Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751386AbaKYTDd (ORCPT ); Tue, 25 Nov 2014 14:03:33 -0500 Received: from cantor2.suse.de ([195.135.220.15]:50977 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750951AbaKYTDb (ORCPT ); Tue, 25 Nov 2014 14:03:31 -0500 Date: Tue, 25 Nov 2014 20:03:26 +0100 From: Borislav Petkov To: Boris Ostrovsky Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Richard Hendershot , Konrad Rzeszutek Wilk , David Vrabel Subject: Re: [PATCH 3.17 100/141] x86, microcode: Fix accessing dis_ucode_ldr on 32-bit Message-ID: <20141125190326.GE4128@pd.tnic> References: <20141119205150.700188369@linuxfoundation.org> <20141119205153.916605840@linuxfoundation.org> <5474C67A.7040200@oracle.com> <20141125182410.GB4128@pd.tnic> <5474CDCE.6040000@oracle.com> <20141125184351.GC4128@pd.tnic> <5474D0A1.2020600@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <5474D0A1.2020600@oracle.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 25, 2014 at 01:55:29PM -0500, Boris Ostrovsky wrote: > On 11/25/2014 01:43 PM, Borislav Petkov wrote: > >On Tue, Nov 25, 2014 at 01:43:26PM -0500, Boris Ostrovsky wrote: > >>I don't think this routine is called on PV. > >They're either both called or none is. At least on baremetal, that is. > > > > PV guests don't start with startup_32. > > We are coming from a resume into load_ucode_ap as: > > [ 38.644599] BUG: unable to handle kernel paging request at 0197eec0 > [ 38.644599] IP: [] load_ucode_ap+0x6/0xe0 Aha, and at that point, the APs have enabled paging and switched to virtual addresses, correct? Does that fix it? --- diff --git a/arch/x86/kernel/cpu/microcode/core_early.c b/arch/x86/kernel/cpu/microcode/core_early.c index 2c017f242a78..11ff39fe9d88 100644 --- a/arch/x86/kernel/cpu/microcode/core_early.c +++ b/arch/x86/kernel/cpu/microcode/core_early.c @@ -123,11 +123,7 @@ void __init load_ucode_bsp(void) static bool check_loader_disabled_ap(void) { -#ifdef CONFIG_X86_32 - return *((bool *)__pa_nodebug(&dis_ucode_ldr)); -#else return dis_ucode_ldr; -#endif } void load_ucode_ap(void) > [ 38.644599] *pdpt = 0000000003267007 *pde = 0000000000000000 > [ 38.644599] Oops: 0000 [#1] SMP > [ 38.644599] Modules linked in: sg sd_mod dm_multipath dm_mod xen_evtchn > iscsi_boot_sysfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi > scsi_mod libcrc32c crc32c_generic radeon fbcon tileblit font bitblit ttm > softcursor drm_kms_helper x86_pkg_temp_thermal crc32c_intel xen_blkfront > xen_netfront xen_fbfront fb_sys_fops sysimgblt sysfillrect syscopyarea > xen_kbdfront xenfs xen_privcmd > [ 38.644599] CPU: 0 PID: 9 Comm: migration/0 Tainted: G W > 3.18.0-rc6upstream-00001-g0de9524 #1 > [ 38.644599] task: eb894650 ti: eb89c000 task.ti: eb89c000 > [ 38.644599] EIP: 0061:[] EFLAGS: 00010082 CPU: 0 > [ 38.644599] EIP is at load_ucode_ap+0x6/0xe0 > [ 38.644599] EAX: 00000000 EBX: c1823160 ECX: 00000000 EDX: c197eee0 > [ 38.644599] ESI: eb9bded0 EDI: c1793e95 EBP: eb89de28 ESP: eb89de20 > [ 38.644599] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0069 > [ 38.644599] CR0: 80050033 CR2: 0197eec0 CR3: 03280000 CR4: 00042660 > [ 38.644599] Stack: > [ 38.644599] eb89de30 c10539b0 eb89de30 c1070f9d eb89de54 c140de9e > eb9bded0 eb89de54 > [ 38.644599] c103dbcc 00000008 deadbeef eb9bded0 eb9bdee4 eb89de80 > c1397f57 00000000 > [ 38.644599] 00000000 80000002 eb9bdf1c 00000000 00000002 00000003 > eb9bded0 eb9bdee4 > [ 38.644599] Call Trace: > [ 38.644599] [] ? i8237A_resume+0xb0/0xe0 > [ 38.644599] [] mc_bp_resume+0x3d/0x50 > [ 38.644599] [] syscore_resume+0x4e/0x190 > [ 38.644599] [] ? xen_timer_resume+0x3c/0x60 > [ 38.644599] [] xen_suspend+0x77/0xf0 > [ 38.644599] [] multi_cpu_stop+0x93/0xc0 > [ 38.644599] [] cpu_stopper_thread+0x46/0x170 > [ 38.644599] [] ? irq_cpu_stop_queue_work+0x20/0x20 > [ 38.644599] [] ? __schedule+0x356/0x880 > [ 38.644599] [] ? default_wake_function+0xb/0x10 > [ 38.644599] [] ? __wake_up_common+0x40/0x70 > [ 38.644599] [] ? _raw_spin_unlock_irqrestore+0x20/0x90 > [ 38.644599] [] ? _raw_spin_unlock_irqrestore+0x20/0x90 > [ 38.644599] [] ? _raw_spin_lock_irqsave+0x1f/0x80 > [ 38.644599] [] ? _raw_spin_lock_irq+0xf/0x60 > [ 38.644599] [] smpboot_thread_fn+0x117/0x1a0 > [ 38.644599] [] kthread+0xa4/0xc0 > [ 38.644599] [] ? smpboot_create_threads+0x60/0x60 > [ 38.644599] [] ret_from_kernel_thread+0x21/0x30 > [ 38.644599] [] ? kthread_freezable_should_stop+0x60/0x60 > [ 38.644599] Code: 55 cc eb 93 89 44 24 04 66 31 f6 c7 04 24 78 f0 74 c1 > e8 84 9f 5b 00 eb ae 90 90 90 90 90 90 90 90 90 90 90 90 55 89 e5 83 ec 08 > <80> 3d c0 ee 97 01 00 89 1c 24 89 74 24 04 74 12 8b 1c 24 8b 74 > [ 38.644599] EIP: [] load_ucode_ap+0x6/0xe0 SS:ESP 0069:eb89de20 > [ 38.644599] CR2: 000000000197eec0 > [ 38.644599] ---[ end trace 0ad7358b42202518 ]--- > [ 38.644599] Kernel panic - not syncing: Fatal exception > [ 38.644599] Kernel Offset: 0x0 from 0xc1000000 (relocation range: > 0xc0000000-0xed7fdfff) > > > > > -boris -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/