uml: fix console writing bugs

[linux-2.6.git] / arch / um / drivers / chan_kern.c

diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index c09dbdfa298a4c5f56fa4a091ed54034909996cf..db3082b4da46573e7b7ddc427d5e4bbdbbdda366 100644 (file)
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -291,6 +291,9 @@ int write_chan(struct list_head *chans, const char *buf, int len,
        struct chan *chan = NULL;
        int n, ret = 0;
 
+       if (len == 0)
+               return 0;
+
        list_for_each(ele, chans) {
                chan = list_entry(ele, struct chan, list);
                if (!chan->output || (chan->ops->write == NULL))