static int
db_gs(struct db_variable *vp, db_expr_t *valuep, int op)
{
if (op == DB_VAR_GET)
*valuep = rgs();
else
load_gs(*valuep);
return (1);
}
/*
* exec_setregs may initialize some registers differently than Linux
* does, thus potentially confusing Linux binaries. If necessary, we
* override the exec_setregs default(s) here.
*/
static void
exec_linux_setregs(struct thread *td, struct image_params *imgp, u_long stack)
{
struct pcb *pcb = td->td_pcb;
exec_setregs(td, imgp, stack);
/* Linux sets %gs to 0, we default to _udatasel */
pcb->pcb_gs = 0;
load_gs(0);
pcb->pcb_initial_npxcw = __LINUX_NPXCW__;
}
void
cpu_setregs(void)
{
#if 0
unsigned int cr0;
cr0 = rcr0();
cr0 |= CR0_NE; /* Done by npxinit() */
cr0 |= CR0_MP | CR0_TS; /* Done at every execve() too. */
cr0 |= CR0_WP | CR0_AM;
load_cr0(cr0);
load_gs(_udatasel);
#endif
}
static int
db_gs(struct db_variable *vp, db_expr_t *valuep, int op)
{
struct trapframe_vm86 *tfp;
if (kdb_frame != NULL && kdb_frame->tf_eflags & PSL_VM) {
tfp = (void *)kdb_frame;
if (op == DB_VAR_GET)
*valuep = tfp->tf_vm86_gs;
else
tfp->tf_vm86_gs = *valuep;
return (1);
}
if (op == DB_VAR_GET)
*valuep = rgs();
else
load_gs(*valuep);
return (1);
}
/*
* All traps come here. It is slower to have all traps call trap()
* rather than directly vectoring the handler. However, this avoids a
* lot of code duplication and possible bugs. The only exception is
* VectorSYSCALL.
* Trap is called with interrupts disabled via interrupt-gates.
*/
void
trap(Ureg* ureg)
{
int clockintr, i, vno, user;
char buf[ERRMAX];
Vctl *ctl, *v;
Mach *mach;
if(!trapinited){
/* fault386 can give a better error message */
if(ureg->trap == VectorPF)
fault386(ureg, nil);
panic("trap %lud: not ready", ureg->trap);
}
m->perf.intrts = perfticks();
user = userureg(ureg);
if(user){
up->dbgreg = ureg;
cycles(&up->kentry);
}
clockintr = 0;
vno = ureg->trap;
if(ctl = vctl[vno]){
if(ctl->isintr){
m->intr++;
if(vno >= VectorPIC && vno != VectorSYSCALL)
m->lastintr = ctl->irq;
}
if(ctl->isr)
ctl->isr(vno);
for(v = ctl; v != nil; v = v->next){
if(v->f)
v->f(ureg, v->a);
}
if(ctl->eoi)
ctl->eoi(vno);
if(ctl->isintr){
intrtime(m, vno);
if(ctl->irq == IrqCLOCK || ctl->irq == IrqTIMER)
clockintr = 1;
if(up && !clockintr)
preempted();
}
}
else if(vno < nelem(excname) && user){
spllo();
sprint(buf, "sys: trap: %s", excname[vno]);
postnote(up, 1, buf, NDebug);
}
else if(vno >= VectorPIC && vno != VectorSYSCALL){
/*
* An unknown interrupt.
* Check for a default IRQ7. This can happen when
* the IRQ input goes away before the acknowledge.
* In this case, a 'default IRQ7' is generated, but
* the corresponding bit in the ISR isn't set.
* In fact, just ignore all such interrupts.
*/
/* call all interrupt routines, just in case */
for(i = VectorPIC; i <= MaxIrqLAPIC; i++){
ctl = vctl[i];
if(ctl == nil)
continue;
if(!ctl->isintr)
continue;
for(v = ctl; v != nil; v = v->next){
if(v->f)
v->f(ureg, v->a);
}
/* should we do this? */
if(ctl->eoi)
ctl->eoi(i);
}
/* clear the interrupt */
i8259isr(vno);
if(0)print("cpu%d: spurious interrupt %d, last %d\n",
m->machno, vno, m->lastintr);
if(0)if(conf.nmach > 1){
for(i = 0; i < 32; i++){
if(!(active.machs & (1<<i)))
continue;
mach = MACHP(i);
if(m->machno == mach->machno)
continue;
print(" cpu%d: last %d",
mach->machno, mach->lastintr);
}
print("\n");
}
m->spuriousintr++;
if(user)
kexit(ureg);
return;
}
else{
if(vno == VectorNMI){
/*
* Don't re-enable, it confuses the crash dumps.
nmienable();
*/
iprint("cpu%d: nmi PC %#8.8lux, status %ux\n",
m->machno, ureg->pc, inb(0x61));
while(m->machno != 0)
;
}
if(!user){
void (*pc)(void);
ulong *sp;
extern void _forkretpopgs(void);
extern void _forkretpopfs(void);
extern void _forkretpopes(void);
extern void _forkretpopds(void);
extern void _forkretiret(void);
extern void _rdmsrinst(void);
extern void _wrmsrinst(void);
extern void load_fs(ulong);
extern void load_gs(ulong);
load_fs(NULLSEL);
load_gs(NULLSEL);
sp = (ulong*)&ureg->sp; /* kernel stack */
pc = (void*)ureg->pc;
if(pc == _forkretpopgs || pc == _forkretpopfs ||
pc == _forkretpopes || pc == _forkretpopds){
if(vno == VectorGPF || vno == VectorSNP){
sp[0] = NULLSEL;
return;
}
} else if(pc == _forkretiret){
if(vno == VectorGPF || vno == VectorSNP){
sp[1] = UESEL; /* CS */
sp[4] = UDSEL; /* SS */
return;
}
} else if(pc == _rdmsrinst || pc == _wrmsrinst){
if(vno == VectorGPF){
ureg->bp = -1;
ureg->pc += 2;
return;
}
}
}
dumpregs(ureg);
if(!user){
ureg->sp = (ulong)&ureg->sp;
_dumpstack(ureg);
}
if(vno < nelem(excname))
panic("%s", excname[vno]);
panic("unknown trap/intr: %d", vno);
}
splhi();
/* delaysched set because we held a lock or because our quantum ended */
if(up && up->delaysched && clockintr){
sched();
splhi();
}
if(user){
if(up->procctl || up->nnote)
notify(ureg);
kexit(ureg);
}
}
