From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 523913054F8; Fri, 28 Nov 2025 10:36:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764326216; cv=none; b=Ub/dRhSiTko+QVtuH6b3cIUfIPT+ZK7OyQAPFSq0letiI22xCkQvlJC7ZVpTRKXGxiLRB9F0SlFmphJcyNUaOkiFPakmC+3XUQj9O5frQ4hzM/ip50SuwR3G5fURCaIuhriUUSZW7gGvKfSREw5xEZHiZt1L4lUYIch/fvTWA3U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764326216; c=relaxed/simple; bh=gS1OFzixQRxxWZtiC2pcNhNU6BQ9IEUj0ZxgJCQzowM=; h=Message-ID:Date:MIME-Version:From:Subject:To:Cc:References: In-Reply-To:Content-Type; b=cHFvtMnT/ZD3LT/9w8DTGwAKUWodAuZ6HxmUslJjG8ogCidSe61vSw3DS7A7kZx871abxs7WzwurUD4Q8N+J90QDZsP57bHKMgDlmJwIamHn8ObT0EVNLdVy8NYgaUogvApGFQCyKT6+N1HXumRFFST8mjKOdKzxxY409Bg1FZk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Rwqadcyn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Rwqadcyn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9AEEDC4CEF1; Fri, 28 Nov 2025 10:36:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764326215; bh=gS1OFzixQRxxWZtiC2pcNhNU6BQ9IEUj0ZxgJCQzowM=; h=Date:From:Subject:To:Cc:References:In-Reply-To:From; b=Rwqadcyn62wfoPCoW86RInP99ZLSG6nJcfnIOKIMS8GFOb1965LtZo5Oi7PM8HKiR f7RI2hVvhUjQqGxSoaotblbciHlile6YWO+2kHJaMK7BFeqDT3lWR22rVgSLBmgwPo xRJTRU33jedFtFsyZOyC3nDDUgWEV/D9M6hUxLiryh0qtrvIUMFquqPU5GKWTGkVG2 vWuMz4fXychHZlAH/SMDolbsup77yLfbtZmbMQXer/f9CF6CP8/bVIxS3Fems7r5Hf 2qRjy56sK0M10A/Fe0ye6nLzEkrXPyLhzuZ5KtPKLYq6ucAQaW+e1t2wSTz9jtJgNV HI9OnXq3tLMeA== Message-ID: <51e2de7a-5913-4c53-9637-6d60f875e3d8@kernel.org> Date: Fri, 28 Nov 2025 11:36:24 +0100 Precedence: bulk X-Mailing-List: imx@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird From: Ahmad Fatoum Subject: Re: CAAM RSA breaks cfg80211 certificate verification on iMX8QXP To: Vitor Soares , Ahmad Fatoum , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, imx@lists.linux.dev Cc: horia.geanta@nxp.com, pankaj.gupta@nxp.com, gaurav.jain@nxp.com, herbert@gondor.apana.org.au, john.ernberg@actia.se, meenakshi.aggarwal@nxp.com References: <3d44957f-8c09-47f3-93e0-78a1d34adfd0@kernel.org> <82e78d56c7df6e1f93de29f9b3a70f7c132603c4.camel@gmail.com> Content-Language: en-US, de-DE, de-BE In-Reply-To: <82e78d56c7df6e1f93de29f9b3a70f7c132603c4.camel@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Vitor, On 11/26/25 7:35 PM, Vitor Soares wrote: > On Wed, 2025-11-26 at 13:59 +0100, Ahmad Fatoum wrote: >> Is the CAAM cache-coherent on your SoC? If so does the DT specify dma-coherent >> as it should? On i.MX8M, it's not cache-coherent, but on Layerscape it was and >> the mismatch with the DT leads to symptoms matching what you are observing. >> > > Thanks for the suggestion. I tested with dma-coherent added to the CAAM and job > ring nodes but the issue persists. > I traced through the DMA path in caampkc.c and confirmed: > > - dma_map_sg() is called in rsa_edesc_alloc() with DMA_FROM_DEVICE > - dma_unmap_sg() is called in rsa_io_unmap() from rsa_pub_done() before > completion > - CAAM returns status err=0x00000000 (success) > - dst_nents=1 > > Yet the output buffer remains untouched (still contains my 0xAA poison pattern). > The kernel DMA handling appears correct. CAAM accepts the job and reports > success, but never writes the RSA result. Given that CAAM reports success but > does not populate the RSA output buffer, the problem appears to be somewhere in > the RSA execution flow (possibly in how the result buffer is handled or > returned), but I don't have enough insight into CAAM's RSA implementation. Ok.. That was the only thing off the top of my head right now. >> Off-topic remark: If you have performance comparison between running with and >> without CAAM RSA acceleration, I'd be interested to hear about them. >> At least for the hashing algorithms, using the Cortex-A53 (+ CE) CPU was a lot >> faster than bothering with the CAAM "acceleration". >> > > I haven't done a kernel-level CAAM vs software RSA comparison, but OpenSSL with > ARM Crypto Extensions shows ~3100 verify ops/sec and ~80 sign ops/sec for RSA > 2048 on the Cortex-A35. I see, thanks. Cheers, Ahmad > > Regards, > Vítor > > > > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |