[PATCH] mm/vma: Return the exact errno for __split_vma() and mas_store_gfp()

[Xiao Yang <ice_yangxiao@163.com>]

__split_vma() and mas_store_gfp() returns several types of errno on
failure so don't ignore them in vms_gather_munmap_vmas(). For example,
__split_vma() returns -EINVAL when an unaligned huge page is unmapped.
This issue is reproduced by ltp memfd_create03 test.

Fixes: 6898c9039bc8 ("mm/vma: extract the gathering of vmas from do_vmi_align_munmap()")
Signed-off-by: Xiao Yang <ice_yangxiao@163.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202409081536.d283a0fb-oliver.sang@intel.com
---
 mm/vma.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/mm/vma.c b/mm/vma.c
index 8d1686fc8d5a..3feeea9a8c3d 100644
--- a/mm/vma.c
+++ b/mm/vma.c
@@ -1200,7 +1200,8 @@ int vms_gather_munmap_vmas(struct vma_munmap_struct *vms,
 			goto start_split_failed;
 		}
 
-		if (__split_vma(vms->vmi, vms->vma, vms->start, 1))
+		error = __split_vma(vms->vmi, vms->vma, vms->start, 1);
+		if (error)
 			goto start_split_failed;
 	}
 	vms->prev = vma_prev(vms->vmi);
@@ -1220,12 +1221,14 @@ int vms_gather_munmap_vmas(struct vma_munmap_struct *vms,
 		}
 		/* Does it split the end? */
 		if (next->vm_end > vms->end) {
-			if (__split_vma(vms->vmi, next, vms->end, 0))
+			error = __split_vma(vms->vmi, next, vms->end, 0);
+			if (error)
 				goto end_split_failed;
 		}
 		vma_start_write(next);
 		mas_set(mas_detach, vms->vma_count++);
-		if (mas_store_gfp(mas_detach, next, GFP_KERNEL))
+		error = mas_store_gfp(mas_detach, next, GFP_KERNEL);
+		if (error)
 			goto munmap_gather_failed;
 
 		vma_mark_detached(next, true);
-- 
2.46.0