timers: Fix timer_migration interface which accepts any number as input

Poornima Nayek reported:

| Timer migration interface /proc/sys/kernel/timer_migration in
| 2.6.30-git9 accepts any numerical value as input.
|
| Steps to reproduce:
| 1. echo -6666666 > /proc/sys/kernel/timer_migration
| 2. cat /proc/sys/kernel/timer_migration
| -6666666
|
| 1. echo 44444444444444444444444444444444444444444444444444444444444 > /proc/sys/kernel/timer_migration
| 2. cat /proc/sys/kernel/timer_migration
| -1357789412
|
| Expected behavior: Should 'echo: write error: Invalid argument' while
| setting any value other then 0 & 1

Restrict valid values to 0 and 1.

Reported-by: Poornima Nayak <[email protected]>
Tested-by: Poornima Nayak <[email protected]>
Signed-off-by: Arun R Bharadwaj <[email protected]>
Cc: poornima nayak <[email protected]>
Cc: Arun Bharadwaj <[email protected]>
LKML-Reference: <20090623043058[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 62e4ff9968b5fe64a06c9f8735af10d3b6a304b9..c428ba161db1e4908b110870eb157f673977c4bc 100644 (file)
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -335,7 +335,10 @@ static struct ctl_table kern_table[] = {
                .data           = &sysctl_timer_migration,
                .maxlen         = sizeof(unsigned int),
                .mode           = 0644,
-               .proc_handler   = &proc_dointvec,
+               .proc_handler   = &proc_dointvec_minmax,
+               .strategy       = &sysctl_intvec,
+               .extra1         = &zero,
+               .extra2         = &one,
        },
 #endif
        {