From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from esa1.hc1455-7.c3s2.iphmx.com (esa1.hc1455-7.c3s2.iphmx.com [207.54.90.47]) (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 E21792459C5; Mon, 6 Jul 2026 05:06:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=207.54.90.47 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783314410; cv=none; b=ILzq3BOCgPz0WS2E0Iphisqo0Ff6hVyYBl7usA1a2jMQowHkJTMtoRKkOPnH/6HRHccnHLjzetOJRxyw5E3gGsrTIFxOb6NOVDE0/Q5ZRktK3iBRaNT4NjWttZle/f09D4DZExQ90kh8M2+hGdN7a+GD1EllKc2Bu4DzBoKC0js= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783314410; c=relaxed/simple; bh=5lEG25gpWK2qINDdzcO8/gLY1vOhbdurY6B83rUorpQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=IJ/MmwpjTNton+jbOasX1l7B8f30YCpYL2lrA9LOmOpj3Z9oNA+Hz+WPr7pOqxESBYIKx7u0F5xajsOfxYhLijvFWTe5LuYaelBIkMmPDtXirXb7gbTWdQskTvgou+2bnAE7E52QmN/3ShwsG/9tt0sfWsQON5sTDZ/OSXcUffk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=fujitsu.com; spf=pass smtp.mailfrom=fujitsu.com; dkim=pass (2048-bit key) header.d=fujitsu.com header.i=@fujitsu.com header.b=XKYVdE/S; arc=none smtp.client-ip=207.54.90.47 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=fujitsu.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=fujitsu.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=fujitsu.com header.i=@fujitsu.com header.b="XKYVdE/S" DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=fujitsu.com; i=@fujitsu.com; q=dns/txt; s=fj2; t=1783314409; x=1814850409; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=5lEG25gpWK2qINDdzcO8/gLY1vOhbdurY6B83rUorpQ=; b=XKYVdE/SDvM4VFsT2iN3XgZS80Aafc7XbQ4KHaJFFghJ9o4upK70X0Ie 7zg9rQuUu3UxslCwRuQ92qSiYZb69BkQZs8WAShHRI3JSC/fumm5xpdku 7kAjnvOI4LFLpYMlXCVGhKmnq4vNBKpC9a/7TuOOeopRtb05wm7WQ8q6O OCxz2b4gSLJRdXhJ0pjm8NG8TbzRA6CE/OBLJ0lDpY5gUgYdzDp0B2opi NMChYbrPNZi5S2sTRUvN8c85ZpgeJq7eTzslRW7BbAHU1R9J2uXwbdXLo yIxNBzHhD0gzxS6c6DpPkFDIYEQGqYrwQ9gwVuD6UUJuN3U5JUJKkRMv5 w==; X-CSE-ConnectionGUID: l3Q8DcAdQY2/2EmwSyEtzg== X-CSE-MsgGUID: 50cDZf4HRl+LB7bpoNNC0g== X-IronPort-AV: E=McAfee;i="6800,10657,11838"; a="246402189" X-IronPort-AV: E=Sophos;i="6.25,149,1779116400"; d="scan'208";a="246402189" Received: from gmgwnl01.global.fujitsu.com ([52.143.17.124]) by esa1.hc1455-7.c3s2.iphmx.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Jul 2026 14:05:39 +0900 Received: from az2nlsmgm4.fujitsu.com (unknown [10.150.26.204]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by gmgwnl01.global.fujitsu.com (Postfix) with ESMTPS id 4E6781C000A9; Mon, 6 Jul 2026 05:05:39 +0000 (UTC) Received: from az2nlsmom1.o.css.fujitsu.com (unknown [10.150.26.198]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by az2nlsmgm4.fujitsu.com (Postfix) with ESMTPS id 076CB101D698; Mon, 6 Jul 2026 05:05:39 +0000 (UTC) Received: from whale.soft.fujitsu.com (unknown [10.125.16.33]) by az2nlsmom1.o.css.fujitsu.com (Postfix) with ESMTP id 2CEC7826FDE; Mon, 6 Jul 2026 05:05:35 +0000 (UTC) From: Iwata Koki To: Jonathan Corbet Cc: Shuah Khan , Matthew Garrett , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, iwata.koki@fujitsu.com Subject: [PATCH] Documentation: admin-guide: fix a doc for efi_no_storage_paranoia the "5KB" instead of the "50%" Date: Mon, 6 Jul 2026 14:05:34 +0900 Message-ID: <20260706050534.1653916-1-iwata.koki@fujitsu.com> X-Mailer: git-send-email 2.52.0 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The documentation for 'efi_no_storage_paranoia' incorrectly states the kernel cannot use "more than 50%" of the EFI variable storage. This percentage-based explanation has been outdated since commit f8b8404337de ("Modify UEFI anti-bricking code") introduced a fixed 5KB minimum reserve threshold (EFI_MIN_RESERVE) in arch/x86/platform/efi/quirks.c. At that time, the documentation was not updated to reflect this change. Update the documentation to reflect the "5KB" instead of the "50%". Fixes: f8b8404337de ("Modify UEFI anti-bricking code") Signed-off-by: Koki Iwata --- Documentation/admin-guide/kernel-parameters.txt | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index b5493a7f8f22..3f75969a679b 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1614,10 +1614,17 @@ Kernel parameters on all PCI bridges while in the EFI boot stub efi_no_storage_paranoia [EFI,X86,EARLY] - Using this parameter you can use more than 50% of - your efi variable storage. Use this parameter only if - you are really sure that your UEFI does sane gc and - fulfills the spec otherwise your board may brick. + The kernel reserves 5KB of EFI variable storage for + safety, because some UEFI implementation may fail to + boot if there's insufficient space in the EFI variable + storage. + + Using this parameter, you can use the 5KB reservation + in the EFI variable storage. + + However, Use this parameter only if you are really + sure that your UEFI does sane gc and fulfills the spec + otherwise your board may brick. efivar_ssdt= [EFI; X86] Name of an EFI variable that contains an SSDT that is to be dynamically loaded by Linux. If there are -- 2.52.0