staging: gasket: cleanup if dma_map_page fails in gasket_perform_mapping

Previously pages would have never been unmapped in this case.

Signed-off-by: Nick Ewalt <nicholasewalt@google.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/gasket/gasket_page_table.c b/drivers/staging/gasket/gasket_page_table.c
index c1ce8f984f8e0a4c1ed9f5abf9795d1425773f2f..779ad2f23ef9b7af0dd0e7379b8129e4a086d8e6 100644 (file)
--- a/drivers/staging/gasket/gasket_page_table.c
+++ b/drivers/staging/gasket/gasket_page_table.c
@@ -433,6 +433,19 @@ static int is_coherent(struct gasket_page_table *pg_tbl, ulong host_addr)
        return min <= host_addr && host_addr < max;
 }
 
+/* Safely return a page to the OS. */
+static bool gasket_release_page(struct page *page)
+{
+       if (!page)
+               return false;
+
+       if (!PageReserved(page))
+               SetPageDirty(page);
+       put_page(page);
+
+       return true;
+}
+
 /*
  * Get and map last level page table buffers.
  *
@@ -500,6 +513,13 @@ static int gasket_perform_mapping(struct gasket_page_table *pg_tbl,
                                        (unsigned long long)ptes[i].dma_addr,
                                        (void *)page_to_pfn(page),
                                        (void *)page_to_phys(page));
+
+                               /* clean up */
+                               if (gasket_release_page(ptes[i].page))
+                                       --pg_tbl->num_active_pages;
+
+                               memset(&ptes[i], 0,
+                                      sizeof(struct gasket_page_table_entry));
                                return -1;
                        }
                }
@@ -571,19 +591,6 @@ static int gasket_alloc_simple_entries(struct gasket_page_table *pg_tbl,
        return 0;
 }
 
-/* Safely return a page to the OS. */
-static bool gasket_release_page(struct page *page)
-{
-       if (!page)
-               return false;
-
-       if (!PageReserved(page))
-               SetPageDirty(page);
-       put_page(page);
-
-       return true;
-}
-
 /*
  * Unmap and release mapped pages.
  * The page table mutex must be held by the caller.