[nimaarek]

Hi,
I have a beginner problem, but I can not answer and can not find it :roll:

I want to use a kernel function, one of its values is the memory address As a result, I wrote an in the user-mode program to print a variable's address. Something like this:

Code: Select all

int main()
{
	while(1)
	{
        printf("%x", &a);
	}
	return 0;
}

And I used the kernel function this way:

Code: Select all

#include <linux/module.h>
#include <linux/kernel.h>

int hello_init (void)
{
    int result = access_ok( VERIFY_WRITE, [color=#FF0000]addr[/color], 10);
    printk ("Hello, result = %d\n", result );
    return 0;
}

void hello_exit (void)
{
    printk ("Goodbye");
}

module_init(hello_init);
module_exit(hello_exit);

Now how does the output of the user-mode application that contains the variable address is entered as a parameter(addr) to the access_ok function like this?

[EP_X0FF]

Your kernel module lacks most of code.

http://derekmolloy.ie/writing-a-linux-k ... er-device/

[nimaarek]

Thank you, but I was wondering something else
The code I provided was an example
I wanted to know if the parameter of this function is an address
How does the kernel determine which address is for which processor?

[EP_X0FF]

https://www.fsl.cs.sunysb.edu/kernel-api/re243.html
https://github.com/torvalds/linux/blob/ ... /uaccess.h