Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751873Ab3CAJkI (ORCPT ); Fri, 1 Mar 2013 04:40:08 -0500 Received: from mail-pb0-f44.google.com ([209.85.160.44]:54782 "EHLO mail-pb0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751246Ab3CAJkB (ORCPT ); Fri, 1 Mar 2013 04:40:01 -0500 Message-ID: <51307767.70605@gmail.com> Date: Fri, 01 Mar 2013 17:39:51 +0800 From: Simon Jeons User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130221 Thunderbird/17.0.3 MIME-Version: 1.0 To: Mel Gorman , Ingo Molnar , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, riel@redhat.com, mhocko@suse.cz, hannes@cmpxchg.org Subject: Re: [PATCH] x86: mm: Check if PUD is large when validating a kernel address v2 References: <20130211145236.GX21389@suse.de> <20130213110202.GI4100@suse.de> <51304E29.40900@gmail.com> <20130301091513.GA11787@gchen.bj.intel.com> <5130731F.4000804@gmail.com> <20130301093537.GA12327@gchen.bj.intel.com> In-Reply-To: <20130301093537.GA12327@gchen.bj.intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4805 Lines: 87 On 03/01/2013 05:35 PM, Chen Gong wrote: > On Fri, Mar 01, 2013 at 05:21:35PM +0800, Simon Jeons wrote: >> Date: Fri, 01 Mar 2013 17:21:35 +0800 >> From: Simon Jeons >> To: Mel Gorman , Ingo Molnar , Andrew >> Morton , linux-kernel@vger.kernel.org, >> linux-mm@kvack.org, riel@redhat.com, mhocko@suse.cz, hannes@cmpxchg.org >> Subject: Re: [PATCH] x86: mm: Check if PUD is large when validating a >> kernel address v2 >> User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130221 >> Thunderbird/17.0.3 >> >> On 03/01/2013 05:15 PM, Chen Gong wrote: >>> On Fri, Mar 01, 2013 at 02:43:53PM +0800, Simon Jeons wrote: >>>> Date: Fri, 01 Mar 2013 14:43:53 +0800 >>>> From: Simon Jeons >>>> To: Mel Gorman >>>> CC: Ingo Molnar , Andrew Morton >>>> , linux-kernel@vger.kernel.org, >>>> linux-mm@kvack.org, riel@redhat.com, mhocko@suse.cz, hannes@cmpxchg.org >>>> Subject: Re: [PATCH] x86: mm: Check if PUD is large when validating a >>>> kernel address v2 >>>> User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130221 >>>> Thunderbird/17.0.3 >>>> >>>> On 02/13/2013 07:02 PM, Mel Gorman wrote: >>>>> Andrew or Ingo, please pick up. >>>>> >>>>> Changelog since v1 >>>>> o Add reviewed-bys and acked-bys >>>>> >>>>> A user reported a bug whereby a backup process accessing /proc/kcore >>>>> caused an oops. >>>>> >>>>> BUG: unable to handle kernel paging request at ffffbb00ff33b000 >>>>> IP: [] kern_addr_valid+0xbe/0x110 >>>>> PGD 0 >>>>> Oops: 0000 [#1] SMP >>>>> CPU 6 >>>>> Modules linked in: af_packet nfs lockd fscache auth_rpcgss nfs_acl sunrpc 8021q garp stp llc cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf microcode fuse nls_iso8859_1 nls_cp437 vfat fat loop dm_mod ioatdma ipv6 ipv6_lib igb dca i7core_edac edac_core i2c_i801 i2c_core cdc_ether usbnet bnx2 mii iTCO_wdt iTCO_vendor_support shpchp rtc_cmos pci_hotplug tpm_tis sg tpm pcspkr tpm_bios serio_raw button ext3 jbd mbcache uhci_hcd ehci_hcd usbcore sd_mod crc_t10dif usb_common processor thermal_sys hwmon scsi_dh_emc scsi_dh_rdac scsi_dh_alua scsi_dh_hp_sw scsi_dh ata_generic ata_piix libata megaraid_sas scsi_mod >>>>> >>>>> Pid: 16196, comm: Hibackp Not tainted 3.0.13-0.27-default #1 IBM System x3550 M3 -[7944 K3G]-/94Y7614 >>>>> RIP: 0010:[] [] kern_addr_valid+0xbe/0x110 >>>>> RSP: 0018:ffff88094165fe80 EFLAGS: 00010246 >>>>> RAX: 00003300ff33b000 RBX: ffff880100000000 RCX: 0000000000000000 >>>>> RDX: 0000000100000000 RSI: ffff880000000000 RDI: ff32b300ff33b400 >>>>> RBP: 0000000000001000 R08: 00003ffffffff000 R09: 0000000000000000 >>>>> R10: 22302e31223d6e6f R11: 0000000000000246 R12: 0000000000001000 >>>>> R13: 0000000000003000 R14: 0000000000571be0 R15: ffff88094165ff50 >>>>> FS: 00007ff152d33700(0000) GS:ffff88097f2c0000(0000) knlGS:0000000000000000 >>>>> CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b >>>>> CR2: ffffbb00ff33b000 CR3: 00000009405a3000 CR4: 00000000000006e0 >>>>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >>>>> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 >>>>> Process Hibackp (pid: 16196, threadinfo ffff88094165e000, task ffff8808eb9ba600) >>>>> Stack: >>>>> ffffffff811b8aaa 0000000000004000 ffff880943fea480 ffff8808ef2bae50 >>>>> ffff880943d32980 fffffffffffffffb ffff8808ef2bae40 ffff88094165ff50 >>>>> 0000000000004000 000000000056ebe0 ffffffff811ad847 000000000056ebe0 >>>>> Call Trace: >>>>> [] read_kcore+0x17a/0x370 >>>>> [] proc_reg_read+0x77/0xc0 >>>>> [] vfs_read+0xc7/0x130 >>>>> [] sys_read+0x53/0xa0 >>>>> [] system_call_fastpath+0x16/0x1b >>>>> >>>>> Investigation determined that the bug triggered when reading system RAM >>>>> at the 4G mark. On this system, that was the first address using 1G pages >>>> Do you mean there is one page which is 1G? >>>> >>> 1GB support in native kernel is started from 2.6.27 with these 2 commits: >> Why call kernel native? Which kend of kernel is not native? > relative to VMM like Xen. Oh, I see. Thanks. :) > >>> 39c11e6 and b4718e6. For Intel CPU, from Westmere it supports 1GB page. >>> BTW, IBM System x3550 M3 is a Westmere based system. >> Is it only used in hugetlbfs page? > Yes by now. -- 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/