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Date: Mon, 3 Aug 2026 09:03:56 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>, Ingo Molnar <mingo@kernel.org>,
	x86@kernel.org, Jinchao Wang <wangjinchao600@gmail.com>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
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	Dave Hansen <dave.hansen@linux.intel.com>,
	"H . Peter Anvin" <hpa@zytor.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
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	linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-perf-users@vger.kernel.org
Subject: Re: [PATCH v11 04/11] tracing: wprobe: Add watchpoint probe event
 based on hardware breakpoint
Message-ID: <20260803070356.GV49951@noisy.programming.kicks-ass.net>
References: <178565870538.714490.11309825813968306287.stgit@devnote2>
 <178565875046.714490.17724442147958346980.stgit@devnote2>
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In-Reply-To: <178565875046.714490.17724442147958346980.stgit@devnote2>

On Sun, Aug 02, 2026 at 05:19:10PM +0900, Masami Hiramatsu (Google) wrote:
> From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> 
> Add a new probe event for the hardware breakpoint called wprobe-event.
> This wprobe allows user to trace (watch) the memory access at the
> specified memory address.

s/the memory/the kernel memory/

> The new syntax is;
> 
>  w[:[GROUP/]EVENT] [r|w|rw]@[ADDR|SYM][:SIZE] [FETCH_ARGs]
> 
> User also can use $addr to fetch the accessed address and $value to fetch
> the accessed memory value (shorthand for '+0($addr)'). No other variables
> are supported.

This seems limited to kernel addresses only? Should not also userspace
addresses be supported?