Commit dbd2667a authored Jun 22, 2017 by Nitin Gupta Committed by David S. Miller Jun 25, 2017

sparc64: Fix gup_huge_pmd



The function assumes that each PMD points to head of a
huge page. This is not correct as a PMD can point to
start of any 8M region with a, say 256M, hugepage. The
fix ensures that it points to the correct head of any PMD
huge page.

Cc: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: Nitin Gupta <nitin.m.gupta@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent d8f431a0

arch/sparc/mm/gup.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -78,8 +78,8 @@ static int gup_huge_pmd(pmd_t *pmdp, pmd_t pmd, unsigned long addr,
		return 0;

		refs = 0;
		head = pmd_page(pmd);
		page = head + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
		page = pmd_page(pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
		head = compound_head(page);
		do {
		VM_BUG_ON(compound_head(page) != head);
		pages[*nr] = page;