linux-kernel - [PATCH v11 29/69] mm/mmap: change do_brk_munmap() to use do_mas_align

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Date:   Sun, 17 Jul 2022 02:46:46 +0000
From:   Liam Howlett <liam.howlett@...cle.com>
To:     "maple-tree@...ts.infradead.org" <maple-tree@...ts.infradead.org>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Yu Zhao <yuzhao@...gle.com>, Hugh Dickins <hughd@...gle.com>
Subject: [PATCH v11 29/69] mm/mmap: change do_brk_munmap() to use
 do_mas_align_munmap()

From: "Liam R. Howlett" <Liam.Howlett@...cle.com>

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.

Link: https://lkml.kernel.org/r/20220504011345.662299-14-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20220519150509.1290067-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20220621204632.3370049-30-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@...cle.com>
Cc: Catalin Marinas <catalin.marinas@....com>
Cc: David Howells <dhowells@...hat.com>
Cc: "Matthew Wilcox (Oracle)" <willy@...radead.org>
Cc: SeongJae Park <sj@...nel.org>
Cc: Vlastimil Babka <vbabka@...e.cz>
Cc: Will Deacon <will@...nel.org>
Cc: Davidlohr Bueso <dave@...olabs.net>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
---
 mm/mmap.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 7f5301ed0213..e4bfee3d2ae2 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -3092,14 +3092,14 @@ 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_end < oldbrk) ||
-		   ((vma->vm_start == newbrk) && (vma->vm_end == oldbrk)))) {
+	if (likely((vma->vm_end < oldbrk) || (vma->vm_start >= newbrk))) {
 		/* remove entire mapping(s) */
-		ret = do_mas_munmap(mas, mm, newbrk, oldbrk-newbrk, uf, true);
+		ret = do_mas_align_munmap(mas, vma, mm, newbrk, oldbrk, uf,
+					  true);
 		goto munmap_full_vma;
 	}
 
-- 
2.35.1