trap.c

早期freebsd实现

		 */
		if ((caddr_t)va >= vm->vm_maxsaddr && map != kernel_map) {
			if (rv == KERN_SUCCESS) {
				unsigned nss;

				nss = clrnd(btoc(USRSTACK-(unsigned)va));
				if (nss > vm->vm_ssize)
					vm->vm_ssize = nss;
			} else if (rv == KERN_PROTECTION_FAILURE)
				rv = KERN_INVALID_ADDRESS;
		}
		if (rv == KERN_SUCCESS) {
			if (type == T_MMUFLT) {
#ifdef LUNA2
				if (mmutype == MMU_68040)
					(void) writeback(&frame, 1);
#endif
				return;
			}
			goto out;
		}
		if (type == T_MMUFLT) {
			if (p->p_addr->u_pcb.pcb_onfault)
				goto copyfault;
			printf("vm_fault(%x, %x, %x, 0) -> %x\n",
			       map, va, ftype, rv);
			printf("  type %x, code [mmu,,ssw]: %x\n",
			       type, code);
			goto dopanic;
		}
		ucode = v;
		i = (rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV;
		break;
	    }
	}
	trapsignal(p, i, ucode);
	if ((type & T_USER) == 0)
		return;
out:
	userret(p, &frame, sticks, v, 1);
}

#ifdef LUNA2
#ifdef DEBUG
struct writebackstats {
	int calls;
	int cpushes;
	int move16s;
	int wb1s, wb2s, wb3s;
	int wbsize[4];
} wbstats;

char *f7sz[] = { "longword", "byte", "word", "line" };
char *f7tt[] = { "normal", "MOVE16", "AFC", "ACK" };
char *f7tm[] = { "d-push", "u-data", "u-code", "M-data",
		 "M-code", "k-data", "k-code", "RES" };
char wberrstr[] =
    "WARNING: pid %d(%s) writeback [%s] failed, pc=%x fa=%x wba=%x wbd=%x\n";
#endif

writeback(fp, docachepush)
	struct frame *fp;
	int docachepush;
{
	register struct fmt7 *f = &fp->f_fmt7;
	register struct proc *p = curproc;
	int err = 0;
	u_int fa;
	caddr_t oonfault = p->p_addr->u_pcb.pcb_onfault;

#ifdef DEBUG
	if ((mmudebug & MDB_WBFOLLOW) || MDB_ISPID(p->p_pid)) {
		printf(" pid=%d, fa=%x,", p->p_pid, f->f_fa);
		dumpssw(f->f_ssw);
	}
	wbstats.calls++;
#endif
	/*
	 * Deal with special cases first.
	 */
	if ((f->f_ssw & SSW4_TMMASK) == SSW4_TMDCP) {
		/*
		 * Dcache push fault.
		 * Line-align the address and write out the push data to
		 * the indicated physical address.
		 */
#ifdef DEBUG
		if ((mmudebug & MDB_WBFOLLOW) || MDB_ISPID(p->p_pid)) {
			printf(" pushing %s to PA %x, data %x",
			       f7sz[(f->f_ssw & SSW4_SZMASK) >> 5],
			       f->f_fa, f->f_pd0);
			if ((f->f_ssw & SSW4_SZMASK) == SSW4_SZLN)
				printf("/%x/%x/%x",
				       f->f_pd1, f->f_pd2, f->f_pd3);
			printf("\n");
		}
		if (f->f_wb1s & SSW4_WBSV)
			panic("writeback: cache push with WB1S valid");
		wbstats.cpushes++;
#endif
		/*
		 * XXX there are security problems if we attempt to do a
		 * cache push after a signal handler has been called.
		 */
		if (docachepush) {
			pmap_enter(kernel_pmap, (vm_offset_t)vmmap,
				   trunc_page(f->f_fa), VM_PROT_WRITE, TRUE);
			fa = (u_int)&vmmap[(f->f_fa & PGOFSET) & ~0xF];
			bcopy((caddr_t)&f->f_pd0, (caddr_t)fa, 16);
			DCFL(pmap_extract(kernel_pmap, (vm_offset_t)fa));
			pmap_remove(kernel_pmap, (vm_offset_t)vmmap,
				    (vm_offset_t)&vmmap[NBPG]);
		} else
			printf("WARNING: pid %d(%s) uid %d: CPUSH not done\n",
			       p->p_pid, p->p_comm, p->p_ucred->cr_uid);
	} else if ((f->f_ssw & (SSW4_RW|SSW4_TTMASK)) == SSW4_TTM16) {
		/*
		 * MOVE16 fault.
		 * Line-align the address and write out the push data to
		 * the indicated virtual address.
		 */
#ifdef DEBUG
		if ((mmudebug & MDB_WBFOLLOW) || MDB_ISPID(p->p_pid))
			printf(" MOVE16 to VA %x(%x), data %x/%x/%x/%x\n",
			       f->f_fa, f->f_fa & ~0xF, f->f_pd0, f->f_pd1,
			       f->f_pd2, f->f_pd3);
		if (f->f_wb1s & SSW4_WBSV)
			panic("writeback: MOVE16 with WB1S valid");
		wbstats.move16s++;
#endif
		if (KDFAULT(f->f_wb1s))
			bcopy((caddr_t)&f->f_pd0, (caddr_t)(f->f_fa & ~0xF), 16);
		else
			err = suline((caddr_t)(f->f_fa & ~0xF), (caddr_t)&f->f_pd0);
		if (err) {
			fa = f->f_fa & ~0xF;
#ifdef DEBUG
			if (mmudebug & MDB_WBFAILED)
				printf(wberrstr, p->p_pid, p->p_comm,
				       "MOVE16", fp->f_pc, f->f_fa,
				       f->f_fa & ~0xF, f->f_pd0);
#endif
		}
	} else if (f->f_wb1s & SSW4_WBSV) {
		/*
		 * Writeback #1.
		 * Position the "memory-aligned" data and write it out.
		 */
		register u_int wb1d = f->f_wb1d;
		register int off;

#ifdef DEBUG
		if ((mmudebug & MDB_WBFOLLOW) || MDB_ISPID(p->p_pid))
			dumpwb(1, f->f_wb1s, f->f_wb1a, f->f_wb1d);
		wbstats.wb1s++;
		wbstats.wbsize[(f->f_wb2s&SSW4_SZMASK)>>5]++;
#endif
		off = (f->f_wb1a & 3) * 8;
		switch (f->f_wb1s & SSW4_SZMASK) {
		case SSW4_SZLW:
			if (off)
				wb1d = (wb1d >> (32 - off)) | (wb1d << off);
			if (KDFAULT(f->f_wb1s))
				*(long *)f->f_wb1a = wb1d;
			else
				err = suword((caddr_t)f->f_wb1a, wb1d);
			break;
		case SSW4_SZB:
			off = 24 - off;
			if (off)
				wb1d >>= off;
			if (KDFAULT(f->f_wb1s))
				*(char *)f->f_wb1a = wb1d;
			else
				err = subyte((caddr_t)f->f_wb1a, wb1d);
			break;
		case SSW4_SZW:
			off = (off + 16) % 32;
			if (off)
				wb1d = (wb1d >> (32 - off)) | (wb1d << off);
			if (KDFAULT(f->f_wb1s))
				*(short *)f->f_wb1a = wb1d;
			else
				err = susword((caddr_t)f->f_wb1a, wb1d);
			break;
		}
		if (err) {
			fa = f->f_wb1a;
#ifdef DEBUG
			if (mmudebug & MDB_WBFAILED)
				printf(wberrstr, p->p_pid, p->p_comm,
				       "#1", fp->f_pc, f->f_fa,
				       f->f_wb1a, f->f_wb1d);
#endif
		}
	}
	/*
	 * Deal with the "normal" writebacks.
	 *
	 * XXX writeback2 is known to reflect a LINE size writeback after
	 * a MOVE16 was already dealt with above.  Ignore it.
	 */
	if (err == 0 && (f->f_wb2s & SSW4_WBSV) &&
	    (f->f_wb2s & SSW4_SZMASK) != SSW4_SZLN) {
#ifdef DEBUG
		if ((mmudebug & MDB_WBFOLLOW) || MDB_ISPID(p->p_pid))
			dumpwb(2, f->f_wb2s, f->f_wb2a, f->f_wb2d);
		wbstats.wb2s++;
		wbstats.wbsize[(f->f_wb2s&SSW4_SZMASK)>>5]++;
#endif
		switch (f->f_wb2s & SSW4_SZMASK) {
		case SSW4_SZLW:
			if (KDFAULT(f->f_wb2s))
				*(long *)f->f_wb2a = f->f_wb2d;
			else
				err = suword((caddr_t)f->f_wb2a, f->f_wb2d);
			break;
		case SSW4_SZB:
			if (KDFAULT(f->f_wb2s))
				*(char *)f->f_wb2a = f->f_wb2d;
			else
				err = subyte((caddr_t)f->f_wb2a, f->f_wb2d);
			break;
		case SSW4_SZW:
			if (KDFAULT(f->f_wb2s))
				*(short *)f->f_wb2a = f->f_wb2d;
			else
				err = susword((caddr_t)f->f_wb2a, f->f_wb2d);
			break;
		}
		if (err) {
			fa = f->f_wb2a;
#ifdef DEBUG
			if (mmudebug & MDB_WBFAILED) {
				printf(wberrstr, p->p_pid, p->p_comm,
				       "#2", fp->f_pc, f->f_fa,
				       f->f_wb2a, f->f_wb2d);
				dumpssw(f->f_ssw);
				dumpwb(2, f->f_wb2s, f->f_wb2a, f->f_wb2d);
			}
#endif
		}
	}
	if (err == 0 && (f->f_wb3s & SSW4_WBSV)) {
#ifdef DEBUG
		if ((mmudebug & MDB_WBFOLLOW) || MDB_ISPID(p->p_pid))
			dumpwb(3, f->f_wb3s, f->f_wb3a, f->f_wb3d);
		wbstats.wb3s++;
		wbstats.wbsize[(f->f_wb3s&SSW4_SZMASK)>>5]++;
#endif
		switch (f->f_wb3s & SSW4_SZMASK) {
		case SSW4_SZLW:
			if (KDFAULT(f->f_wb3s))
				*(long *)f->f_wb3a = f->f_wb3d;
			else
				err = suword((caddr_t)f->f_wb3a, f->f_wb3d);
			break;
		case SSW4_SZB:
			if (KDFAULT(f->f_wb3s))
				*(char *)f->f_wb3a = f->f_wb3d;
			else
				err = subyte((caddr_t)f->f_wb3a, f->f_wb3d);
			break;
		case SSW4_SZW:
			if (KDFAULT(f->f_wb3s))
				*(short *)f->f_wb3a = f->f_wb3d;
			else
				err = susword((caddr_t)f->f_wb3a, f->f_wb3d);
			break;
#ifdef DEBUG
		case SSW4_SZLN:
			panic("writeback: wb3s indicates LINE write");
#endif
		}
		if (err) {
			fa = f->f_wb3a;
#ifdef DEBUG
			if (mmudebug & MDB_WBFAILED)
				printf(wberrstr, p->p_pid, p->p_comm,
				       "#3", fp->f_pc, f->f_fa,
				       f->f_wb3a, f->f_wb3d);
#endif
		}
	}
	p->p_addr->u_pcb.pcb_onfault = oonfault;
	/*
	 * Determine the cause of the failure if any translating to
	 * a signal.  If the corresponding VA is valid and RO it is
	 * a protection fault (SIGBUS) otherwise consider it an
	 * illegal reference (SIGSEGV).
	 */
	if (err) {
		if (vm_map_check_protection(&p->p_vmspace->vm_map,	
					    trunc_page(fa), round_page(fa),
					    VM_PROT_READ) &&
		    !vm_map_check_protection(&p->p_vmspace->vm_map,
					     trunc_page(fa), round_page(fa),
					     VM_PROT_WRITE))
			err = SIGBUS;
		else
			err = SIGSEGV;
	}
	return(err);
}

#ifdef DEBUG
dumpssw(ssw)
	register u_short ssw;
{
	printf(" SSW: %x: ", ssw);
	if (ssw & SSW4_CP)
		printf("CP,");
	if (ssw & SSW4_CU)
		printf("CU,");
	if (ssw & SSW4_CT)
		printf("CT,");
	if (ssw & SSW4_CM)
		printf("CM,");
	if (ssw & SSW4_MA)
		printf("MA,");
	if (ssw & SSW4_ATC)
		printf("ATC,");
	if (ssw & SSW4_LK)
		printf("LK,");
	if (ssw & SSW4_RW)
		printf("RW,");
	printf(" SZ=%s, TT=%s, TM=%s\n",
	       f7sz[(ssw & SSW4_SZMASK) >> 5],
	       f7tt[(ssw & SSW4_TTMASK) >> 3],
	       f7tm[ssw & SSW4_TMMASK]);
}

dumpwb(num, s, a, d)
	int num;
	u_short s;
	u_int a, d;
{
	register struct proc *p = curproc;
	vm_offset_t pa;

	printf(" writeback #%d: VA %x, data %x, SZ=%s, TT=%s, TM=%s\n",
	       num, a, d, f7sz[(s & SSW4_SZMASK) >> 5],
	       f7tt[(s & SSW4_TTMASK) >> 3], f7tm[s & SSW4_TMMASK]);
	printf("               PA ");
	pa = pmap_extract(&p->p_vmspace->vm_pmap, (vm_offset_t)a);
	if (pa == 0)
		printf("<invalid address>");
	else
		printf("%x, current value %x", pa, fuword((caddr_t)a));
	printf("\n");
}
#endif
#endif

/*
 * Proces a system call.
 */
syscall(code, frame)
	u_int code;
	struct frame frame;
{
	register caddr_t params;
	register struct sysent *callp;
	register struct proc *p;
	int error, opc, numsys, s;
	u_int argsize;
	struct args {
		int i[8];
	} args;
	int rval[2];
	u_quad_t sticks;

	cnt.v_syscall++;
	if (!USERMODE(frame.f_sr))
		panic("syscall");
	p = curproc;
	sticks = p->p_sticks;
	p->p_md.md_regs = frame.f_regs;
	opc = frame.f_pc - 2;
	callp = sysent, numsys = nsysent;
	params = (caddr_t)frame.f_regs[SP] + sizeof(int);
	switch (code) {

	case SYS_syscall:
		/*
		 * Code is first argument, followed by actual args.
		 */
		code = fuword(params);
		params += sizeof(int);
		/*
		 * XXX sigreturn requires special stack manipulation
		 * that is only done if entered via the sigreturn
		 * trap.  Cannot allow it here so make sure we fail.
		 */
		if (code == SYS_sigreturn)
			code = numsys;
		break;

	case SYS___syscall:
		/*
		 * Like syscall, but code is a quad, so as to maintain
		 * quad alignment for the rest of the arguments.
		 */
		code = fuword(params + _QUAD_LOWWORD * sizeof(int));
		params += sizeof(quad_t);
		break;

	default:
		/* nothing to do by default */
		break;
	}
	if (code < numsys)
		callp += code;
	else
		callp += SYS_syscall;	/* => nosys */
	argsize = callp->sy_narg * sizeof(int);
	if (argsize && (error = copyin(params, (caddr_t)&args, argsize))) {
#ifdef KTRACE
		if (KTRPOINT(p, KTR_SYSCALL))
			ktrsyscall(p->p_tracep, code, callp->sy_narg, args.i);
#endif
		goto bad;
	}
#ifdef KTRACE
	if (KTRPOINT(p, KTR_SYSCALL))
		ktrsyscall(p->p_tracep, code, callp->sy_narg, args.i);
#endif
	rval[0] = 0;
	rval[1] = frame.f_regs[D1];
	error = (*callp->sy_call)(p, &args, rval);
	switch (error) {

	case 0:
		/*
		 * Reinitialize proc pointer `p' as it may be different
		 * if this is a child returning from fork syscall.
		 */
		p = curproc;
		frame.f_regs[D0] = rval[0];
		frame.f_regs[D1] = rval[1];
		frame.f_sr &= ~PSL_C;
		break;

	case ERESTART:
		frame.f_pc = opc;
		break;

	case EJUSTRETURN:
		break;		/* nothing to do */

	default:
	bad:
		frame.f_regs[D0] = error;
		frame.f_sr |= PSL_C;
		break;
	}

	userret(p, &frame, sticks, (u_int)0, 0);
#ifdef KTRACE
	if (KTRPOINT(p, KTR_SYSRET))
		ktrsysret(p->p_tracep, code, error, rval[0]);
#endif
}