4.11-stable review patch. If anyone has any objections, please let me know.
------------------ From: Nitin Gupta <[email protected]> [ Upstream commit dbd2667a4fb9ce4f547982b07cd69dda127c47ea ] 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 <[email protected]> Signed-off-by: Nitin Gupta <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/sparc/mm/gup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/sparc/mm/gup.c +++ b/arch/sparc/mm/gup.c @@ -78,8 +78,8 @@ static int gup_huge_pmd(pmd_t *pmdp, pmd 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;
