trap.c revision 333205 
1/*-
2 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
3 * Copyright (C) 1995, 1996 TooLs GmbH.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 *    must display the following acknowledgement:
16 *	This product includes software developed by TooLs GmbH.
17 * 4. The name of TooLs GmbH may not be used to endorse or promote products
18 *    derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 *
31 * $NetBSD: trap.c,v 1.58 2002/03/04 04:07:35 dbj Exp $
32 */
33
34#include <sys/cdefs.h>
35__FBSDID("$FreeBSD: stable/10/sys/powerpc/booke/trap.c 333205 2018-05-03 07:57:08Z avg $");
36
37#include "opt_fpu_emu.h"
38
39#include <sys/param.h>
40#include <sys/kdb.h>
41#include <sys/proc.h>
42#include <sys/ktr.h>
43#include <sys/lock.h>
44#include <sys/mutex.h>
45#include <sys/pioctl.h>
46#include <sys/ptrace.h>
47#include <sys/reboot.h>
48#include <sys/syscall.h>
49#include <sys/sysent.h>
50#include <sys/systm.h>
51#include <sys/kernel.h>
52#include <sys/uio.h>
53#include <sys/signalvar.h>
54#include <sys/vmmeter.h>
55
56#include <security/audit/audit.h>
57
58#include <vm/vm.h>
59#include <vm/pmap.h>
60#include <vm/vm_extern.h>
61#include <vm/vm_param.h>
62#include <vm/vm_kern.h>
63#include <vm/vm_map.h>
64#include <vm/vm_page.h>
65
66#include <machine/cpu.h>
67#include <machine/db_machdep.h>
68#include <machine/frame.h>
69#include <machine/pcb.h>
70#include <machine/pmap.h>
71#include <machine/psl.h>
72#include <machine/trap.h>
73#include <machine/spr.h>
74
75#define	FAULTBUF_LR	0
76#define	FAULTBUF_R1	1
77#define	FAULTBUF_R2	2
78#define	FAULTBUF_CR	3
79#define	FAULTBUF_CTR	4
80#define	FAULTBUF_XER	5
81#define	FAULTBUF_R13	6
82
83static void	trap_fatal(struct trapframe *frame);
84static void	printtrap(u_int vector, struct trapframe *frame, int isfatal,
85    int user);
86static int	trap_pfault(struct trapframe *frame, int user);
87static int	fix_unaligned(struct thread *td, struct trapframe *frame);
88static int	handle_onfault(struct trapframe *frame);
89static void	syscall(struct trapframe *frame);
90
91struct powerpc_exception {
92	u_int	vector;
93	char	*name;
94};
95
96static struct powerpc_exception powerpc_exceptions[] = {
97	{ EXC_CRIT,	"critical input" },
98	{ EXC_MCHK,	"machine check" },
99	{ EXC_DSI,	"data storage interrupt" },
100	{ EXC_ISI,	"instruction storage interrupt" },
101	{ EXC_EXI,	"external interrupt" },
102	{ EXC_ALI,	"alignment" },
103	{ EXC_PGM,	"program" },
104	{ EXC_SC,	"system call" },
105	{ EXC_APU,	"auxiliary proc unavailable" },
106	{ EXC_DECR,	"decrementer" },
107	{ EXC_FIT,	"fixed-interval timer" },
108	{ EXC_WDOG,	"watchdog timer" },
109	{ EXC_DTMISS,	"data tlb miss" },
110	{ EXC_ITMISS,	"instruction tlb miss" },
111	{ EXC_DEBUG,	"debug" },
112	{ EXC_PERF,	"performance monitoring" },
113	{ EXC_LAST,	NULL }
114};
115
116static const char *
117trapname(u_int vector)
118{
119	struct	powerpc_exception *pe;
120
121	for (pe = powerpc_exceptions; pe->vector != EXC_LAST; pe++) {
122		if (pe->vector == vector)
123			return (pe->name);
124	}
125
126	return ("unknown");
127}
128
129void
130trap(struct trapframe *frame)
131{
132	struct thread	*td;
133	struct proc	*p;
134	int		sig, type, user;
135	ksiginfo_t	ksi;
136
137#ifdef KDB
138	if (kdb_active) {
139		kdb_reenter();
140		return;
141	}
142#endif
143
144	PCPU_INC(cnt.v_trap);
145
146	td = curthread;
147	p = td->td_proc;
148
149	type = frame->exc;
150	sig = 0;
151	user = (frame->srr1 & PSL_PR) ? 1 : 0;
152
153	CTR3(KTR_TRAP, "trap: %s type=%s (%s)", p->p_comm,
154	    trapname(type), user ? "user" : "kernel");
155
156	if (user) {
157		td->td_frame = frame;
158		if (td->td_ucred != p->p_ucred)
159			cred_update_thread(td);
160
161		/* User Mode Traps */
162		switch (type) {
163		case EXC_DSI:
164		case EXC_ISI:
165			sig = trap_pfault(frame, 1);
166			break;
167
168		case EXC_SC:
169			syscall(frame);
170			break;
171
172		case EXC_ALI:
173			if (fix_unaligned(td, frame) != 0)
174				sig = SIGBUS;
175			else
176				frame->srr0 += 4;
177			break;
178
179		case EXC_DEBUG:	/* Single stepping */
180			mtspr(SPR_DBSR, mfspr(SPR_DBSR));
181			frame->srr1 &= ~PSL_DE;
182			frame->cpu.booke.dbcr0 &= ~(DBCR0_IDM || DBCR0_IC);
183			sig = SIGTRAP;
184			break;
185
186		case EXC_PGM:	/* Program exception */
187			sig = ppc_instr_emulate(frame, td->td_pcb);
188			break;
189
190		default:
191			trap_fatal(frame);
192		}
193	} else {
194		/* Kernel Mode Traps */
195		KASSERT(cold || td->td_ucred != NULL,
196		    ("kernel trap doesn't have ucred"));
197
198		switch (type) {
199		case EXC_DEBUG:
200			mtspr(SPR_DBSR, mfspr(SPR_DBSR));
201			kdb_trap(frame->exc, 0, frame);
202			return;
203
204		case EXC_DSI:
205			if (trap_pfault(frame, 0) == 0)
206 				return;
207			break;
208
209		case EXC_MCHK:
210			if (handle_onfault(frame))
211 				return;
212			break;
213#ifdef KDB
214		case EXC_PGM:
215			if (frame->cpu.booke.esr & ESR_PTR)
216				kdb_trap(EXC_PGM, 0, frame);
217			return;
218#endif
219		default:
220			break;
221		}
222		trap_fatal(frame);
223	}
224
225	if (sig != 0) {
226		if (p->p_sysent->sv_transtrap != NULL)
227			sig = (p->p_sysent->sv_transtrap)(sig, type);
228		ksiginfo_init_trap(&ksi);
229		ksi.ksi_signo = sig;
230		ksi.ksi_code = type; /* XXX, not POSIX */
231		/* ksi.ksi_addr = ? */
232		ksi.ksi_trapno = type;
233		trapsignal(td, &ksi);
234	}
235
236	userret(td, frame);
237}
238
239static void
240trap_fatal(struct trapframe *frame)
241{
242#ifdef KDB
243	bool handled;
244#endif
245
246	printtrap(frame->exc, frame, 1, (frame->srr1 & PSL_PR));
247#ifdef KDB
248	if (debugger_on_panic) {
249		kdb_why = KDB_WHY_TRAP;
250		handled = kdb_trap(frame->exc, 0, frame);
251		kdb_why = KDB_WHY_UNSET;
252		if (handled)
253			return;
254	}
255#endif
256	panic("%s trap", trapname(frame->exc));
257}
258
259static void
260printtrap(u_int vector, struct trapframe *frame, int isfatal, int user)
261{
262	register_t va = 0;
263
264	printf("\n");
265	printf("%s %s trap:\n", isfatal ? "fatal" : "handled",
266	    user ? "user" : "kernel");
267	printf("\n");
268	printf("   exception       = 0x%x (%s)\n", vector, trapname(vector));
269
270	switch (vector) {
271	case EXC_DTMISS:
272	case EXC_DSI:
273		va = frame->cpu.booke.dear;
274		break;
275
276	case EXC_ITMISS:
277	case EXC_ISI:
278		va = frame->srr0;
279		break;
280	}
281
282	printf("   virtual address = 0x%08x\n", va);
283	printf("   srr0            = 0x%08x\n", frame->srr0);
284	printf("   srr1            = 0x%08x\n", frame->srr1);
285	printf("   curthread       = %p\n", curthread);
286	if (curthread != NULL)
287		printf("          pid = %d, comm = %s\n",
288		    curthread->td_proc->p_pid, curthread->td_proc->p_comm);
289	printf("\n");
290}
291
292/*
293 * Handles a fatal fault when we have onfault state to recover.  Returns
294 * non-zero if there was onfault recovery state available.
295 */
296static int
297handle_onfault(struct trapframe *frame)
298{
299	struct		thread *td;
300	faultbuf	*fb;
301
302	td = curthread;
303	fb = td->td_pcb->pcb_onfault;
304	if (fb != NULL) {
305		frame->srr0 = (*fb)[FAULTBUF_LR];
306		frame->fixreg[1] = (*fb)[FAULTBUF_R1];
307		frame->fixreg[2] = (*fb)[FAULTBUF_R2];
308		frame->fixreg[3] = 1;
309		frame->cr = (*fb)[FAULTBUF_CR];
310		frame->ctr = (*fb)[FAULTBUF_CTR];
311		frame->xer = (*fb)[FAULTBUF_XER];
312		bcopy(&(*fb)[FAULTBUF_R13], &frame->fixreg[13],
313		    19 * sizeof(register_t));
314		return (1);
315	}
316	return (0);
317}
318
319int
320cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
321{
322	struct proc *p;
323	struct trapframe *frame;
324	caddr_t	params;
325	int error, n;
326
327	p = td->td_proc;
328	frame = td->td_frame;
329
330	sa->code = frame->fixreg[0];
331	params = (caddr_t)(frame->fixreg + FIRSTARG);
332	n = NARGREG;
333
334	if (sa->code == SYS_syscall) {
335		/*
336		 * code is first argument,
337		 * followed by actual args.
338		 */
339		sa->code = *(u_int *) params;
340		params += sizeof(register_t);
341		n -= 1;
342	} else if (sa->code == SYS___syscall) {
343		/*
344		 * Like syscall, but code is a quad,
345		 * so as to maintain quad alignment
346		 * for the rest of the args.
347		 */
348		params += sizeof(register_t);
349		sa->code = *(u_int *) params;
350		params += sizeof(register_t);
351		n -= 2;
352	}
353
354	if (p->p_sysent->sv_mask)
355		sa->code &= p->p_sysent->sv_mask;
356	if (sa->code >= p->p_sysent->sv_size)
357		sa->callp = &p->p_sysent->sv_table[0];
358	else
359		sa->callp = &p->p_sysent->sv_table[sa->code];
360	sa->narg = sa->callp->sy_narg;
361
362	bcopy(params, sa->args, n * sizeof(register_t));
363	if (sa->narg > n) {
364		error = copyin(MOREARGS(frame->fixreg[1]), sa->args + n,
365		    (sa->narg - n) * sizeof(register_t));
366	} else
367		error = 0;
368
369	if (error == 0) {
370		td->td_retval[0] = 0;
371		td->td_retval[1] = frame->fixreg[FIRSTARG + 1];
372	}
373	return (error);
374}
375
376#include "../../kern/subr_syscall.c"
377
378void
379syscall(struct trapframe *frame)
380{
381	struct thread *td;
382	struct syscall_args sa;
383	int error;
384
385	td = curthread;
386	td->td_frame = frame;
387
388	error = syscallenter(td, &sa);
389	syscallret(td, error, &sa);
390}
391
392static int
393trap_pfault(struct trapframe *frame, int user)
394{
395	vm_offset_t	eva, va;
396	struct		thread *td;
397	struct		proc *p;
398	vm_map_t	map;
399	vm_prot_t	ftype;
400	int		rv;
401
402	td = curthread;
403	p = td->td_proc;
404
405	if (frame->exc == EXC_ISI) {
406		eva = frame->srr0;
407		ftype = VM_PROT_READ | VM_PROT_EXECUTE;
408
409	} else {
410		eva = frame->cpu.booke.dear;
411		if (frame->cpu.booke.esr & ESR_ST)
412			ftype = VM_PROT_WRITE;
413		else
414			ftype = VM_PROT_READ;
415	}
416
417	if (user) {
418		KASSERT(p->p_vmspace != NULL, ("trap_pfault: vmspace  NULL"));
419		map = &p->p_vmspace->vm_map;
420	} else {
421		if (eva < VM_MAXUSER_ADDRESS) {
422
423			if (p->p_vmspace == NULL)
424				return (SIGSEGV);
425
426			map = &p->p_vmspace->vm_map;
427
428		} else {
429			map = kernel_map;
430		}
431	}
432	va = trunc_page(eva);
433
434	if (map != kernel_map) {
435		/*
436		 * Keep swapout from messing with us during this
437		 *	critical time.
438		 */
439		PROC_LOCK(p);
440		++p->p_lock;
441		PROC_UNLOCK(p);
442
443		/* Fault in the user page: */
444		rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
445
446		PROC_LOCK(p);
447		--p->p_lock;
448		PROC_UNLOCK(p);
449	} else {
450		/*
451		 * Don't have to worry about process locking or stacks in the
452		 * kernel.
453		 */
454		rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
455	}
456
457	if (rv == KERN_SUCCESS)
458		return (0);
459
460	if (!user && handle_onfault(frame))
461		return (0);
462
463	return ((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV);
464}
465
466/*
467 * For now, this only deals with the particular unaligned access case
468 * that gcc tends to generate.  Eventually it should handle all of the
469 * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
470 */
471
472static int
473fix_unaligned(struct thread *td, struct trapframe *frame)
474{
475#if 0
476	struct thread	*fputhread;
477	int		indicator, reg;
478	double		*fpr;
479
480	indicator = EXC_ALI_OPCODE_INDICATOR(frame->dsisr);
481
482	switch (indicator) {
483	case EXC_ALI_LFD:
484	case EXC_ALI_STFD:
485		reg = EXC_ALI_RST(frame->dsisr);
486		fpr = &td->td_pcb->pcb_fpu.fpr[reg];
487		fputhread = PCPU_GET(fputhread);
488		/* Juggle the FPU to ensure that we've initialized
489		 * the FPRs, and that their current state is in
490		 * the PCB.
491		 */
492		if (fputhread != td) {
493			if (fputhread)
494				save_fpu(fputhread);
495			enable_fpu(td);
496		}
497		save_fpu(td);
498
499		if (indicator == EXC_ALI_LFD) {
500			if (copyin((void *)frame->dar, fpr,
501			    sizeof(double)) != 0)
502				return -1;
503			enable_fpu(td);
504		} else {
505			if (copyout(fpr, (void *)frame->dar,
506			    sizeof(double)) != 0)
507				return -1;
508		}
509		return 0;
510		break;
511	}
512
513#endif
514	return (-1);
515}
516
517#ifdef KDB
518int db_trap_glue(struct trapframe *);
519int
520db_trap_glue(struct trapframe *tf)
521{
522	if (!(tf->srr1 & PSL_PR))
523		return (kdb_trap(tf->exc, 0, tf));
524	return (0);
525}
526#endif
527