From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from www345.your-server.de (www345.your-server.de [78.46.144.83]) (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 C1B7B33B6EF; Thu, 20 Aug 2026 18:35:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.46.144.83 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787250906; cv=none; b=SbXCXLYrYEv0Vah/6Bz0ODLC/dVXZRPySC3z3OCMGLjlpEvl9X1PFL6WggkQmCgz7LFEPk0PM7f16idxWgLslOmGolSYHImG+Cj6fMUvpOr+M7pzzZIeyY4gqMlISO4BqzS+5AGJN8bMkp7T/NzC4eWRzPcbUp8htIll002LPHs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787250906; c=relaxed/simple; bh=SMdx/iOHRmi1Z8kVQZ/h7oFdxdJSzOry9cZyYI1ThvE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=FC+dc5LJB+uVPCEcJEjLG1uwHkiYTWHJmE8AeohyVgCkXD8XUGod2v6c/UABajC4Absbtsb5Uxcz7ODipEgHo11cZKvJxE3Y7IFhs743eISfkOP18cvOrqCX77Wpc7QCnY7S7hfV1h7nNyioyEjFy3gt62dhzXb8RVFQqbUJCbo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tti0.net; spf=pass smtp.mailfrom=tti0.net; dkim=pass (2048-bit key) header.d=tti0.net header.i=@tti0.net header.b=LIti40xN; arc=none smtp.client-ip=78.46.144.83 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tti0.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=tti0.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=tti0.net header.i=@tti0.net header.b="LIti40xN" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tti0.net; s=default2601; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID; bh=JNzjv835lyUqrhzNovsIHGPkQXAwt05OC21nFFA3FE4=; b=LIti40xNgGRkhIkUh2yNFZZPy6 IodQP9HNDPuAJh3LOrquMpaoLeZJuxuzdjy6gDCVVyBkLBhy7otHEyvjs19mV8ibfkq1fYmfoVEgh NSq8b3sJmAi4pqdtHPp54sK7F2W3I3awVRjVEreLbFxP3U3nfeRNd9NBawo/WVWLd/Yc8+djD3lmH BJbHQAMCP1+oV/d229jzW7I90xKf0X14tboYtWjGL/cy13SsHhtK3HtVyz3IqyRB+G/bb5fq2OCfH sgYIpJhkHgHYzkxm241Zkd7s3Lfs03ah2rtBQfyUI8+kxjhbKzhXNAPxft3xyY4YAM1W7DUDbhzWj nI+LMDkg==; Received: from sslproxy06.your-server.de ([78.46.172.3]) by www345.your-server.de with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.96.2) (envelope-from ) id 1wx6yR-0005zC-0H; Thu, 20 Aug 2026 19:54:43 +0200 Received: from localhost ([127.0.0.1]) by sslproxy06.your-server.de with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1wx6yQ-000HOb-0M; Thu, 20 Aug 2026 19:54:42 +0200 Message-ID: <04e11e34-1b3f-4892-adc5-ae2ea040c004@tti0.net> Date: Thu, 20 Aug 2026 18:54:39 +0100 Precedence: bulk X-Mailing-List: linux-efi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] efi: Make EFI_VARS_PSTORE depend on EFIVAR_FS To: Ard Biesheuvel , linux-kernel@vger.kernel.org Cc: linux-efi@vger.kernel.org, "Guilherme G. Piccoli" , Tony Luck , Kees Cook , Ilias Apalodimas References: <20260625171214.8058-1-theodore@tti0.net> <6ecd6385-37c6-4ae8-8413-53a6e8602635@app.fastmail.com> <55870f62-ee17-4aed-850e-790517f68eee@app.fastmail.com> Content-Language: en-GB From: Theodore Tucker Autocrypt: addr=theodore@tti0.net; keydata= xsFNBGmHP+gBEACnnPcUqdwqLoLADUrUMkvjz7Nl8+tCr9JRFjnbBiXtBwZ6vijws0sJg3b2 lktWjyqVK/IxMItoT2zzqOAv7JruY4vTPwuqBvTg6V29b62Pty0SHi9ZyjhPt0avI209ietU jYfntiAfXLZAqiN6k6PN11tURqUm4WD4aJh0/JDA0adhAX0B5wgTChRCh6GVbvis29kJYusW /OBpUGrpq1vNwDvKdHlSvTbpKEaFftkTLqJdjNroybRClzy/2iNZjA0pv5Uft13AtB/8jNXc gmz2AGPvtMKzYZqPzFvrz6IksdU7jwFC/zXyAzGuPTwE8srYHrKMcf+Ir3e9pzJnYWiUtf1a k+JJ7eDp3M0Ihdsog1WGei2y85AncF5USJ3ELsSoBxZXok86taowdRwgSgsCmRrdSPS3yCNY bkjCGKYY/JtBaeBeXnl6D5OqzBl007IUUNM7PbUUMPi3sfTKyYSPxbPspNrUm7UdKIB0//Pe ls0P87Roqy/ojATgEzD+UJJBHEcVPFjB8uA6aZv8D/GDA/nQQZLlz/+OHhHiybSKIFo7jGas qsAOEH0XE6HxNRJeVD0p0Qdk8Xx2bJNTaFtAQDknpKStqC70GSck5DCRMypwjahIkETiGs1D +FoAZFmq984kRQv6+vmJiDdKteBiGqS84cgnEpA9rMiIqDStIQARAQABzSNUaGVvZG9yZSBU dWNrZXIgPHRoZW9kb3JlQHR0aTAubmV0PsLBlAQTAQoAPhYhBPJELXhAeV8EDgEYqySfAQz1 WPWEBQJphz/oAhsDBQkFo5qABQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAAAoJECSfAQz1WPWE s+gP/1+aqZSH04H1tv8jjo04QH2cRlVRo2O2oC5TBtQ2lk7c2UZmvY7/CHHxl0/kb123zqRW AxE2oIaEhnY6aZcodWP7BUvovfcumLf+TpIcwDdeTjEvzNqI2U7wQx2+aLR1kn97cYSSIBwI u911gaWZlVLDr006Bj4/Xa0P6EAxC5AD4uSs/jA9dO8ZJU+gBTvHtUVjrs67PD5LMbqGdbpH ISU8eXjYb6P0mn24n4/V92z7lQl+yVvKfPD/NiVWltD0B27x1w7oQ9GEIvTVrSt8HirlS6UQ tC/mxKCAX3RrAgUnGMAGkXGfJt4L+ul7IuashuyirR+3rv7fY5mAKbiRsUCJyPI6Flph2XSY PYn5xz1uYkdK0n1eUtPerX3LRHoiRevPaDY8p5RcaGXzHDARHkX9h9SuKo7mv6bm7v7+3Rq1 80oV95EQ8Y8iCihuUPgz7VrUvj4bWYBabeeRumibaPbfdDe1VGz+SvM5Y5Tyqevu/IRlf5ps zrquf/xSObfHJ/zJC9iNffTi7eEtkJA+lKYPN1LarTk59qaN2nXNr5fOdLJaWSM4ON4MGoME pt1on83wdFs9hJGXmNCTvAKw9/oR5iX2t//p+mV1RqTbBFfIo+rGJdoGYvWjJdqpDvscBVez +93jOD1QV3A4Jx+7wvPF0xg4luEOXfiecnw9J9tlzsFNBGmHP+gBEADzTiUDLGABhhGM0q+f AXSxp6Z5lo5plQwXKsXZ9np3R5b6DOYOJ5zkdUFrQAJJJ4worAYyiQqVjKsBhh+5ux8YFF2q eD1znydJYd3fLDxH0gkm0wLE0GWnjL6A/PhAgARbKoowQZ7Tsfh3LAUpM7iv1bfZqMPAFdiQ qdAH4+w2I3lFkvkjYcEfLUq4OBGNvp96Dgcckw2Vc3IyHszpyxjaPeFnEQOwCpv59YM3RLb8 w9dSVQ/2cw+xAr7VIEVGWKOwqaDW0JelqVcftT4YZYxvXCT07A4Bv29C3jEeQFYjn+EEiCgW 0vK7exq17wRKEe+fEMUcD820C4kNmBiuGak5WDBUtyjdxroV9gxvkRAEWQecwImRCkEzmwVq DOaDDTFzgIJpYTp0MdoDX1KY/UaUmX8BnPaUNB8lSFGvV3oshKaoYREUxBMooWJN5KIDdGML s5bWq2RiXQdUhjoSnnNruvyvWFWFj/hkbRGztvg4PmfOXlcUqDDCRVTm/MRzfSGa0rWF7AZN 3TO7fEy43pgnE8erhkLu83dEkn8HX2ZHh1mgvChkRxqrC/xADfirovQ4SBXvN61kNsN5b/Wp LhWsmPJxHRRIvGrvXApZASQWzrhVer7uHYufALSQpGmLg+gHzkatwgudIC5b/07sWFYqF6fI WDIDPuUmPlk7BSQmDwARAQABwsF8BBgBCgAmFiEE8kQteEB5XwQOARirJJ8BDPVY9YQFAmmH P+gCGwwFCQWjmoAACgkQJJ8BDPVY9YTpDw/9EA/0tasC6TKKlq9oaqonaELCoC5DGkJoBglO OIComnR/nwgftMvpPFlGmhmbF/bKoEHQQ/Js3chhVZoPAmNO9z9Q14quo2a4BkctAo+72Rqz DROnCGkNk+Kx8CWfUmM4WLXBm6fhHY3daIYZP0AeA7bJfWh7gw8tB3sOolqRYQ6ueichQTtZ MOQisgFUmCmBDefn5+YIKIybhLV8pcfr8DWnJoSdHkk6Ak7TW/XKPkgOZABrSa0xkVIqRG65 Rrp52rTZbgRSkBxPDFxgeFpkuqdX4/marYCdyGDToWfxVVz9odsy8tPTyUiWd1MhcE7sfLQc sJ44BUIVSYbbxxG2XE6NwY/8l6EeXLtGvBkLu+pPN+YKlyFvMJ3JxCWkJFvNiiETCWcydsLg NfK2JUiAMMc45TreZWZ2uekquGgfzCe8OVhjCWwIRPn5qAVY/Ub7E+/O/VF5hqBsvxkf0iEb /x1Me9VDOKFYE1chgAYGSqrkZ71odYUV9g2/oK05T1kaAKaXSGT3sJNSTM04SBQIW71jT9vU sf0l1NAHBWcjBOiaXqUGxVZVzDs+dD+jSqxHmEw+AVw52yQehVt5g/sBFxc7EqBhHNt7QDBJ Mw9TCk2uzzqNKDWK5M5YgT8Zww3tRW8yfDzD1HTM0WV7/lmFRnjj7wYYzZeX4rf+m7pfZlM= In-Reply-To: <55870f62-ee17-4aed-850e-790517f68eee@app.fastmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Clear (ClamAV 1.4.3/28098/Thu Aug 20 08:24:22 2026) Hi, On 20/08/2026 12:49, Ard Biesheuvel wrote: > > Actually, EFI pstore does not depend on efivarfs, it only depends on > the efivars layer. > > Why do you think it needs to depend on EFIVAR_FS? When building a 7.0 kernel for x86 with `make alldefconfig` and then enabling CONFIG_EFI, CONFIG_PSTORE, and CONFIG_EFI_VARS_PSTORE, I found that the EFI pstore backend failed to register (/sys/module/pstore/parameters/backend was empty after boot) unless CONFIG_EFIVAR_FS had also been enabled explicitly. I can see now that EFI pstore code should not need the efivarfs, and neither should userspace, since it gets access to any logs through /sys/fs/pstore. So I do appreciate that my patch may not be the right fix here, and I proposed it not as an expert on the internals of EFI pstore, but from experimentation as a user. Sorry for the noise. I eventually ended up using the ramoops pstore backend so unfortunately no longer have the exact kernel configurations I used when this tripped me up. Thanks and kind regards, Theodore -- Theodore Tucker theodore@tti0.net