From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yk0-f179.google.com (mail-yk0-f179.google.com [209.85.160.179]) by kanga.kvack.org (Postfix) with ESMTP id E082E6B0035 for ; Fri, 11 Apr 2014 08:50:14 -0400 (EDT) Received: by mail-yk0-f179.google.com with SMTP id 9so4801012ykp.38 for ; Fri, 11 Apr 2014 05:50:13 -0700 (PDT) Received: from userp1040.oracle.com (userp1040.oracle.com. [156.151.31.81]) by mx.google.com with ESMTPS id b21si7911307yhl.138.2014.04.11.05.50.13 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Fri, 11 Apr 2014 05:50:13 -0700 (PDT) Message-ID: <5347E4FB.2090705@oracle.com> Date: Fri, 11 Apr 2014 08:50:03 -0400 From: Sasha Levin MIME-Version: 1.0 Subject: mm,x86: warning at arch/x86/mm/pat.c:781 untrack_pfn+0x65/0xb0() Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "linux-mm@kvack.org" Cc: Andrew Morton , Konstantin Khlebnikov , suresh.b.siddha@intel.com, Ingo Molnar , "H. Peter Anvin" , LKML , Dave Jones Hi all, While fuzzing with trinity inside a KVM tools guest running the latest -next kernel I've stumbled on the following: [ 3431.738346] WARNING: CPU: 12 PID: 17371 at arch/x86/mm/pat.c:781 untrack_pfn+0x65/0xb0() [ 3431.741153] Modules linked in: [ 3431.742138] CPU: 12 PID: 17371 Comm: trinity-c361 Not tainted 3.14.0-next-20140410-sasha-00022-gb3d9015-dirty #390 [ 3431.745365] 0000000000000009 ffff8801b5635be8 ffffffffae51f40b 0000000000005b10 [ 3431.747699] 0000000000000000 ffff8801b5635c28 ffffffffab15a37c ffff8801b5635c38 [ 3431.750401] ffff8802e8fd2e00 0000000000000000 ffff8801b5635d68 ffff8801b5635d68 [ 3431.752853] Call Trace: [ 3431.753625] dump_stack (lib/dump_stack.c:52) [ 3431.755244] warn_slowpath_common (kernel/panic.c:418) [ 3431.757062] warn_slowpath_null (kernel/panic.c:453) [ 3431.758828] untrack_pfn (arch/x86/mm/pat.c:781 (discriminator 3)) [ 3431.760785] unmap_single_vma (mm/memory.c:1316) [ 3431.762703] ? sched_clock (arch/x86/include/asm/paravirt.h:192 arch/x86/kernel/tsc.c:305) [ 3431.764366] ? sched_clock_local (kernel/sched/clock.c:214) [ 3431.766253] ? move_page_tables (mm/mremap.c:156 mm/mremap.c:217) [ 3431.768071] unmap_vmas (mm/memory.c:1366 (discriminator 1)) [ 3431.769686] unmap_region (mm/mmap.c:2361 (discriminator 3)) [ 3431.771776] ? validate_mm_rb (mm/mmap.c:401) [ 3431.773606] ? vma_rb_erase (mm/mmap.c:446 include/linux/rbtree_augmented.h:219 include/linux/rbtree_augmented.h:227 mm/mmap.c:485) [ 3431.775268] do_munmap (mm/mmap.c:3259 mm/mmap.c:2559) [ 3431.777012] move_vma (mm/mremap.c:306) [ 3431.778621] SyS_mremap (mm/mremap.c:439 mm/mremap.c:501 mm/mremap.c:470) [ 3431.780576] tracesys (arch/x86/kernel/entry_64.S:749) Thanks, Sasha -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yh0-f50.google.com (mail-yh0-f50.google.com [209.85.213.50]) by kanga.kvack.org (Postfix) with ESMTP id 92EF26B0031 for ; Sat, 7 Jun 2014 23:33:53 -0400 (EDT) Received: by mail-yh0-f50.google.com with SMTP id 29so1665605yhl.9 for ; Sat, 07 Jun 2014 20:33:53 -0700 (PDT) Received: from userp1040.oracle.com (userp1040.oracle.com. [156.151.31.81]) by mx.google.com with ESMTPS id u74si16394154yha.48.2014.06.07.20.33.52 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Sat, 07 Jun 2014 20:33:52 -0700 (PDT) Message-ID: <5393D995.8010805@oracle.com> Date: Sat, 07 Jun 2014 23:33:41 -0400 From: Sasha Levin MIME-Version: 1.0 Subject: Re: mm,x86: warning at arch/x86/mm/pat.c:781 untrack_pfn+0x65/0xb0() References: <5347E4FB.2090705@oracle.com> In-Reply-To: <5347E4FB.2090705@oracle.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "linux-mm@kvack.org" Cc: Andrew Morton , Konstantin Khlebnikov , suresh.b.siddha@intel.com, Ingo Molnar , "H. Peter Anvin" , LKML , Dave Jones On 04/11/2014 08:50 AM, Sasha Levin wrote: > Hi all, > > While fuzzing with trinity inside a KVM tools guest running the latest -next > kernel I've stumbled on the following: Ping? Still happening (rarely on -next): [ 5818.038245] WARNING: CPU: 4 PID: 22726 at arch/x86/mm/pat.c:781 untrack_pfn+0x65/0xb0() [ 5818.044203] Modules linked in: [ 5818.045172] CPU: 4 PID: 22726 Comm: trinity-c239 Tainted: G W 3.15.0-rc8-next-20140606-sasha-00021-ga9d3a0b-dirty #596 [ 5818.048317] 0000000000000009 ffff8800024d3be8 ffffffff9e50fe6b 0000000000000001 [ 5818.050516] 0000000000000000 ffff8800024d3c28 ffffffff9b15f96c ffff8800024d3c38 [ 5818.052567] ffff88000203f400 0000000000000000 ffff8800024d3d68 ffff8800024d3d68 [ 5818.053785] Call Trace: [ 5818.054483] dump_stack (lib/dump_stack.c:52) [ 5818.055586] warn_slowpath_common (kernel/panic.c:430) [ 5818.056763] warn_slowpath_null (kernel/panic.c:465) [ 5818.057789] untrack_pfn (arch/x86/mm/pat.c:781 (discriminator 3)) [ 5818.059412] unmap_single_vma (mm/memory.c:1327) [ 5818.061530] ? pagevec_lru_move_fn (include/linux/pagevec.h:44 mm/swap.c:435) [ 5818.063412] unmap_vmas (mm/memory.c:1377 (discriminator 1)) [ 5818.064610] unmap_region (mm/mmap.c:2363 (discriminator 3)) [ 5818.065453] ? validate_mm_rb (mm/mmap.c:404) [ 5818.066422] ? vma_rb_erase (mm/mmap.c:449 include/linux/rbtree_augmented.h:219 include/linux/rbtree_augmented.h:227 mm/mmap.c:488) [ 5818.067316] do_munmap (mm/mmap.c:3359 mm/mmap.c:2561) [ 5818.068126] move_vma (mm/mremap.c:313) [ 5818.069000] SyS_mremap (mm/mremap.c:446 mm/mremap.c:508 mm/mremap.c:477) [ 5818.069839] tracesys (arch/x86/kernel/entry_64.S:542) Thanks, Sasha -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f45.google.com (mail-pa0-f45.google.com [209.85.220.45]) by kanga.kvack.org (Postfix) with ESMTP id EDDF26B00D9 for ; Tue, 10 Jun 2014 00:36:41 -0400 (EDT) Received: by mail-pa0-f45.google.com with SMTP id hz1so256838pad.18 for ; Mon, 09 Jun 2014 21:36:41 -0700 (PDT) Received: from mail-pd0-x232.google.com (mail-pd0-x232.google.com [2607:f8b0:400e:c02::232]) by mx.google.com with ESMTPS id bm3si32976893pbc.86.2014.06.09.21.36.40 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 09 Jun 2014 21:36:41 -0700 (PDT) Received: by mail-pd0-f178.google.com with SMTP id v10so5642286pde.23 for ; Mon, 09 Jun 2014 21:36:40 -0700 (PDT) Date: Mon, 9 Jun 2014 21:35:21 -0700 (PDT) From: Hugh Dickins Subject: Re: mm,x86: warning at arch/x86/mm/pat.c:781 untrack_pfn+0x65/0xb0() In-Reply-To: <5393D995.8010805@oracle.com> Message-ID: References: <5347E4FB.2090705@oracle.com> <5393D995.8010805@oracle.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Sasha Levin Cc: "linux-mm@kvack.org" , Andrew Morton , Konstantin Khlebnikov , suresh.b.siddha@intel.com, Ingo Molnar , "H. Peter Anvin" , LKML , Dave Jones On Sat, 7 Jun 2014, Sasha Levin wrote: > On 04/11/2014 08:50 AM, Sasha Levin wrote: > > Hi all, > > > > While fuzzing with trinity inside a KVM tools guest running the latest -next > > kernel I've stumbled on the following: > > Ping? Still happening (rarely on -next): > > [ 5818.038245] WARNING: CPU: 4 PID: 22726 at arch/x86/mm/pat.c:781 untrack_pfn+0x65/0xb0() > [ 5818.044203] Modules linked in: > [ 5818.045172] CPU: 4 PID: 22726 Comm: trinity-c239 Tainted: G W 3.15.0-rc8-next-20140606-sasha-00021-ga9d3a0b-dirty #596 > [ 5818.048317] 0000000000000009 ffff8800024d3be8 ffffffff9e50fe6b 0000000000000001 > [ 5818.050516] 0000000000000000 ffff8800024d3c28 ffffffff9b15f96c ffff8800024d3c38 > [ 5818.052567] ffff88000203f400 0000000000000000 ffff8800024d3d68 ffff8800024d3d68 > [ 5818.053785] Call Trace: > [ 5818.054483] dump_stack (lib/dump_stack.c:52) > [ 5818.055586] warn_slowpath_common (kernel/panic.c:430) > [ 5818.056763] warn_slowpath_null (kernel/panic.c:465) > [ 5818.057789] untrack_pfn (arch/x86/mm/pat.c:781 (discriminator 3)) > [ 5818.059412] unmap_single_vma (mm/memory.c:1327) > [ 5818.061530] ? pagevec_lru_move_fn (include/linux/pagevec.h:44 mm/swap.c:435) > [ 5818.063412] unmap_vmas (mm/memory.c:1377 (discriminator 1)) > [ 5818.064610] unmap_region (mm/mmap.c:2363 (discriminator 3)) > [ 5818.065453] ? validate_mm_rb (mm/mmap.c:404) > [ 5818.066422] ? vma_rb_erase (mm/mmap.c:449 include/linux/rbtree_augmented.h:219 include/linux/rbtree_augmented.h:227 mm/mmap.c:488) > [ 5818.067316] do_munmap (mm/mmap.c:3359 mm/mmap.c:2561) > [ 5818.068126] move_vma (mm/mremap.c:313) > [ 5818.069000] SyS_mremap (mm/mremap.c:446 mm/mremap.c:508 mm/mremap.c:477) > [ 5818.069839] tracesys (arch/x86/kernel/entry_64.S:542) I could easily be wrong, but I think of this one as another manifestation of the filemap.c:202 BUG_ON(page_mapped(page)) bug, whatever that is. In each case, we have a BUG or WARNING at the point where we detect that there should have been a pte in a page table, but it somehow disappeared. VM_PFNMAP in this case, an ordinary file mapping in the other case; and nothing to show in the anonymous case, there the page would just leak. Hugh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757195AbaDKMuY (ORCPT ); Fri, 11 Apr 2014 08:50:24 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:50656 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754438AbaDKMuU (ORCPT ); Fri, 11 Apr 2014 08:50:20 -0400 Message-ID: <5347E4FB.2090705@oracle.com> Date: Fri, 11 Apr 2014 08:50:03 -0400 From: Sasha Levin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: "linux-mm@kvack.org" CC: Andrew Morton , Konstantin Khlebnikov , suresh.b.siddha@intel.com, Ingo Molnar , "H. Peter Anvin" , LKML , Dave Jones Subject: mm,x86: warning at arch/x86/mm/pat.c:781 untrack_pfn+0x65/0xb0() X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all, While fuzzing with trinity inside a KVM tools guest running the latest -next kernel I've stumbled on the following: [ 3431.738346] WARNING: CPU: 12 PID: 17371 at arch/x86/mm/pat.c:781 untrack_pfn+0x65/0xb0() [ 3431.741153] Modules linked in: [ 3431.742138] CPU: 12 PID: 17371 Comm: trinity-c361 Not tainted 3.14.0-next-20140410-sasha-00022-gb3d9015-dirty #390 [ 3431.745365] 0000000000000009 ffff8801b5635be8 ffffffffae51f40b 0000000000005b10 [ 3431.747699] 0000000000000000 ffff8801b5635c28 ffffffffab15a37c ffff8801b5635c38 [ 3431.750401] ffff8802e8fd2e00 0000000000000000 ffff8801b5635d68 ffff8801b5635d68 [ 3431.752853] Call Trace: [ 3431.753625] dump_stack (lib/dump_stack.c:52) [ 3431.755244] warn_slowpath_common (kernel/panic.c:418) [ 3431.757062] warn_slowpath_null (kernel/panic.c:453) [ 3431.758828] untrack_pfn (arch/x86/mm/pat.c:781 (discriminator 3)) [ 3431.760785] unmap_single_vma (mm/memory.c:1316) [ 3431.762703] ? sched_clock (arch/x86/include/asm/paravirt.h:192 arch/x86/kernel/tsc.c:305) [ 3431.764366] ? sched_clock_local (kernel/sched/clock.c:214) [ 3431.766253] ? move_page_tables (mm/mremap.c:156 mm/mremap.c:217) [ 3431.768071] unmap_vmas (mm/memory.c:1366 (discriminator 1)) [ 3431.769686] unmap_region (mm/mmap.c:2361 (discriminator 3)) [ 3431.771776] ? validate_mm_rb (mm/mmap.c:401) [ 3431.773606] ? vma_rb_erase (mm/mmap.c:446 include/linux/rbtree_augmented.h:219 include/linux/rbtree_augmented.h:227 mm/mmap.c:485) [ 3431.775268] do_munmap (mm/mmap.c:3259 mm/mmap.c:2559) [ 3431.777012] move_vma (mm/mremap.c:306) [ 3431.778621] SyS_mremap (mm/mremap.c:439 mm/mremap.c:501 mm/mremap.c:470) [ 3431.780576] tracesys (arch/x86/kernel/entry_64.S:749) Thanks, Sasha From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753377AbaFHDd5 (ORCPT ); Sat, 7 Jun 2014 23:33:57 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:24980 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753187AbaFHDd4 (ORCPT ); Sat, 7 Jun 2014 23:33:56 -0400 Message-ID: <5393D995.8010805@oracle.com> Date: Sat, 07 Jun 2014 23:33:41 -0400 From: Sasha Levin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: "linux-mm@kvack.org" CC: Andrew Morton , Konstantin Khlebnikov , suresh.b.siddha@intel.com, Ingo Molnar , "H. Peter Anvin" , LKML , Dave Jones Subject: Re: mm,x86: warning at arch/x86/mm/pat.c:781 untrack_pfn+0x65/0xb0() References: <5347E4FB.2090705@oracle.com> In-Reply-To: <5347E4FB.2090705@oracle.com> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/11/2014 08:50 AM, Sasha Levin wrote: > Hi all, > > While fuzzing with trinity inside a KVM tools guest running the latest -next > kernel I've stumbled on the following: Ping? Still happening (rarely on -next): [ 5818.038245] WARNING: CPU: 4 PID: 22726 at arch/x86/mm/pat.c:781 untrack_pfn+0x65/0xb0() [ 5818.044203] Modules linked in: [ 5818.045172] CPU: 4 PID: 22726 Comm: trinity-c239 Tainted: G W 3.15.0-rc8-next-20140606-sasha-00021-ga9d3a0b-dirty #596 [ 5818.048317] 0000000000000009 ffff8800024d3be8 ffffffff9e50fe6b 0000000000000001 [ 5818.050516] 0000000000000000 ffff8800024d3c28 ffffffff9b15f96c ffff8800024d3c38 [ 5818.052567] ffff88000203f400 0000000000000000 ffff8800024d3d68 ffff8800024d3d68 [ 5818.053785] Call Trace: [ 5818.054483] dump_stack (lib/dump_stack.c:52) [ 5818.055586] warn_slowpath_common (kernel/panic.c:430) [ 5818.056763] warn_slowpath_null (kernel/panic.c:465) [ 5818.057789] untrack_pfn (arch/x86/mm/pat.c:781 (discriminator 3)) [ 5818.059412] unmap_single_vma (mm/memory.c:1327) [ 5818.061530] ? pagevec_lru_move_fn (include/linux/pagevec.h:44 mm/swap.c:435) [ 5818.063412] unmap_vmas (mm/memory.c:1377 (discriminator 1)) [ 5818.064610] unmap_region (mm/mmap.c:2363 (discriminator 3)) [ 5818.065453] ? validate_mm_rb (mm/mmap.c:404) [ 5818.066422] ? vma_rb_erase (mm/mmap.c:449 include/linux/rbtree_augmented.h:219 include/linux/rbtree_augmented.h:227 mm/mmap.c:488) [ 5818.067316] do_munmap (mm/mmap.c:3359 mm/mmap.c:2561) [ 5818.068126] move_vma (mm/mremap.c:313) [ 5818.069000] SyS_mremap (mm/mremap.c:446 mm/mremap.c:508 mm/mremap.c:477) [ 5818.069839] tracesys (arch/x86/kernel/entry_64.S:542) Thanks, Sasha From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751050AbaFJEgm (ORCPT ); Tue, 10 Jun 2014 00:36:42 -0400 Received: from mail-pd0-f173.google.com ([209.85.192.173]:46778 "EHLO mail-pd0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750902AbaFJEgl (ORCPT ); Tue, 10 Jun 2014 00:36:41 -0400 Date: Mon, 9 Jun 2014 21:35:21 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: Sasha Levin cc: "linux-mm@kvack.org" , Andrew Morton , Konstantin Khlebnikov , suresh.b.siddha@intel.com, Ingo Molnar , "H. Peter Anvin" , LKML , Dave Jones Subject: Re: mm,x86: warning at arch/x86/mm/pat.c:781 untrack_pfn+0x65/0xb0() In-Reply-To: <5393D995.8010805@oracle.com> Message-ID: References: <5347E4FB.2090705@oracle.com> <5393D995.8010805@oracle.com> User-Agent: Alpine 2.11 (LSU 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 7 Jun 2014, Sasha Levin wrote: > On 04/11/2014 08:50 AM, Sasha Levin wrote: > > Hi all, > > > > While fuzzing with trinity inside a KVM tools guest running the latest -next > > kernel I've stumbled on the following: > > Ping? Still happening (rarely on -next): > > [ 5818.038245] WARNING: CPU: 4 PID: 22726 at arch/x86/mm/pat.c:781 untrack_pfn+0x65/0xb0() > [ 5818.044203] Modules linked in: > [ 5818.045172] CPU: 4 PID: 22726 Comm: trinity-c239 Tainted: G W 3.15.0-rc8-next-20140606-sasha-00021-ga9d3a0b-dirty #596 > [ 5818.048317] 0000000000000009 ffff8800024d3be8 ffffffff9e50fe6b 0000000000000001 > [ 5818.050516] 0000000000000000 ffff8800024d3c28 ffffffff9b15f96c ffff8800024d3c38 > [ 5818.052567] ffff88000203f400 0000000000000000 ffff8800024d3d68 ffff8800024d3d68 > [ 5818.053785] Call Trace: > [ 5818.054483] dump_stack (lib/dump_stack.c:52) > [ 5818.055586] warn_slowpath_common (kernel/panic.c:430) > [ 5818.056763] warn_slowpath_null (kernel/panic.c:465) > [ 5818.057789] untrack_pfn (arch/x86/mm/pat.c:781 (discriminator 3)) > [ 5818.059412] unmap_single_vma (mm/memory.c:1327) > [ 5818.061530] ? pagevec_lru_move_fn (include/linux/pagevec.h:44 mm/swap.c:435) > [ 5818.063412] unmap_vmas (mm/memory.c:1377 (discriminator 1)) > [ 5818.064610] unmap_region (mm/mmap.c:2363 (discriminator 3)) > [ 5818.065453] ? validate_mm_rb (mm/mmap.c:404) > [ 5818.066422] ? vma_rb_erase (mm/mmap.c:449 include/linux/rbtree_augmented.h:219 include/linux/rbtree_augmented.h:227 mm/mmap.c:488) > [ 5818.067316] do_munmap (mm/mmap.c:3359 mm/mmap.c:2561) > [ 5818.068126] move_vma (mm/mremap.c:313) > [ 5818.069000] SyS_mremap (mm/mremap.c:446 mm/mremap.c:508 mm/mremap.c:477) > [ 5818.069839] tracesys (arch/x86/kernel/entry_64.S:542) I could easily be wrong, but I think of this one as another manifestation of the filemap.c:202 BUG_ON(page_mapped(page)) bug, whatever that is. In each case, we have a BUG or WARNING at the point where we detect that there should have been a pte in a page table, but it somehow disappeared. VM_PFNMAP in this case, an ordinary file mapping in the other case; and nothing to show in the anonymous case, there the page would just leak. Hugh