From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out2-smtp.messagingengine.com (out2-smtp.messagingengine.com [66.111.4.26]) (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 4CBFE47F55 for ; Mon, 18 Dec 2023 12:04:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arndb.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arndb.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=arndb.de header.i=@arndb.de header.b="C6ud4NCV"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="TgCOrFzC" Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailout.nyi.internal (Postfix) with ESMTP id 780655C00C3; Mon, 18 Dec 2023 07:04:12 -0500 (EST) Received: from imap51 ([10.202.2.101]) by compute5.internal (MEProxy); Mon, 18 Dec 2023 07:04:12 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arndb.de; h=cc :cc:content-transfer-encoding:content-type:content-type:date :date:from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to; s=fm1; t=1702901052; x=1702987452; bh=TJvghgd2GT0U8gbW8eh0n+GYx6gyP4lfuYSZLcygGD8=; b= C6ud4NCV1Lil6O1w/uNBWMckLfddsiZHNSTb67P6DFP7hJrUmUfLzIjxlWgmRAOx xa5joMPdupYgLFnVMXzl584t6geMAfnyea7MF3YO3GIoLm2ETJx0OdlBUEPVsIit lawBQ2rsb4+iutfvY78+Q/sAaum3CZNgND/qeK8t5UyaS4gnxAF9aRVHex7lIzyy tT+Vxxhy56PYqYCTw+TFTjnbvBPab6bv366Mv2cs9Bjri6jHfb9kl2n02VFlzuw5 QUKEgTOGt/3oNCu0Adh/5GWm67P/DX/qwNeH/aqFwMSBJrE8IeBYxgvjgCb4U/wJ HcdLiSEXhYrl54J3jE7F1Q== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:content-type:date:date:feedback-id:feedback-id :from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to:x-me-proxy:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t=1702901052; x= 1702987452; bh=TJvghgd2GT0U8gbW8eh0n+GYx6gyP4lfuYSZLcygGD8=; b=T gCOrFzCFp+6QnP7BPNt0/Hxs0GjmQ4zTxr05TmYA2ys2E2fhxPQJEECaVipqp3AC p/HQ2Ojap56r9YfeePhGn2CGlQJXxfWT4HUvZqun9A0XULSlnoVD8yBiEB4DIjQt z//CImX2RPBtXqNNefUtzdop05ZIBEZSau2xYhTlJo6LWSy1chNvkvzirzPub56+ hufVKdU6XRvTKT0uU7pbI4R4NFnZlpNK6zGEdn03nTNZPX5iKBb0Fyd1zkFzpcMs /u801jXtZ23H70/6QUqMPLHI1KulYAy81uWIwJ0RdNnIrTTwWAs9H5o7uo6iZr9i hO28gJCSMDYUVRUenSILA== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvkedrvddtkedgfeegucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepofgfggfkjghffffhvfevufgtgfesthhqredtreerjeenucfhrhhomhepfdet rhhnugcuuegvrhhgmhgrnhhnfdcuoegrrhhnugesrghrnhgusgdruggvqeenucggtffrrg htthgvrhhnpeegfeejhedvledvffeijeeijeeivddvhfeliedvleevheejleetgedukedt gfejveenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpe grrhhnugesrghrnhgusgdruggv X-ME-Proxy: Feedback-ID: i56a14606:Fastmail Received: by mailuser.nyi.internal (Postfix, from userid 501) id E10CBB6008D; Mon, 18 Dec 2023 07:04:11 -0500 (EST) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.9.0-alpha0-1283-g327e3ec917-fm-20231207.002-g327e3ec9 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <487cfd35-fe68-416f-9bfd-6bb417f98304@app.fastmail.com> In-Reply-To: References: <202312171924.4FozI5FG-lkp@intel.com> <3fb66648-5581-4371-b15e-23e52e6469ba@t-8ch.de> Date: Mon, 18 Dec 2023 12:03:53 +0000 From: "Arnd Bergmann" To: =?UTF-8?Q?Thomas_Wei=C3=9Fschuh?= Cc: "kernel test robot" , oe-kbuild-all@lists.linux.dev, linux-kernel@vger.kernel.org, "Jakub Kicinski" , "Simon Horman" Subject: Re: include/linux/compiler_types.h:397:45: error: call to '__compiletime_assert_810' declared with attribute error: BUILD_BUG_ON failed: skb_ext_total_length() > 255 Content-Type: text/plain;charset=utf-8 Content-Transfer-Encoding: quoted-printable On Mon, Dec 18, 2023, at 11:11, Thomas Wei=C3=9Fschuh wrote: > On 2023-12-18 10:12:03+0000, Arnd Bergmann wrote: >> On Sun, Dec 17, 2023, at 17:13, Thomas Wei=C3=9Fschuh wrote: >>=20 >> The -fno-tree-loop-im option would likely stop the loop from getting >> unrolled, which is how the skb_ext_total_length() return code is no >> longer constant. >>=20 >> Does manually unrolling this loop avoid the problem? > > That also works. > > The offending commit was a change from a manually unrolled loop to the > current code. Ah, I missed that. I also see that I added -fno-tree-loop-im back in 2016 as a workaround for gcc-4.9 and higher, but I don't know if it's still required with modern compilers and I'm currently unable to do large scale testing of this until maybe early January. My guess would be that it's still needed. If you want to fix it sooner and not revert your earlier patch, I would suggest changing the BUILD_BUG_ON to only evaluate the length argument if CONFIG_GCOV_PROFILE_ALL is disabled. It's not great but if we ever exceed the limit for real it would still be caught in normal defconfig and allmodconfig builds since they disable the option. Arnd