Merge tag 'rproc-v4.9' of git://github.com/andersson/remoteproc

[cascardo/linux.git] / mm / mremap.c

diff --git a/mm/mremap.c b/mm/mremap.c
index 3fa0a46..da22ad2 100644 (file)
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -70,6 +70,22 @@ static pmd_t *alloc_new_pmd(struct mm_struct *mm, struct vm_area_struct *vma,
        return pmd;
 }
 
+static void take_rmap_locks(struct vm_area_struct *vma)
+{
+       if (vma->vm_file)
+               i_mmap_lock_write(vma->vm_file->f_mapping);
+       if (vma->anon_vma)
+               anon_vma_lock_write(vma->anon_vma);
+}
+
+static void drop_rmap_locks(struct vm_area_struct *vma)
+{
+       if (vma->anon_vma)
+               anon_vma_unlock_write(vma->anon_vma);
+       if (vma->vm_file)
+               i_mmap_unlock_write(vma->vm_file->f_mapping);
+}
+
 static pte_t move_soft_dirty_pte(pte_t pte)
 {
        /*
@@ -90,8 +106,6 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
                struct vm_area_struct *new_vma, pmd_t *new_pmd,
                unsigned long new_addr, bool need_rmap_locks)
 {
-       struct address_space *mapping = NULL;
-       struct anon_vma *anon_vma = NULL;
        struct mm_struct *mm = vma->vm_mm;
        pte_t *old_pte, *new_pte, pte;
        spinlock_t *old_ptl, *new_ptl;
@@ -114,16 +128,8 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
         *   serialize access to individual ptes, but only rmap traversal
         *   order guarantees that we won't miss both the old and new ptes).
         */
-       if (need_rmap_locks) {
-               if (vma->vm_file) {
-                       mapping = vma->vm_file->f_mapping;
-                       i_mmap_lock_write(mapping);
-               }
-               if (vma->anon_vma) {
-                       anon_vma = vma->anon_vma;
-                       anon_vma_lock_write(anon_vma);
-               }
-       }
+       if (need_rmap_locks)
+               take_rmap_locks(vma);
 
        /*
         * We don't have to worry about the ordering of src and dst
@@ -151,10 +157,8 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
                spin_unlock(new_ptl);
        pte_unmap(new_pte - 1);
        pte_unmap_unlock(old_pte - 1, old_ptl);
-       if (anon_vma)
-               anon_vma_unlock_write(anon_vma);
-       if (mapping)
-               i_mmap_unlock_write(mapping);
+       if (need_rmap_locks)
+               drop_rmap_locks(vma);
 }
 
 #define LATENCY_LIMIT  (64 * PAGE_SIZE)
@@ -193,25 +197,21 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
                if (pmd_trans_huge(*old_pmd)) {
                        if (extent == HPAGE_PMD_SIZE) {
                                bool moved;
-                               VM_BUG_ON_VMA(vma->vm_file || !vma->anon_vma,
-                                             vma);
                                /* See comment in move_ptes() */
                                if (need_rmap_locks)
-                                       anon_vma_lock_write(vma->anon_vma);
-                               moved = move_huge_pmd(vma, new_vma, old_addr,
-                                                   new_addr, old_end,
-                                                   old_pmd, new_pmd);
+                                       take_rmap_locks(vma);
+                               moved = move_huge_pmd(vma, old_addr, new_addr,
+                                                   old_end, old_pmd, new_pmd);
                                if (need_rmap_locks)
-                                       anon_vma_unlock_write(vma->anon_vma);
+                                       drop_rmap_locks(vma);
                                if (moved) {
                                        need_flush = true;
                                        continue;
                                }
                        }
                        split_huge_pmd(vma, old_pmd, old_addr);
-                       if (pmd_none(*old_pmd))
+                       if (pmd_trans_unstable(old_pmd))
                                continue;
-                       VM_BUG_ON(pmd_trans_huge(*old_pmd));
                }
                if (pte_alloc(new_vma->vm_mm, new_pmd, new_addr))
                        break;
@@ -502,7 +502,8 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
        if (!new_len)
                return ret;
 
-       down_write(&current->mm->mmap_sem);
+       if (down_write_killable(&current->mm->mmap_sem))
+               return -EINTR;
 
        if (flags & MREMAP_FIXED) {
                ret = mremap_to(addr, old_len, new_addr, new_len,