8a8be1b8c3
fix acquire() to cli() *before* incrementing nlock make T_SYSCALL a trap gate, not an interrupt gate sadly, various crashes if you hold down a keyboard key...
111 lines
2.5 KiB
C
111 lines
2.5 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];
|
|
extern uint vectors[]; /* vectors.S, array of 256 entry point addresses */
|
|
|
|
extern void trapenter(void);
|
|
extern void trapenter1(void);
|
|
|
|
void
|
|
tvinit(void)
|
|
{
|
|
int i;
|
|
|
|
for(i = 0; i < 256; i++){
|
|
SETGATE(idt[i], 1, SEG_KCODE << 3, vectors[i], 0);
|
|
}
|
|
SETGATE(idt[T_SYSCALL], 1, SEG_KCODE << 3, vectors[48], 3);
|
|
}
|
|
|
|
void
|
|
idtinit(void)
|
|
{
|
|
lidt(idt, sizeof idt);
|
|
}
|
|
|
|
void
|
|
trap(struct trapframe *tf)
|
|
{
|
|
int v = tf->trapno;
|
|
|
|
if(cpus[cpu()].nlock){
|
|
cprintf("trap v %d eip %x cpu %d nlock %d\n",
|
|
v, tf->eip, cpu(), cpus[cpu()].nlock);
|
|
panic("interrupt while holding a lock");
|
|
}
|
|
|
|
if(v == T_SYSCALL){
|
|
struct proc *cp = curproc[cpu()];
|
|
int num = cp->tf->eax;
|
|
if((read_eflags() & FL_IF) == 0)
|
|
panic("syscall but interrupts now disabled");
|
|
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() < (uint)cp->kstack ||
|
|
read_esp() >= (uint)cp->kstack + KSTACKSIZE)
|
|
panic("trap ret esp wrong");
|
|
if(cp->killed)
|
|
proc_exit();
|
|
// XXX probably ought to lgdt on trap return
|
|
return;
|
|
}
|
|
|
|
//if(read_eflags() & FL_IF)
|
|
//panic("interrupt but interrupts enabled");
|
|
|
|
if(v == (IRQ_OFFSET + IRQ_TIMER)){
|
|
struct proc *cp = curproc[cpu()];
|
|
lapic_timerintr();
|
|
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->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;
|
|
}
|
|
|
|
if(v == (IRQ_OFFSET + IRQ_KBD)){
|
|
kbd_intr();
|
|
return;
|
|
}
|
|
|
|
cprintf("trap %d\n", v);
|
|
|
|
return;
|
|
}
|