From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.203 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793287573; b=dZFu4wSCXtx7rYtUanowZTE9X/7k/d8qSZX2yMEsH6PFFWrOJZHzj4JK2H+/Xu5rwU5O l0/Mt3Azr3rYiGiTRWrt41VLFlgFxuvBn/3+o1GQThZVOeMRFQnji/7x2pSAVGCr9Fuhj RYIuFY08WjqlaX/ydEtalh7X7Z2Exsuv/SPGfHotEnN6Zhgpg4hXOIFoP2BfMJNCHlutp 1KTGeArHRDNP+1k40dj8PA1Ibz/UKHHm/iu1KgfSSewEG/nL6iTqU/nmW7R3xiAl19qkT h3y/h8+wKKAbAqGZ0for5LnBwx50FwEyGvNbs6Lqlap6Ex6a4ZX1sXdqNbjCEYMLNrg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793287573; 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=f0C23GuMsm/ND9YrZz0GInxzasZImif5deUYKUFyf9hugR90OkPK3p3ZK2P3H513f/b3 hOLkyem3fxOxHs3KiInRyOe7olgsnM6I2DwmURAsU57jaoaTfhpWui/++hAebeiN8wmHJ pvQK9KSULc0moAzrZz1UIermsGVWrcuG6mto0Fcfoasp2nsca86Sn4st9LPmVrDpVRfJC GTF4T2XPRWPODHLBqmpPoLxzbzieN+FSUO8JkQ8wELmixvlcrEGu7OUvUdxeyCCAqoz10 yTB09HXLdrFYnyQy2r3YHtBy6pSIX0/3MtFzapWNHPl1zqUwWL6K5ivWqYCYtZwWm8w== 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=YBgfSxG8; arc=none smtp.remote-ip=95.215.58.203 Received: from mta1.migadu.com (out-203.mta1.migadu.com [95.215.58.203]) (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 C4DDB606A31F for ; Thu, 29 Oct 2026 15:26:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org C4DDB606A31F 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=YBgfSxG8 X-Envelope-To: asahi@lists.linux.dev 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=1793287569; v=1; x=1793892369; b=YBgfSxG83dv1diMdnfa5stNTtVYFbYu5M/s6nixvJfI6REU4klZeGEO2+DBDz6RS7XsOUMJa fcd47m13F+ytxndj7FB0JdXIczh7G4TJ84TcotWcydzDjpvSngLd0FBZPBqBQjFV+d3JRfsK3bu sVmaoJAaMrpEOp1prSlDJrEA= X-Envelope-To: asahi@lists.linux.dev 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: asahi@lists.linux.dev 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?