This is needed because in handle_pte_fault() pte_offset_map() is called and then fe->ptl is fetched and spin_locked.
This was previously embedded in the call to pte_offset_map_lock(). Signed-off-by: Laurent Dufour <[email protected]> --- mm/memory.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index bce32c9d73c2..441c0e3f3a0f 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2100,6 +2100,13 @@ static inline void wp_page_reuse(struct vm_fault *vmf) pte_unmap_unlock(vmf->pte, vmf->ptl); } +static bool pte_spinlock(struct vm_fault *vmf) +{ + vmf->ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd); + spin_lock(vmf->ptl); + return true; +} + static bool pte_map_lock(struct vm_fault *vmf) { vmf->pte = pte_offset_map_lock(vmf->vma->vm_mm, vmf->pmd, vmf->address, &vmf->ptl); @@ -3398,8 +3405,8 @@ static int do_numa_page(struct vm_fault *vmf) * page table entry is not accessible, so there would be no * concurrent hardware modifications to the PTE. */ - vmf->ptl = pte_lockptr(vma->vm_mm, vmf->pmd); - spin_lock(vmf->ptl); + if (!pte_spinlock(vmf)) + return VM_FAULT_RETRY; if (unlikely(!pte_same(*vmf->pte, pte))) { pte_unmap_unlock(vmf->pte, vmf->ptl); goto out; @@ -3566,8 +3573,8 @@ static int handle_pte_fault(struct vm_fault *vmf) if (pte_protnone(vmf->orig_pte) && vma_is_accessible(vmf->vma)) return do_numa_page(vmf); - vmf->ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd); - spin_lock(vmf->ptl); + if (!pte_spinlock(vmf)) + return VM_FAULT_RETRY; entry = vmf->orig_pte; if (unlikely(!pte_same(*vmf->pte, entry))) goto unlock; -- 2.7.4
