[PATCH] server: clear area when file size is not full page.

[Chao Long]

From: chenjiangyi

Signed-off-by: chenjiangyi 
---
 server/mapping.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/server/mapping.c b/server/mapping.c
index 8d4332d240f..4730d93be90 100644
--- a/server/mapping.c
+++ b/server/mapping.c
@@ -558,7 +558,7 @@ static int build_shared_mapping( struct mapping *mapping, int fd,
     struct file *file;
     unsigned int i;
     mem_size_t total_size;
-    size_t file_size, map_size, max_size;
+    size_t file_size, map_size, max_size, file_roundsize;
     off_t shared_pos, read_pos, write_pos;
     char *buffer = NULL;
     int shared_fd;
@@ -595,6 +595,7 @@ static int build_shared_mapping( struct mapping *mapping, int fd,
     {
         if (!(sec[i].Characteristics & IMAGE_SCN_MEM_SHARED)) continue;
         if (!(sec[i].Characteristics & IMAGE_SCN_MEM_WRITE)) continue;
+        memset(buffer, 0, max_size);
         get_section_sizes( &sec[i], &map_size, &read_pos, &file_size );
         write_pos = shared_pos;
         shared_pos += map_size;
@@ -612,7 +613,16 @@ static int build_shared_mapping( struct mapping *mapping, int fd,
             toread -= res;
             read_pos += res;
         }
-        if (pwrite( shared_fd, buffer, file_size, write_pos ) != file_size) goto error;
+        if (file_size & page_mask)
+        {
+            file_roundsize = ROUND_SIZE( file_size );
+            if (file_roundsize > map_size) file_roundsize = map_size;
+            if (pwrite( shared_fd, buffer, file_roundsize, write_pos ) != file_roundsize) goto error;
+        }
+        else
+        {
+            if (pwrite( shared_fd, buffer, file_size, write_pos ) != file_size) goto error;
+        }
     }

if (!(shared = alloc_object( &shared_map_ops ))) goto error;