[PATCH, RFC 2/6] mm: make clear_huge_page tolerate non aligned address

["Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>]

From: Andi Kleen <ak@linux.intel.com>

hugetlb does not necessarily pass in an aligned address, so the
low level address computation is wrong.

This will fix architectures that actually use the address for flushing
the cleared address (very few, like xtensa/sparc/...?)

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 mm/memory.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 2466d12..c356ead 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3975,16 +3975,17 @@ void clear_huge_page(struct page *page,
 		     unsigned long addr, unsigned int pages_per_huge_page)
 {
 	int i;
+	unsigned long haddr = addr & HPAGE_PMD_MASK;
 
 	if (unlikely(pages_per_huge_page > MAX_ORDER_NR_PAGES)) {
-		clear_gigantic_page(page, addr, pages_per_huge_page);
+		clear_gigantic_page(page, haddr, pages_per_huge_page);
 		return;
 	}
 
 	might_sleep();
 	for (i = 0; i < pages_per_huge_page; i++) {
 		cond_resched();
-		clear_user_highpage(page + i, addr + i * PAGE_SIZE);
+		clear_user_highpage(page + i, haddr + i * PAGE_SIZE);
 	}
 }
 
-- 
1.7.7.6

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