From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754295Ab2D1QWh (ORCPT ); Sat, 28 Apr 2012 12:22:37 -0400 Received: from mail-lpp01m010-f46.google.com ([209.85.215.46]:44023 "EHLO mail-lpp01m010-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752090Ab2D1QWg (ORCPT ); Sat, 28 Apr 2012 12:22:36 -0400 Subject: [PATCH bugfix] proc/pagemap: correctly report non-present ptes and holes between vmas To: Andrew Morton From: Konstantin Khlebnikov Cc: Andi Kleen , Pavel Emelyanov , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Naoya Horiguchi , KAMEZAWA Hiroyuki Date: Sat, 28 Apr 2012 20:22:30 +0400 Message-ID: <20120428162229.15658.56316.stgit@zurg> User-Agent: StGit/0.15 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch resets current pagemap-entry if current pte isn't present, or if current vma is over. Otherwise pagemap reports last entry again and again. non-present pte reporting was broken in commit v3.3-3738-g092b50b ("pagemap: introduce data structure for pagemap entry") reporting for holes was broken in commit v3.3-3734-g5aaabe8 ("pagemap: avoid splitting thp when reading /proc/pid/pagemap") Signed-off-by: Konstantin Khlebnikov Reported-by: Pavel Emelyanov Cc: Naoya Horiguchi Cc: KAMEZAWA Hiroyuki Cc: Andi Kleen --- fs/proc/task_mmu.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index a580c69..9f9c033 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -747,6 +747,8 @@ static void pte_to_pagemap_entry(pagemap_entry_t *pme, pte_t pte) else if (pte_present(pte)) *pme = make_pme(PM_PFRAME(pte_pfn(pte)) | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT); + else + *pme = make_pme(PM_NOT_PRESENT); } #ifdef CONFIG_TRANSPARENT_HUGEPAGE @@ -761,6 +763,8 @@ static void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme, if (pmd_present(pmd)) *pme = make_pme(PM_PFRAME(pmd_pfn(pmd) + offset) | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT); + else + *pme = make_pme(PM_NOT_PRESENT); } #else static inline void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme, @@ -801,8 +805,10 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, /* check to see if we've left 'vma' behind * and need a new, higher one */ - if (vma && (addr >= vma->vm_end)) + if (vma && (addr >= vma->vm_end)) { vma = find_vma(walk->mm, addr); + pme = make_pme(PM_NOT_PRESENT); + } /* check that 'vma' actually covers this address, * and that it isn't a huge page vma */ @@ -830,6 +836,8 @@ static void huge_pte_to_pagemap_entry(pagemap_entry_t *pme, if (pte_present(pte)) *pme = make_pme(PM_PFRAME(pte_pfn(pte) + offset) | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT); + else + *pme = make_pme(PM_NOT_PRESENT); } /* This function walks within one hugetlb entry in the single call */ @@ -839,7 +847,7 @@ static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask, { struct pagemapread *pm = walk->private; int err = 0; - pagemap_entry_t pme = make_pme(PM_NOT_PRESENT); + pagemap_entry_t pme; for (; addr != end; addr += PAGE_SIZE) { int offset = (addr & ~hmask) >> PAGE_SHIFT;