xen/xenbus: don't reimplement kvasprintf via a fixed size buffer

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Haogang Chen <haogangchen@gmail.com>
Acked-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index 6f0121e..226d1ac 100644 (file)
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -532,21 +532,18 @@ int xenbus_printf(struct xenbus_transaction t,
 {
        va_list ap;
        int ret;
-#define PRINTF_BUFFER_SIZE 4096
-       char *printf_buffer;
-
-       printf_buffer = kmalloc(PRINTF_BUFFER_SIZE, GFP_NOIO | __GFP_HIGH);
-       if (printf_buffer == NULL)
-               return -ENOMEM;
+       char *buf;
 
        va_start(ap, fmt);
-       ret = vsnprintf(printf_buffer, PRINTF_BUFFER_SIZE, fmt, ap);
+       buf = kvasprintf(GFP_NOIO | __GFP_HIGH, fmt, ap);
        va_end(ap);
 
-       BUG_ON(ret > PRINTF_BUFFER_SIZE-1);
-       ret = xenbus_write(t, dir, node, printf_buffer);
+       if (!buf)
+               return -ENOMEM;
+
+       ret = xenbus_write(t, dir, node, buf);
 
-       kfree(printf_buffer);
+       kfree(buf);
 
        return ret;
 }