From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.47 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793287579; b=Ta6/V8/c3GTIrMnkiu0qBrjDjx3ZSr5dWaBSGTnAo+q+EeB2UJDnlvLNcW5ZLZu/uZ5M anHYYouKhC3Sq9E6t+1HDMtyQW1RY8fmW4ks4ZYsMRyPqC8oqPX0aphv7fKTQQzf0hDO/ raUItD4+/9kIURSlv9QvpPfv7uz6SX+6I42XL7XlwuyavSNSvDyaPveDFG86sesgrKpea 1aLz9BQKj/zXXadedPmVqJB2dN+U/r5AZNii3EPAndFpd+u4A6L6ilaH70ug2BdjZLSl1 whR+pC/YSZRl6cbd9fd1h1B0Tk2bpkZnQUIKkpXmFbhJRiF16GZB0xsDOatQkjE43PQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793287579; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Message-ID:Date:MIME-Version:User-Agent: Subject:To:Cc:References:Content-Language:From:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=mpW7Rx8PuBJeOKNX2dQ8d9XnAjnbB8743kHyv8YBQHw=; b=AGpeemJD0gy43HIeu8icj9tJ9VDC0p86P9L8WVyK6GTVCjqifDhV7tIiJIGYqmb5vDmS YgtvTVBWAGSOrTBLaxuQateKAFq2lx9qvduEjZ9FullBFMv0WvDmaVHAw0tfTXyG3pDQl Z9hLJxkcTp48DGbFdb8URbokjbYNhmUEcWI8qMQ0hgdKh0MDz7aSDcn8cWD3toEBdI5A/ LyvCtP8ko9krCx1nPxtHuVW3aKymmBLbPt+5zLH+ZxaF88vdrRS+69qZc0ApZYLOyQ4lt /oHTtRSemTjTN6mpLdirb1hFxMiFAx81wxzn97X+5rQxUSTkP4HGZp60C2v8AXjDifw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b="CFHq/4I7"; arc=none smtp.remote-ip=91.218.175.47 Received: from mta0.migadu.com (out-47.mta0.migadu.com [91.218.175.47]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6D734606A31D for ; Thu, 29 Oct 2026 15:26:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 6D734606A31D Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=CFHq/4I7 X-Envelope-To: linux-pci@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=vYqatMBexbASiH/pDoDg+soUpC7jr6OsHv3SiCXY0DQ=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793287570; v=1; x=1793892370; b=CFHq/4I7/Ryp9pDrYCokipvX9Q3IBM65pbtpLZ0ZnxwtpVp4/KZergKO2A6hs85u2EgK1XI4 salYWiH7GwXrPHodZwh3cocV/ZBi2TKG3EyzBZ710vT60x7aM4qAx1NbVH12ki0e43SO8KIm1bB HywAW1I7jNTMsiGuMH2y4/qo= X-Envelope-To: linux-pci@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 7378328bbc0346d2; Thu, 29 Oct 2026 15:26:09 +0000 X-Mizu-Trace-ID: 7378328bbc0346d2 X-Migadu-Flow: FLOW_OUT Message-ID: <12988c8e-95ad-4989-a6de-e02af3c9ef1b@linux.dev> Date: Thu, 29 Oct 2026 20:55:53 +0530 X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 14/14] mfd/macsmc: add ioctl to access smc keys To: Sasha Finkelstein , Atharva Tiwari Cc: alexandre.belloni@bootlin.com, andy@kernel.org, asahi@lists.linux.dev, bhelgaas@google.com, bp@alien8.de, brgl@kernel.org, dave.hansen@linux.intel.com, dlechner@baylibre.com, dmitry.kasatkin@gmail.com, eric.snowberg@oracle.com, griffin@kroah.com, hansg@kernel.org, hpa@zytor.com, ilpo.jarvinen@linux.intel.com, j@jannau.net, jarkko@kernel.org, jic23@kernel.org, jmorris@namei.org, lee@kernel.org, lenb@kernel.org, linusw@kernel.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-gpio@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-pm@vger.kernel.org, linux-rtc@vger.kernel.org, linux-watchdog@vger.kernel.org, linux@roeck-us.net, mfd@lists.linux.dev, mingo@redhat.com, neal@gompa.dev, nuno.sa@analog.com, paul@paul-moore.com, pavel@kernel.org, platform-driver-x86@vger.kernel.org, rafael@kernel.org, roberto.sassu@huawei.com, serge@hallyn.com, sre@kernel.org, sven@kernel.org, tglx@kernel.org, wim@linux-watchdog.org, x86@kernel.org, zohar@linux.ibm.com References: <525E5B4D-A947-4567-9FCD-5FFF2CA8B161@chaosmail.tech> <20261029143926.1246-1-atharvatiwarilinuxdev@gmail.com> <0683C803-C578-4C55-B893-BC03EBF9A9F1@chaosmail.tech> Content-Language: en-US From: Aditya Garg In-Reply-To: <0683C803-C578-4C55-B893-BC03EBF9A9F1@chaosmail.tech> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/29/26 8:23 PM, Sasha Finkelstein wrote: > On Oct 29, 2026, at 15:39, Atharva Tiwari wrote: >> 1. The patch is required, atleast on intel macs, as without writing GPU and CPU >> states to smc, the system gives PROCHOT signal under small load >> , and heats up a lot. > > In that case, why are you exposing a generic smc key interface instead > of one that just does that? If you think that this data should be set > from userspace - whitelist the set of keys that are needed. > Whitelisting will create an endless cycle of upstreaming new keys. But considering T2 no longer is receiving updates, Asahi would be happy to send their keys they wish to be whitelisted right ;)> >> 2. the smc dosent expose keys of nature that can physically damage the system >> it only exposes power/volt data, and the most you can poke is reboot >> keys and gpu/cpu p-states. > > Are you willing to make that claim for every smc-equipped device, not > just T2? Are you willing to make the same claim for future versions of > smc firmware? Fair enough. We can restrict it to T2 Macs, and Asahi can later adopt if useful?> >> 3. If a person is randomly touching keys, Its their problem and not ours. >> >> 4. There are a lot of things that can mess the system way more and permanently >> than smc (undervolting for example), but they are not safe guarded, why >> should this be then? > > I think it is inadvisable to leave a loaded footgun around and then > blame the user for using it. As an "OS Vendor" you have a duty of care > to your users. It would say the "duty of care" argument is more of a philosophical thing than a technical argument here. Still, I respect that but there needs to be a balance between adding features and respecting the duty. It seems various vendors have different views in determining the balance. The above 2 arguments look like a good balance. What do you think?