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Fri, 13 Nov 2026 08:25:57 +0100 Received: from ore by pty.whiteo.stw.pengutronix.de with local (Exim 4.98.2) (envelope-from ) id 1xRlfZ-0000000FpS4-36Tn; Fri, 13 Nov 2026 08:25:57 +0100 Date: Fri, 13 Nov 2026 08:25:57 +0100 From: Oleksij Rempel To: Chaosheng Qu Cc: netdev-bot+sashiko@kernel.org, Robin van der Gracht , Oliver Hartkopp , Marc Kleine-Budde , kernel@pengutronix.de, linux-can@vger.kernel.org, linux-kernel@vger.kernel.org, Jakub Kicinski Subject: Re: [PATCH net v7 3/4] can: j1939: drop the message when the reassembled skb is gone Message-ID: References: <179410166346.60581.12668181404057434786@163.com> <179452018024.488853.2874336452045412196@kernel.org> <179453947398.30993.12910253526180673543@163.com> X-Mailing-List: linux-can@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <179453947398.30993.12910253526180673543@163.com> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-Accept-Language: de,en X-Accept-Content-Type: text/plain On Fri, Nov 13, 2026 at 11:11:13AM +0800, Chaosheng Qu wrote: > Hi, > > Both accepted. > > Dropping the message silently is the weak part. session->err stays 0, so > j1939_session_destroy() queues nothing, and the only trace is a netdev_dbg() > that is off by default. For an RTS/CTS receive session this runs when the > receiver's own EOMA comes back, after the originator has already been told > the message was delivered, so the two sides end up disagreeing with nothing > in the log. The next version uses WARN_ON_ONCE(!se_skb) and sets > session->err = -EBADMSG before dropping. Hm... will a stack trace provide an additional value in this case? If not, please use netdev_err_once() -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |