linux-kernel - [Patch v4 3/4] mm/mremap: start addresses are properly aligned

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Message-Id: <20200708095028.41706-4-richard.weiyang@linux.alibaba.com>
Date:   Wed,  8 Jul 2020 17:50:27 +0800
From:   Wei Yang <richard.weiyang@...ux.alibaba.com>
To:     akpm@...ux-foundation.org, kirill.shutemov@...ux.intel.com,
        vbabka@...e.cz, yang.shi@...ux.alibaba.com, thomas_os@...pmail.org,
        anshuman.khandual@....com, sean.j.christopherson@...el.com,
        richard.weiyang@...ux.alibaba.com, peterx@...hat.com,
        aneesh.kumar@...ux.ibm.com, willy@...radead.org,
        thellstrom@...are.com
Cc:     linux-kernel@...r.kernel.org, linux-mm@...ck.org, digetx@...il.com
Subject: [Patch v4 3/4] mm/mremap: start addresses are properly aligned

After previous cleanup, extent is the minimal step for both source and
destination. This means when extent is HPAGE_PMD_SIZE or PMD_SIZE,
old_addr and new_addr are properly aligned too.

Since these two functions are only invoked in move_page_tables, it is
safe to remove the check now.

Signed-off-by: Wei Yang <richard.weiyang@...ux.alibaba.com>
Tested-by: Dmitry Osipenko <digetx@...il.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
---
 mm/huge_memory.c | 3 ---
 mm/mremap.c      | 3 ---
 2 files changed, 6 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 1e580fdad4d0..462a7dbd6350 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1729,9 +1729,6 @@ bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
 	struct mm_struct *mm = vma->vm_mm;
 	bool force_flush = false;
 
-	if ((old_addr & ~HPAGE_PMD_MASK) || (new_addr & ~HPAGE_PMD_MASK))
-		return false;
-
 	/*
 	 * The destination pmd shouldn't be established, free_pgtables()
 	 * should have release it.
diff --git a/mm/mremap.c b/mm/mremap.c
index a30b3e86cc99..f5f17d050617 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -199,9 +199,6 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr,
 	struct mm_struct *mm = vma->vm_mm;
 	pmd_t pmd;
 
-	if ((old_addr & ~PMD_MASK) || (new_addr & ~PMD_MASK))
-		return false;
-
 	/*
 	 * The destination pmd shouldn't be established, free_pgtables()
 	 * should have release it.
-- 
2.20.1 (Apple Git-117)