tree-wide: convert open calls to remove spaces to skip_spaces() lib function

Makes use of skip_spaces() defined in lib/string.c for removing leading
spaces from strings all over the tree.

It decreases lib.a code size by 47 bytes and reuses the function tree-wide:
   text    data     bss     dec     hex filename
  64688     584     592   65864   10148 (TOTALS-BEFORE)
  64641     584     592   65817   10119 (TOTALS-AFTER)

Also, while at it, if we see (*str && isspace(*str)), we can be sure to
remove the first condition (*str) as the second one (isspace(*str)) also
evaluates to 0 whenever *str == 0, making it redundant. In other words,
"a char equals zero is never a space".

Julia Lawall tried the semantic patch (http://coccinelle.lip6.fr) below,
and found occurrences of this pattern on 3 more files:
    drivers/leds/led-class.c
    drivers/leds/ledtrig-timer.c
    drivers/video/output.c

@@
expression str;
@@

( // ignore skip_spaces cases
while (*str &&  isspace(*str)) { \(str++;\|++str;\) }
|
- *str &&
isspace(*str)
)

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Cc: Julia Lawall <julia@diku.dk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: David Howells <dhowells@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Samuel Ortiz <samuel@sortiz.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 9 insertions, 23 deletions

diff --git a/lib/argv_split.c b/lib/argv_split.c
index 5205a8d..4b1b083 100644
--- a/lib/argv_split.c
+++ b/lib/argv_split.c
@@ -4,17 +4,10 @@
 
 #include <linux/kernel.h>
 #include <linux/ctype.h>
+#include <linux/string.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 
-static const char *skip_sep(const char *cp)
-{
-	while (*cp && isspace(*cp))
-		cp++;
-
-	return cp;
-}
-
 static const char *skip_arg(const char *cp)
 {
 	while (*cp && !isspace(*cp))
@@ -28,7 +21,7 @@ static int count_argc(const char *str)
 	int count = 0;
 
 	while (*str) {
-		str = skip_sep(str);
+		str = skip_spaces(str);
 		if (*str) {
 			count++;
 			str = skip_arg(str);
@@ -82,7 +75,7 @@ char **argv_split(gfp_t gfp, const char *str, int *argcp)
 	argvp = argv;
 
 	while (*str) {
-		str = skip_sep(str);
+		str = skip_spaces(str);
 
 		if (*str) {
 			const char *p = str;
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index e22c148..f935029 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -21,6 +21,7 @@
 #include <linux/list.h>
 #include <linux/sysctl.h>
 #include <linux/ctype.h>
+#include <linux/string.h>
 #include <linux/uaccess.h>
 #include <linux/dynamic_debug.h>
 #include <linux/debugfs.h>
@@ -209,8 +210,7 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
 		char *end;
 
 		/* Skip leading whitespace */
-		while (*buf && isspace(*buf))
-			buf++;
+		buf = skip_spaces(buf);
 		if (!*buf)
 			break;	/* oh, it was trailing whitespace */
 
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index c50733a..7857d4d 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1766,13 +1766,6 @@ EXPORT_SYMBOL_GPL(bprintf);
 
 #endif /* CONFIG_BINARY_PRINTF */
 
-static noinline char *skip_space(const char *str)
-{
-	while (isspace(*str))
-		++str;
-	return (char *)str;
-}
-
 /**
  * vsscanf - Unformat a buffer into a list of arguments
  * @buf:	input buffer
@@ -1794,8 +1787,8 @@ int vsscanf(const char *buf, const char *fmt, va_list args)
 		 * white space, including none, in the input.
 		 */
 		if (isspace(*fmt)) {
-			fmt = skip_space(fmt);
-			str = skip_space(str);
+			fmt = skip_spaces(++fmt);
+			str = skip_spaces(str);
 		}
 
 		/* anything that is not a conversion must match exactly */
@@ -1865,7 +1858,7 @@ int vsscanf(const char *buf, const char *fmt, va_list args)
 			if (field_width == -1)
 				field_width = INT_MAX;
 			/* first, skip leading white space in buffer */
-			str = skip_space(str);
+			str = skip_spaces(str);
 
 			/* now copy until next white space */
 			while (*str && !isspace(*str) && field_width--)
@@ -1907,7 +1900,7 @@ int vsscanf(const char *buf, const char *fmt, va_list args)
 		/* have some sort of integer conversion.
 		 * first, skip white space in buffer.
 		 */
-		str = skip_space(str);
+		str = skip_spaces(str);
 
 		digit = *str;
 		if (is_sign && digit == '-')