lib/vsprintf.c: pull out padding code from dentry_name()

Pull out the logic in dentry_name() which handles field width space
padding, in preparation for reusing it from string().  Rename the
widen() helper to move_right(), since it is used for handling the
!(flags & LEFT) case.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Maurizio Lombardi <mlombard@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 31 insertions, 15 deletions

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index ac3f9476b776..3f37b478c429 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -541,7 +541,7 @@ char *string(char *buf, char *end, const char *s, struct printf_spec spec)
         return buf;
 }
 
-static void widen(char *buf, char *end, unsigned len, unsigned spaces)
+static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
 {
         size_t size;
         if (buf >= end) /* nowhere to put anything */
@@ -559,6 +559,35 @@ static void widen(char *buf, char *end, unsigned len, unsigned spaces)
         memset(buf, ' ', spaces);
 }
 
+/*
+ * Handle field width padding for a string.
+ * @buf: current buffer position
+ * @n: length of string
+ * @end: end of output buffer
+ * @spec: for field width and flags
+ * Returns: new buffer position after padding.
+ */
+static noinline_for_stack
+char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
+{
+        unsigned spaces;
+
+        if (likely(n >= spec.field_width))
+                return buf;
+        /* we want to pad the sucker */
+        spaces = spec.field_width - n;
+        if (!(spec.flags & LEFT)) {
+                move_right(buf - n, end, n, spaces);
+                return buf + spaces;
+        }
+        while (spaces--) {
+                if (buf < end)
+                        *buf = ' ';
+                ++buf;
+        }
+        return buf;
+}
+
 static noinline_for_stack
 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
                   const char *fmt)
@@ -600,20 +629,7 @@ char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_sp
                         *buf = c;
         }
         rcu_read_unlock();
-        if (n < spec.field_width) {
-                /* we want to pad the sucker */
-                unsigned spaces = spec.field_width - n;
-                if (!(spec.flags & LEFT)) {
-                        widen(buf - n, end, n, spaces);
-                        return buf + spaces;
-                }
-                while (spaces--) {
-                        if (buf < end)
-                                *buf = ' ';
-                        ++buf;
-                }
-        }
-        return buf;
+        return widen_string(buf, n, end, spec);
 }
 
 #ifdef CONFIG_BLOCK