101 lines
2.3 KiB
C
101 lines
2.3 KiB
C
#include "types.h"
|
|
#include "param.h"
|
|
#include "mmu.h"
|
|
#include "proc.h"
|
|
#include "defs.h"
|
|
#include "x86.h"
|
|
#include "traps.h"
|
|
#include "syscall.h"
|
|
|
|
struct Gatedesc idt[256];
|
|
struct Pseudodesc idt_pd = { 0, sizeof(idt) - 1, (unsigned) &idt };
|
|
extern unsigned vectors[]; /* vectors.S, array of 256 entry point addresses */
|
|
|
|
extern void trapenter();
|
|
extern void trapenter1();
|
|
|
|
void
|
|
tvinit()
|
|
{
|
|
int i;
|
|
|
|
for(i = 0; i < 256; i++){
|
|
SETGATE(idt[i], 1, SEG_KCODE << 3, vectors[i], 0);
|
|
}
|
|
SETGATE(idt[T_SYSCALL], T_SYSCALL, SEG_KCODE << 3, vectors[48], 3);
|
|
}
|
|
|
|
void
|
|
idtinit()
|
|
{
|
|
asm volatile("lidt %0" : : "g" (idt_pd.pd_lim));
|
|
}
|
|
|
|
void
|
|
trap(struct Trapframe *tf)
|
|
{
|
|
int v = tf->tf_trapno;
|
|
|
|
if(v == T_SYSCALL){
|
|
struct proc *cp = curproc[cpu()];
|
|
int num = cp->tf->tf_regs.reg_eax;
|
|
if(cp == 0)
|
|
panic("syscall with no proc");
|
|
if(cp->killed)
|
|
proc_exit();
|
|
cp->tf = tf;
|
|
syscall();
|
|
if(cp != curproc[cpu()])
|
|
panic("trap ret wrong curproc");
|
|
if(cp->state != RUNNING)
|
|
panic("trap ret but not RUNNING");
|
|
if(tf != cp->tf)
|
|
panic("trap ret wrong tf");
|
|
if(cpus[cpu()].nlock){
|
|
cprintf("num=%d\n", num);
|
|
panic("syscall returning locks held");
|
|
}
|
|
if((read_eflags() & FL_IF) == 0)
|
|
panic("syscall returning but FL_IF clear");
|
|
if(read_esp() < (unsigned)cp->kstack ||
|
|
read_esp() >= (unsigned)cp->kstack + KSTACKSIZE)
|
|
panic("trap ret esp wrong");
|
|
if(cp->killed)
|
|
proc_exit();
|
|
return;
|
|
}
|
|
|
|
if(v == (IRQ_OFFSET + IRQ_TIMER)){
|
|
struct proc *cp = curproc[cpu()];
|
|
lapic_timerintr();
|
|
if(cpus[cpu()].nlock)
|
|
panic("timer interrupt while holding a lock");
|
|
if((read_eflags() & FL_IF) == 0)
|
|
panic("timer interrupt but interrupts now disabled");
|
|
if(cp){
|
|
// Force process exit if it has been killed
|
|
// and the interrupt came from user space.
|
|
// (If the kernel was executing at time of interrupt,
|
|
// don't kill the process. Let the process get back
|
|
// out to its regular system call return.)
|
|
if((tf->tf_cs&3) == 3 && cp->killed)
|
|
proc_exit();
|
|
|
|
// Force process to give up CPU and let others run.
|
|
if(cp->state == RUNNING)
|
|
yield();
|
|
}
|
|
return;
|
|
}
|
|
|
|
if(v == (IRQ_OFFSET + IRQ_IDE)){
|
|
ide_intr();
|
|
return;
|
|
}
|
|
|
|
|
|
// XXX probably ought to lgdt on trap return
|
|
|
|
return;
|
|
}
|