From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Fri, 8 May 2020 02:12:58 +0000 (-0400)
Subject: mm/mmap: Fix unmapped_area_topdown with align_offset
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=a16b40c835a7fa326b181e5273b8203594321ee3;p=users%2Fjedix%2Flinux-maple.git

mm/mmap: Fix unmapped_area_topdown with align_offset

align_offset should be aligned to align_mask.. apparently.

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---

diff --git a/mm/mmap.c b/mm/mmap.c
index cf15423b1f4cf..ef16957d5ae40 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2267,8 +2267,8 @@ static unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info)
 		return -ENOMEM;
 
 	rcu_read_unlock();
-	gap = (mas.index + info->align_mask - info->align_offset) &
-		(~info->align_mask);
+	gap = (mas.index + info->align_mask) & ~info->align_mask;
+	gap -= info->align_offset & info->align_mask;
 	/*
 	 * Adjust search limits by the desired length.
 	 * See implementation comment at top of unmapped_area().