diff options
author | Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> | 2010-05-28 00:29:21 (GMT) |
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committer | Andi Kleen <ak@linux.intel.com> | 2010-08-11 07:23:01 (GMT) |
commit | fd6a03edd271cf2d69a61aa8df98dd05fa6b9afd (patch) | |
tree | 32d3e89f1f66a3d9b68bccc88fec548acc361bf5 /mm | |
parent | 93f70f900da36fbc19c13c2aa04b2e468c8d00fb (diff) | |
download | linux-fd6a03edd271cf2d69a61aa8df98dd05fa6b9afd.tar.xz |
HWPOISON, hugetlb: detect hwpoison in hugetlb code
This patch enables to block access to hwpoisoned hugepage and
also enables to block unmapping for it.
Dependency:
"HWPOISON, hugetlb: enable error handling path for hugepage"
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Fengguang Wu <fengguang.wu@intel.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/hugetlb.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 8c163f6..4c2efc0f 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -19,6 +19,8 @@ #include <linux/sysfs.h> #include <linux/slab.h> #include <linux/rmap.h> +#include <linux/swap.h> +#include <linux/swapops.h> #include <asm/page.h> #include <asm/pgtable.h> @@ -2149,6 +2151,19 @@ nomem: return -ENOMEM; } +static int is_hugetlb_entry_hwpoisoned(pte_t pte) +{ + swp_entry_t swp; + + if (huge_pte_none(pte) || pte_present(pte)) + return 0; + swp = pte_to_swp_entry(pte); + if (non_swap_entry(swp) && is_hwpoison_entry(swp)) { + return 1; + } else + return 0; +} + void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, unsigned long end, struct page *ref_page) { @@ -2207,6 +2222,12 @@ void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, if (huge_pte_none(pte)) continue; + /* + * HWPoisoned hugepage is already unmapped and dropped reference + */ + if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) + continue; + page = pte_page(pte); if (pte_dirty(pte)) set_page_dirty(page); @@ -2491,6 +2512,18 @@ retry: } /* + * Since memory error handler replaces pte into hwpoison swap entry + * at the time of error handling, a process which reserved but not have + * the mapping to the error hugepage does not have hwpoison swap entry. + * So we need to block accesses from such a process by checking + * PG_hwpoison bit here. + */ + if (unlikely(PageHWPoison(page))) { + ret = VM_FAULT_HWPOISON; + goto backout_unlocked; + } + + /* * If we are going to COW a private mapping later, we examine the * pending reservations for this page now. This will ensure that * any allocations necessary to record that reservation occur outside @@ -2544,6 +2577,13 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, static DEFINE_MUTEX(hugetlb_instantiation_mutex); struct hstate *h = hstate_vma(vma); + ptep = huge_pte_offset(mm, address); + if (ptep) { + entry = huge_ptep_get(ptep); + if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) + return VM_FAULT_HWPOISON; + } + ptep = huge_pte_alloc(mm, address, huge_page_size(h)); if (!ptep) return VM_FAULT_OOM; |