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Mon, 25 Aug 2025 06:11:38 -0700 (PDT) Received: from [127.0.0.1] ([2403:2c80:6::3058]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2466885ed8fsm68579725ad.71.2025.08.25.06.11.34 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 25 Aug 2025 06:11:37 -0700 (PDT) Message-ID: Date: Mon, 25 Aug 2025 21:11:30 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 07/13] mm/kstackwatch: Add kprobe and stack watch control Content-Language: en-US To: "Masami Hiramatsu (Google)" Cc: akpm@linux-foundation.org, naveen@kernel.org, davem@davemloft.net, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org References: <20250818122720.434981-1-wangjinchao600@gmail.com> <20250818122720.434981-2-wangjinchao600@gmail.com> <20250818122720.434981-3-wangjinchao600@gmail.com> <20250818122720.434981-4-wangjinchao600@gmail.com> <20250818122720.434981-5-wangjinchao600@gmail.com> <20250818122720.434981-6-wangjinchao600@gmail.com> <20250818122720.434981-7-wangjinchao600@gmail.com> <20250818122720.434981-8-wangjinchao600@gmail.com> <20250825193127.a0acb9831733e0e51a5ef81d@kernel.org> From: Jinchao Wang In-Reply-To: <20250825193127.a0acb9831733e0e51a5ef81d@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 8/25/25 18:31, Masami Hiramatsu (Google) wrote: > On Mon, 18 Aug 2025 20:26:12 +0800 > Jinchao Wang wrote: > >> This patch adds the core logic for controlling the kernel >> stack watch mechanism using a combination of kprobes and kretprobes. >> >> A kprobe is registered at function + ip_offset to turn on >> the hardware breakpoint that monitors the stack. This allows >> the tool to begin watching from a specific instruction within >> the function. At the same time, a kretprobe is registered to be >> triggered when the function returns. Its handler is responsible >> for turning off the hardware breakpoint. > > Could you use fprobe instead of kretprobe for hooking function exit? > kretprobe is an old feature and will be replaced by fprobe. > > You can find an example in samples/fprobe/fprobe_example.c > > Thank you, Hi Masami, Thanks for the feedback. I will respin the patchset and replace the kretprobe with fprobe, as you advised. -- Best regards, Jinchao