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-rw-r--r--arch/x86/mm/hugetlbpage.c21
-rw-r--r--arch/x86/mm/pageattr.c10
2 files changed, 20 insertions, 11 deletions
diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
index f6679a7..b91e485 100644
--- a/arch/x86/mm/hugetlbpage.c
+++ b/arch/x86/mm/hugetlbpage.c
@@ -56,9 +56,16 @@ static int vma_shareable(struct vm_area_struct *vma, unsigned long addr)
}
/*
- * search for a shareable pmd page for hugetlb.
+ * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc()
+ * and returns the corresponding pte. While this is not necessary for the
+ * !shared pmd case because we can allocate the pmd later as well, it makes the
+ * code much cleaner. pmd allocation is essential for the shared case because
+ * pud has to be populated inside the same i_mmap_mutex section - otherwise
+ * racing tasks could either miss the sharing (see huge_pte_offset) or select a
+ * bad pmd for sharing.
*/
-static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
+static pte_t *
+huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
{
struct vm_area_struct *vma = find_vma(mm, addr);
struct address_space *mapping = vma->vm_file->f_mapping;
@@ -68,9 +75,10 @@ static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
struct vm_area_struct *svma;
unsigned long saddr;
pte_t *spte = NULL;
+ pte_t *pte;
if (!vma_shareable(vma, addr))
- return;
+ return (pte_t *)pmd_alloc(mm, pud, addr);
mutex_lock(&mapping->i_mmap_mutex);
vma_prio_tree_foreach(svma, &iter, &mapping->i_mmap, idx, idx) {
@@ -97,7 +105,9 @@ static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
put_page(virt_to_page(spte));
spin_unlock(&mm->page_table_lock);
out:
+ pte = (pte_t *)pmd_alloc(mm, pud, addr);
mutex_unlock(&mapping->i_mmap_mutex);
+ return pte;
}
/*
@@ -142,8 +152,9 @@ pte_t *huge_pte_alloc(struct mm_struct *mm,
} else {
BUG_ON(sz != PMD_SIZE);
if (pud_none(*pud))
- huge_pmd_share(mm, addr, pud);
- pte = (pte_t *) pmd_alloc(mm, pud, addr);
+ pte = huge_pmd_share(mm, addr, pud);
+ else
+ pte = (pte_t *)pmd_alloc(mm, pud, addr);
}
}
BUG_ON(pte && !pte_none(*pte) && !pte_huge(*pte));
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 931930a..a718e0d 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -919,13 +919,11 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages,
/*
* On success we use clflush, when the CPU supports it to
- * avoid the wbindv. If the CPU does not support it, in the
- * error case, and during early boot (for EFI) we fall back
- * to cpa_flush_all (which uses wbinvd):
+ * avoid the wbindv. If the CPU does not support it and in the
+ * error case we fall back to cpa_flush_all (which uses
+ * wbindv):
*/
- if (early_boot_irqs_disabled)
- __cpa_flush_all((void *)(long)cache);
- else if (!ret && cpu_has_clflush) {
+ if (!ret && cpu_has_clflush) {
if (cpa.flags & (CPA_PAGES_ARRAY | CPA_ARRAY)) {
cpa_flush_array(addr, numpages, cache,
cpa.flags, pages);