Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751870AbcDXEGS (ORCPT ); Sun, 24 Apr 2016 00:06:18 -0400 Received: from e23smtp04.au.ibm.com ([202.81.31.146]:38760 "EHLO e23smtp04.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751425AbcDXEGR (ORCPT ); Sun, 24 Apr 2016 00:06:17 -0400 X-IBM-Helo: d23dlp02.au.ibm.com X-IBM-MailFrom: xyjxie@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org From: Yongji Xie To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: akpm@linux-foundation.org, kirill.shutemov@linux.intel.com, jmarchan@redhat.com, mingo@kernel.org, vbabka@suse.cz, dave.hansen@linux.intel.com, dan.j.williams@intel.com, matthew.r.wilcox@intel.com, aarcange@redhat.com, mhocko@suse.com, luto@kernel.org, dahi@linux.vnet.ibm.com, Yongji Xie Subject: [PATCH v2] mm: fix incorrect pfn passed to untrack_pfn() in remap_pfn_range() Date: Sun, 24 Apr 2016 12:01:41 +0800 Message-Id: <1461470501-5044-1-git-send-email-xyjxie@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.1 X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16042404-0013-0000-0000-000004E91D4A Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1447 Lines: 54 We use generic hooks in remap_pfn_range() to help archs to track pfnmap regions. The code is something like: int remap_pfn_range() { ... track_pfn_remap(vma, &prot, pfn, addr, PAGE_ALIGN(size)); ... pfn -= addr >> PAGE_SHIFT; ... untrack_pfn(vma, pfn, PAGE_ALIGN(size)); ... } Here we can easily find the pfn is changed but not recovered before untrack_pfn() is called. That's incorrect. Signed-off-by: Yongji Xie --- mm/memory.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 098f00d..eee75ed 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1711,6 +1711,7 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, unsigned long next; unsigned long end = addr + PAGE_ALIGN(size); struct mm_struct *mm = vma->vm_mm; + unsigned long remap_pfn = pfn; int err; /* @@ -1737,7 +1738,7 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, vma->vm_pgoff = pfn; } - err = track_pfn_remap(vma, &prot, pfn, addr, PAGE_ALIGN(size)); + err = track_pfn_remap(vma, &prot, remap_pfn, addr, PAGE_ALIGN(size)); if (err) return -EINVAL; @@ -1756,7 +1757,7 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, } while (pgd++, addr = next, addr != end); if (err) - untrack_pfn(vma, pfn, PAGE_ALIGN(size)); + untrack_pfn(vma, remap_pfn, PAGE_ALIGN(size)); return err; } -- 1.7.9.5