1 files changed, 30 insertions, 7 deletions

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index b025864d2e43..017290241261 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -825,6 +825,17 @@ int vsscanf(const char * buf, const char * fmt, va_list args)
                         break;
                 str = next;
         }
+
+        /*
+         * Now we've come all the way through so either the input string or the
+         * format ended. In the former case, there can be a %n at the current
+         * position in the format that needs to be filled.
+         */
+        if (*fmt == '%' && *(fmt + 1) == 'n') {
+                int *p = (int *)va_arg(args, int *);
+                *p = str - buf;
+        }
+
         return num;
 }
 
@@ -851,23 +862,35 @@ EXPORT_SYMBOL(sscanf);
 
 
 /* Simplified asprintf. */
-char *kasprintf(gfp_t gfp, const char *fmt, ...)
+char *kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
 {
-        va_list ap;
         unsigned int len;
         char *p;
+        va_list aq;
 
-        va_start(ap, fmt);
-        len = vsnprintf(NULL, 0, fmt, ap);
-        va_end(ap);
+        va_copy(aq, ap);
+        len = vsnprintf(NULL, 0, fmt, aq);
+        va_end(aq);
 
         p = kmalloc(len+1, gfp);
         if (!p)
                 return NULL;
-        va_start(ap, fmt);
+
         vsnprintf(p, len+1, fmt, ap);
-        va_end(ap);
+
         return p;
 }
+EXPORT_SYMBOL(kvasprintf);
 
+char *kasprintf(gfp_t gfp, const char *fmt, ...)
+{
+        va_list ap;
+        char *p;
+
+        va_start(ap, fmt);
+        p = kvasprintf(gfp, fmt, ap);
+        va_end(ap);
+
+        return p;
+}
 EXPORT_SYMBOL(kasprintf);