From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Tue, 1 Dec 2020 02:30:04 +0000 (-0500)
Subject: mm/mmap: Change do_brk_munmap() to use do_mas_align_munmap()
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=94f959fff847955bea102b9c38b3708439505d07;p=users%2Fwilly%2Flinux.git

mm/mmap: Change do_brk_munmap() to use do_mas_align_munmap()

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@Oracle.com>
---

diff --git a/mm/mmap.c b/mm/mmap.c
index f64de2c62d73..3f9bec49202d 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -3021,13 +3021,16 @@ 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;