#include <linux/init.h>

#include <linux/init.h>

#include <linux/module.h>

#include <linux/kernel.h>

MODULE_LICENSE("Dual BSD/GPL");

unsigned long long my_rdmsr(unsigned long val) {

unsigned long low = 0, high = 0;

__asm__ volatile ("rdmsr" :

"=a"(low), "=d"(high)

: "c"(val));

return ((unsigned long long)high << 32) + low;

}

void my_wrmsr(unsigned long val, unsigned long low, unsigned long high) {

__asm__ volatile ("wrmsr"

:

: "a"(low), "d"(high), "c"(val));

}

static int my_init(void) {

my_wrmsr(0x1d9, 0x3, 0x0);

printk("<1> Attempt #1 %llx.n", my_rdmsr(0x1d9));

wrmsr(0x1d9, 0x1, 0x0);

int low;

int high;

rdmsr(0x1d9, low, high);

printk("<1> Attempt #2 %x, %x.n", low, high);

return 0;

}

static void my_exit(void) {

printk("<1> unloadn");

}

module_init(my_init);

module_exit(my_exit);

obj-m := hello.o

me@debian:~/code$ sudo make -C /usr/src/linux-headers-3.2.0-4-amd64/ M=`pwd` modules && sudo insmod hello.ko && sudo rmmod hello && sudo dmesg | tail

make: Entering directory `/usr/src/linux-headers-3.2.0-4-amd64'

Building modules, stage 2.

MODPOST 1 modules

make: Leaving directory `/usr/src/linux-headers-3.2.0-4-amd64'

[ 2231.367819] unload

[ 2248.363261] Attempt #1 0.

[ 2248.363267] Attempt #2 0, 0.

[ 2248.378066] unload

[ 2288.395359] Attempt #1 0.

[ 2288.395366] Attempt #2 0, 0.

[ 2288.409889] unload

[ 3021.984748] Attempt #1 0.

[ 3021.984760] Attempt #2 0, 0.

[ 3022.017626] unload