From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sipsolutions.net (s3.sipsolutions.net [168.119.38.16]) (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 6FFC11BEF71; Wed, 19 Feb 2025 07:42:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=168.119.38.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739950942; cv=none; b=D292e8cPhTAiOAouH3tBGf8YgkoO2EEULoTXUIYMTzVNNl/ItdFRZFwTfSj8PdzdAuk0FwvouS7wsH888BRNlxthPQX4HpDrV3p2TEOF5BJm9fNCRV4rughUezBWpVb7/tZnJb54glBOEsihjKx2mhWyzNohrd/xqxX839YSmuY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739950942; c=relaxed/simple; bh=IYZV4DKyRp83gdcIJ59Kj8qWqMhJv05T8ZY9PYuaYMU=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=fDhmfIO3/kKxkCz53aH/2eh66jgm+LY6fOhR/IAx8tgIvEOgKL+QGdH2Q5GlAyUj054pjrArMZElGmq1Vpgx81DYes1ym53/KkKjEHrycAbxL1t3h3jXmdWxduFPhnd5rJ3c4UK04sJHfyOdloh9BdmuPUYj+cNFUbANRnkohYs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sipsolutions.net; spf=pass smtp.mailfrom=sipsolutions.net; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b=nt4n4ND+; arc=none smtp.client-ip=168.119.38.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b="nt4n4ND+" 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=1739950940; x=1741160540; b=nt4n4ND+hTK+Wh8MxowQLAyQhH2bFT50tAv2l1G3/vZBHY4 Rs18KCiZN8YkhnzWzWIdLtkGgqpd2oAUiAqfRWJjPCW4mwMkzbXdA2taAVw5wrD5xQB6sR7vmAKFy V/f6eO1jKLvTg+ila9b0nA8BZKL1ylrTkAPSaAEXYbXvuHsO14VtGLF3RkOhHqimebVISrYgWcuGm 9DYaxTIYFxBJFC/RvHknn4LLkgttKfZmJRIJnbGmeB87sd0xjQCC+3TeL4EpAHeB8ZDXJ9iCMY4ma h2Wym2HJY0DArWqj6oHAqBJ+1ttatubfY3tRNDdIzKj5iMd+Wo7fwbA8j03cpsHw==; 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) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-malware-bazaar: not-scanned 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