From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 4E76933F394; Mon, 13 Jul 2026 17:30:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783963808; cv=none; b=RDqggmIf/b1cU4CIgpOg3aL8WJf7lu7UxJA9U6Tm1MzGTTolR1zxjQzZ6istVsGpuAKuOA7Ex2E41Vq1l4unS+Hi/whSYBr/ZWkEOod9F3daYLHd7NTKbe1dPDEptPj5vF1fLS1DnP6x4Nvm04YU7BZ+/seflY/02rxEyl90e1g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783963808; c=relaxed/simple; bh=nCBADfPl5UsjVCRyiNTCceL+P86FRzL33UOwfs8iADs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=emyvNi+gBVdQ2x4xxX8Tcud1VZDrlxSgG5GZKZXatFCpD9Bm+Q2kNkfsBTU4ouwzxTaGfJa4hppVlsyoP7pb7Me2KW66wTO7x0qGCpDk/pW6rwtT3MduvHBFV2JXd94zPA4WVtnKgxmlxHKxiFUrmecPhbVknKQfUm1aGCn3Si8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=SQpHgpa6; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="SQpHgpa6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B2F4D1F000E9; Mon, 13 Jul 2026 17:30:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1783963807; bh=N/4PU6ql3rOySt5KicKXIt7AV1IpkBb2vzqjVBjyUR8=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=SQpHgpa6Bddqrt5e4wZBV5qUJS3Mhqs53xW1KXK4/OcQaWxYSrlffGG0+7RJ7Ff5P Ilr/w47ByeZ1JoKIacFgU18uOHaDmXxfIFNJ2cipARFf8egODA7qnw8Yts2sakC5TK esMNDaPE4rdcf/jk1JKik1hAZ/Kq1yhOKl+zjMl0= Date: Mon, 13 Jul 2026 17:31:08 +0200 From: Greg KH To: Demi Marie Obenour Cc: Eric Biggers , Russell King , Herbert Xu , "David S. Miller" , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v2] drivers/crypto: Mark QCE as BROKEN Message-ID: <2026071320-encode-modify-6193@gregkh> References: <20260712-qce-broken-v2-1-b2dfff47f7f5@gmail.com> <2026071312-uncover-refining-8cac@gregkh> <20260713130745.GA2254@quark> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Mon, Jul 13, 2026 at 10:42:04AM -0400, Demi Marie Obenour wrote: > On 7/13/26 09:07, Eric Biggers wrote: > > On Mon, Jul 13, 2026 at 06:47:07AM +0200, Greg KH wrote: > >> On Sun, Jul 12, 2026 at 05:31:31PM -0400, Demi Marie Obenour via B4 Relay wrote: > >>> From: Demi Marie Obenour > >>> > >>> This driver is harmful: > >>> > >>> - It is much slower than the CPU [1] [2]. > >>> - It Has a history of bugs [2] [3]. > >>> - It does not have exclusive access to the hardware [4], causing races > >>> with the secure world. > >>> - It register its implementations with too low a cra_priority for them > >>> to be actually used [5]. > >>> > >>> Therefore, disable it to ensure that nobody builds it into kernels they > >>> intend to ship. > >>> > >>> In the future, the driver will be used for processing restricted media > >>> content. However, the kernel does not currently support this. Since > >>> the driver will have future uses, allow building it if COMPILE_TEST is > >>> enabled. > >> > >> Why not just delete it now, and then bring it back when it is needed in > >> the future? Otherwise this will just trip up the static code checkers > >> who will attempt to "fix" things in it. > > > > That makes sense to me, but Qualcomm pushed back on deletion: > > https://lore.kernel.org/linux-crypto/20260602-qcom-qce-broken-v1-1-a4ef756089e0@oss.qualcomm.com/ > > > > But I've still not seen any evidence that this driver is useful for > > anything or has any users. Even Qualcomm seems to be unwilling to make > > such claims; they only claim that the IP is used (i.e., not in Linux) > > and that new features are planned. > > > > - Eric > > Here is my reading of Qualcomm's statements: > > QCE is currently used by the Arm secure world. In the future, QCE > will be used by the kernel as part of restricted content playback. > Qualcomm wants to add the needed features to the existing driver. > This will not use the crypto API. Why is a crypto driver not going to use the crypto API? > I would be fine with the driver being removed, but not if it means > another out-of-tree Android driver. It's not another out-of-tree Android driver if nothing in Android actually uses it :) thanks, greg k-h