mm: use mm_populate() for mremap() of VM_LOCKED vmas

Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: Greg Ungerer <gregungerer@westnet.com.au>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 13 insertions, 12 deletions

diff --git a/mm/mremap.c b/mm/mremap.c
index f9766f460299..ebe27a8efa62 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -209,7 +209,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
 
 static unsigned long move_vma(struct vm_area_struct *vma,
                 unsigned long old_addr, unsigned long old_len,
-                unsigned long new_len, unsigned long new_addr)
+                unsigned long new_len, unsigned long new_addr, bool *locked)
 {
         struct mm_struct *mm = vma->vm_mm;
         struct vm_area_struct *new_vma;
@@ -300,9 +300,7 @@ static unsigned long move_vma(struct vm_area_struct *vma,
 
         if (vm_flags & VM_LOCKED) {
                 mm->locked_vm += new_len >> PAGE_SHIFT;
-                if (new_len > old_len)
-                        mlock_vma_pages_range(new_vma, new_addr + old_len,
-                                                       new_addr + new_len);
+                *locked = true;
         }
 
         return new_addr;
@@ -367,9 +365,8 @@ Eagain:
         return ERR_PTR(-EAGAIN);
 }
 
-static unsigned long mremap_to(unsigned long addr,
-        unsigned long old_len, unsigned long new_addr,
-        unsigned long new_len)
+static unsigned long mremap_to(unsigned long addr, unsigned long old_len,
+                unsigned long new_addr, unsigned long new_len, bool *locked)
 {
         struct mm_struct *mm = current->mm;
         struct vm_area_struct *vma;
@@ -419,7 +416,7 @@ static unsigned long mremap_to(unsigned long addr,
         if (ret & ~PAGE_MASK)
                 goto out1;
 
-        ret = move_vma(vma, addr, old_len, new_len, new_addr);
+        ret = move_vma(vma, addr, old_len, new_len, new_addr, locked);
         if (!(ret & ~PAGE_MASK))
                 goto out;
 out1:
@@ -457,6 +454,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
         struct vm_area_struct *vma;
         unsigned long ret = -EINVAL;
         unsigned long charged = 0;
+        bool locked = false;
 
         down_write(&current->mm->mmap_sem);
 
@@ -479,7 +477,8 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
 
         if (flags & MREMAP_FIXED) {
                 if (flags & MREMAP_MAYMOVE)
-                        ret = mremap_to(addr, old_len, new_addr, new_len);
+                        ret = mremap_to(addr, old_len, new_addr, new_len,
+                                        &locked);
                 goto out;
         }
 
@@ -521,8 +520,8 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
                         vm_stat_account(mm, vma->vm_flags, vma->vm_file, pages);
                         if (vma->vm_flags & VM_LOCKED) {
                                 mm->locked_vm += pages;
-                                mlock_vma_pages_range(vma, addr + old_len,
-                                                   addr + new_len);
+                                locked = true;
+                                new_addr = addr;
                         }
                         ret = addr;
                         goto out;
@@ -548,11 +547,13 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
                         goto out;
                 }
 
-                ret = move_vma(vma, addr, old_len, new_len, new_addr);
+                ret = move_vma(vma, addr, old_len, new_len, new_addr, &locked);
         }
 out:
         if (ret & ~PAGE_MASK)
                 vm_unacct_memory(charged);
         up_write(&current->mm->mmap_sem);
+        if (locked && new_len > old_len)
+                mm_populate(new_addr + old_len, new_len - old_len);
         return ret;
 }