linux-kernel - [Patch v2 4/4] mm/mremap: start addresses are properly aligned

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Message-Id: <20200129002642.13508-5-richardw.yang@linux.intel.com>
Date:   Wed, 29 Jan 2020 08:26:42 +0800
From:   Wei Yang <richardw.yang@...ux.intel.com>
To:     akpm@...ux-foundation.org, aneesh.kumar@...ux.ibm.com,
        kirill@...temov.name, dan.j.williams@...el.com,
        yang.shi@...ux.alibaba.com, thellstrom@...are.com,
        richardw.yang@...ux.intel.com
Cc:     linux-kernel@...r.kernel.org, linux-mm@...ck.org, digetx@...il.com
Subject: [Patch v2 4/4] 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 <richardw.yang@...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 8f1bbbf01f5b..cc98d0f07d0a 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1878,9 +1878,6 @@ 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 b2f3344d090a..7510f4e03fca 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.
-- 
2.17.1