vm: add VM_FAULT_SIGSEGV handling support

[pandora-kernel.git] / mm / huge_memory.c

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 8f005e9..79166c2 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -682,7 +682,7 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
        if (haddr >= vma->vm_start && haddr + HPAGE_PMD_SIZE <= vma->vm_end) {
                if (unlikely(anon_vma_prepare(vma)))
                        return VM_FAULT_OOM;
-               if (unlikely(khugepaged_enter(vma)))
+               if (unlikely(khugepaged_enter(vma, vma->vm_flags)))
                        return VM_FAULT_OOM;
                page = alloc_hugepage_vma(transparent_hugepage_defrag(vma),
                                          vma, haddr, numa_node_id(), 0);
@@ -921,6 +921,8 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
                count_vm_event(THP_FAULT_FALLBACK);
                ret = do_huge_pmd_wp_page_fallback(mm, vma, address,
                                                   pmd, orig_pmd, page, haddr);
+               if (ret & VM_FAULT_OOM)
+                       split_huge_page(page);
                put_page(page);
                goto out;
        }
@@ -928,6 +930,7 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
 
        if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
                put_page(new_page);
+               split_huge_page(page);
                put_page(page);
                ret |= VM_FAULT_OOM;
                goto out;
@@ -1490,7 +1493,7 @@ int hugepage_madvise(struct vm_area_struct *vma,
                 * register it here without waiting a page fault that
                 * may not happen any time soon.
                 */
-               if (unlikely(khugepaged_enter_vma_merge(vma)))
+               if (unlikely(khugepaged_enter_vma_merge(vma, *vm_flags)))
                        return -ENOMEM;
                break;
        case MADV_NOHUGEPAGE:
@@ -1622,7 +1625,8 @@ int __khugepaged_enter(struct mm_struct *mm)
        return 0;
 }
 
-int khugepaged_enter_vma_merge(struct vm_area_struct *vma)
+int khugepaged_enter_vma_merge(struct vm_area_struct *vma,
+                              unsigned long vm_flags)
 {
        unsigned long hstart, hend;
        if (!vma->anon_vma)
@@ -1638,11 +1642,11 @@ int khugepaged_enter_vma_merge(struct vm_area_struct *vma)
         * If is_pfn_mapping() is true is_learn_pfn_mapping() must be
         * true too, verify it here.
         */
-       VM_BUG_ON(is_linear_pfn_mapping(vma) || vma->vm_flags & VM_NO_THP);
+       VM_BUG_ON(is_linear_pfn_mapping(vma) || vm_flags & VM_NO_THP);
        hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
        hend = vma->vm_end & HPAGE_PMD_MASK;
        if (hstart < hend)
-               return khugepaged_enter(vma);
+               return khugepaged_enter(vma, vm_flags);
        return 0;
 }
 
@@ -1879,6 +1883,8 @@ static void collapse_huge_page(struct mm_struct *mm,
                goto out;
 
        vma = find_vma(mm, address);
+       if (!vma)
+               goto out;
        hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
        hend = vma->vm_end & HPAGE_PMD_MASK;
        if (address < hstart || address + HPAGE_PMD_SIZE > hend)
@@ -1934,7 +1940,12 @@ static void collapse_huge_page(struct mm_struct *mm,
                pte_unmap(pte);
                spin_lock(&mm->page_table_lock);
                BUG_ON(!pmd_none(*pmd));
-               set_pmd_at(mm, address, pmd, _pmd);
+               /*
+                * We can only use set_pmd_at when establishing
+                * hugepmds and never for establishing regular pmds that
+                * points to regular pagetables. Use pmd_populate for that
+                */
+               pmd_populate(mm, pmd, pmd_pgtable(_pmd));
                spin_unlock(&mm->page_table_lock);
                anon_vma_unlock(vma->anon_vma);
                goto out;