From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dianne.skoll.ca (dianne.skoll.ca [144.217.161.9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4286013EFE4; Wed, 15 May 2024 13:49:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=144.217.161.9 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715780993; cv=none; b=W5eQVfEOH7GZCV2h+WEdHnYdY4ntApRUqKRWjoSz6ZkESMyNKGxBT24QnNyTNK0YQ+4un2Huy5K9ttAT/jn5bYlhFni6dtNYsxm58XEc78YdwxGmaY2wb30zjIHmYAyReF/xx+RrHkBy/vXnbCrnfCzM6tcf363rZfnXJTHGY7o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715780993; c=relaxed/simple; bh=ph199rVCo0b/EbNzAie21c0eAUet5W0TtmezyXByfqw=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=P2YqgzFg2/ZKNJp1QiGIs63eL4Ooy0JeGnexQguvlMRO83wfBIVCJ3CmxYT2nkiqrvliDVmpZquD+CTaIzMhrjahY33E0HV8IrE/vWv6NR87DghHzRkmUSQOaL5OhptnQCFifUHzHs6uTdzzmAq6OmV1UtgYQ3KpAFWcMb3fVAw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=skoll.ca; spf=pass smtp.mailfrom=skoll.ca; dkim=pass (2048-bit key) header.d=skoll.ca header.i=@skoll.ca header.b=BXG0mP7q; arc=none smtp.client-ip=144.217.161.9 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=skoll.ca Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=skoll.ca Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=skoll.ca header.i=@skoll.ca header.b="BXG0mP7q" Received: from pi4.skoll.ca ([192.168.84.18]) by dianne.skoll.ca (8.17.1.9/8.17.1.9/Debian-2) with ESMTPS id 44FDgrdt1088392 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Wed, 15 May 2024 09:42:54 -0400 Received: from gato.skoll.ca (gato.skoll.ca [192.168.83.21]) by pi4.skoll.ca (Postfix) with ESMTPS id 4VfZDF3bvFzgd52Y; Wed, 15 May 2024 09:42:53 -0400 (EDT) Date: Wed, 15 May 2024 09:42:52 -0400 From: Dianne Skoll To: Jiri Slaby Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Greg Kroah-Hartman Subject: Re: N_HDLC line discipline: Race condition Message-ID: <20240515094252.5f63fce9@gato.skoll.ca> In-Reply-To: References: <20240424173114.035ddd7b@gato.skoll.ca> <20240425140127.6504ade1@gato.skoll.ca> Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=skoll.ca; h=date :from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-type:content-transfer-encoding; s=canit2; bh=ZLc/hObTwxSDwUWL0r4G3UTmP3/rKzazoUIqIj/jfAc=; b=BXG0mP7qeWlb 8b3t+6UXjLFwfsfzJSjxJBDyggW1Ty2kdz7j8PmAgg9+w66uUqA7/aWt5iiMXYGP VsA/ndoDLP4FBXNySVzbdOH0pnEOerZs/tlWzId8mMBKoMa4mIx9cSoOyiMuD3i+ 9RlflKwC6nVZ7+z5ZjewKKqZyNv0hI0zVGuzvokxBfYVjncRNFoXplEu6fibSYHp QDdISJLR11vZiQBqdcUzc2hl10OBNEsehwddEKbmNv0hBjUklVuiv1v9dZJEGyis 9WK4apA4PU3zKwtU8S7UB0EGuU4fYVWxz84OpHKLfvumNoWtFykH8p5mNj+hPSDd bOrrSdBShA== X-Scanned-By: CanIt (www . roaringpenguin . com) X-Scanned-By: mailmunge 3.16 on 192.168.83.18 X-Spam-Score: undef - relay 192.168.84.18 marked with skip_spam_scan X-CanIt-Geo: No geolocation information available for 192.168.84.18 X-CanItPRO-Stream: outbound (inherits from default) X-Canit-Stats-ID: Bayes signature not available X-CanIt-Archive-Cluster: tWKWaF/NcZkqjWIj0BEJTBHJhwY X-CanIt-Archived-As: base/20240515 / 01cnpGS3r On Wed, 15 May 2024 12:33:24 +0200 Jiri Slaby wrote: > I can repro even with 4.19: Huh! I managed to make it happen on Debian's 4.19.67 kernel. I had to redirect stdout/stderr to a file because printing to the terminal slowed down the writes enough to prevent it from happening for me. I guess it's hardware-dependent because I can't reproduce it on kernel 6.6 on a Raspberry Pi. > > So I guess it was introduced sometime between 4.19.67 and 5.10.209. > > I'll take a look to see if I can do a git bisect. > Were you able to do so? Unfortunately not; the older kernels failed to compile on my machine and since I'm not a kernel developer and don't actually use any software that relies on N_HDLC, I gave up... sorry. Regards, Dianne.