From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0F449C021AA for ; Wed, 19 Feb 2025 07:44:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:MIME-Version: Content-Transfer-Encoding:Content-Type:References:In-Reply-To:Date:Cc:To:From :Subject:Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=IYZV4DKyRp83gdcIJ59Kj8qWqMhJv05T8ZY9PYuaYMU=; b=miqScXmzZAHRRAVEJwr5Mjw776 yx0lUcQNV3vHEATo/VeotkB3t/F4uru+OEDybloEOmSpo4M56LtUJJaXMYVRXV3AdUTXwVoD4tTlF 319LmYcxvIalf6ThcEFq/P0QRsk82fWCzB33A/GUHgJlCikVVxj8AdLU/ly2FRxy0qtdv4nf9Oh95 8f92tzxWu9PYWqodUN2y4RBcw9CVGaLY41qKZ1lvj/acGzyIlmtCz7Gbli20amztL7OouqaCg2OhW ew83HNCXArh6lhmeE2FpKrpbDrb8FIqXiJg7ySeZM2jmH1EjYQE84Gn+d87TmJf5pfbT4s4qsS3d9 s+mZTs6w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tkekj-0000000BJvN-3QhO; Wed, 19 Feb 2025 07:44:17 +0000 Received: from s3.sipsolutions.net ([2a01:4f8:242:246e::2] helo=sipsolutions.net) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tkej0-0000000BJOG-3r2w for linux-um@lists.infradead.org; Wed, 19 Feb 2025 07:42:32 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=MIME-Version:Content-Transfer-Encoding: Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=IYZV4DKyRp83gdcIJ59Kj8qWqMhJv05T8ZY9PYuaYMU=; t=1739950948; x=1741160548; b=tVi7mKEEjT997yD7Zs3v+Q+I6ZGSJ5GIfOzOCYiTOSPSlkH a/4eZhEcTAfnRpnGWNlaCJCtJAhUYwt7UoHZ/EY1iQ9S++kBngAAXLDBIZrIv4RPLxshoy7sJzpty jFGCqg5hJAco+nlqnu0iqHzOGqaQiz/cjIoyvTqP1xeVRklQHyGd9boGq8G9o0YNluhIERaSPMA4Y uIWN+ALb/sbhSFhrzFbEhOKKWZWxl/jTKvfha/sulk7JtXr9i2sKC7VYqrTWijLz4GSgNdCseu0Yo 2LG/FGkCovpvz3XW9k7HGflulu7U+Oykl5on0EsQzFqM66PRKnWAvRf8UkTWL6yA==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.98) (envelope-from ) id 1tkeiZ-00000002TFX-0bSF; Wed, 19 Feb 2025 08:42:03 +0100 Message-ID: Subject: Re: [PATCH AUTOSEL 6.6 14/17] um: virt-pci: don't use kmalloc() From: Johannes Berg To: Sasha Levin , linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Richard Weinberger , anton.ivanov@cambridgegreys.com, mst@redhat.com, jiri@resnulli.us, tglx@linutronix.de, viro@zeniv.linux.org.uk, krzysztof.kozlowski@linaro.org, herve.codina@bootlin.com, linux-um@lists.infradead.org Date: Wed, 19 Feb 2025 08:42:01 +0100 In-Reply-To: <20250218202743.3593296-14-sashal@kernel.org> References: <20250218202743.3593296-1-sashal@kernel.org> <20250218202743.3593296-14-sashal@kernel.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.54.3 (3.54.3-1.fc41) MIME-Version: 1.0 X-malware-bazaar: not-scanned X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250218_234230_957406_974E9598 X-CRM114-Status: UNSURE ( 8.92 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org On Tue, 2025-02-18 at 15:27 -0500, Sasha Levin wrote: > From: Johannes Berg >=20 > [ Upstream commit 5b166b782d327f4b66190cc43afd3be36f2b3b7a ] >=20 > This code can be called deep in the IRQ handling, for > example, and then cannot normally use kmalloc(). Have > its own pre-allocated memory and use from there instead > so this doesn't occur. Only in the (very rare) case of > memcpy_toio() we'd still need to allocate memory. I don't believe this patch, "um: convert irq_lock to raw spinlock" and "um: virtio_uml: use raw spinlock", are relevant to anything older than 6.12. I don't see how applying them would _hurt_, but I didn't have them before 6.12 and had no lockdep complaints about it; I believe some other internal IRQ rework caused the issues to pop up. Never mind that we (Intel WiFi stuff) are probably the only ones ever running this virtio_uml/virt-pci with lockdep :) johannes