From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C315C282CE for ; Wed, 24 Apr 2019 17:43:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5975A2064A for ; Wed, 24 Apr 2019 17:43:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556127780; bh=tqkGpJGwOVo6XQncQffXaW5+FEV12kvcQdDx5u1IYUQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=cJ7DAUDyFxopgVDesNdE0uhgr8QXg/YMv6XQlWqdqQ7y7MRq9PKqbFxmF5rlrIC5F HBwCjzXIYot6prv990eKOC9UUv2j95LIgpkXV2lu7lvnnyxZLRRAGQ3vPVAvA7NREQ lDlVS5u0vDIG6sEdzYdGH4nwr6fqVImqh27UgJIA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391531AbfDXRff (ORCPT ); Wed, 24 Apr 2019 13:35:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:34354 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391886AbfDXRf2 (ORCPT ); Wed, 24 Apr 2019 13:35:28 -0400 Received: from localhost (62-193-50-229.as16211.net [62.193.50.229]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B07B42054F; Wed, 24 Apr 2019 17:35:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556127327; bh=tqkGpJGwOVo6XQncQffXaW5+FEV12kvcQdDx5u1IYUQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tpn4RD159eIDoKZ/wVZUT8zCccHunLVo7yYBBOtA1iwWWyhEYP7Lx3e5Dr0geTW8h 1lkvaGq1tmveSi8V3lald+uMObhtQ9vSanCIYLAzQvMSX6iz6rfMc6DWbdAI/gTT+0 AlvA8eQ1avrKVkhS76bI6Qx23QNr3LJQpRi4f27M= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Kara , "Aneesh Kumar K.V" , Dan Williams Subject: [PATCH 5.0 049/115] fs/dax: Deposit pagetable even when installing zero page Date: Wed, 24 Apr 2019 19:09:45 +0200 Message-Id: <20190424170927.876092256@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190424170924.797924502@linuxfoundation.org> References: <20190424170924.797924502@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Aneesh Kumar K.V commit 11cf9d863dcb583345723b0ed72173348761e9c0 upstream. Architectures like ppc64 use the deposited page table to store hardware page table slot information. Make sure we deposit a page table when using zero page at the pmd level for hash. Without this we hit Unable to handle kernel paging request for data at address 0x00000000 Faulting instruction address: 0xc000000000082a74 Oops: Kernel access of bad area, sig: 11 [#1] .... NIP [c000000000082a74] __hash_page_thp+0x224/0x5b0 LR [c0000000000829a4] __hash_page_thp+0x154/0x5b0 Call Trace: hash_page_mm+0x43c/0x740 do_hash_page+0x2c/0x3c copy_from_iter_flushcache+0xa4/0x4a0 pmem_copy_from_iter+0x2c/0x50 [nd_pmem] dax_copy_from_iter+0x40/0x70 dax_iomap_actor+0x134/0x360 iomap_apply+0xfc/0x1b0 dax_iomap_rw+0xac/0x130 ext4_file_write_iter+0x254/0x460 [ext4] __vfs_write+0x120/0x1e0 vfs_write+0xd8/0x220 SyS_write+0x6c/0x110 system_call+0x3c/0x130 Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions") Cc: Reviewed-by: Jan Kara Signed-off-by: Aneesh Kumar K.V Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman --- fs/dax.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) --- a/fs/dax.c +++ b/fs/dax.c @@ -33,6 +33,7 @@ #include #include #include +#include #include "internal.h" #define CREATE_TRACE_POINTS @@ -1409,7 +1410,9 @@ static vm_fault_t dax_pmd_load_hole(stru { struct address_space *mapping = vmf->vma->vm_file->f_mapping; unsigned long pmd_addr = vmf->address & PMD_MASK; + struct vm_area_struct *vma = vmf->vma; struct inode *inode = mapping->host; + pgtable_t pgtable = NULL; struct page *zero_page; spinlock_t *ptl; pmd_t pmd_entry; @@ -1424,12 +1427,22 @@ static vm_fault_t dax_pmd_load_hole(stru *entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn, DAX_PMD | DAX_ZERO_PAGE, false); + if (arch_needs_pgtable_deposit()) { + pgtable = pte_alloc_one(vma->vm_mm); + if (!pgtable) + return VM_FAULT_OOM; + } + ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd); if (!pmd_none(*(vmf->pmd))) { spin_unlock(ptl); goto fallback; } + if (pgtable) { + pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable); + mm_inc_nr_ptes(vma->vm_mm); + } pmd_entry = mk_pmd(zero_page, vmf->vma->vm_page_prot); pmd_entry = pmd_mkhuge(pmd_entry); set_pmd_at(vmf->vma->vm_mm, pmd_addr, vmf->pmd, pmd_entry); @@ -1438,6 +1451,8 @@ static vm_fault_t dax_pmd_load_hole(stru return VM_FAULT_NOPAGE; fallback: + if (pgtable) + pte_free(vma->vm_mm, pgtable); trace_dax_pmd_load_hole_fallback(inode, vmf, zero_page, *entry); return VM_FAULT_FALLBACK; }