Esempio n. 1
0
File: trap.c Progetto: MarginC/kame
void
m88110_trap(unsigned type, struct trapframe *frame)
{
	struct proc *p;
	u_quad_t sticks = 0;
	struct vm_map *map;
	vaddr_t va, pcb_onfault;
	vm_prot_t ftype;
	int fault_type;
	u_long fault_code;
	unsigned nss, fault_addr;
	struct vmspace *vm;
	union sigval sv;
	int result;
#ifdef DDB
        int s;
#endif
	int sig = 0;
	pt_entry_t *pte;

	extern struct vm_map *kernel_map;
	extern unsigned guarded_access_start;
	extern unsigned guarded_access_end;
	extern unsigned guarded_access_bad;
	extern pt_entry_t *pmap_pte(pmap_t, vaddr_t);

	uvmexp.traps++;
	if ((p = curproc) == NULL)
		p = &proc0;

	if (USERMODE(frame->tf_epsr)) {
		sticks = p->p_sticks;
		type += T_USER;
		p->p_md.md_tf = frame;	/* for ptrace/signals */
	}
	fault_type = 0;
	fault_code = 0;
	fault_addr = frame->tf_exip & XIP_ADDR;

	switch (type) {
	default:
		panictrap(frame->tf_vector, frame);
		break;
		/*NOTREACHED*/

	case T_197_READ+T_USER:
	case T_197_READ:
		printf("DMMU read miss: Hardware Table Searches should be enabled!\n");
		panictrap(frame->tf_vector, frame);
		break;
		/*NOTREACHED*/
	case T_197_WRITE+T_USER:
	case T_197_WRITE:
		printf("DMMU write miss: Hardware Table Searches should be enabled!\n");
		panictrap(frame->tf_vector, frame);
		break;
		/*NOTREACHED*/
	case T_197_INST+T_USER:
	case T_197_INST:
		printf("IMMU miss: Hardware Table Searches should be enabled!\n");
		panictrap(frame->tf_vector, frame);
		break;
		/*NOTREACHED*/
#ifdef DDB
	case T_KDB_TRACE:
		s = splhigh();
		db_enable_interrupt();
		ddb_break_trap(T_KDB_TRACE, (db_regs_t*)frame);
		db_disable_interrupt();
		splx(s);
		return;
	case T_KDB_BREAK:
		s = splhigh();
		db_enable_interrupt();
		ddb_break_trap(T_KDB_BREAK, (db_regs_t*)frame);
		db_disable_interrupt();
		splx(s);
		return;
	case T_KDB_ENTRY:
		s = splhigh();
		db_enable_interrupt();
		ddb_entry_trap(T_KDB_ENTRY, (db_regs_t*)frame);
		db_disable_interrupt();
		/* skip one instruction */
		if (frame->tf_exip & 1)
			frame->tf_exip = frame->tf_enip;
		else
			frame->tf_exip += 4;
		splx(s);
		return;
#if 0
	case T_ILLFLT:
		s = splhigh();
		db_enable_interrupt();
		ddb_error_trap(type == T_ILLFLT ? "unimplemented opcode" :
		       "error fault", (db_regs_t*)frame);
		db_disable_interrupt();
		splx(s);
		return;
#endif /* 0 */
#endif /* DDB */
	case T_ILLFLT:
		printf("Unimplemented opcode!\n");
		panictrap(frame->tf_vector, frame);
		break;
	case T_NON_MASK:
	case T_NON_MASK+T_USER:
		(*md.interrupt_func)(T_NON_MASK, frame);
		return;
	case T_INT:
	case T_INT+T_USER:
		(*md.interrupt_func)(T_INT, frame);
		return;
	case T_MISALGNFLT:
		printf("kernel mode misaligned access exception @ 0x%08x\n",
		    frame->tf_exip);
		panictrap(frame->tf_vector, frame);
		break;
		/*NOTREACHED*/

	case T_INSTFLT:
		/* kernel mode instruction access fault.
		 * Should never, never happen for a non-paged kernel.
		 */
#ifdef TRAPDEBUG
		printf("Kernel Instruction fault exip %x isr %x ilar %x\n",
		    frame->tf_exip, frame->tf_isr, frame->tf_ilar);
#endif
		panictrap(frame->tf_vector, frame);
		break;
		/*NOTREACHED*/

	case T_DATAFLT:
		/* kernel mode data fault */

		/* data fault on the user address? */
		if ((frame->tf_dsr & CMMU_DSR_SU) == 0) {
			type = T_DATAFLT + T_USER;
			goto m88110_user_fault;
		}

#ifdef TRAPDEBUG
		printf("Kernel Data access fault exip %x dsr %x dlar %x\n",
		    frame->tf_exip, frame->tf_dsr, frame->tf_dlar);
#endif

		fault_addr = frame->tf_dlar;
		if (frame->tf_dsr & CMMU_DSR_RW) {
			ftype = VM_PROT_READ;
			fault_code = VM_PROT_READ;
		} else {
			ftype = VM_PROT_READ|VM_PROT_WRITE;
			fault_code = VM_PROT_WRITE;
		}

		va = trunc_page((vaddr_t)fault_addr);
		if (va == 0) {
			panic("trap: bad kernel access at %x", fault_addr);
		}

		vm = p->p_vmspace;
		map = kernel_map;

		if (frame->tf_dsr & CMMU_DSR_BE) {
			/*
			 * If it is a guarded access, bus error is OK.
			 */
			if ((frame->tf_exip & XIP_ADDR) >=
			      (unsigned)&guarded_access_start &&
			    (frame->tf_exip & XIP_ADDR) <=
			      (unsigned)&guarded_access_end) {
				frame->tf_exip = (unsigned)&guarded_access_bad;
				return;
			}
		}
		if (frame->tf_dsr & (CMMU_DSR_SI | CMMU_DSR_PI)) {
			frame->tf_dsr &= ~CMMU_DSR_WE;	/* undefined */
			/*
			 * On a segment or a page fault, call uvm_fault() to
			 * resolve the fault.
			 */
			if ((pcb_onfault = p->p_addr->u_pcb.pcb_onfault) != 0)
				p->p_addr->u_pcb.pcb_onfault = 0;
			result = uvm_fault(map, va, VM_FAULT_INVALID, ftype);
			p->p_addr->u_pcb.pcb_onfault = pcb_onfault;
			if (result == 0)
				return;
		}
		if (frame->tf_dsr & CMMU_DSR_WE) {	/* write fault  */
			/*
			 * This could be a write protection fault or an
			 * exception to set the used and modified bits
			 * in the pte. Basically, if we got a write error,
			 * then we already have a pte entry that faulted
			 * in from a previous seg fault or page fault.
			 * Get the pte and check the status of the
			 * modified and valid bits to determine if this
			 * indeed a real write fault.  XXX smurph
			 */
			pte = pmap_pte(map->pmap, va);
#ifdef DEBUG
			if (pte == PT_ENTRY_NULL)
				panic("NULL pte on write fault??");
#endif
			if (!(*pte & PG_M) && !(*pte & PG_RO)) {
				/* Set modified bit and try the write again. */
#ifdef TRAPDEBUG
				printf("Corrected kernel write fault, map %x pte %x\n",
				    map->pmap, *pte);
#endif
				*pte |= PG_M;
				return;
#if 1	/* shouldn't happen */
			} else {
				/* must be a real wp fault */
#ifdef TRAPDEBUG
				printf("Uncorrected kernel write fault, map %x pte %x\n",
				    map->pmap, *pte);
#endif
				if ((pcb_onfault = p->p_addr->u_pcb.pcb_onfault) != 0)
					p->p_addr->u_pcb.pcb_onfault = 0;
				result = uvm_fault(map, va, VM_FAULT_INVALID, ftype);
				p->p_addr->u_pcb.pcb_onfault = pcb_onfault;
				if (result == 0)
					return;
#endif
			}
		}
		panictrap(frame->tf_vector, frame);
		/* NOTREACHED */
	case T_INSTFLT+T_USER:
		/* User mode instruction access fault */
		/* FALLTHROUGH */
	case T_DATAFLT+T_USER:
m88110_user_fault:
		if (type == T_INSTFLT+T_USER) {
			ftype = VM_PROT_READ;
			fault_code = VM_PROT_READ;
#ifdef TRAPDEBUG
			printf("User Instruction fault exip %x isr %x ilar %x\n",
			    frame->tf_exip, frame->tf_isr, frame->tf_ilar);
#endif
		} else {
			fault_addr = frame->tf_dlar;
			if (frame->tf_dsr & CMMU_DSR_RW) {
				ftype = VM_PROT_READ;
				fault_code = VM_PROT_READ;
			} else {
				ftype = VM_PROT_READ|VM_PROT_WRITE;
				fault_code = VM_PROT_WRITE;
			}
#ifdef TRAPDEBUG
			printf("User Data access fault exip %x dsr %x dlar %x\n",
			    frame->tf_exip, frame->tf_dsr, frame->tf_dlar);
#endif
		}

		va = trunc_page((vaddr_t)fault_addr);

		vm = p->p_vmspace;
		map = &vm->vm_map;
		if ((pcb_onfault = p->p_addr->u_pcb.pcb_onfault) != 0)
			p->p_addr->u_pcb.pcb_onfault = 0;

		/*
		 * Call uvm_fault() to resolve non-bus error faults
		 * whenever possible.
		 */
		if (type == T_DATAFLT+T_USER) {
			/* data faults */
			if (frame->tf_dsr & CMMU_DSR_BE) {
				/* bus error */
				result = EACCES;
			} else
			if (frame->tf_dsr & (CMMU_DSR_SI | CMMU_DSR_PI)) {
				/* segment or page fault */
				result = uvm_fault(map, va, VM_FAULT_INVALID, ftype);
				p->p_addr->u_pcb.pcb_onfault = pcb_onfault;
				if (result == EACCES)
					result = EFAULT;
			} else
			if (frame->tf_dsr & (CMMU_DSR_CP | CMMU_DSR_WA)) {
				/* copyback or write allocate error */
				result = EACCES;
			} else
			if (frame->tf_dsr & CMMU_DSR_WE) {
				/* write fault  */
				/* This could be a write protection fault or an
				 * exception to set the used and modified bits
				 * in the pte. Basically, if we got a write
				 * error, then we already have a pte entry that
				 * faulted in from a previous seg fault or page
				 * fault.
				 * Get the pte and check the status of the
				 * modified and valid bits to determine if this
				 * indeed a real write fault.  XXX smurph
				 */
				pte = pmap_pte(vm_map_pmap(map), va);
#ifdef DEBUG
				if (pte == PT_ENTRY_NULL)
					panic("NULL pte on write fault??");
#endif
				if (!(*pte & PG_M) && !(*pte & PG_RO)) {
					/*
					 * Set modified bit and try the
					 * write again.
					 */
#ifdef TRAPDEBUG
					printf("Corrected userland write fault, map %x pte %x\n",
					    map->pmap, *pte);
#endif
					*pte |= PG_M;
					/*
					 * invalidate ATCs to force
					 * table search
					 */
					set_dcmd(CMMU_DCMD_INV_UATC);
					return;
				} else {
					/* must be a real wp fault */
#ifdef TRAPDEBUG
					printf("Uncorrected userland write fault, map %x pte %x\n",
					    map->pmap, *pte);
#endif
					result = uvm_fault(map, va, VM_FAULT_INVALID, ftype);
					p->p_addr->u_pcb.pcb_onfault = pcb_onfault;
					if (result == EACCES)
						result = EFAULT;
				}
			} else {
#ifdef TRAPDEBUG
				printf("Unexpected Data access fault dsr %x\n",
				    frame->tf_dsr);
#endif
				panictrap(frame->tf_vector, frame);
			}
		} else {
			/* instruction faults */
			if (frame->tf_isr &
			    (CMMU_ISR_BE | CMMU_ISR_SP | CMMU_ISR_TBE)) {
				/* bus error, supervisor protection */
				result = EACCES;
			} else
			if (frame->tf_isr & (CMMU_ISR_SI | CMMU_ISR_PI)) {
				/* segment or page fault */
				result = uvm_fault(map, va, VM_FAULT_INVALID, ftype);
				p->p_addr->u_pcb.pcb_onfault = pcb_onfault;
				if (result == EACCES)
					result = EFAULT;
			} else {
#ifdef TRAPDEBUG
				printf("Unexpected Instruction fault isr %x\n",
				    frame->tf_isr);
#endif
				panictrap(frame->tf_vector, frame);
			}
		}

		if ((caddr_t)va >= vm->vm_maxsaddr) {
			if (result == 0) {
				nss = btoc(USRSTACK - va);/* XXX check this */
				if (nss > vm->vm_ssize)
					vm->vm_ssize = nss;
			}
		}

		/*
		 * This could be a fault caused in copyin*()
		 * while accessing user space.
		 */
		if (result != 0 && pcb_onfault != 0) {
			frame->tf_exip = pcb_onfault;
			/*
			 * Continue as if the fault had been resolved.
			 */
			result = 0;
		}

		if (result != 0) {
			sig = result == EACCES ? SIGBUS : SIGSEGV;
			fault_type = result == EACCES ?
			    BUS_ADRERR : SEGV_MAPERR;
		}
		break;
	case T_MISALGNFLT+T_USER:
		/* Fix any misaligned ld.d or st.d instructions */
		sig = double_reg_fixup(frame);
		fault_type = BUS_ADRALN;
		break;
	case T_PRIVINFLT+T_USER:
	case T_ILLFLT+T_USER:
#ifndef DDB
	case T_KDB_BREAK:
	case T_KDB_ENTRY:
	case T_KDB_TRACE:
#endif
	case T_KDB_BREAK+T_USER:
	case T_KDB_ENTRY+T_USER:
	case T_KDB_TRACE+T_USER:
		sig = SIGILL;
		break;
	case T_BNDFLT+T_USER:
		sig = SIGFPE;
		break;
	case T_ZERODIV+T_USER:
		sig = SIGFPE;
		fault_type = FPE_INTDIV;
		break;
	case T_OVFFLT+T_USER:
		sig = SIGFPE;
		fault_type = FPE_INTOVF;
		break;
	case T_FPEPFLT+T_USER:
	case T_FPEIFLT+T_USER:
		sig = SIGFPE;
		break;
	case T_SIGSYS+T_USER:
		sig = SIGSYS;
		break;
	case T_SIGTRAP+T_USER:
		sig = SIGTRAP;
		fault_type = TRAP_TRACE;
		break;
	case T_STEPBPT+T_USER:
#ifdef PTRACE
		/*
		 * This trap is used by the kernel to support single-step
		 * debugging (although any user could generate this trap
		 * which should probably be handled differently). When a
		 * process is continued by a debugger with the PT_STEP
		 * function of ptrace (single step), the kernel inserts
		 * one or two breakpoints in the user process so that only
		 * one instruction (or two in the case of a delayed branch)
		 * is executed.  When this breakpoint is hit, we get the
		 * T_STEPBPT trap.
		 */
		{
			unsigned instr;
			unsigned pc = PC_REGS(&frame->tf_regs);

			/* read break instruction */
			copyin((caddr_t)pc, &instr, sizeof(unsigned));
#if 0
			printf("trap: %s (%d) breakpoint %x at %x: (adr %x ins %x)\n",
			       p->p_comm, p->p_pid, instr, pc,
			       p->p_md.md_ss_addr, p->p_md.md_ss_instr); /* XXX */
#endif
			/* check and see if we got here by accident */
#ifdef notyet
			if (p->p_md.md_ss_addr != pc || instr != SSBREAKPOINT) {
				sig = SIGTRAP;
				fault_type = TRAP_TRACE;
				break;
			}
#endif
			/* restore original instruction and clear BP  */
			instr = p->p_md.md_ss_instr;
			if (instr != 0)
				ss_put_value(p, pc, instr, sizeof(instr));

			p->p_md.md_ss_addr = 0;
			p->p_md.md_ss_instr = 0;
			sig = SIGTRAP;
			fault_type = TRAP_BRKPT;
		}
#else
		sig = SIGTRAP;
		fault_type = TRAP_TRACE;
#endif
		break;
	case T_USERBPT+T_USER:
		/*
		 * This trap is meant to be used by debuggers to implement
		 * breakpoint debugging.  When we get this trap, we just
		 * return a signal which gets caught by the debugger.
		 */
		sig = SIGTRAP;
		fault_type = TRAP_BRKPT;
		break;

	case T_ASTFLT+T_USER:
		uvmexp.softs++;
		want_ast = 0;
		if (p->p_flag & P_OWEUPC) {
			p->p_flag &= ~P_OWEUPC;
			ADDUPROF(p);
		}
		break;
	}

	/*
	 * If trap from supervisor mode, just return
	 */
	if (type < T_USER)
		return;

	if (sig) {
		sv.sival_int = fault_addr;
		trapsignal(p, sig, fault_code, fault_type, sv);
	}

	userret(p, frame, sticks);
}
Esempio n. 2
0
void
m88100_trap(unsigned type, struct trapframe *frame)
{
	struct proc *p;
	struct vm_map *map;
	vaddr_t va, pcb_onfault;
	vm_prot_t ftype;
	int fault_type, pbus_type;
	u_long fault_code;
	unsigned fault_addr;
	struct vmspace *vm;
	union sigval sv;
	int result;
#ifdef DDB
	int s;
	u_int psr;
#endif
	int sig = 0;

	extern struct vm_map *kernel_map;

	uvmexp.traps++;
	if ((p = curproc) == NULL)
		p = &proc0;

	if (USERMODE(frame->tf_epsr)) {
		type += T_USER;
		p->p_md.md_tf = frame;	/* for ptrace/signals */
	}
	fault_type = 0;
	fault_code = 0;
	fault_addr = frame->tf_sxip & XIP_ADDR;

	switch (type) {
	default:
		panictrap(frame->tf_vector, frame);
		break;
		/*NOTREACHED*/

#if defined(DDB)
	case T_KDB_BREAK:
		s = splhigh();
		set_psr((psr = get_psr()) & ~PSR_IND);
		ddb_break_trap(T_KDB_BREAK, (db_regs_t*)frame);
		set_psr(psr);
		splx(s);
		return;
	case T_KDB_ENTRY:
		s = splhigh();
		set_psr((psr = get_psr()) & ~PSR_IND);
		ddb_entry_trap(T_KDB_ENTRY, (db_regs_t*)frame);
		set_psr(psr);
		splx(s);
		return;
#endif /* DDB */
	case T_ILLFLT:
		printf("Unimplemented opcode!\n");
		panictrap(frame->tf_vector, frame);
		break;
	case T_INT:
	case T_INT+T_USER:
		curcpu()->ci_intrdepth++;
		md_interrupt_func(T_INT, frame);
		curcpu()->ci_intrdepth--;
		return;

	case T_MISALGNFLT:
		printf("kernel misaligned access exception @ 0x%08x\n",
		    frame->tf_sxip);
		panictrap(frame->tf_vector, frame);
		break;

	case T_INSTFLT:
		/* kernel mode instruction access fault.
		 * Should never, never happen for a non-paged kernel.
		 */
#ifdef TRAPDEBUG
		pbus_type = CMMU_PFSR_FAULT(frame->tf_ipfsr);
		printf("Kernel Instruction fault #%d (%s) v = 0x%x, frame 0x%x cpu %p\n",
		    pbus_type, pbus_exception_type[pbus_type],
		    fault_addr, frame, frame->tf_cpu);
#endif
		panictrap(frame->tf_vector, frame);
		break;

	case T_DATAFLT:
		/* kernel mode data fault */

		/* data fault on the user address? */
		if ((frame->tf_dmt0 & DMT_DAS) == 0) {
			type = T_DATAFLT + T_USER;
			goto user_fault;
		}

		fault_addr = frame->tf_dma0;
		if (frame->tf_dmt0 & (DMT_WRITE|DMT_LOCKBAR)) {
			ftype = VM_PROT_READ|VM_PROT_WRITE;
			fault_code = VM_PROT_WRITE;
		} else {
			ftype = VM_PROT_READ;
			fault_code = VM_PROT_READ;
		}

		va = trunc_page((vaddr_t)fault_addr);
		if (va == 0) {
			panic("trap: bad kernel access at %x", fault_addr);
		}

		KERNEL_LOCK(LK_CANRECURSE | LK_EXCLUSIVE);
		vm = p->p_vmspace;
		map = kernel_map;

		pbus_type = CMMU_PFSR_FAULT(frame->tf_dpfsr);
#ifdef TRAPDEBUG
		printf("Kernel Data access fault #%d (%s) v = 0x%x, frame 0x%x cpu %p\n",
		    pbus_type, pbus_exception_type[pbus_type],
		    fault_addr, frame, frame->tf_cpu);
#endif

		switch (pbus_type) {
		case CMMU_PFSR_SUCCESS:
			/*
			 * The fault was resolved. Call data_access_emulation
			 * to drain the data unit pipe line and reset dmt0
			 * so that trap won't get called again.
			 */
			data_access_emulation((unsigned *)frame);
			frame->tf_dpfsr = 0;
			frame->tf_dmt0 = 0;
			KERNEL_UNLOCK();
			return;
		case CMMU_PFSR_SFAULT:
		case CMMU_PFSR_PFAULT:
			if ((pcb_onfault = p->p_addr->u_pcb.pcb_onfault) != 0)
				p->p_addr->u_pcb.pcb_onfault = 0;
			result = uvm_fault(map, va, VM_FAULT_INVALID, ftype);
			p->p_addr->u_pcb.pcb_onfault = pcb_onfault;
			if (result == 0) {
				/*
				 * We could resolve the fault. Call
				 * data_access_emulation to drain the data
				 * unit pipe line and reset dmt0 so that trap
				 * won't get called again.
				 */
				data_access_emulation((unsigned *)frame);
				frame->tf_dpfsr = 0;
				frame->tf_dmt0 = 0;
				KERNEL_UNLOCK();
				return;
			}
			break;
		}
#ifdef TRAPDEBUG
		printf("PBUS Fault %d (%s) va = 0x%x\n", pbus_type,
		    pbus_exception_type[pbus_type], va);
#endif
		KERNEL_UNLOCK();
		panictrap(frame->tf_vector, frame);
		/* NOTREACHED */
	case T_INSTFLT+T_USER:
		/* User mode instruction access fault */
		/* FALLTHROUGH */
	case T_DATAFLT+T_USER:
user_fault:
		if (type == T_INSTFLT + T_USER) {
			pbus_type = CMMU_PFSR_FAULT(frame->tf_ipfsr);
#ifdef TRAPDEBUG
			printf("User Instruction fault #%d (%s) v = 0x%x, frame 0x%x cpu %p\n",
			    pbus_type, pbus_exception_type[pbus_type],
			    fault_addr, frame, frame->tf_cpu);
#endif
		} else {
			fault_addr = frame->tf_dma0;
			pbus_type = CMMU_PFSR_FAULT(frame->tf_dpfsr);
#ifdef TRAPDEBUG
			printf("User Data access fault #%d (%s) v = 0x%x, frame 0x%x cpu %p\n",
			    pbus_type, pbus_exception_type[pbus_type],
			    fault_addr, frame, frame->tf_cpu);
#endif
		}

		if (frame->tf_dmt0 & (DMT_WRITE | DMT_LOCKBAR)) {
			ftype = VM_PROT_READ | VM_PROT_WRITE;
			fault_code = VM_PROT_WRITE;
		} else {
			ftype = VM_PROT_READ;
			fault_code = VM_PROT_READ;
		}

		va = trunc_page((vaddr_t)fault_addr);

		KERNEL_PROC_LOCK(p);
		vm = p->p_vmspace;
		map = &vm->vm_map;
		if ((pcb_onfault = p->p_addr->u_pcb.pcb_onfault) != 0)
			p->p_addr->u_pcb.pcb_onfault = 0;

		/* Call uvm_fault() to resolve non-bus error faults */
		switch (pbus_type) {
		case CMMU_PFSR_SUCCESS:
			result = 0;
			break;
		case CMMU_PFSR_BERROR:
			result = EACCES;
			break;
		default:
			result = uvm_fault(map, va, VM_FAULT_INVALID, ftype);
			break;
		}

		p->p_addr->u_pcb.pcb_onfault = pcb_onfault;

		if ((caddr_t)va >= vm->vm_maxsaddr) {
			if (result == 0)
				uvm_grow(p, va);
			else if (result == EACCES)
				result = EFAULT;
		}
		KERNEL_PROC_UNLOCK(p);

		/*
		 * This could be a fault caused in copyin*()
		 * while accessing user space.
		 */
		if (result != 0 && pcb_onfault != 0) {
			frame->tf_snip = pcb_onfault | NIP_V;
			frame->tf_sfip = (pcb_onfault + 4) | FIP_V;
			frame->tf_sxip = 0;
			/*
			 * Continue as if the fault had been resolved, but
			 * do not try to complete the faulting access.
			 */
			frame->tf_dmt0 |= DMT_SKIP;
			result = 0;
		}

		if (result == 0) {
			if (type == T_DATAFLT+T_USER) {
				/*
			 	 * We could resolve the fault. Call
			 	 * data_access_emulation to drain the data unit
			 	 * pipe line and reset dmt0 so that trap won't
			 	 * get called again.
			 	 */
				data_access_emulation((unsigned *)frame);
				frame->tf_dpfsr = 0;
				frame->tf_dmt0 = 0;
			} else {
				/*
				 * back up SXIP, SNIP,
				 * clearing the Error bit
				 */
				frame->tf_sfip = frame->tf_snip & ~FIP_E;
				frame->tf_snip = frame->tf_sxip & ~NIP_E;
				frame->tf_ipfsr = 0;
			}
		} else {
			sig = result == EACCES ? SIGBUS : SIGSEGV;
			fault_type = result == EACCES ?
			    BUS_ADRERR : SEGV_MAPERR;
		}
		break;
	case T_MISALGNFLT+T_USER:
		/* Fix any misaligned ld.d or st.d instructions */
		sig = double_reg_fixup(frame);
		fault_type = BUS_ADRALN;
		break;
	case T_PRIVINFLT+T_USER:
	case T_ILLFLT+T_USER:
#ifndef DDB
	case T_KDB_BREAK:
	case T_KDB_ENTRY:
#endif
	case T_KDB_BREAK+T_USER:
	case T_KDB_ENTRY+T_USER:
	case T_KDB_TRACE:
	case T_KDB_TRACE+T_USER:
		sig = SIGILL;
		break;
	case T_BNDFLT+T_USER:
		sig = SIGFPE;
		break;
	case T_ZERODIV+T_USER:
		sig = SIGFPE;
		fault_type = FPE_INTDIV;
		break;
	case T_OVFFLT+T_USER:
		sig = SIGFPE;
		fault_type = FPE_INTOVF;
		break;
	case T_FPEPFLT+T_USER:
		sig = SIGFPE;
		break;
	case T_SIGSYS+T_USER:
		sig = SIGSYS;
		break;
	case T_STEPBPT+T_USER:
#ifdef PTRACE
		/*
		 * This trap is used by the kernel to support single-step
		 * debugging (although any user could generate this trap
		 * which should probably be handled differently). When a
		 * process is continued by a debugger with the PT_STEP
		 * function of ptrace (single step), the kernel inserts
		 * one or two breakpoints in the user process so that only
		 * one instruction (or two in the case of a delayed branch)
		 * is executed.  When this breakpoint is hit, we get the
		 * T_STEPBPT trap.
		 */
		{
			u_int instr;
			vaddr_t pc = PC_REGS(&frame->tf_regs);

			/* read break instruction */
			copyin((caddr_t)pc, &instr, sizeof(u_int));

			/* check and see if we got here by accident */
			if ((p->p_md.md_bp0va != pc &&
			     p->p_md.md_bp1va != pc) ||
			    instr != SSBREAKPOINT) {
				sig = SIGTRAP;
				fault_type = TRAP_TRACE;
				break;
			}

			/* restore original instruction and clear breakpoint */
			if (p->p_md.md_bp0va == pc) {
				ss_put_value(p, pc, p->p_md.md_bp0save);
				p->p_md.md_bp0va = 0;
			}
			if (p->p_md.md_bp1va == pc) {
				ss_put_value(p, pc, p->p_md.md_bp1save);
				p->p_md.md_bp1va = 0;
			}

#if 1
			frame->tf_sfip = frame->tf_snip;
			frame->tf_snip = pc | NIP_V;
#endif
			sig = SIGTRAP;
			fault_type = TRAP_BRKPT;
		}
#else
		sig = SIGTRAP;
		fault_type = TRAP_TRACE;
#endif
		break;

	case T_USERBPT+T_USER:
		/*
		 * This trap is meant to be used by debuggers to implement
		 * breakpoint debugging.  When we get this trap, we just
		 * return a signal which gets caught by the debugger.
		 */
		frame->tf_sfip = frame->tf_snip;
		frame->tf_snip = frame->tf_sxip;
		sig = SIGTRAP;
		fault_type = TRAP_BRKPT;
		break;

	case T_ASTFLT+T_USER:
		uvmexp.softs++;
		p->p_md.md_astpending = 0;
		if (p->p_flag & P_OWEUPC) {
			KERNEL_PROC_LOCK(p);
			ADDUPROF(p);
			KERNEL_PROC_UNLOCK(p);
		}
		if (curcpu()->ci_want_resched)
			preempt(NULL);
		break;
	}

	/*
	 * If trap from supervisor mode, just return
	 */
	if (type < T_USER)
		return;

	if (sig) {
		sv.sival_int = fault_addr;
		KERNEL_PROC_LOCK(p);
		trapsignal(p, sig, fault_code, fault_type, sv);
		KERNEL_PROC_UNLOCK(p);
		/*
		 * don't want multiple faults - we are going to
		 * deliver signal.
		 */
		frame->tf_dmt0 = 0;
		frame->tf_ipfsr = frame->tf_dpfsr = 0;
	}

	userret(p);
}
Esempio n. 3
0
File: trap.c Progetto: MarginC/kame
void
m88100_trap(unsigned type, struct trapframe *frame)
{
	struct proc *p;
	u_quad_t sticks = 0;
	struct vm_map *map;
	vaddr_t va, pcb_onfault;
	vm_prot_t ftype;
	int fault_type, pbus_type;
	u_long fault_code;
	unsigned nss, fault_addr;
	struct vmspace *vm;
	union sigval sv;
	int result;
#ifdef DDB
	int s;
#endif
	int sig = 0;

	extern struct vm_map *kernel_map;
	extern caddr_t guarded_access_start;
	extern caddr_t guarded_access_end;
	extern caddr_t guarded_access_bad;

	uvmexp.traps++;
	if ((p = curproc) == NULL)
		p = &proc0;

	if (USERMODE(frame->tf_epsr)) {
		sticks = p->p_sticks;
		type += T_USER;
		p->p_md.md_tf = frame;	/* for ptrace/signals */
	}
	fault_type = 0;
	fault_code = 0;
	fault_addr = frame->tf_sxip & XIP_ADDR;

	switch (type) {
	default:
		panictrap(frame->tf_vector, frame);
		break;
		/*NOTREACHED*/

#if defined(DDB)
	case T_KDB_BREAK:
		s = splhigh();
		db_enable_interrupt();
		ddb_break_trap(T_KDB_BREAK, (db_regs_t*)frame);
		db_disable_interrupt();
		splx(s);
		return;
	case T_KDB_ENTRY:
		s = splhigh();
		db_enable_interrupt();
		ddb_entry_trap(T_KDB_ENTRY, (db_regs_t*)frame);
		db_disable_interrupt();
		splx(s);
		return;
#endif /* DDB */
	case T_ILLFLT:
		printf("Unimplemented opcode!\n");
		panictrap(frame->tf_vector, frame);
		break;
	case T_INT:
	case T_INT+T_USER:
		/* This function pointer is set in machdep.c
		   It calls m188_ext_int or sbc_ext_int depending
		   on the value of brdtyp - smurph */
		(*md.interrupt_func)(T_INT, frame);
		return;

	case T_MISALGNFLT:
		printf("kernel misaligned access exception @ 0x%08x\n",
		    frame->tf_sxip);
		panictrap(frame->tf_vector, frame);
		break;

	case T_INSTFLT:
		/* kernel mode instruction access fault.
		 * Should never, never happen for a non-paged kernel.
		 */
#ifdef TRAPDEBUG
		pbus_type = CMMU_PFSR_FAULT(frame->tf_ipfsr);
		printf("Kernel Instruction fault #%d (%s) v = 0x%x, frame 0x%x cpu %d\n",
		    pbus_type, pbus_exception_type[pbus_type],
		    fault_addr, frame, frame->tf_cpu);
#endif
		panictrap(frame->tf_vector, frame);
		break;

	case T_DATAFLT:
		/* kernel mode data fault */

		/* data fault on the user address? */
		if ((frame->tf_dmt0 & DMT_DAS) == 0) {
			type = T_DATAFLT + T_USER;
			goto user_fault;
		}

		fault_addr = frame->tf_dma0;
		if (frame->tf_dmt0 & (DMT_WRITE|DMT_LOCKBAR)) {
			ftype = VM_PROT_READ|VM_PROT_WRITE;
			fault_code = VM_PROT_WRITE;
		} else {
			ftype = VM_PROT_READ;
			fault_code = VM_PROT_READ;
		}

		va = trunc_page((vaddr_t)fault_addr);
		if (va == 0) {
			panic("trap: bad kernel access at %x", fault_addr);
		}

		vm = p->p_vmspace;
		map = kernel_map;

		pbus_type = CMMU_PFSR_FAULT(frame->tf_dpfsr);
#ifdef TRAPDEBUG
		printf("Kernel Data access fault #%d (%s) v = 0x%x, frame 0x%x cpu %d\n",
		    pbus_type, pbus_exception_type[pbus_type],
		    fault_addr, frame, frame->tf_cpu);
#endif

		switch (pbus_type) {
		case CMMU_PFSR_BERROR:
			/*
		 	 * If it is a guarded access, bus error is OK.
		 	 */
			if ((frame->tf_sxip & XIP_ADDR) >=
			      (unsigned)&guarded_access_start &&
			    (frame->tf_sxip & XIP_ADDR) <=
			      (unsigned)&guarded_access_end) {
				frame->tf_snip =
				  ((unsigned)&guarded_access_bad    ) | NIP_V;
				frame->tf_sfip =
				  ((unsigned)&guarded_access_bad + 4) | FIP_V;
				frame->tf_sxip = 0;
				/* We sort of resolved the fault ourselves
				 * because we know where it came from
				 * [guarded_access()]. But we must still think
				 * about the other possible transactions in
				 * dmt1 & dmt2.  Mark dmt0 so that
				 * data_access_emulation skips it.  XXX smurph
				 */
				frame->tf_dmt0 |= DMT_SKIP;
				data_access_emulation((unsigned *)frame);
				frame->tf_dpfsr = 0;
				frame->tf_dmt0 = 0;
				return;
			}
			break;
		case CMMU_PFSR_SUCCESS:
			/*
			 * The fault was resolved. Call data_access_emulation
			 * to drain the data unit pipe line and reset dmt0
			 * so that trap won't get called again.
			 */
			data_access_emulation((unsigned *)frame);
			frame->tf_dpfsr = 0;
			frame->tf_dmt0 = 0;
			return;
		case CMMU_PFSR_SFAULT:
		case CMMU_PFSR_PFAULT:
			if ((pcb_onfault = p->p_addr->u_pcb.pcb_onfault) != 0)
				p->p_addr->u_pcb.pcb_onfault = 0;
			result = uvm_fault(map, va, VM_FAULT_INVALID, ftype);
			p->p_addr->u_pcb.pcb_onfault = pcb_onfault;
			if (result == 0) {
				/*
				 * We could resolve the fault. Call
				 * data_access_emulation to drain the data
				 * unit pipe line and reset dmt0 so that trap
				 * won't get called again.
				 */
				data_access_emulation((unsigned *)frame);
				frame->tf_dpfsr = 0;
				frame->tf_dmt0 = 0;
				return;
			}
			break;
		}
#ifdef TRAPDEBUG
		printf("PBUS Fault %d (%s) va = 0x%x\n", pbus_type,
		    pbus_exception_type[pbus_type], va);
#endif
		panictrap(frame->tf_vector, frame);
		/* NOTREACHED */
	case T_INSTFLT+T_USER:
		/* User mode instruction access fault */
		/* FALLTHROUGH */
	case T_DATAFLT+T_USER:
user_fault:
		if (type == T_INSTFLT + T_USER) {
			pbus_type = CMMU_PFSR_FAULT(frame->tf_ipfsr);
#ifdef TRAPDEBUG
			printf("User Instruction fault #%d (%s) v = 0x%x, frame 0x%x cpu %d\n",
			    pbus_type, pbus_exception_type[pbus_type],
			    fault_addr, frame, frame->tf_cpu);
#endif
		} else {
			fault_addr = frame->tf_dma0;
			pbus_type = CMMU_PFSR_FAULT(frame->tf_dpfsr);
#ifdef TRAPDEBUG
			printf("User Data access fault #%d (%s) v = 0x%x, frame 0x%x cpu %d\n",
			    pbus_type, pbus_exception_type[pbus_type],
			    fault_addr, frame, frame->tf_cpu);
#endif
		}

		if (frame->tf_dmt0 & (DMT_WRITE | DMT_LOCKBAR)) {
			ftype = VM_PROT_READ | VM_PROT_WRITE;
			fault_code = VM_PROT_WRITE;
		} else {
			ftype = VM_PROT_READ;
			fault_code = VM_PROT_READ;
		}

		va = trunc_page((vaddr_t)fault_addr);

		vm = p->p_vmspace;
		map = &vm->vm_map;
		if ((pcb_onfault = p->p_addr->u_pcb.pcb_onfault) != 0)
			p->p_addr->u_pcb.pcb_onfault = 0;

		/* Call uvm_fault() to resolve non-bus error faults */
		switch (pbus_type) {
		case CMMU_PFSR_SUCCESS:
			result = 0;
			break;
		case CMMU_PFSR_BERROR:
			result = EACCES;
			break;
		default:
			result = uvm_fault(map, va, VM_FAULT_INVALID, ftype);
			if (result == EACCES)
				result = EFAULT;
			break;
		}

		p->p_addr->u_pcb.pcb_onfault = pcb_onfault;

		if ((caddr_t)va >= vm->vm_maxsaddr) {
			if (result == 0) {
				nss = btoc(USRSTACK - va);/* XXX check this */
				if (nss > vm->vm_ssize)
					vm->vm_ssize = nss;
			}
		}

		/*
		 * This could be a fault caused in copyin*()
		 * while accessing user space.
		 */
		if (result != 0 && pcb_onfault != 0) {
			frame->tf_snip = pcb_onfault | NIP_V;
			frame->tf_sfip = (pcb_onfault + 4) | FIP_V;
			frame->tf_sxip = 0;
			/*
			 * Continue as if the fault had been resolved, but
			 * do not try to complete the faulting access.
			 */
			frame->tf_dmt0 |= DMT_SKIP;
			result = 0;
		}

		if (result == 0) {
			if (type == T_DATAFLT+T_USER) {
				/*
			 	 * We could resolve the fault. Call
			 	 * data_access_emulation to drain the data unit
			 	 * pipe line and reset dmt0 so that trap won't
			 	 * get called again.
			 	 */
				data_access_emulation((unsigned *)frame);
				frame->tf_dpfsr = 0;
				frame->tf_dmt0 = 0;
			} else {
				/*
				 * back up SXIP, SNIP,
				 * clearing the Error bit
				 */
				frame->tf_sfip = frame->tf_snip & ~FIP_E;
				frame->tf_snip = frame->tf_sxip & ~NIP_E;
				frame->tf_ipfsr = 0;
			}
		} else {
			sig = result == EACCES ? SIGBUS : SIGSEGV;
			fault_type = result == EACCES ?
			    BUS_ADRERR : SEGV_MAPERR;
		}
		break;
	case T_MISALGNFLT+T_USER:
		/* Fix any misaligned ld.d or st.d instructions */
		sig = double_reg_fixup(frame);
		fault_type = BUS_ADRALN;
		break;
	case T_PRIVINFLT+T_USER:
	case T_ILLFLT+T_USER:
#ifndef DDB
	case T_KDB_BREAK:
	case T_KDB_ENTRY:
#endif
	case T_KDB_BREAK+T_USER:
	case T_KDB_ENTRY+T_USER:
	case T_KDB_TRACE:
	case T_KDB_TRACE+T_USER:
		sig = SIGILL;
		break;
	case T_BNDFLT+T_USER:
		sig = SIGFPE;
		break;
	case T_ZERODIV+T_USER:
		sig = SIGFPE;
		fault_type = FPE_INTDIV;
		break;
	case T_OVFFLT+T_USER:
		sig = SIGFPE;
		fault_type = FPE_INTOVF;
		break;
	case T_FPEPFLT+T_USER:
	case T_FPEIFLT+T_USER:
		sig = SIGFPE;
		break;
	case T_SIGSYS+T_USER:
		sig = SIGSYS;
		break;
	case T_SIGTRAP+T_USER:
		sig = SIGTRAP;
		fault_type = TRAP_TRACE;
		break;
	case T_STEPBPT+T_USER:
#ifdef PTRACE
		/*
		 * This trap is used by the kernel to support single-step
		 * debugging (although any user could generate this trap
		 * which should probably be handled differently). When a
		 * process is continued by a debugger with the PT_STEP
		 * function of ptrace (single step), the kernel inserts
		 * one or two breakpoints in the user process so that only
		 * one instruction (or two in the case of a delayed branch)
		 * is executed.  When this breakpoint is hit, we get the
		 * T_STEPBPT trap.
		 */
		{
			unsigned va;
			unsigned instr;
			unsigned pc = PC_REGS(&frame->tf_regs);

			/* read break instruction */
			copyin((caddr_t)pc, &instr, sizeof(unsigned));
#if 0
			printf("trap: %s (%d) breakpoint %x at %x: (adr %x ins %x)\n",
			       p->p_comm, p->p_pid, instr, pc,
			       p->p_md.md_ss_addr, p->p_md.md_ss_instr); /* XXX */
#endif
			/* check and see if we got here by accident */
			if ((p->p_md.md_ss_addr != pc &&
			     p->p_md.md_ss_taken_addr != pc) ||
			    instr != SSBREAKPOINT) {
				sig = SIGTRAP;
				fault_type = TRAP_TRACE;
				break;
			}
			/* restore original instruction and clear BP  */
			va = p->p_md.md_ss_addr;
			if (va != 0) {
				instr = p->p_md.md_ss_instr;
				ss_put_value(p, va, instr, sizeof(instr));
			}

			/* branch taken instruction */
			instr = p->p_md.md_ss_taken_instr;
			if (instr != 0) {
				va = p->p_md.md_ss_taken_addr;
				ss_put_value(p, va, instr, sizeof(instr));
			}
#if 1
			frame->tf_sfip = frame->tf_snip;
			frame->tf_snip = pc | NIP_V;
#endif
			p->p_md.md_ss_addr = 0;
			p->p_md.md_ss_instr = 0;
			p->p_md.md_ss_taken_addr = 0;
			p->p_md.md_ss_taken_instr = 0;
			sig = SIGTRAP;
			fault_type = TRAP_BRKPT;
		}
#else
		sig = SIGTRAP;
		fault_type = TRAP_TRACE;
#endif
		break;

	case T_USERBPT+T_USER:
		/*
		 * This trap is meant to be used by debuggers to implement
		 * breakpoint debugging.  When we get this trap, we just
		 * return a signal which gets caught by the debugger.
		 */
		frame->tf_sfip = frame->tf_snip;
		frame->tf_snip = frame->tf_sxip;
		sig = SIGTRAP;
		fault_type = TRAP_BRKPT;
		break;

	case T_ASTFLT+T_USER:
		uvmexp.softs++;
		want_ast = 0;
		if (p->p_flag & P_OWEUPC) {
			p->p_flag &= ~P_OWEUPC;
			ADDUPROF(p);
		}
		break;
	}

	/*
	 * If trap from supervisor mode, just return
	 */
	if (type < T_USER)
		return;

	if (sig) {
		sv.sival_int = fault_addr;
		trapsignal(p, sig, fault_code, fault_type, sv);
		/*
		 * don't want multiple faults - we are going to
		 * deliver signal.
		 */
		frame->tf_dmt0 = 0;
		frame->tf_ipfsr = frame->tf_dpfsr = 0;
	}

	userret(p, frame, sticks);
}
Esempio n. 4
0
void
m88110_trap(u_int type, struct trapframe *frame)
{
	struct proc *p;
	struct vm_map *map;
	vaddr_t va, pcb_onfault;
	vm_prot_t ftype;
	int fault_type;
	u_long fault_code;
	vaddr_t fault_addr;
	struct vmspace *vm;
	union sigval sv;
	int result;
#ifdef DDB
        int s;
	u_int psr;
#endif
	int sig = 0;

	uvmexp.traps++;
	if ((p = curproc) == NULL)
		p = &proc0;

	fault_type = SI_NOINFO;
	fault_code = 0;
	fault_addr = frame->tf_exip & XIP_ADDR;

	/*
	 * 88110 errata #16 (4.2) or #3 (5.1.1):
	 * ``bsr, br, bcnd, jsr and jmp instructions with the .n extension
	 *   can cause the enip value to be incremented by 4 incorrectly
	 *   if the instruction in the delay slot is the first word of a
	 *   page which misses in the mmu and results in a hardware
	 *   tablewalk which encounters an exception or an invalid
	 *   descriptor.  The exip value in this case will point to the
	 *   first word of the page, and the D bit will be set.
	 *
	 *   Note: if the instruction is a jsr.n r1, r1 will be overwritten
	 *   with erroneous data.  Therefore, no recovery is possible. Do
	 *   not allow this instruction to occupy the last word of a page.
	 *
	 *   Suggested fix: recover in general by backing up the exip by 4
	 *   and clearing the delay bit before an rte when the lower 3 hex
	 *   digits of the exip are 001.''
	 */
	if ((frame->tf_exip & PAGE_MASK) == 0x00000001 && type == T_INSTFLT) {
		u_int instr;

		/*
		 * Note that we have initialized fault_addr above, so that
		 * signals provide the correct address if necessary.
		 */
		frame->tf_exip = (frame->tf_exip & ~1) - 4;

		/*
		 * Check the instruction at the (backed up) exip.
		 * If it is a jsr.n, abort.
		 */
		if (!USERMODE(frame->tf_epsr)) {
			instr = *(u_int *)fault_addr;
			if (instr == 0xf400cc01)
				panic("mc88110 errata #16, exip %p enip %p",
				    (frame->tf_exip + 4) | 1, frame->tf_enip);
		} else {
			/* copyin here should not fail */
			if (copyin((const void *)frame->tf_exip, &instr,
			    sizeof instr) == 0 &&
			    instr == 0xf400cc01) {
				uprintf("mc88110 errata #16, exip %p enip %p",
				    (frame->tf_exip + 4) | 1, frame->tf_enip);
				sig = SIGILL;
			}
		}
	}

	if (USERMODE(frame->tf_epsr)) {
		type += T_USER;
		p->p_md.md_tf = frame;	/* for ptrace/signals */
	}

	if (sig != 0)
		goto deliver;

	switch (type) {
	default:
lose:
		panictrap(frame->tf_vector, frame);
		break;
		/*NOTREACHED*/

#ifdef DEBUG
	case T_110_DRM+T_USER:
	case T_110_DRM:
		printf("DMMU read miss: Hardware Table Searches should be enabled!\n");
		goto lose;
	case T_110_DWM+T_USER:
	case T_110_DWM:
		printf("DMMU write miss: Hardware Table Searches should be enabled!\n");
		goto lose;
	case T_110_IAM+T_USER:
	case T_110_IAM:
		printf("IMMU miss: Hardware Table Searches should be enabled!\n");
		goto lose;
#endif

#ifdef DDB
	case T_KDB_TRACE:
		s = splhigh();
		set_psr((psr = get_psr()) & ~PSR_IND);
		ddb_break_trap(T_KDB_TRACE, (db_regs_t*)frame);
		set_psr(psr);
		splx(s);
		return;
	case T_KDB_BREAK:
		s = splhigh();
		set_psr((psr = get_psr()) & ~PSR_IND);
		ddb_break_trap(T_KDB_BREAK, (db_regs_t*)frame);
		set_psr(psr);
		splx(s);
		return;
	case T_KDB_ENTRY:
		s = splhigh();
		set_psr((psr = get_psr()) & ~PSR_IND);
		ddb_entry_trap(T_KDB_ENTRY, (db_regs_t*)frame);
		set_psr(psr);
		/* skip trap instruction */
		m88110_skip_insn(frame);
		splx(s);
		return;
#endif /* DDB */
	case T_ILLFLT:
		/*
		 * The 88110 seems to trigger an instruction fault in
		 * supervisor mode when running the following sequence:
		 *
		 *	bcnd.n cond, reg, 1f
		 *	arithmetic insn
		 *	...
		 *  	the same exact arithmetic insn
		 *  1:	another arithmetic insn stalled by the previous one
		 *	...
		 *
		 * The exception is reported with exip pointing to the
		 * branch address. I don't know, at this point, if there
		 * is any better workaround than the aggressive one
		 * implemented below; I don't see how this could relate to
		 * any of the 88110 errata (although it might be related to
		 * branch prediction).
		 *
		 * For the record, the exact sequence triggering the
		 * spurious exception is:
		 *
		 *	bcnd.n	eq0, r2,  1f
		 *	 or	r25, r0,  r22
		 *	bsr	somewhere
		 *	or	r25, r0,  r22
		 *  1:	cmp	r13, r25, r20
		 *
		 * within the same cache line.
		 *
		 * Simply ignoring the exception and returning does not
		 * cause the exception to disappear. Clearing the
		 * instruction cache works, but on 88110+88410 systems,
		 * the 88410 needs to be invalidated as well. (note that
		 * the size passed to the flush routines does not matter
		 * since there is no way to flush a subset of the 88110
		 * I$ anyway)
		 */
	    {
		extern void *kernel_text, *etext;

		if (fault_addr >= (vaddr_t)&kernel_text &&
		    fault_addr < (vaddr_t)&etext) {
			cmmu_icache_inv(curcpu()->ci_cpuid,
			    trunc_page(fault_addr), PAGE_SIZE);
			cmmu_cache_wbinv(curcpu()->ci_cpuid,
			    trunc_page(fault_addr), PAGE_SIZE);
			return;
		}
	    }
		goto lose;
	case T_MISALGNFLT:
		printf("kernel misaligned access exception @%p\n",
		    frame->tf_exip);
		goto lose;
	case T_INSTFLT:
		/* kernel mode instruction access fault.
		 * Should never, never happen for a non-paged kernel.
		 */
#ifdef TRAPDEBUG
		printf("Kernel Instruction fault exip %x isr %x ilar %x\n",
		    frame->tf_exip, frame->tf_isr, frame->tf_ilar);
#endif
		goto lose;

	case T_DATAFLT:
		/* kernel mode data fault */

		/* data fault on the user address? */
		if ((frame->tf_dsr & CMMU_DSR_SU) == 0) {
			KERNEL_LOCK();
			goto m88110_user_fault;
		}

#ifdef TRAPDEBUG
		printf("Kernel Data access fault exip %x dsr %x dlar %x\n",
		    frame->tf_exip, frame->tf_dsr, frame->tf_dlar);
#endif

		fault_addr = frame->tf_dlar;
		if (frame->tf_dsr & CMMU_DSR_RW) {
			ftype = VM_PROT_READ;
			fault_code = VM_PROT_READ;
		} else {
			ftype = VM_PROT_READ|VM_PROT_WRITE;
			fault_code = VM_PROT_WRITE;
		}

		va = trunc_page((vaddr_t)fault_addr);

		KERNEL_LOCK();
		vm = p->p_vmspace;
		map = kernel_map;

		if (frame->tf_dsr & (CMMU_DSR_SI | CMMU_DSR_PI)) {
			/*
			 * On a segment or a page fault, call uvm_fault() to
			 * resolve the fault.
			 */
			if ((pcb_onfault = p->p_addr->u_pcb.pcb_onfault) != 0)
				p->p_addr->u_pcb.pcb_onfault = 0;
			result = uvm_fault(map, va, VM_FAULT_INVALID, ftype);
			p->p_addr->u_pcb.pcb_onfault = pcb_onfault;
			/*
			 * This could be a fault caused in copyout*()
			 * while accessing kernel space.
			 */
			if (result != 0 && pcb_onfault != 0) {
				frame->tf_exip = pcb_onfault;
				/*
				 * Continue as if the fault had been resolved.
				 */
				result = 0;
			}
			if (result == 0) {
				KERNEL_UNLOCK();
				return;
			}
		}
		KERNEL_UNLOCK();
		goto lose;
	case T_INSTFLT+T_USER:
		/* User mode instruction access fault */
		/* FALLTHROUGH */
	case T_DATAFLT+T_USER:
		KERNEL_LOCK();
m88110_user_fault:
		if (type == T_INSTFLT+T_USER) {
			ftype = VM_PROT_READ;
			fault_code = VM_PROT_READ;
#ifdef TRAPDEBUG
			printf("User Instruction fault exip %x isr %x ilar %x\n",
			    frame->tf_exip, frame->tf_isr, frame->tf_ilar);
#endif
		} else {
			fault_addr = frame->tf_dlar;
			if (frame->tf_dsr & CMMU_DSR_RW) {
				ftype = VM_PROT_READ;
				fault_code = VM_PROT_READ;
			} else {
				ftype = VM_PROT_READ|VM_PROT_WRITE;
				fault_code = VM_PROT_WRITE;
			}
#ifdef TRAPDEBUG
			printf("User Data access fault exip %x dsr %x dlar %x\n",
			    frame->tf_exip, frame->tf_dsr, frame->tf_dlar);
#endif
		}

		va = trunc_page((vaddr_t)fault_addr);

		vm = p->p_vmspace;
		map = &vm->vm_map;
		if ((pcb_onfault = p->p_addr->u_pcb.pcb_onfault) != 0)
			p->p_addr->u_pcb.pcb_onfault = 0;

		/*
		 * Call uvm_fault() to resolve non-bus error faults
		 * whenever possible.
		 */
		if (type == T_INSTFLT+T_USER) {
			/* instruction faults */
			if (frame->tf_isr &
			    (CMMU_ISR_BE | CMMU_ISR_SP | CMMU_ISR_TBE)) {
				/* bus error, supervisor protection */
				result = EACCES;
			} else
			if (frame->tf_isr & (CMMU_ISR_SI | CMMU_ISR_PI)) {
				/* segment or page fault */
				result = uvm_fault(map, va, VM_FAULT_INVALID, ftype);
			} else {
#ifdef TRAPDEBUG
				printf("Unexpected Instruction fault isr %x\n",
				    frame->tf_isr);
#endif
				KERNEL_UNLOCK();
				goto lose;
			}
		} else {
			/* data faults */
			if (frame->tf_dsr & CMMU_DSR_BE) {
				/* bus error */
				result = EACCES;
			} else
			if (frame->tf_dsr & (CMMU_DSR_SI | CMMU_DSR_PI)) {
				/* segment or page fault */
				result = uvm_fault(map, va, VM_FAULT_INVALID, ftype);
			} else
			if (frame->tf_dsr & (CMMU_DSR_CP | CMMU_DSR_WA)) {
				/* copyback or write allocate error */
				result = EACCES;
			} else
			if (frame->tf_dsr & CMMU_DSR_WE) {
				/* write fault  */
				/* This could be a write protection fault or an
				 * exception to set the used and modified bits
				 * in the pte. Basically, if we got a write
				 * error, then we already have a pte entry that
				 * faulted in from a previous seg fault or page
				 * fault.
				 * Get the pte and check the status of the
				 * modified and valid bits to determine if this
				 * indeed a real write fault.  XXX smurph
				 */
				if (pmap_set_modify(map->pmap, va)) {
#ifdef TRAPDEBUG
					printf("Corrected userland write fault, pmap %p va %p\n",
					    map->pmap, va);
#endif
					result = 0;
				} else {
					/* must be a real wp fault */
#ifdef TRAPDEBUG
					printf("Uncorrected userland write fault, pmap %p va %p\n",
					    map->pmap, va);
#endif
					result = uvm_fault(map, va, VM_FAULT_INVALID, ftype);
				}
			} else {
#ifdef TRAPDEBUG
				printf("Unexpected Data access fault dsr %x\n",
				    frame->tf_dsr);
#endif
				KERNEL_UNLOCK();
				goto lose;
			}
		}
		p->p_addr->u_pcb.pcb_onfault = pcb_onfault;

		if ((caddr_t)va >= vm->vm_maxsaddr) {
			if (result == 0)
				uvm_grow(p, va);
			else if (result == EACCES)
				result = EFAULT;
		}
		KERNEL_UNLOCK();

		/*
		 * This could be a fault caused in copyin*()
		 * while accessing user space.
		 */
		if (result != 0 && pcb_onfault != 0) {
			frame->tf_exip = pcb_onfault;
			/*
			 * Continue as if the fault had been resolved.
			 */
			result = 0;
		}

		if (result != 0) {
			sig = result == EACCES ? SIGBUS : SIGSEGV;
			fault_type = result == EACCES ?
			    BUS_ADRERR : SEGV_MAPERR;
		}
		break;
	case T_MISALGNFLT+T_USER:
		/* Fix any misaligned ld.d or st.d instructions */
		sig = double_reg_fixup(frame);
		fault_type = BUS_ADRALN;
		if (sig == 0) {
			/* skip recovered instruction */
			m88110_skip_insn(frame);
			goto userexit;
		}
		break;
	case T_PRIVINFLT+T_USER:
		fault_type = ILL_PRVREG;
		/* FALLTHROUGH */
	case T_ILLFLT+T_USER:
#ifndef DDB
	case T_KDB_BREAK:
	case T_KDB_ENTRY:
	case T_KDB_TRACE:
#endif
	case T_KDB_BREAK+T_USER:
	case T_KDB_ENTRY+T_USER:
	case T_KDB_TRACE+T_USER:
		sig = SIGILL;
		break;
	case T_BNDFLT+T_USER:
		sig = SIGFPE;
		/* skip trap instruction */
		m88110_skip_insn(frame);
		break;
	case T_ZERODIV+T_USER:
		sig = SIGFPE;
		fault_type = FPE_INTDIV;
		/* skip trap instruction */
		m88110_skip_insn(frame);
		break;
	case T_OVFFLT+T_USER:
		sig = SIGFPE;
		fault_type = FPE_INTOVF;
		/* skip trap instruction */
		m88110_skip_insn(frame);
		break;
	case T_FPEPFLT+T_USER:
		m88110_fpu_exception(frame);
		goto userexit;
	case T_SIGSYS+T_USER:
		sig = SIGSYS;
		break;
	case T_STEPBPT+T_USER:
#ifdef PTRACE
		/*
		 * This trap is used by the kernel to support single-step
		 * debugging (although any user could generate this trap
		 * which should probably be handled differently). When a
		 * process is continued by a debugger with the PT_STEP
		 * function of ptrace (single step), the kernel inserts
		 * one or two breakpoints in the user process so that only
		 * one instruction (or two in the case of a delayed branch)
		 * is executed.  When this breakpoint is hit, we get the
		 * T_STEPBPT trap.
		 */
		{
			u_int instr;
			vaddr_t pc = PC_REGS(&frame->tf_regs);

			/* read break instruction */
			copyin((caddr_t)pc, &instr, sizeof(u_int));

			/* check and see if we got here by accident */
			if ((p->p_md.md_bp0va != pc &&
			     p->p_md.md_bp1va != pc) ||
			    instr != SSBREAKPOINT) {
				sig = SIGTRAP;
				fault_type = TRAP_TRACE;
				break;
			}

			/* restore original instruction and clear breakpoint */
			if (p->p_md.md_bp0va == pc) {
				ss_put_value(p, pc, p->p_md.md_bp0save);
				p->p_md.md_bp0va = 0;
			}
			if (p->p_md.md_bp1va == pc) {
				ss_put_value(p, pc, p->p_md.md_bp1save);
				p->p_md.md_bp1va = 0;
			}

			sig = SIGTRAP;
			fault_type = TRAP_BRKPT;
		}
#else
		sig = SIGTRAP;
		fault_type = TRAP_TRACE;
#endif
		break;
	case T_USERBPT+T_USER:
		/*
		 * This trap is meant to be used by debuggers to implement
		 * breakpoint debugging.  When we get this trap, we just
		 * return a signal which gets caught by the debugger.
		 */
		sig = SIGTRAP;
		fault_type = TRAP_BRKPT;
		break;
	}

	/*
	 * If trap from supervisor mode, just return
	 */
	if (type < T_USER)
		return;

	if (sig) {
deliver:
		sv.sival_ptr = (void *)fault_addr;
		KERNEL_LOCK();
		trapsignal(p, sig, fault_code, fault_type, sv);
		KERNEL_UNLOCK();
	}

userexit:
	userret(p);
}