From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx200.postini.com [74.125.245.200]) by kanga.kvack.org (Postfix) with SMTP id 829426B0002 for ; Fri, 1 Mar 2013 04:37:51 -0500 (EST) Date: Fri, 1 Mar 2013 04:35:37 -0500 From: Chen Gong Subject: Re: [PATCH] x86: mm: Check if PUD is large when validating a kernel address v2 Message-ID: <20130301093537.GA12327@gchen.bj.intel.com> References: <20130211145236.GX21389@suse.de> <20130213110202.GI4100@suse.de> <51304E29.40900@gmail.com> <20130301091513.GA11787@gchen.bj.intel.com> <5130731F.4000804@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="pf9I7BMVVzbSWLtt" Content-Disposition: inline In-Reply-To: <5130731F.4000804@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Simon Jeons Cc: Mel Gorman , Ingo Molnar , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, riel@redhat.com, mhocko@suse.cz, hannes@cmpxchg.org --pf9I7BMVVzbSWLtt Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable 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 >=20 > 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.o= rg > >>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 s= unrpc 8021q garp stp llc cpufreq_conservative cpufreq_userspace cpufreq_pow= ersave acpi_cpufreq mperf microcode fuse nls_iso8859_1 nls_cp437 vfat fat l= oop 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_cmo= s pci_hotplug tpm_tis sg tpm pcspkr tpm_bios serio_raw button ext3 jbd mbca= che uhci_hcd ehci_hcd usbcore sd_mod crc_t10dif usb_common processor therma= l_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 Sys= tem 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:00000000= 00000000 > >>> 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 ffff8= 808eb9ba600) > >>> 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 pa= ges > >>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: >=20 > Why call kernel native? Which kend of kernel is not native? relative to VMM like Xen. >=20 > >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. --pf9I7BMVVzbSWLtt Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJRMHZpAAoJEI01n1+kOSLHMWcP/RUoDZHPpbe2oAwoN07Z/2CB 3hS/kCAOUriOt+76eouVQ2EsW5FGBHW7ojTihoO6znvAptPlMRkBIcGwjYH8HBN2 P0Bio74FhdQThnfYv0jexrMQI2LHuagJJ3z1ILzOdHADq40tIyMbomN6a6DmaYD9 ij1pVFKKKWUaGbl69oaX+MbPQd6xe/Y5GlhlQJId2JQxJCrxEP28QL5OkLC295OQ 3vGAoRiG8RJ9HsfJJ2o0SREYTkwfEJyTYo8BPZ6e3VSIlqcILig5BxLCAJoz5c29 pY/wc7kXCzrxBNUI1oxFqBN6Vst2PC0+tMjArLd/CNhcE/GNJ5SDTSvGy4ReGsHc xEWjnG79N1VWQ9m3/Jjf7vuwwR1b/j9CTDrqtL/yxqOTbF2BGCK/KEieyoCatDgB 6GepsRXvZjtqmNrLPH4Tw3xUd+qsxVkJ4YhsxDNm/M77O4QplgE59fbAVlEOvZ8n KPQsoEQ9hNJ93DitaZ4R7hTX7m7Bi7k3Jul1Q1JUMQ6n2mkO3bU0jgSmG318iKwy LcifJj+jKIRGu2uO0pa1Ur0SR5FXjkYhxNRyZunWkCAkjB31R2/mwX+dRT4RmVDR PRavQvL9BLY0TKp/OhGZISaRrL+MbG6C9JpDaxxX3a4SjzBrAU2HxfYB86LnP8y+ xPPUApjPDJ43OEEFt3oQ =1VVA -----END PGP SIGNATURE----- --pf9I7BMVVzbSWLtt-- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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