[PATCH 1/3] mm/mmap/vma_merge: actually set next to NULL if not applicable

Arnd Bergmann
2023-03-23T11:59:17Z

As clang builds point out, the variable 'next' is now uninitialized
in some conditions as a result of a previous patch that tried to
rely on it being NULL here:

mm/mmap.c:939:11: error: variable 'next' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
else if (!curr)
^~~~~
mm/mmap.c:952:15: note: uninitialized use occurs here
merge_next = next && mpol_equal(policy, vma_policy(next)) &&
^~~~

Fixes: e887ecae997e ("mm/mmap/vma_merge: set next to NULL if not applicable")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
mm/mmap.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/mm/mmap.c b/mm/mmap.c
index 54099a604cf8..c01d43bd694e 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -939,6 +939,8 @@ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm,
else if (!curr)
/* Is there a VMA next to a hole (case 1 - 3) or prev (4)? */
next = vma_lookup(mm, end);
+ else
+ next = NULL;

/* Can we merge the predecessor? */
if (prev && addr == prev->vm_end && mpol_equal(vma_policy(prev), policy)
--
2.39.2