vsprintf: pre-calculate final string length for later use

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 4 deletions

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index e5ab51fc2d9e..99747a58ec72 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1496,13 +1496,14 @@ do {									\
                 case FORMAT_TYPE_STR: {
                         const char *save_str = va_arg(args, char *);
                         size_t len;
+
                         if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
                                         || (unsigned long)save_str < PAGE_SIZE)
                                 save_str = "(null)";
-                        len = strlen(save_str);
-                        if (str + len + 1 < end)
-                                memcpy(str, save_str, len + 1);
-                        str += len + 1;
+                        len = strlen(save_str) + 1;
+                        if (str + len < end)
+                                memcpy(str, save_str, len);
+                        str += len;
                         break;
                 }