sparc64: Fix hugepage page table free

Make sure the start adderess is aligned to PMD_SIZE
boundary when freeing page table backing a hugepage
region. The issue was causing segfaults when a region
backed by 64K pages was unmapped since such a region
is in general not PMD_SIZE aligned.

Signed-off-by: Nitin Gupta <nitin.m.gupta@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c
index ee5273ad918de6302cb0f6644b2a4179f8c26351..7c29d38e6b99c68c5ac746eb3d3a3fe1da8394a5 100644 (file)
--- a/arch/sparc/mm/hugetlbpage.c
+++ b/arch/sparc/mm/hugetlbpage.c
@@ -461,6 +461,22 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb,
        pgd_t *pgd;
        unsigned long next;
 
+       addr &= PMD_MASK;
+       if (addr < floor) {
+               addr += PMD_SIZE;
+               if (!addr)
+                       return;
+       }
+       if (ceiling) {
+               ceiling &= PMD_MASK;
+               if (!ceiling)
+                       return;
+       }
+       if (end - 1 > ceiling - 1)
+               end -= PMD_SIZE;
+       if (addr > end - 1)
+               return;
+
        pgd = pgd_offset(tlb->mm, addr);
        do {
                next = pgd_addr_end(addr, end);