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-rw-r--r--arch/arm/mm/fault-armv.c28
1 files changed, 26 insertions, 2 deletions
diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c
index c493d72..83e59f8 100644
--- a/arch/arm/mm/fault-armv.c
+++ b/arch/arm/mm/fault-armv.c
@@ -66,6 +66,30 @@ static int do_adjust_pte(struct vm_area_struct *vma, unsigned long address,
return ret;
}
+#if USE_SPLIT_PTLOCKS
+/*
+ * If we are using split PTE locks, then we need to take the page
+ * lock here. Otherwise we are using shared mm->page_table_lock
+ * which is already locked, thus cannot take it.
+ */
+static inline void do_pte_lock(spinlock_t *ptl)
+{
+ /*
+ * Use nested version here to indicate that we are already
+ * holding one similar spinlock.
+ */
+ spin_lock_nested(ptl, SINGLE_DEPTH_NESTING);
+}
+
+static inline void do_pte_unlock(spinlock_t *ptl)
+{
+ spin_unlock(ptl);
+}
+#else /* !USE_SPLIT_PTLOCKS */
+static inline void do_pte_lock(spinlock_t *ptl) {}
+static inline void do_pte_unlock(spinlock_t *ptl) {}
+#endif /* USE_SPLIT_PTLOCKS */
+
static int adjust_pte(struct vm_area_struct *vma, unsigned long address,
unsigned long pfn)
{
@@ -90,11 +114,11 @@ static int adjust_pte(struct vm_area_struct *vma, unsigned long address,
*/
ptl = pte_lockptr(vma->vm_mm, pmd);
pte = pte_offset_map(pmd, address);
- spin_lock(ptl);
+ do_pte_lock(ptl);
ret = do_adjust_pte(vma, address, pfn, pte);
- spin_unlock(ptl);
+ do_pte_unlock(ptl);
pte_unmap(pte);
return ret;
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