gdb_server: fix 'null' pointer passed as 'nonnull' parameter

The null pointer used as second parameter to gdb_put_packet() is
passed as second parameter to the memcpy() in line 408 of
gdb_put_packet_inner(). In this case memcpy() does not segfault
because also the parameter length is zero. Nevertheless, the
prototype of memcpy() requires a nonnull pointer.

Fixed by passing an empty string in place of the null pointer.

Issue highlighted by clang 7.0.0 with warning message:
"Null pointer passed as an argument to a 'nonnull' parameter"

Change-Id: Ib3dde95d76fcc5fb245ee2d6669e5535d0e0b127
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/4946
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>

diff --git a/src/server/gdb_server.c b/src/server/gdb_server.c
index 6047a482036f624dc7b87bfc0ded8d9ed1bbc309..54cf9aff8e06f9637bbdfac61bae4177a8d67e3d 100644 (file)
--- a/src/server/gdb_server.c
+++ b/src/server/gdb_server.c
@@ -1437,7 +1437,7 @@ static int gdb_read_memory_packet(struct connection *connection,
 
        if (!len) {
                LOG_WARNING("invalid read memory packet received (len == 0)");
-               gdb_put_packet(connection, NULL, 0);
+               gdb_put_packet(connection, "", 0);
                return ERROR_OK;
        }
 
@@ -3337,7 +3337,7 @@ static int gdb_input_inner(struct connection *connection)
                                default:
                                        /* ignore unknown packets */
                                        LOG_DEBUG("ignoring 0x%2.2x packet", packet[0]);
-                                       gdb_put_packet(connection, NULL, 0);
+                                       gdb_put_packet(connection, "", 0);
                                        break;
                        }