/*!
* @fn void cpumon_Set_IDT_Func(idt, func)
*
* @param GATE_STRUCT* - address of the idt vector
* @param PVOID - function to set in IDT
*
* @return None No return needed
*
* @brief Set up the interrupt handler.
* @brief Save the old handler for restoration when done
*
*/
static VOID
cpumon_Set_IDT_Func (
GATE_STRUCT *idt,
PVOID func
)
{
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
_set_gate(&idt[CPU_PERF_VECTOR], GATE_INTERRUPT, (unsigned long) func, 3, 0);
#else
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,10,0)
unsigned long cr0_value;
#endif
GATE_STRUCT local;
// _set_gate() cannot be used because the IDT table is not exported.
pack_gate(&local, GATE_INTERRUPT, (unsigned long)func, 3, 0, __KERNEL_CS);
// From 3.10 kernel, the IDT memory has been moved to a read-only location
// which is controlled by the bit 16 in the CR0 register.
// The write protection should be temporarily released to update the IDT.
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,10,0)
cr0_value = read_cr0();
write_cr0(cr0_value & ~X86_CR0_WP);
#endif
write_idt_entry((idt), CPU_PERF_VECTOR, &local);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,10,0)
write_cr0(cr0_value);
#endif
#endif
return;
}
static void __init set_trap_gate(unsigned int n, void *addr)
{
/**
* DESCTYPE_TRAP es el tipo de gate, addr es
* el handler, __KERNEL_CS es el selector donde
* va a estar el codigo
*/
_set_gate(n, DESCTYPE_TRAP, addr, __KERNEL_CS);
}
/*!
* @fn void cpumon_Set_IDT_Func(idt, func)
*
* @param GATE_STRUCT* - address of the idt vector
* @param PVOID - function to set in IDT
*
* @return None No return needed
*
* @brief Set up the interrupt handler.
* @brief Save the old handler for restoration when done
*
*/
static VOID
cpumon_Set_IDT_Func (
GATE_STRUCT *idt,
PVOID func
)
{
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
_set_gate(&idt[CPU_PERF_VECTOR], GATE_INTERRUPT, (unsigned long) func, 3, 0);
#else
GATE_STRUCT local;
// _set_gate() cannot be used because the IDT table is not exported.
pack_gate(&local, GATE_INTERRUPT, (unsigned long)func, 3, 0, __KERNEL_CS);
write_idt_entry(idt, CPU_PERF_VECTOR, &local);
#endif
return;
}
