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>

1 files changed, 7 insertions, 10 deletions

diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index 6f0121e3be69..226d1ac55cf4 100644
--- 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;
 }