Example #1
0
static inline int
save_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
{
	int err = 0;
#ifdef CONFIG_SMP
	if (test_tsk_thread_flag(current, TIF_USEDFPU)) {
		put_psr(get_psr() | PSR_EF);
		fpsave(&current->thread.float_regs[0], &current->thread.fsr,
		       &current->thread.fpqueue[0], &current->thread.fpqdepth);
		regs->psr &= ~(PSR_EF);
		clear_tsk_thread_flag(current, TIF_USEDFPU);
	}
#else
	if (current == last_task_used_math) {
		put_psr(get_psr() | PSR_EF);
		fpsave(&current->thread.float_regs[0], &current->thread.fsr,
		       &current->thread.fpqueue[0], &current->thread.fpqdepth);
		last_task_used_math = NULL;
		regs->psr &= ~(PSR_EF);
	}
#endif
	err |= __copy_to_user(&fpu->si_float_regs[0],
			      &current->thread.float_regs[0],
			      (sizeof(unsigned long) * 32));
	err |= __put_user(current->thread.fsr, &fpu->si_fsr);
	err |= __put_user(current->thread.fpqdepth, &fpu->si_fpqdepth);
	if (current->thread.fpqdepth != 0)
		err |= __copy_to_user(&fpu->si_fpqueue[0],
				      &current->thread.fpqueue[0],
				      ((sizeof(unsigned long) +
				      (sizeof(unsigned long *)))*16));
	clear_used_math();
	return err;
}
Example #2
0
/*
 *  math coprocessor error
 */
static void
matherror(Ureg *ur, void*)
{
	ulong status, pc;

	/*
	 *  a write cycle to port 0xF0 clears the interrupt latch attached
	 *  to the error# line from the 387
	 */
	if(!(m->cpuiddx & Fpuonchip))
		outb(0xF0, 0xFF);

	/*
	 *  save floating point state to check out error
	 */
	fpenv(&up->fpsave);	/* result ignored, but masks fp exceptions */
	fpsave(&up->fpsave);		/* also turns fpu off */
	fpon();
	mathnote();

	if((ur->pc & 0xf0000000) == KZERO){
		mathstate(&status, &pc, nil);
		panic("fp: status %#lux fppc=%#lux pc=%#lux", status, pc, ur->pc);
	}
}
Example #3
0
File: main.c Project: 99years/plan9
void
main(void)
{
	memset(edata, 0, (ulong)end-(ulong)edata);
	conf.nmach = 1;
	machinit();
	confinit();
	xinit();
	trapinit();
	mmuinit();
	plan9iniinit();
	hwintrinit();
	clockinit();
	timerinit();
	console();
	quotefmtinstall();
	printinit();
	cpuidprint();
	print("\nPlan 9 from Bell Labs\n");
	procinit0();
	initseg();
	timersinit();
	links();
	chandevreset();
	pageinit();
	swapinit();
	sharedseginit();
	fpsave(&initfp);
	initfp.fpscr = 0;
	userinit();
	schedinit();
}
Example #4
0
static inline int
setup_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
{
	int err = 0;
	int fpvalid;

	fpvalid = !!used_math();
	err |= __put_user(fpvalid, &sc->sc_fpvalid);
	if (! fpvalid)
		return err;

	if (current == last_task_used_math) {
		grab_fpu();
		fpsave(&current->thread.fpu.hard);
		release_fpu();
		last_task_used_math = NULL;
		regs->sr |= SR_FD;
	}

	err |= __copy_to_user(&sc->sc_fpregs[0], &current->thread.fpu.hard,
			      (sizeof(long long) * 32) + (sizeof(int) * 1));
	clear_used_math();

	return err;
}
Example #5
0
void flush_thread(void)
{
	/* Make sure old user windows don't get in the way. */
	flush_user_windows();
	current->tss.w_saved = 0;
	current->tss.uwinmask = 0;
	current->tss.sig_address = 0;
	current->tss.sig_desc = 0;
	current->tss.sstk_info.cur_status = 0;
	current->tss.sstk_info.the_stack = 0;

	if(last_task_used_math == current) {
		/* Clean the fpu. */
		put_psr(get_psr() | PSR_EF);
		fpsave(&current->tss.float_regs[0], &current->tss.fsr,
		       &current->tss.fpqueue[0], &current->tss.fpqdepth);
		last_task_used_math = NULL;
	}

	memset(&current->tss.reg_window[0], 0,
	       (sizeof(struct dummy_reg_window) * NSWINS));
	memset(&current->tss.rwbuf_stkptrs[0], 0,
	       (sizeof(unsigned long) * NSWINS));
	/* Now, this task is no longer a kernel thread. */
	current->tss.flags &= ~SPARC_FLAG_KTHREAD;
}
Example #6
0
/*
 *  Save the mach dependent part of the process state.
 */
void
procsave(Proc *p)
{
	if(p->fpstate == FPactive){
		if(p->state != Moribund)
			fpsave(&up->fpsave);
		p->fpstate = FPinactive;
	}
}
Example #7
0
File: main.c Project: 99years/plan9
/*
 *  Save the mach dependent part of the process state.
 */
void
procsave(Proc *p)
{
	uvlong t;

	cycles(&t);
	p->pcycles += t;
	if(p->fpstate == FPactive){
		if(p->state != Moribund)
			fpsave(&up->fpsave);
		p->fpstate = FPinactive;
	}
}
Example #8
0
/*
 * Free current thread data structures etc..
 */
void exit_thread(void)
{
	
  //flush_user_windows();

  //printk("exit_thread %i\n",current->pid);
  
  if(last_task_used_math == current) {
    /* Keep process from leaving FPU in a bogon state. */
    put_psr(get_psr() | PSR_EF);
    fpsave(&current->tss.float_regs[0], &current->tss.fsr,
	   &current->tss.fpqueue[0], &current->tss.fpqdepth);
    last_task_used_math = NULL;
  }
}
Example #9
0
/*
 *  Save the mach dependent part of the process state.
 */
void
procsave(Proc *p)
{
	uvlong t;

	cycles(&t);
	p->kentry -= t;
	p->pcycles += t;

	if(p->fpstate == FPactive){
		if(p->state == Moribund)
			fpclear();
		else{
			/*
			 * Fpsave() stores without handling pending
			 * unmasked exeptions. Postnote() can't be called
			 * here as sleep() already has up->rlock, so
			 * the handling of pending exceptions is delayed
			 * until the process runs again and generates an
			 * emulation fault to activate the FPU.
			 */
			fpsave(&p->fpsave);
		}
		p->fpstate = FPinactive;
	}

	/*
	 * While this processor is in the scheduler, the process could run
	 * on another processor and exit, returning the page tables to
	 * the free list where they could be reallocated and overwritten.
	 * When this processor eventually has to get an entry from the
	 * trashed page tables it will crash.
	 *
	 * If there's only one processor, this can't happen.
	 * You might think it would be a win not to do this in that case,
	 * especially on VMware, but it turns out not to matter.
	 */
	mmuflushtlb(PADDR(m->pdb));
}
Example #10
0
void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
		 unsigned long psr)
{
	/* Sanity check... */
	if(psr & PSR_PS)
		die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);

	put_psr(get_psr() | PSR_EF);    /* Allow FPU ops. */
	regs->psr |= PSR_EF;
#ifndef CONFIG_SMP
	if(last_task_used_math == current)
		return;
	if(last_task_used_math) {
		/* Other processes fpu state, save away */
		struct task_struct *fptask = last_task_used_math;
		fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
		       &fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
	}
	last_task_used_math = current;
	if(current->used_math) {
		fpload(&current->thread.float_regs[0], &current->thread.fsr);
	} else {
		/* Set initial sane state. */
		fpload(&init_fregs[0], &init_fsr);
		current->used_math = 1;
	}
#else
	if(!current->used_math) {
		fpload(&init_fregs[0], &init_fsr);
		current->used_math = 1;
	} else {
		fpload(&current->thread.float_regs[0], &current->thread.fsr);
	}
	current->flags |= PF_USEDFPU;
#endif
}
Example #11
0
/*
 * Free current thread data structures etc..
 */
void exit_thread(void)
{
#ifndef CONFIG_SMP
	if(last_task_used_math == current) {
#else
	if(current->flags & PF_USEDFPU) {
#endif
		/* Keep process from leaving FPU in a bogon state. */
		put_psr(get_psr() | PSR_EF);
		fpsave(&current->thread.float_regs[0], &current->thread.fsr,
		       &current->thread.fpqueue[0], &current->thread.fpqdepth);
#ifndef CONFIG_SMP
		last_task_used_math = NULL;
#else
		current->flags &= ~PF_USEDFPU;
#endif
	}
}

void flush_thread(void)
{
	current->thread.w_saved = 0;

	/* No new signal delivery by default */
	current->thread.new_signal = 0;
#ifndef CONFIG_SMP
	if(last_task_used_math == current) {
#else
	if(current->flags & PF_USEDFPU) {
#endif
		/* Clean the fpu. */
		put_psr(get_psr() | PSR_EF);
		fpsave(&current->thread.float_regs[0], &current->thread.fsr,
		       &current->thread.fpqueue[0], &current->thread.fpqdepth);
#ifndef CONFIG_SMP
		last_task_used_math = NULL;
#else
		current->flags &= ~PF_USEDFPU;
#endif
	}

	/* Now, this task is no longer a kernel thread. */
	current->thread.current_ds = USER_DS;
	if (current->thread.flags & SPARC_FLAG_KTHREAD) {
		current->thread.flags &= ~SPARC_FLAG_KTHREAD;

		/* We must fixup kregs as well. */
		current->thread.kregs = (struct pt_regs *)
			(((unsigned long)current) +
			 (TASK_UNION_SIZE - TRACEREG_SZ));
	}
}

static __inline__ void copy_regs(struct pt_regs *dst, struct pt_regs *src)
{
	__asm__ __volatile__("ldd\t[%1 + 0x00], %%g2\n\t"
			     "ldd\t[%1 + 0x08], %%g4\n\t"
			     "ldd\t[%1 + 0x10], %%o4\n\t"
			     "std\t%%g2, [%0 + 0x00]\n\t"
			     "std\t%%g4, [%0 + 0x08]\n\t"
			     "std\t%%o4, [%0 + 0x10]\n\t"
			     "ldd\t[%1 + 0x18], %%g2\n\t"
			     "ldd\t[%1 + 0x20], %%g4\n\t"
			     "ldd\t[%1 + 0x28], %%o4\n\t"
			     "std\t%%g2, [%0 + 0x18]\n\t"
			     "std\t%%g4, [%0 + 0x20]\n\t"
			     "std\t%%o4, [%0 + 0x28]\n\t"
			     "ldd\t[%1 + 0x30], %%g2\n\t"
			     "ldd\t[%1 + 0x38], %%g4\n\t"
			     "ldd\t[%1 + 0x40], %%o4\n\t"
			     "std\t%%g2, [%0 + 0x30]\n\t"
			     "std\t%%g4, [%0 + 0x38]\n\t"
			     "ldd\t[%1 + 0x48], %%g2\n\t"
			     "std\t%%o4, [%0 + 0x40]\n\t"
			     "std\t%%g2, [%0 + 0x48]\n\t" : :
			     "r" (dst), "r" (src) :
			     "g2", "g3", "g4", "g5", "o4", "o5");
}
Example #12
0
/*
 *  Call user, if necessary, with note.
 *  Pass user the Ureg struct and the note on his stack.
 */
int
notify(Ureg* ureg)
{
	int l;
	ulong s, sp;
	Note *n;

	if(up->procctl)
		procctl(up);
	if(up->nnote == 0)
		return 0;

	if(up->fpstate == FPactive){
		fpsave(&up->fpsave);
		up->fpstate = FPinactive;
	}
	up->fpstate |= FPillegal;

	s = spllo();
	qlock(&up->debug);
	up->notepending = 0;
	n = &up->note[0];
	if(strncmp(n->msg, "sys:", 4) == 0){
		l = strlen(n->msg);
		if(l > ERRMAX-15)	/* " pc=0x12345678\0" */
			l = ERRMAX-15;
		sprint(n->msg+l, " pc=0x%.8lux", ureg->pc);
	}

	if(n->flag!=NUser && (up->notified || up->notify==0)){
		if(n->flag == NDebug)
			pprint("suicide: %s\n", n->msg);
		qunlock(&up->debug);
		pexit(n->msg, n->flag!=NDebug);
	}

	if(up->notified){
		qunlock(&up->debug);
		splhi();
		return 0;
	}

	if(!up->notify){
		qunlock(&up->debug);
		pexit(n->msg, n->flag!=NDebug);
	}
	sp = ureg->usp;
	sp -= 256;	/* debugging: preserve context causing problem */
	sp -= sizeof(Ureg);
if(0) print("%s %lud: notify %.8lux %.8lux %.8lux %s\n", 
	up->text, up->pid, ureg->pc, ureg->usp, sp, n->msg);

	if(!okaddr((ulong)up->notify, 1, 0)
	|| !okaddr(sp-ERRMAX-4*BY2WD, sizeof(Ureg)+ERRMAX+4*BY2WD, 1)){
		pprint("suicide: bad address in notify\n");
		qunlock(&up->debug);
		pexit("Suicide", 0);
	}

	memmove((Ureg*)sp, ureg, sizeof(Ureg));
	*(Ureg**)(sp-BY2WD) = up->ureg;	/* word under Ureg is old up->ureg */
	up->ureg = (void*)sp;
	sp -= BY2WD+ERRMAX;
	memmove((char*)sp, up->note[0].msg, ERRMAX);
	sp -= 3*BY2WD;
	*(ulong*)(sp+2*BY2WD) = sp+3*BY2WD;		/* arg 2 is string */
	*(ulong*)(sp+1*BY2WD) = (ulong)up->ureg;	/* arg 1 is ureg* */
	*(ulong*)(sp+0*BY2WD) = 0;			/* arg 0 is pc */
	ureg->usp = sp;
	ureg->pc = (ulong)up->notify;
	up->notified = 1;
	up->nnote--;
	memmove(&up->lastnote, &up->note[0], sizeof(Note));
	memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));

	qunlock(&up->debug);
	splx(s);
	return 1;
}
Example #13
0
/*
 *  Syscall is called directly from assembler without going through trap().
 */
void
syscall(Ureg* ureg)
{
	char *e;
	ulong	sp;
	long	ret;
	int	i, s;
	ulong scallnr;

	if((ureg->cs & 0xFFFF) != UESEL)
		panic("syscall: cs 0x%4.4luX", ureg->cs);

	cycles(&up->kentry);

	m->syscall++;
	up->insyscall = 1;
	up->pc = ureg->pc;
	up->dbgreg = ureg;

	if(up->procctl == Proc_tracesyscall){
		up->procctl = Proc_stopme;
		procctl(up);
	}

	scallnr = ureg->ax;
	up->scallnr = scallnr;
	if(scallnr == RFORK && up->fpstate == FPactive){
		fpsave(&up->fpsave);
		up->fpstate = FPinactive;
	}
	spllo();

	sp = ureg->usp;
	up->nerrlab = 0;
	ret = -1;
	if(!waserror()){
		if(scallnr >= nsyscall || systab[scallnr] == 0){
			pprint("bad sys call number %lud pc %lux\n",
				scallnr, ureg->pc);
			postnote(up, 1, "sys: bad sys call", NDebug);
			error(Ebadarg);
		}

		if(sp<(USTKTOP-BY2PG) || sp>(USTKTOP-sizeof(Sargs)-BY2WD))
			validaddr(sp, sizeof(Sargs)+BY2WD, 0);

		up->s = *((Sargs*)(sp+BY2WD));
		up->psstate = sysctab[scallnr];

		ret = systab[scallnr](up->s.args);
		poperror();
	}else{
		/* failure: save the error buffer for errstr */
		e = up->syserrstr;
		up->syserrstr = up->errstr;
		up->errstr = e;
		if(0 && up->pid == 1)
			print("syscall %lud error %s\n", scallnr, up->syserrstr);
	}
	if(up->nerrlab){
		print("bad errstack [%lud]: %d extra\n", scallnr, up->nerrlab);
		for(i = 0; i < NERR; i++)
			print("sp=%lux pc=%lux\n",
				up->errlab[i].sp, up->errlab[i].pc);
		panic("error stack");
	}

	/*
	 *  Put return value in frame.  On the x86 the syscall is
	 *  just another trap and the return value from syscall is
	 *  ignored.  On other machines the return value is put into
	 *  the results register by caller of syscall.
	 */
	ureg->ax = ret;

	if(up->procctl == Proc_tracesyscall){
		up->procctl = Proc_stopme;
		s = splhi();
		procctl(up);
		splx(s);
	}

	up->insyscall = 0;
	up->psstate = 0;

	if(scallnr == NOTED)
		noted(ureg, *(ulong*)(sp+BY2WD));

	if(scallnr!=RFORK && (up->procctl || up->nnote)){
		splhi();
		notify(ureg);
	}
	/* if we delayed sched because we held a lock, sched now */
	if(up->delaysched)
		sched();
	kexit(ureg);
}
Example #14
0
void copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
		 struct task_struct *p, struct pt_regs *regs)
{
	struct pt_regs *childregs;
	struct sparc_stackf *old_stack, *new_stack;
	unsigned long stack_offset;

	//flush_user_windows();

	//printk ("copy_thread\n");
	//show_regs(regs);
	
	if(last_task_used_math == current) {
		put_psr(get_psr() | PSR_EF);
		fpsave(&p->tss.float_regs[0], &p->tss.fsr,
		       &p->tss.fpqueue[0], &p->tss.fpqdepth);
	}

	/* Calculate offset to stack_frame & pt_regs */
	stack_offset = ((PAGE_SIZE ) - TRACEREG_SZ);



	/*
	 *  p->kernel_stack_page   new_stack   childregs
	 *  !                      !           !             {if(PSR_PS) }
	 *  V                      V (stk.fr.) V  (pt_regs)  { (stk.fr.) }
	 *  +----- - - - - - ------+===========+============={+==========}+
	 */

	if(regs->psr & PSR_PS)
		stack_offset -= REGWIN_SZ;
	childregs = ((struct pt_regs *) (p->kernel_stack_page + stack_offset));
	*childregs = *regs;
	new_stack = (((struct sparc_stackf *) childregs) - 1);
	old_stack = (((struct sparc_stackf *) regs) - 1);
	*new_stack = *old_stack;
	
	
	p->tss.ksp = p->saved_kernel_stack = (unsigned long) new_stack;
	p->tss.kpc = (((unsigned long) ret_sys_call) - 0x8);
	p->tss.kpsr = current->tss.fork_kpsr;
	p->tss.kwim = current->tss.fork_kwim;
	p->tss.kregs = childregs;
	childregs->u_regs[UREG_FP] = sp;

	if(regs->psr & PSR_PS) {
		stack_offset += TRACEREG_SZ;
		childregs->u_regs[UREG_FP] = p->kernel_stack_page + stack_offset;
		p->tss.flags |= SPARC_FLAG_KTHREAD;
	} else {
		struct sparc_stackf *childstack;
		struct sparc_stackf *parentstack;
		
		p->tss.flags &= ~SPARC_FLAG_KTHREAD;
		
		childstack = (struct sparc_stackf *) (sp & ~0x7UL);
		parentstack = (struct sparc_stackf *) regs->u_regs[UREG_FP];

                if (childstack == parentstack) {
                  //adapt the copy depth when after fork() parent pushes more stack frames.
                  childstack = clone_stackframe(childstack, parentstack,3,1024);
                } else {
                  childstack = clone_stackframe(childstack, parentstack,3,0);
                }
                
                childregs->u_regs[UREG_FP] = (unsigned long)childstack;
		
		/*
		  printk("Parent stack\n");
		__show_backtrace(parentstack);
		printk("Child stack\n");
		__show_backtrace(childstack);
		*/
		
	}

	/* Set the return value for the child. */
	childregs->u_regs[UREG_I0] = current->pid;
	childregs->u_regs[UREG_I1] = 1;

	/* Set the return value for the parent. */
	regs->u_regs[UREG_I1] = 0;

	/*
       	printk("Parent: (%i)\n",current->pid);
	show_regs(regs);
	printk("Child: (%i)\n",p->pid);
	show_regs(childregs);
	*/
}
Example #15
0
void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
		 unsigned long psr)
{
	static int calls;
	siginfo_t info;
	unsigned long fsr;
	int ret = 0;
#ifndef CONFIG_SMP
	struct task_struct *fpt = last_task_used_math;
#else
	struct task_struct *fpt = current;
#endif
	put_psr(get_psr() | PSR_EF);
	/* If nobody owns the fpu right now, just clear the
	 * error into our fake static buffer and hope it don't
	 * happen again.  Thank you crashme...
	 */
#ifndef CONFIG_SMP
	if(!fpt) {
#else
        if(!(fpt->flags & PF_USEDFPU)) {
#endif
		fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
		regs->psr &= ~PSR_EF;
		return;
	}
	fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
	       &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
#ifdef DEBUG_FPU
	printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
#endif

	switch ((fpt->thread.fsr & 0x1c000)) {
	/* switch on the contents of the ftt [floating point trap type] field */
#ifdef DEBUG_FPU
	case (1 << 14):
		printk("IEEE_754_exception\n");
		break;
#endif
	case (2 << 14):  /* unfinished_FPop (underflow & co) */
	case (3 << 14):  /* unimplemented_FPop (quad stuff, maybe sqrt) */
		ret = do_mathemu(regs, fpt);
		break;
#ifdef DEBUG_FPU
	case (4 << 14):
		printk("sequence_error (OS bug...)\n");
		break;
	case (5 << 14):
		printk("hardware_error (uhoh!)\n");
		break;
	case (6 << 14):
		printk("invalid_fp_register (user error)\n");
		break;
#endif /* DEBUG_FPU */
	}
	/* If we successfully emulated the FPop, we pretend the trap never happened :-> */
	if (ret) {
		fpload(&current->thread.float_regs[0], &current->thread.fsr);
		return;
	}
	/* nope, better SIGFPE the offending process... */
	       
#ifdef CONFIG_SMP
	fpt->flags &= ~PF_USEDFPU;
#endif
	if(psr & PSR_PS) {
		/* The first fsr store/load we tried trapped,
		 * the second one will not (we hope).
		 */
		printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
		       regs->pc);
		regs->pc = regs->npc;
		regs->npc += 4;
		calls++;
		if(calls > 2)
			die_if_kernel("Too many Penguin-FPU traps from kernel mode",
				      regs);
		return;
	}

	fsr = fpt->thread.fsr;
	info.si_signo = SIGFPE;
	info.si_errno = 0;
	info.si_addr = (void *)pc;
	info.si_trapno = 0;
	info.si_code = __SI_FAULT;
	if ((fsr & 0x1c000) == (1 << 14)) {
		if (fsr & 0x10)
			info.si_code = FPE_FLTINV;
		else if (fsr & 0x08)
			info.si_code = FPE_FLTOVF;
		else if (fsr & 0x04)
			info.si_code = FPE_FLTUND;
		else if (fsr & 0x02)
			info.si_code = FPE_FLTDIV;
		else if (fsr & 0x01)
			info.si_code = FPE_FLTRES;
	}
	send_sig_info(SIGFPE, &info, fpt);
#ifndef CONFIG_SMP
	last_task_used_math = NULL;
#endif
	regs->psr &= ~PSR_EF;
	if(calls > 0)
		calls=0;
}

void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			 unsigned long psr)
{
	siginfo_t info;

	if(psr & PSR_PS)
		die_if_kernel("Penguin overflow trap from kernel mode", regs);
	info.si_signo = SIGEMT;
	info.si_errno = 0;
	info.si_code = EMT_TAGOVF;
	info.si_addr = (void *)pc;
	info.si_trapno = 0;
	send_sig_info(SIGEMT, &info, current);
}
Example #16
0
void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
		 unsigned long psr)
{
	static calls = 0;
#ifndef __SMP__
	struct task_struct *fpt = last_task_used_math;
#else
	struct task_struct *fpt = current;
#endif

	put_psr(get_psr() | PSR_EF);
	/* If nobody owns the fpu right now, just clear the
	 * error into our fake static buffer and hope it don't
	 * happen again.  Thank you crashme...
	 */
#ifndef __SMP__
	if(!fpt) {
#else
        if(!(fpt->flags & PF_USEDFPU)) {
#endif
		fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
		regs->psr &= ~PSR_EF;
		return;
	}
	fpsave(&fpt->tss.float_regs[0], &fpt->tss.fsr,
	       &fpt->tss.fpqueue[0], &fpt->tss.fpqdepth);
	fpt->tss.sig_address = pc;
	fpt->tss.sig_desc = SUBSIG_FPERROR; /* as good as any */
#ifdef __SMP__
	fpt->flags &= ~PF_USEDFPU;
#endif
	if(psr & PSR_PS) {
		/* The first fsr store/load we tried trapped,
		 * the second one will not (we hope).
		 */
		printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
		       regs->pc);
		regs->pc = regs->npc;
		regs->npc += 4;
		calls++;
		if(calls > 2)
			die_if_kernel("Too many Penguin-FPU traps from kernel mode",
				      regs);
		return;
	}
	send_sig(SIGFPE, fpt, 1);
#ifndef __SMP__
	last_task_used_math = NULL;
#endif
	regs->psr &= ~PSR_EF;
	if(calls > 0)
		calls=0;
}

void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			 unsigned long psr)
{
	if(psr & PSR_PS)
		die_if_kernel("Penguin overflow trap from kernel mode", regs);
	current->tss.sig_address = pc;
	current->tss.sig_desc = SUBSIG_TAG; /* as good as any */
	send_sig(SIGEMT, current, 1);
}

void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
		       unsigned long psr)
{
#ifdef TRAP_DEBUG
	printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
	       pc, npc, psr);
#endif
	if(psr & PSR_PS)
		panic("Tell me what a watchpoint trap is, and I'll then deal "
		      "with such a beast...");
}