From 16fbdce62d9c89b794e303f4a232e4749b77e9ac Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Thu, 10 May 2012 13:01:43 -0700 Subject: [PATCH] proc/pid/pagemap: correctly report non-present ptes and holes between vmas Reset the current pagemap-entry if the 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 092b50bacd1c ("pagemap: introduce data structure for pagemap entry") Reporting for holes was broken in commit 5aaabe831eb5 ("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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 2d60492d6df8..1030a716d155 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;