[patch 116/163] mm/mremap: start addresses are properly aligned

Andrew Morton
2020-08-07T06:23:51Z

From: Wei Yang <richard.weiyang@linux.alibaba.com>
Subject: 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.

Link: http://lkml.kernel.org/r/20200708095028.41706-4-richard.weiyang@linux.alibaba.com
Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Thomas Hellstrom (VMware) <thomas_os@shipmail.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

mm/huge_memory.c | 3 ---
mm/mremap.c | 3 ---
2 files changed, 6 deletions(-)

--- a/mm/huge_memory.c~mm-mremap-start-addresses-are-properly-aligned
+++ a/mm/huge_memory.c
@@ -1729,9 +1729,6 @@ bool move_huge_pmd(struct vm_area_struct
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.
--- a/mm/mremap.c~mm-mremap-start-addresses-are-properly-aligned
+++ a/mm/mremap.c
@@ -199,9 +199,6 @@ static bool move_normal_pmd(struct vm_ar
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 released it.
_