From patchwork Tue Sep 6 16:49:36 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 9317585 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 5E382601C0 for ; Tue, 6 Sep 2016 16:52:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 56D7728DF1 for ; Tue, 6 Sep 2016 16:52:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4B19A28DFC; Tue, 6 Sep 2016 16:52:57 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RDNS_NONE autolearn=no version=3.3.1 Received: from ml01.01.org (unknown [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id D255728DF1 for ; Tue, 6 Sep 2016 16:52:55 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id B697B1A1E6C; Tue, 6 Sep 2016 09:52:38 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) (using TLSv1 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 44B081A1E6C for ; Tue, 6 Sep 2016 09:52:37 -0700 (PDT) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga101.jf.intel.com with ESMTP; 06 Sep 2016 09:52:37 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos; i="5.30,292,1470726000"; d="scan'208"; a="1052147348" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.14]) by fmsmga002.fm.intel.com with ESMTP; 06 Sep 2016 09:52:35 -0700 Subject: [PATCH 3/5] mm: fix show_smap() for zone_device-pmd ranges From: Dan Williams To: linux-nvdimm@lists.01.org Date: Tue, 06 Sep 2016 09:49:36 -0700 Message-ID: <147318057623.30325.10495460878595242707.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <147318056046.30325.5100892122988191500.stgit@dwillia2-desk3.amr.corp.intel.com> References: <147318056046.30325.5100892122988191500.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-9-g687f MIME-Version: 1.0 X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-mm@kvack.org, akpm@linux-foundation.org, "Kirill A. Shutemov" , linux-kernel@vger.kernel.org Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP Attempting to dump /proc//smaps for a process with pmd dax mappings currently results in the following VM_BUG_ONs: kernel BUG at mm/huge_memory.c:1105! task: ffff88045f16b140 task.stack: ffff88045be14000 RIP: 0010:[] [] follow_trans_huge_pmd+0x2cb/0x340 [..] Call Trace: [] smaps_pte_range+0xa0/0x4b0 [] ? vsnprintf+0x255/0x4c0 [] __walk_page_range+0x1fe/0x4d0 [] walk_page_vma+0x62/0x80 [] show_smap+0xa6/0x2b0 kernel BUG at fs/proc/task_mmu.c:585! RIP: 0010:[] [] smaps_pte_range+0x499/0x4b0 Call Trace: [] ? vsnprintf+0x255/0x4c0 [] __walk_page_range+0x1fe/0x4d0 [] walk_page_vma+0x62/0x80 [] show_smap+0xa6/0x2b0 These locations are sanity checking page flags that must be set for an anonymous transparent huge page, but are not set for the zone_device pages associated with dax mappings. Cc: Ross Zwisler Cc: Kirill A. Shutemov Cc: Andrew Morton Signed-off-by: Dan Williams Acked-by: Andrew Morton --- fs/proc/task_mmu.c | 2 ++ mm/huge_memory.c | 4 ++-- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 187d84ef9de9..f6fa99eca515 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -581,6 +581,8 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, mss->anonymous_thp += HPAGE_PMD_SIZE; else if (PageSwapBacked(page)) mss->shmem_thp += HPAGE_PMD_SIZE; + else if (is_zone_device_page(page)) + /* pass */; else VM_BUG_ON_PAGE(1, page); smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd)); diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 2db2112aa31e..a6abd76baa72 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1078,7 +1078,7 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, goto out; page = pmd_page(*pmd); - VM_BUG_ON_PAGE(!PageHead(page), page); + VM_BUG_ON_PAGE(!PageHead(page) && !is_zone_device_page(page), page); if (flags & FOLL_TOUCH) touch_pmd(vma, addr, pmd); if ((flags & FOLL_MLOCK) && (vma->vm_flags & VM_LOCKED)) { @@ -1116,7 +1116,7 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, } skip_mlock: page += (addr & ~HPAGE_PMD_MASK) >> PAGE_SHIFT; - VM_BUG_ON_PAGE(!PageCompound(page), page); + VM_BUG_ON_PAGE(!PageCompound(page) && !is_zone_device_page(page), page); if (flags & FOLL_GET) get_page(page);