How to call system call from usb driver's code

Mr.J · 09-27-2008, 08:52 AM

Hello,

I need to call one system call inside linux-2.6.22.14/drivers/usb/storage/usb.c .
I just included <linux/syscalls.h>
and called the api like (sys_getpid())...
but when I compiled the code, I got error ..undefined refence to sys_getpid....

If anybody has any idea on how to call system call within drivers code..
plz advise..

Mr.J

ashok449 · 09-29-2008, 12:15 AM

I'm not sure but let me guess...

EXPORT_SYMBOL for the API you wanna use, and u can access in driver code

getpid() in kernel space ? you need to use process descriptor (struct task_struct) I guess ...

-- Ashok

krishna_123 · 09-29-2008, 12:17 AM

sys_getpid is not exported since there is no EXPORT_SYMBOL(sys_getpid) defined in the kernel source tree.

krishna_123 · 09-29-2008, 12:20 AM

u can get the pid of a process using the current pointer which is defined in linux/sched.h. current->pid will prints the pid of the user space program that invoked the driver

Mr.J · 09-29-2008, 03:47 AM

After exporting symbol, it worked.... Thanks for your help.