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>

1 files changed, 7 insertions, 9 deletions

diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index f0fa47f10e6c..51069245b79a 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -6,6 +6,7 @@
 
 #include <linux/console.h>
 #include <linux/ctype.h>
+#include <linux/string.h>
 #include <linux/interrupt.h>
 #include <linux/list.h>
 #include <linux/mm.h>
@@ -131,7 +132,7 @@ void mconsole_proc(struct mc_request *req)
 	char *ptr = req->request.data, *buf;
 
 	ptr += strlen("proc");
-	while (isspace(*ptr)) ptr++;
+	ptr = skip_spaces(ptr);
 
 	proc = get_fs_type("proc");
 	if (proc == NULL) {
@@ -212,8 +213,7 @@ void mconsole_proc(struct mc_request *req)
 	char *ptr = req->request.data;
 
 	ptr += strlen("proc");
-	while (isspace(*ptr))
-		ptr++;
+	ptr = skip_spaces(ptr);
 	snprintf(path, sizeof(path), "/proc/%s", ptr);
 
 	fd = sys_open(path, 0, 0);
@@ -560,8 +560,7 @@ void mconsole_config(struct mc_request *req)
 	int err;
 
 	ptr += strlen("config");
-	while (isspace(*ptr))
-		ptr++;
+	ptr = skip_spaces(ptr);
 	dev = mconsole_find_dev(ptr);
 	if (dev == NULL) {
 		mconsole_reply(req, "Bad configuration option", 1, 0);
@@ -588,7 +587,7 @@ void mconsole_remove(struct mc_request *req)
 	int err, start, end, n;
 
 	ptr += strlen("remove");
-	while (isspace(*ptr)) ptr++;
+	ptr = skip_spaces(ptr);
 	dev = mconsole_find_dev(ptr);
 	if (dev == NULL) {
 		mconsole_reply(req, "Bad remove option", 1, 0);
@@ -712,7 +711,7 @@ void mconsole_sysrq(struct mc_request *req)
 	char *ptr = req->request.data;
 
 	ptr += strlen("sysrq");
-	while (isspace(*ptr)) ptr++;
+	ptr = skip_spaces(ptr);
 
 	/*
 	 * With 'b', the system will shut down without a chance to reply,
@@ -757,8 +756,7 @@ void mconsole_stack(struct mc_request *req)
 	 */
 
 	ptr += strlen("stack");
-	while (isspace(*ptr))
-		ptr++;
+	ptr = skip_spaces(ptr);
 
 	/*
 	 * Should really check for multiple pids or reject bad args here