[PATCH 50/94] mm/mmap: Change do_brk_munmap() to use do_mas_align_munmap()

Liam Howlett liam.howlett at oracle.com
Wed Apr 28 16:36:13 BST 2021


do_brk_munmap() already has aligned addresses.

Signed-off-by: Liam R. Howlett <Liam.Howlett at Oracle.com>
---
 mm/mmap.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index cf4aa715eb63..3b1a9f6bc39b 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2965,12 +2965,16 @@ static int do_brk_munmap(struct ma_state *mas, struct vm_area_struct *vma,
 	struct mm_struct *mm = vma->vm_mm;
 	struct vm_area_struct unmap;
 	unsigned long unmap_pages;
-	int ret = 1;
+	int ret;
 
 	arch_unmap(mm, newbrk, oldbrk);
 
-	if (likely(vma->vm_start >= newbrk)) { // remove entire mapping(s)
-		ret = do_mas_munmap(mas, mm, newbrk, oldbrk-newbrk, uf, true);
+	if (likely((vma->vm_end < oldbrk) ||
+		   ((vma->vm_start == newbrk) && (vma->vm_end == oldbrk)))) {
+		// remove entire mapping(s)
+		mas->last = oldbrk - 1;
+		ret = do_mas_align_munmap(mas, vma, mm, newbrk, oldbrk, uf,
+					  true);
 		goto munmap_full_vma;
 	}
 
-- 
2.30.2



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