[PATCH v3 23/66] mm/mmap: Change do_brk_munmap() to use do_mas_align_munmap()

From: Liam Howlett
Date: Mon Oct 04 2021 - 21:32:50 EST


From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>

do_brk_munmap() has already aligned the address and has a maple tree
state to be used. Use the new do_mas_align_munmap() to avoid
unnecessary alignment and error checks.

Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
mm/mmap.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 25fcdf2ff739..56da5a23e293 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -3009,13 +3009,16 @@ 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)
+ if (likely((vma->vm_end < oldbrk) ||
+ ((vma->vm_start == newbrk) && (vma->vm_end == oldbrk)))) {
+ // remove entire mapping(s)
mas_lock(mas);
- ret = do_mas_munmap(mas, mm, newbrk, oldbrk-newbrk, uf, true);
+ ret = do_mas_align_munmap(mas, vma, mm, newbrk, oldbrk, uf,
+ true);
if (ret != 1)
mas_unlock(mas);
goto munmap_full_vma;
--
2.30.2