x86: idle process - add checking for NULL early param

[ Upstream commit ab6bc3e343fbe3be4a0f67225e849d0db6b4b7ac ]

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: akpm@linux-foundation.org
Cc: andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
CC: Oliver Pinter <oliver.pntr@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index ba370dc8685bf8f9bf31e9100f78c4e800ea755e..58325a6604a4fa650952bf49323abbb82e5007e5 100644 (file)
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -164,6 +164,9 @@ void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
 
 static int __init idle_setup(char *str)
 {
+       if (!str)
+               return -EINVAL;
+
        if (!strcmp(str, "poll")) {
                printk("using polling idle threads.\n");
                pm_idle = poll_idle;