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
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