sched: Fix string comparison in /proc/sched_features

commit 7740191cd909b75d75685fb08a5d1f54b8a9d28b upstream.

Fix incorrect handling of the following case:

 INTERACTIVE
 INTERACTIVE_SOMETHING_ELSE

The comparison only checks up to each element's length.

Changelog since v1:
 - Embellish using some Rostedtisms.
  [ mingo:                 ^^ == smaller and cleaner ]

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tony Lindgren <tony@atomide.com>
LKML-Reference: <20100913214700.GB16118@Krystal>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/kernel/sched.c b/kernel/sched.c
index dd7c170ae6535777adefac801a5834788abef11b..12ee156150972cfeaee9c299b6c220b6c35bbdc4 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -713,7 +713,7 @@ sched_feat_write(struct file *filp, const char __user *ubuf,
                size_t cnt, loff_t *ppos)
 {
        char buf[64];
-       char *cmp = buf;
+       char *cmp;
        int neg = 0;
        int i;
 
@@ -724,6 +724,7 @@ sched_feat_write(struct file *filp, const char __user *ubuf,
                return -EFAULT;
 
        buf[cnt] = 0;
+       cmp = strstrip(buf);
 
        if (strncmp(buf, "NO_", 3) == 0) {
                neg = 1;
@@ -731,9 +732,7 @@ sched_feat_write(struct file *filp, const char __user *ubuf,
        }
 
        for (i = 0; sched_feat_names[i]; i++) {
-               int len = strlen(sched_feat_names[i]);
-
-               if (strncmp(cmp, sched_feat_names[i], len) == 0) {
+               if (strcmp(cmp, sched_feat_names[i]) == 0) {
                        if (neg)
                                sysctl_sched_features &= ~(1UL << i);
                        else