1 files changed, 31 insertions, 15 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index 13d16a2b7623..1cec28d20583 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -176,7 +176,7 @@ static struct vm_area_struct *remove_vma(struct vm_area_struct *vma)
         return next;
 }
 
-static int do_brk(unsigned long addr, unsigned long len);
+static int do_brk(unsigned long addr, unsigned long len, struct list_head *uf);
 
 SYSCALL_DEFINE1(brk, unsigned long, brk)
 {
@@ -185,6 +185,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
         struct mm_struct *mm = current->mm;
         unsigned long min_brk;
         bool populate;
+        LIST_HEAD(uf);
 
         if (down_write_killable(&mm->mmap_sem))
                 return -EINTR;
@@ -222,7 +223,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
 
         /* Always allow shrinking brk. */
         if (brk <= mm->brk) {
-                if (!do_munmap(mm, newbrk, oldbrk-newbrk))
+                if (!do_munmap(mm, newbrk, oldbrk-newbrk, &uf))
                         goto set_brk;
                 goto out;
         }
@@ -232,13 +233,14 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
                 goto out;
 
         /* Ok, looks good - let it rip. */
-        if (do_brk(oldbrk, newbrk-oldbrk) < 0)
+        if (do_brk(oldbrk, newbrk-oldbrk, &uf) < 0)
                 goto out;
 
 set_brk:
         mm->brk = brk;
         populate = newbrk > oldbrk && (mm->def_flags & VM_LOCKED) != 0;
         up_write(&mm->mmap_sem);
+        userfaultfd_unmap_complete(mm, &uf);
         if (populate)
                 mm_populate(oldbrk, newbrk - oldbrk);
         return brk;
@@ -1304,7 +1306,8 @@ static inline int mlock_future_check(struct mm_struct *mm,
 unsigned long do_mmap(struct file *file, unsigned long addr,
                         unsigned long len, unsigned long prot,
                         unsigned long flags, vm_flags_t vm_flags,
-                        unsigned long pgoff, unsigned long *populate)
+                        unsigned long pgoff, unsigned long *populate,
+                        struct list_head *uf)
 {
         struct mm_struct *mm = current->mm;
         int pkey = 0;
@@ -1447,7 +1450,7 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
                         vm_flags |= VM_NORESERVE;
         }
 
-        addr = mmap_region(file, addr, len, vm_flags, pgoff);
+        addr = mmap_region(file, addr, len, vm_flags, pgoff, uf);
         if (!IS_ERR_VALUE(addr) &&
             ((vm_flags & VM_LOCKED) ||
              (flags & (MAP_POPULATE | MAP_NONBLOCK)) == MAP_POPULATE))
@@ -1583,7 +1586,8 @@ static inline int accountable_mapping(struct file *file, vm_flags_t vm_flags)
 }
 
 unsigned long mmap_region(struct file *file, unsigned long addr,
-                unsigned long len, vm_flags_t vm_flags, unsigned long pgoff)
+                unsigned long len, vm_flags_t vm_flags, unsigned long pgoff,
+                struct list_head *uf)
 {
         struct mm_struct *mm = current->mm;
         struct vm_area_struct *vma, *prev;
@@ -1609,7 +1613,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
         /* Clear old maps */
         while (find_vma_links(mm, addr, addr + len, &prev, &rb_link,
                               &rb_parent)) {
-                if (do_munmap(mm, addr, len))
+                if (do_munmap(mm, addr, len, uf))
                         return -ENOMEM;
         }
 
@@ -2579,7 +2583,8 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
  * work.  This now handles partial unmappings.
  * Jeremy Fitzhardinge <jeremy@goop.org>
  */
-int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
+int do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
+              struct list_head *uf)
 {
         unsigned long end;
         struct vm_area_struct *vma, *prev, *last;
@@ -2603,6 +2608,13 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
         if (vma->vm_start >= end)
                 return 0;
 
+        if (uf) {
+                int error = userfaultfd_unmap_prep(vma, start, end, uf);
+
+                if (error)
+                        return error;
+        }
+
         /*
          * If we need to split any vma, do it now to save pain later.
          *
@@ -2668,12 +2680,14 @@ int vm_munmap(unsigned long start, size_t len)
 {
         int ret;
         struct mm_struct *mm = current->mm;
+        LIST_HEAD(uf);
 
         if (down_write_killable(&mm->mmap_sem))
                 return -EINTR;
 
-        ret = do_munmap(mm, start, len);
+        ret = do_munmap(mm, start, len, &uf);
         up_write(&mm->mmap_sem);
+        userfaultfd_unmap_complete(mm, &uf);
         return ret;
 }
 EXPORT_SYMBOL(vm_munmap);
@@ -2773,7 +2787,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
 
         file = get_file(vma->vm_file);
         ret = do_mmap_pgoff(vma->vm_file, start, size,
-                        prot, flags, pgoff, &populate);
+                        prot, flags, pgoff, &populate, NULL);
         fput(file);
 out:
         up_write(&mm->mmap_sem);
@@ -2799,7 +2813,7 @@ static inline void verify_mm_writelocked(struct mm_struct *mm)
  *  anonymous maps.  eventually we may be able to do some
  *  brk-specific accounting here.
  */
-static int do_brk_flags(unsigned long addr, unsigned long request, unsigned long flags)
+static int do_brk_flags(unsigned long addr, unsigned long request, unsigned long flags, struct list_head *uf)
 {
         struct mm_struct *mm = current->mm;
         struct vm_area_struct *vma, *prev;
@@ -2838,7 +2852,7 @@ static int do_brk_flags(unsigned long addr, unsigned long request, unsigned long
          */
         while (find_vma_links(mm, addr, addr + len, &prev, &rb_link,
                               &rb_parent)) {
-                if (do_munmap(mm, addr, len))
+                if (do_munmap(mm, addr, len, uf))
                         return -ENOMEM;
         }
 
@@ -2885,9 +2899,9 @@ out:
         return 0;
 }
 
-static int do_brk(unsigned long addr, unsigned long len)
+static int do_brk(unsigned long addr, unsigned long len, struct list_head *uf)
 {
-        return do_brk_flags(addr, len, 0);
+        return do_brk_flags(addr, len, 0, uf);
 }
 
 int vm_brk_flags(unsigned long addr, unsigned long len, unsigned long flags)
@@ -2895,13 +2909,15 @@ int vm_brk_flags(unsigned long addr, unsigned long len, unsigned long flags)
         struct mm_struct *mm = current->mm;
         int ret;
         bool populate;
+        LIST_HEAD(uf);
 
         if (down_write_killable(&mm->mmap_sem))
                 return -EINTR;
 
-        ret = do_brk_flags(addr, len, flags);
+        ret = do_brk_flags(addr, len, flags, &uf);
         populate = ((mm->def_flags & VM_LOCKED) != 0);
         up_write(&mm->mmap_sem);
+        userfaultfd_unmap_complete(mm, &uf);
         if (populate && !ret)
                 mm_populate(addr, len);
         return ret;