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| author | Andi Kleen <ak@linux.intel.com> | 2010-10-06 23:45:00 +0400 |
|---|---|---|
| committer | Andi Kleen <ak@linux.intel.com> | 2010-10-08 11:32:46 +0400 |
| commit | aa50d3a7aa8147b9e14dc9d5972a5d2359db4ef8 (patch) | |
| tree | 68fae5060333dcc24c17e9dd00a87bd760d883e9 /mm/hugetlb.c | |
| parent | 6f39ce056ab2ab2d29b2fae4aed61ed0b485972f (diff) | |
| download | linux-aa50d3a7aa8147b9e14dc9d5972a5d2359db4ef8.tar.xz | |
Encode huge page size for VM_FAULT_HWPOISON errors
This fixes a problem introduced with the hugetlb hwpoison handling
The user space SIGBUS signalling wants to know the size of the hugepage
that caused a HWPOISON fault.
Unfortunately the architecture page fault handlers do not have easy
access to the struct page.
Pass the information out in the fault error code instead.
I added a separate VM_FAULT_HWPOISON_LARGE bit for this case and encode
the hpage index in some free upper bits of the fault code. The small
page hwpoison keeps stays with the VM_FAULT_HWPOISON name to minimize
changes.
Also add code to hugetlb.h to convert that index into a page shift.
Will be used in a further patch.
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: fengguang.wu@intel.com
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Diffstat (limited to 'mm/hugetlb.c')
| -rw-r--r-- | mm/hugetlb.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 67cd03239b75..96991ded82fe 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2589,7 +2589,8 @@ retry: * So we need to block hugepage fault by PG_hwpoison bit check. */ if (unlikely(PageHWPoison(page))) { - ret = VM_FAULT_HWPOISON; + ret = VM_FAULT_HWPOISON | + VM_FAULT_SET_HINDEX(h - hstates); goto backout_unlocked; } page_dup_rmap(page); @@ -2656,7 +2657,8 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, migration_entry_wait(mm, (pmd_t *)ptep, address); return 0; } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) - return VM_FAULT_HWPOISON; + return VM_FAULT_HWPOISON_LARGE | + VM_FAULT_SET_HINDEX(h - hstates); } ptep = huge_pte_alloc(mm, address, huge_page_size(h)); |