1 files changed, 14 insertions, 2 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a790ef4be74e..3222193c46c6 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6939,9 +6939,21 @@ unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
         start = (void *)PAGE_ALIGN((unsigned long)start);
         end = (void *)((unsigned long)end & PAGE_MASK);
         for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
+                struct page *page = virt_to_page(pos);
+                void *direct_map_addr;
+
+                /*
+                 * 'direct_map_addr' might be different from 'pos'
+                 * because some architectures' virt_to_page()
+                 * work with aliases.  Getting the direct map
+                 * address ensures that we get a _writeable_
+                 * alias for the memset().
+                 */
+                direct_map_addr = page_address(page);
                 if ((unsigned int)poison <= 0xFF)
-                        memset(pos, poison, PAGE_SIZE);
-                free_reserved_page(virt_to_page(pos));
+                        memset(direct_map_addr, poison, PAGE_SIZE);
+
+                free_reserved_page(page);
         }
 
         if (pages && s)