linux-kernel - Re: [PATCH v4 03/21] HWBP: Add modify_wide_hw_breakpoint

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Message-Id: <20250914220242.1e8dc83e011b9568dd7a5ace@kernel.org>
Date: Sun, 14 Sep 2025 22:02:42 +0900
From: Masami Hiramatsu (Google) <mhiramat@...nel.org>
To: Randy Dunlap <rdunlap@...radead.org>
Cc: Jinchao Wang <wangjinchao600@...il.com>, Andrew Morton
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Subject: Re: [PATCH v4 03/21] HWBP: Add modify_wide_hw_breakpoint_local()
 API

On Fri, 12 Sep 2025 21:13:07 -0700
Randy Dunlap <rdunlap@...radead.org> wrote:

> 
> 
> On 9/12/25 3:11 AM, Jinchao Wang wrote:
> > +/**
> > + * modify_wide_hw_breakpoint_local - update breakpoint config for local cpu
> > + * @bp: the hwbp perf event for this cpu
> > + * @attr: the new attribute for @bp
> > + *
> > + * This does not release and reserve the slot of HWBP, just reuse the current
> 
>                                                  of a HWBP; it just reuses

OK,

> 
> and preferable s/cpu/CPU/ in comments.

OK.

Thanks for review!

> 
> > + * slot on local CPU. So the users must update the other CPUs by themselves.
> > + * Also, since this does not release/reserve the slot, this can not change the
> > + * type to incompatible type of the HWBP.
> > + * Return err if attr is invalid or the cpu fails to update debug register
> > + * for new @attr.
> > + */
> > +#ifdef CONFIG_HAVE_REINSTALL_HW_BREAKPOINT
> > +int modify_wide_hw_breakpoint_local(struct perf_event *bp,
> > +				    struct perf_event_attr *attr)
> > +{
> 
> -- 
> ~Randy
> 

-- 
Masami Hiramatsu (Google) <mhiramat@...nel.org>