From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757033AbZBJWAy (ORCPT ); Tue, 10 Feb 2009 17:00:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756180AbZBJWAm (ORCPT ); Tue, 10 Feb 2009 17:00:42 -0500 Received: from smtp-outbound-1.vmware.com ([65.115.85.69]:43624 "EHLO smtp-outbound-1.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756152AbZBJWAl (ORCPT ); Tue, 10 Feb 2009 17:00:41 -0500 Subject: Re: [BUGFIX/x86] Fix initialization of wakeup_cpu. From: Alok Kataria Reply-To: akataria@vmware.com To: Yinghai Lu Cc: Ingo Molnar , the arch/x86 maintainers , LKML In-Reply-To: <86802c440902101303u2fe671b0xe811543d40e0cd9@mail.gmail.com> References: <1234297715.24155.29.camel@alok-dev1> <86802c440902101303u2fe671b0xe811543d40e0cd9@mail.gmail.com> Content-Type: text/plain Organization: VMware INC. Date: Tue, 10 Feb 2009 14:00:40 -0800 Message-Id: <1234303240.24155.36.camel@alok-dev1> Mime-Version: 1.0 X-Mailer: Evolution 2.8.0 (2.8.0-40.el5_1.1) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2009-02-10 at 13:03 -0800, Yinghai Lu wrote: > On Tue, Feb 10, 2009 at 12:28 PM, Alok Kataria wrote: > > Was originally reported in the.. > > "Re: [PARAVIRT/x86] BUGFIX: Put a missing paravirt_release_pmd in pgd_dtor" thread > > > > -- > > With the patches for refactoring of wake_cpu macros, the 32bit code > > in tip doesn't execute generic_apic_probe if CONFIG_X86_32_NON_STANDARD > > is not set. > > > > Even on a x86 STANDARD cpu we need to execute the generic_apic_probe > > function, as we rely on this function to execute the update_genapic > > quirk which initilizes apic->wakeup_cpu. > > > > Failing to do so results in we making a call to a null function in do_boot_cpu. > > > > The stack trace without the patch goes like this. > > > > Booting processor 1 APIC 0x1 ip 0x6000 > > BUG: unable to handle kernel NULL pointer dereference at (null) > > IP: [<(null)>] (null) > > *pdpt = 0000000000839001 *pde = 0000000000c97067 *pte = 0000000000000163 > > Oops: 0000 [#1] SMP > > last sysfs file: > > Modules linked in: > > > > Pid: 1, comm: swapper Not tainted (2.6.29-rc4-tip #18) VMware Virtual Platform > > EIP: 0062:[<00000000>] EFLAGS: 00010293 CPU: 0 > > EIP is at 0x0 > > EAX: 00000001 EBX: 00006000 ECX: c077ed00 EDX: 00006000 > > ESI: 00000001 EDI: 00000001 EBP: ef04cf40 ESP: ef04cf1c > > DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 006a > > Process swapper (pid: 1, ti=ef04c000 task=ef050000 task.ti=ef04c000) > > Stack: > > c0644e52 00000000 ef04cf24 ef04cf24 c064468d c0886dc0 00000000 c0702aea > > ef055480 00000001 00000101 dead4ead ffffffff ffffffff c08af530 00000000 > > c0709715 ef04cf60 ef04cf60 00000001 00000000 00000000 dead4ead ffffffff > > Call Trace: > > [] ? native_cpu_up+0x2de/0x45b > > [] ? do_fork_idle+0x0/0x19 > > [] ? _cpu_up+0x88/0xe8 > > [] ? cpu_up+0x42/0x4e > > [] ? kernel_init+0x99/0x14b > > [] ? kernel_init+0x0/0x14b > > [] ? kernel_thread_helper+0x7/0x10 > > Code: Bad EIP value. > > EIP: [<00000000>] 0x0 SS:ESP 006a:ef04cf1c > > > > I think we should call generic_apic_probe unconditionally now. > > > > Signed-off-by: Alok N Kataria > > > > Index: linux-tip-master/arch/x86/kernel/setup.c > > =================================================================== > > --- linux-tip-master.orig/arch/x86/kernel/setup.c 2009-02-10 11:37:31.000000000 -0800 > > +++ linux-tip-master/arch/x86/kernel/setup.c 2009-02-10 11:50:37.000000000 -0800 > > @@ -936,9 +936,7 @@ > > map_vsyscall(); > > #endif > > > > -#if defined(CONFIG_X86_32_NON_STANDARD) || defined(CONFIG_X86_BIGSMP) > > generic_apic_probe(); > > -#endif > > > > early_quirks(); > > > > 1. only es7000 and numaq has update_genapic() ==> they need > X86_32_NON_STANDARD.. There is one here too static struct x86_quirks default_x86_quirks __initdata = { .update_genapic = default_update_genapic, } > 2. also will break 64 bit.... isn't the default_x86_quirks defined for 64 bit too ? -- Alok