nds32: fix up stack guard gap

Commit 1be7107fbe18 ("mm: larger stack guard gap, between vmas") fixed
up all architectures to deal with the stack guard gap.  But when nds32
was added to the tree, it forgot to do the same thing.

Resolve this by properly fixing up the nsd32's version of
arch_get_unmapped_area()

Cc: Nick Hu <nickhu@andestech.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Qiang Liu <cyruscyliu@gmail.com>
Cc: stable <stable@vger.kernel.org>
Reported-by: iLifetruth <yixiaonn@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Link: https://lore.kernel.org/r/20210629104024.2293615-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/nds32/mm/mmap.c b/arch/nds32/mm/mmap.c
index c206b31..1bdf5e7 100644 (file)
--- a/arch/nds32/mm/mmap.c
+++ b/arch/nds32/mm/mmap.c
@@ -59,7 +59,7 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
 
                vma = find_vma(mm, addr);
                if (TASK_SIZE - len >= addr &&
-                   (!vma || addr + len <= vma->vm_start))
+                   (!vma || addr + len <= vm_start_gap(vma)))
                        return addr;
        }