From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 6C6DD21164890 for ; Tue, 9 Oct 2018 06:07:56 -0700 (PDT) Date: Tue, 9 Oct 2018 15:07:54 +0200 From: Michal Hocko Subject: Re: [PATCH] mm: Preserve _PAGE_DEVMAP across mprotect() calls Message-ID: <20181009130754.GQ8528@dhcp22.suse.cz> References: <20181009101917.32497-1-jack@suse.cz> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20181009101917.32497-1-jack@suse.cz> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Jan Kara Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org, linux-nvdimm@lists.01.org List-ID: On Tue 09-10-18 12:19:17, Jan Kara wrote: > Currently _PAGE_DEVMAP bit is not preserved in mprotect(2) calls. As a > result we will see warnings such as: > > BUG: Bad page map in process JobWrk0013 pte:800001803875ea25 pmd:7624381067 > addr:00007f0930720000 vm_flags:280000f9 anon_vma: (null) mapping:ffff97f2384056f0 index:0 > file:457-000000fe00000030-00000009-000000ca-00000001_2001.fileblock fault:xfs_filemap_fault [xfs] mmap:xfs_file_mmap [xfs] readpage: (null) > CPU: 3 PID: 15848 Comm: JobWrk0013 Tainted: G W 4.12.14-2.g7573215-default #1 SLE12-SP4 (unreleased) > Hardware name: Intel Corporation S2600WFD/S2600WFD, BIOS SE5C620.86B.01.00.0833.051120182255 05/11/2018 > Call Trace: > dump_stack+0x5a/0x75 > print_bad_pte+0x217/0x2c0 > ? enqueue_task_fair+0x76/0x9f0 > _vm_normal_page+0xe5/0x100 > zap_pte_range+0x148/0x740 > unmap_page_range+0x39a/0x4b0 > unmap_vmas+0x42/0x90 > unmap_region+0x99/0xf0 > ? vma_gap_callbacks_rotate+0x1a/0x20 > do_munmap+0x255/0x3a0 > vm_munmap+0x54/0x80 > SyS_munmap+0x1d/0x30 > do_syscall_64+0x74/0x150 > entry_SYSCALL_64_after_hwframe+0x3d/0xa2 > ... > > when mprotect(2) gets used on DAX mappings. Also there is a wide variety > of other failures that can result from the missing _PAGE_DEVMAP flag > when the area gets used by get_user_pages() later. > > Fix the problem by including _PAGE_DEVMAP in a set of flags that get > preserved by mprotect(2). > > Fixes: 69660fd797c3 ("x86, mm: introduce _PAGE_DEVMAP") > Fixes: ebd31197931d ("powerpc/mm: Add devmap support for ppc64") > CC: stable@vger.kernel.org > Signed-off-by: Jan Kara Acked-by: Michal Hocko > --- > arch/powerpc/include/asm/book3s/64/pgtable.h | 4 ++-- > arch/x86/include/asm/pgtable_types.h | 2 +- > 2 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h > index 2fdc865ca374..2a2486526d1f 100644 > --- a/arch/powerpc/include/asm/book3s/64/pgtable.h > +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h > @@ -114,7 +114,7 @@ > */ > #define _HPAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \ > _PAGE_ACCESSED | H_PAGE_THP_HUGE | _PAGE_PTE | \ > - _PAGE_SOFT_DIRTY) > + _PAGE_SOFT_DIRTY | _PAGE_DEVMAP) > /* > * user access blocked by key > */ > @@ -132,7 +132,7 @@ > */ > #define _PAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \ > _PAGE_ACCESSED | _PAGE_SPECIAL | _PAGE_PTE | \ > - _PAGE_SOFT_DIRTY) > + _PAGE_SOFT_DIRTY | _PAGE_DEVMAP) > > #define H_PTE_PKEY (H_PTE_PKEY_BIT0 | H_PTE_PKEY_BIT1 | H_PTE_PKEY_BIT2 | \ > H_PTE_PKEY_BIT3 | H_PTE_PKEY_BIT4) > diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h > index b64acb08a62b..106b7d0e2dae 100644 > --- a/arch/x86/include/asm/pgtable_types.h > +++ b/arch/x86/include/asm/pgtable_types.h > @@ -124,7 +124,7 @@ > */ > #define _PAGE_CHG_MASK (PTE_PFN_MASK | _PAGE_PCD | _PAGE_PWT | \ > _PAGE_SPECIAL | _PAGE_ACCESSED | _PAGE_DIRTY | \ > - _PAGE_SOFT_DIRTY) > + _PAGE_SOFT_DIRTY | _PAGE_DEVMAP) > #define _HPAGE_CHG_MASK (_PAGE_CHG_MASK | _PAGE_PSE) > > /* > -- > 2.16.4 -- Michal Hocko SUSE Labs _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm