Thread: LKM programming - using set_task_comm

Hi...

I'm trying to compile the following code:

mod.c

Code:

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
int init_module(void)
{
        struct task_struct *task;
        for_each_process(task) {
                printk("%s [%d] state: [%ld]\n", task->comm, task->pid, task->state);
                if ( strstr(task->comm, "leafpad") )
                        set_task_comm(task, "leafpod");
        }
        return 0;
}
void cleanup_module(void)
{
        printk(KERN_INFO "Exiting...\n");
}
 

Makefile:

Code:

obj-m += mod.o

all:
        make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
clean:
        make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean

make output:

Code:

root@devil:/home/erick# make
make -C /lib/modules/3.2.0-2-686-pae/build M=/home/erick modules
make[1]: Entering directory `/usr/src/linux-headers-3.2.0-2-686-pae'
  Building modules, stage 2.
  MODPOST 1 modules
WARNING: "set_task_comm" [/home/erick/mod.ko] undefined!
make[1]: Leaving directory `/usr/src/linux-headers-3.2.0-2-686-pae'
root@devil:/home/erick#

Anyone knows what is happening?


set_task_comm is in linux/sched.h


Thank you.

When you copy-paste code from your IDE/editor, please do so as plain text, and let our forum do the line numbering, highlighting, etc.

I'm far from an expert in this stuff, but notice on line 10 it's "leafpad" and on line 11 "leafpod". Is that it?

Originally Posted by anduril462

I'm far from an expert in this stuff, but notice on line 10 it's "leafpad" and on line 11 "leafpod". Is that it?

It's right...


The problem is specifically with 'set_task_comm undefined'.



[]s

Originally Posted by anduril462

See if this helps at all: c++ - linux kernel module linker warnings: "*** Warning: <function> [<module>] undefined!" - any way to get rid of them? - Stack Overflow.

EDIT: Or this: [PATCH] export kernel call get_task_comm(). | Linux | Kernel. It looks like the get_task_comm (and presumably set_task_comm) kernel symbols may not be available for export. Not sure if this holds for your version of the kernel, since it's quite new.

So.. i'm trying to use a function that is not available to me.


I'll see what i can do.



Thank you, anduril.