pid_task function fails to execute

Hello friends, I am having issue with the pid_task function with arguments first as userspace pid (using getpid fn) and 2nd argument PIDTYPE_PID. "pid_task(<pid from userspace>, PIDTYPE_PID);" Can anyone assist me what can be the cause? Have a Good Day, Thank you, Ankur. *The kernel gives exception as below:* Unable to handle kernel NULL pointer dereference at virtual address 000001dd pgd = c7c04000 [000001dd] *pgd=779fe031, *pte=00000000, *ppte=00000000 Internal error: Oops: 1 [#1] last sysfs file: /sys/devices/platform/i2c-gpio.1/i2c-1/1-0048/temp1_pid <8>Modules linked in: tmp102 <8>CPU: 0 Tainted: G W (2.6.33.2 #100) <8>PC is at pid_task+0x18/0x44