When dealing with the speculative fault path we should use the VMA's field
cached value stored in the vm_fault structure.

Currently vm_normal_page() is using the pointer to the VMA to fetch the
vm_flags value. This patch provides a new __vm_normal_page() which is
receiving the vm_flags flags value as parameter.

Note: The speculative path is turned on for architecture providing support
for special PTE flag. So only the first block of vm_normal_page is used
during the speculative path.

Signed-off-by: Laurent Dufour <lduf...@linux.vnet.ibm.com>
---
 include/linux/mm.h |  7 +++++--
 mm/memory.c        | 18 ++++++++++--------
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index a84ddc218bbd..73b8b99f482b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1263,8 +1263,11 @@ struct zap_details {
        pgoff_t last_index;                     /* Highest page->index to unmap 
*/
 };
 
-struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
-                            pte_t pte, bool with_public_device);
+struct page *__vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
+                             pte_t pte, bool with_public_device,
+                             unsigned long vma_flags);
+#define _vm_normal_page(vma, addr, pte, with_public_device) \
+       __vm_normal_page(vma, addr, pte, with_public_device, (vma)->vm_flags)
 #define vm_normal_page(vma, addr, pte) _vm_normal_page(vma, addr, pte, false)
 
 struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
diff --git a/mm/memory.c b/mm/memory.c
index af0338fbc34d..184a0d663a76 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -826,8 +826,9 @@ static void print_bad_pte(struct vm_area_struct *vma, 
unsigned long addr,
 #else
 # define HAVE_PTE_SPECIAL 0
 #endif
-struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
-                            pte_t pte, bool with_public_device)
+struct page *__vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
+                             pte_t pte, bool with_public_device,
+                             unsigned long vma_flags)
 {
        unsigned long pfn = pte_pfn(pte);
 
@@ -836,7 +837,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, 
unsigned long addr,
                        goto check_pfn;
                if (vma->vm_ops && vma->vm_ops->find_special_page)
                        return vma->vm_ops->find_special_page(vma, addr);
-               if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
+               if (vma_flags & (VM_PFNMAP | VM_MIXEDMAP))
                        return NULL;
                if (is_zero_pfn(pfn))
                        return NULL;
@@ -868,8 +869,8 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, 
unsigned long addr,
 
        /* !HAVE_PTE_SPECIAL case follows: */
 
-       if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
-               if (vma->vm_flags & VM_MIXEDMAP) {
+       if (unlikely(vma_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
+               if (vma_flags & VM_MIXEDMAP) {
                        if (!pfn_valid(pfn))
                                return NULL;
                        goto out;
@@ -878,7 +879,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, 
unsigned long addr,
                        off = (addr - vma->vm_start) >> PAGE_SHIFT;
                        if (pfn == vma->vm_pgoff + off)
                                return NULL;
-                       if (!is_cow_mapping(vma->vm_flags))
+                       if (!is_cow_mapping(vma_flags))
                                return NULL;
                }
        }
@@ -2742,7 +2743,8 @@ static int do_wp_page(struct vm_fault *vmf)
 {
        struct vm_area_struct *vma = vmf->vma;
 
-       vmf->page = vm_normal_page(vma, vmf->address, vmf->orig_pte);
+       vmf->page = __vm_normal_page(vma, vmf->address, vmf->orig_pte, false,
+                                    vmf->vma_flags);
        if (!vmf->page) {
                /*
                 * VM_MIXEDMAP !pfn_valid() case, or VM_SOFTDIRTY clear on a
@@ -3839,7 +3841,7 @@ static int do_numa_page(struct vm_fault *vmf)
        ptep_modify_prot_commit(vma->vm_mm, vmf->address, vmf->pte, pte);
        update_mmu_cache(vma, vmf->address, vmf->pte);
 
-       page = vm_normal_page(vma, vmf->address, pte);
+       page = __vm_normal_page(vma, vmf->address, pte, false, vmf->vma_flags);
        if (!page) {
                pte_unmap_unlock(vmf->pte, vmf->ptl);
                return 0;
-- 
2.7.4

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