[SPARC64]: Fix loop termination in mark_kpte_bitmap()

If we were aligned, but didn't have at least 256MB left
to process, we would loop forever.

Thanks to fabbione for the report and testing the fix.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 1 deletions

diff --git a/arch/sparc64/mm/init.c b/arch/sparc64/mm/init.c
index 5930e87dafbc..9bbd0bf64af0 100644
--- a/arch/sparc64/mm/init.c
+++ b/arch/sparc64/mm/init.c
@@ -973,12 +973,15 @@ static void __init mark_kpte_bitmap(unsigned long start, unsigned long end)
         while (start < end) {
                 long remains;
 
+                remains = end - start;
+                if (remains < size_256MB)
+                        break;
+
                 if (start & mask_256MB) {
                         start = (start + size_256MB) & ~mask_256MB;
                         continue;
                 }
 
-                remains = end - start;
                 while (remains >= size_256MB) {
                         unsigned long index = start >> shift_256MB;