mm: thp: correct split_huge_pages file permission

[deliverable/linux.git] / mm / huge_memory.c

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 86f9f8b82f8ecfc47b92554e3a82501346b0fcb8..f7daa7de8f4867dc871edb8ea3a1ec6189e4d54f 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -232,7 +232,7 @@ retry:
        return READ_ONCE(huge_zero_page);
 }
 
-static void put_huge_zero_page(void)
+void put_huge_zero_page(void)
 {
        /*
         * Counter should never go to zero here. Only shrinker can put
@@ -1684,12 +1684,12 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
        if (vma_is_dax(vma)) {
                spin_unlock(ptl);
                if (is_huge_zero_pmd(orig_pmd))
-                       put_huge_zero_page();
+                       tlb_remove_page(tlb, pmd_page(orig_pmd));
        } else if (is_huge_zero_pmd(orig_pmd)) {
                pte_free(tlb->mm, pgtable_trans_huge_withdraw(tlb->mm, pmd));
                atomic_long_dec(&tlb->mm->nr_ptes);
                spin_unlock(ptl);
-               put_huge_zero_page();
+               tlb_remove_page(tlb, pmd_page(orig_pmd));
        } else {
                struct page *page = pmd_page(orig_pmd);
                page_remove_rmap(page, true);
@@ -1960,10 +1960,9 @@ int khugepaged_enter_vma_merge(struct vm_area_struct *vma,
                 * page fault if needed.
                 */
                return 0;
-       if (vma->vm_ops)
+       if (vma->vm_ops || (vm_flags & VM_NO_THP))
                /* khugepaged not yet working on file or special mappings */
                return 0;
-       VM_BUG_ON_VMA(vm_flags & VM_NO_THP, vma);
        hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
        hend = vma->vm_end & HPAGE_PMD_MASK;
        if (hstart < hend)
@@ -2352,8 +2351,7 @@ static bool hugepage_vma_check(struct vm_area_struct *vma)
                return false;
        if (is_vma_temporary_stack(vma))
                return false;
-       VM_BUG_ON_VMA(vma->vm_flags & VM_NO_THP, vma);
-       return true;
+       return !(vma->vm_flags & VM_NO_THP);
 }
 
 static void collapse_huge_page(struct mm_struct *mm,
@@ -3454,7 +3452,7 @@ next:
                }
        }
 
-       pr_info("%lu of %lu THP split", split, total);
+       pr_info("%lu of %lu THP split\n", split, total);
 
        return 0;
 }
@@ -3465,7 +3463,7 @@ static int __init split_huge_pages_debugfs(void)
 {
        void *ret;
 
-       ret = debugfs_create_file("split_huge_pages", 0644, NULL, NULL,
+       ret = debugfs_create_file("split_huge_pages", 0200, NULL, NULL,
                        &split_huge_pages_fops);
        if (!ret)
                pr_warn("Failed to create split_huge_pages in debugfs");