From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ombertech.com (ombertech.com [74.48.158.51]) (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 0074B17F7 for ; Sun, 6 Apr 2025 05:40:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.48.158.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743918018; cv=none; b=neuxkeToi9BE5NTlU8Uu26WpChKrZ6g9NZdVdrA0Z508NZMSZRM9tH+zVIIJoH/jGapRB343xSHvQ3Ky0xz1hRSfsIvD2uUjOVoDyBjixmq1/JxFoZo4gB5CEiDTBdmdEGekbetvqZI2ZfrxfYMWFUKlOcAmAiScJ6xxlqX3cro= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743918018; c=relaxed/simple; bh=eGPssONKMwss0s7vqd0jkbyJcrBZkDhYjLj39eimxAY=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=DELEDJUhGQJ8nJlpc+cV23T0pO5yZYfePptrAHzZX/fRBaGmqPsHTGmL00snp/w/odRNnq3coNl9PnqyVrU1wsmfTvCVE0n7BFXeEHsy/r/wtRRxqFwFE0Jg1u1i5VT0LBt9DwFFnRGXTvQViOTRjZ2QAzSnAZqR1cjWcztil1c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ombertech.com; spf=pass smtp.mailfrom=ombertech.com; dkim=pass (2048-bit key) header.d=ombertech.com header.i=@ombertech.com header.b=dDfbTuCZ; arc=none smtp.client-ip=74.48.158.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ombertech.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ombertech.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ombertech.com header.i=@ombertech.com header.b="dDfbTuCZ" DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=ombertech.com; s=2022; t=1743917719; bh=eGPssONKMwss0s7vqd0jkbyJcrBZkDhYjLj39eimxAY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=dDfbTuCZEafoGGy1GD/g+2379zozMNWQOB/VUGBnPjAwQWJXVNJgRcFKfFgiakDTk h3VfJG+XLup0EdfWVvoFlFOt3KZUbfG5m+w2jwFq3IXrwhmgLavlyfA2TM1UlHGVNH uNFgtkJP0uLyLIW2+VcNqV/dwcNiO5qZATAbktWJFHN5uRGCQ3GIyZ6HP+cTs3pSQD Yu/ubppb5dkBWNDI1a4WtILASI9qgyJZYVJAIkayhNNk07dm16iWtOqqWUwOKHtEJU sS5vjw/KVZD+/rWMXl5c2gau61C6fT7W7PxGp9TxKYXgGOtxgq138tRfoK8L7JaF1h /H9+v5MBNAbiA== Received: from 192.168.1.100 (unknown [1.145.161.245]) by ombertech.com (Postfix) with ESMTPSA id 9A7F766946; Sun, 6 Apr 2025 05:35:17 +0000 (UTC) Date: Sun, 6 Apr 2025 16:40:49 +1000 From: Kevin Koster To: Borislav Petkov Cc: Oerg866 , linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Dave Hansen , x86@kernel.org, "H. Peter Anvin" Subject: Re: [PATCH] x86/microcode: Fix crashes on early 486 CPUs due to usage of 'cpuid'. Message-Id: <20250406164049.c0666bc18073e3b88c92d1f1@ombertech.com> In-Reply-To: <20250405093127.GAZ_D4b6NdyTS-UW1J@fat_crate.local> References: <20250405130306.ca9822c1f27db119cc973603@ombertech.com> <20250405093127.GAZ_D4b6NdyTS-UW1J@fat_crate.local> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-unknown-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Sat, 5 Apr 2025 11:32:26 +0200 Borislav Petkov wrote: > On Sat, Apr 05, 2025 at 01:03:06PM +1100, Kevin Koster wrote: > > On Sat, 19 Oct 2024 08:29:04 +0200 > > Oerg866 wrote: > > > > > Starting with v6.7-rc1, the kernel was no longer able to boot on > > > early i486-class CPUs. > > > > Thanks for this patch! It solves my problem with kernel 6.12.11 > > rebooting at start-up on 486 CPUs, which had me puzzled. (tested on > > AM486DX2-66 and CX486DX4-100) > > > > Is there a reason why the patch wasn't accepted? > > Yes, too many patches, too little time. :-( > > Anyway, does the one below - only build-tested - work for both y'all > too? On my AM486DX2-66 it gets past the immediate reboot problem but gets an Oops and kernel panic here: [snip] smpboot: SMP disabled Performance Events: no PMU driver, software events only. signal: max sigframe size: 928 Oops: invalid opcode: 0000 [#1] SMP CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.14.0 #1 EIP: 0xc0b5e1d7 Code: 7d dc 00 74 0b b9 07 00 00 00 89 df b0 01 f3 a5 83 c4 1c 5b 5e 5f 5d c3 55 b8 01 00 00 00 89 e5 57 56 31 f6 53 89 f1 83 ec 30 <0f> a2 b9 04 00 00 00 89 45 c4 8d 7d c8 89 f0 f3 ab e8 a0 fc ff ff EAX: 00000001 EBX: c0be6b00 ECX: 00000000 EDX: 00000246 ESI: 00000000 EDI: 00000000 EBP: c1309f08 ESP: c1309ecc DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00010286 CR0: 80050033 CR2: ffd38000 CR3: 00c16000 CR4: 00000000 Call Trace: ? 0xc01231af ? 0xc01231c8 ? 0xc0123222 ? 0xc0123245 ? 0xc01215ef ? 0xc01217f7 ? 0xc0b5e1d7 ? 0xc0848e09 ? 0xc012186f ? 0xc0b5e1d7 ? 0xc0848e41 ? 0xc010105d ? 0xc01500d8 ? 0xc0848e09 ? 0xc0b5e1d7 ? 0xc01500d8 ? 0xc0848e09 ? 0xc0b5e1d7 ? 0xc085148a ? 0xc0524da8 ? 0xc0b5e1c5 0xc0102100 ? 0xc08514d5 ? 0xc085148a ? 0xc0171bde ? 0xc0175987 ? 0xc016d672 0xc0b4c9e2 ? 0xc084c9b8 0xc084c9ca 0xc0127d3a ? 0xc084c9b8 0xc01027a2 0xc0100e3d Modules linked in: ---[ end trace 0000000000000000 ]--- EIP: 0xc0b5e1d7 Code: 7d dc 00 74 0b b9 07 00 00 00 89 df b0 01 f3 a5 83 c4 1c 5b 5e 5f 5d c3 55 b8 01 00 00 00 89 e5 57 56 31 f6 53 89 f1 83 ec 30 <0f> a2 b9 04 00 00 00 89 45 c4 8d 7d c8 89 f0 f3 ab e8 a0 fc ff ff EAX: 00000001 EBX: c0be6b00 ECX: 00000000 EDX: 00000246 ESI: 00000000 EDI: 00000000 EBP: c1309f08 ESP: c1309ecc DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00010286 CR0: 80050033 CR2: ffd38000 CR3: 00c16000 CR4: 00000000 Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b Rebooting in 60 seconds..