thomas.weissschuh@...utronix.de
Subject: Re: [PATCH 1/2] watchdog: refactor watchdog_hld functionality

Hi,

On Wed, Aug 27, 2025 at 3:10 AM Yunhui Cui <cuiyunhui@...edance.com> wrote:
>
> Move watchdog_hld.c to kernel/, and rename arm_pmu_irq_is_nmi()
> to arch_pmu_irq_is_nmi() for cross-arch reusability.
>
> Signed-off-by: Yunhui Cui <cuiyunhui@...edance.com>
> ---
>  arch/arm64/kernel/Makefile                   | 1 -
>  drivers/perf/arm_pmu.c                       | 2 +-
>  include/linux/nmi.h                          | 1 +
>  include/linux/perf/arm_pmu.h                 | 2 --
>  kernel/Makefile                              | 2 +-
>  {arch/arm64/kernel => kernel}/watchdog_hld.c | 8 ++++++--
>  6 files changed, 9 insertions(+), 7 deletions(-)
>  rename {arch/arm64/kernel => kernel}/watchdog_hld.c (97%)

I'm not a huge fan of the perf hardlockup detector and IMO we should
maybe just delete it. Thus spreading it to support a new architecture
isn't my favorite thing to do. Can't you use the buddy hardlockup
detector?

That being said, I did a quick look at your patch. I'm pretty sure you
can't just move the arm64 "watchdog_hld.c" to be generic. Won't
hw_nmi_get_sample_period() conflict with everyone else's (x86 and
powerpc)?

-Doug