[PATCH] mmotm: userfaultfd-non-cooperative-add-event-for-memory-unmaps-fix

[Michal Hocko]

This breaks compilation on nommu configs.
mm/nommu.c:1201:15: error: conflicting types for 'do_mmap'
 unsigned long do_mmap(struct file *file,
               ^
In file included from mm/nommu.c:19:0:
./include/linux/mm.h:2089:22: note: previous declaration of 'do_mmap' was here
 extern unsigned long do_mmap(struct file *file, unsigned long addr,
                      ^
mm/nommu.c:1580:5: error: conflicting types for 'do_munmap'
 int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
     ^
In file included from mm/nommu.c:19:0:
./include/linux/mm.h:2093:12: note: previous declaration of 'do_munmap' was here
 extern int do_munmap(struct mm_struct *, unsigned long, size_t,
            ^
make[1]: *** [mm/nommu.o] Error 1

CONFIG_USERFAULTFD depends on CONFIG_MMU so I guess we are OK to just ignore the
argument.

Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
---
 mm/nommu.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/mm/nommu.c b/mm/nommu.c
index d35088a4b73d..f78d06459ba4 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1205,7 +1205,8 @@ unsigned long do_mmap(struct file *file,
 			unsigned long flags,
 			vm_flags_t vm_flags,
 			unsigned long pgoff,
-			unsigned long *populate)
+			unsigned long *populate,
+			struct list_head *uf_unused)
 {
 	struct vm_area_struct *vma;
 	struct vm_region *region;
@@ -1577,7 +1578,7 @@ static int shrink_vma(struct mm_struct *mm,
  * - under NOMMU conditions the chunk to be unmapped must be backed by a single
  *   VMA, though it need not cover the whole VMA
  */
-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)
 {
 	struct vm_area_struct *vma;
 	unsigned long end;
@@ -1643,7 +1644,7 @@ int vm_munmap(unsigned long addr, size_t len)
 	int ret;
 
 	down_write(&mm->mmap_sem);
-	ret = do_munmap(mm, addr, len);
+	ret = do_munmap(mm, addr, len, NULL);
 	up_write(&mm->mmap_sem);
 	return ret;
 }
-- 
2.11.0

-- 
Michal Hocko
SUSE Labs