xref: /freebsd/sys/cddl/dev/dtrace/i386/dtrace_isa.c (revision 7ee6b0f125a092ed99d327bb8d608dd2ff77b7aa)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  *
22  * $FreeBSD$
23  */
24 /*
25  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
26  * Use is subject to license terms.
27  */
28 #include <sys/cdefs.h>
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
33 #include <sys/stack.h>
34 #include <sys/pcpu.h>
35 
36 #include <machine/frame.h>
37 #include <machine/md_var.h>
38 #include <machine/pcb.h>
39 #include <machine/stack.h>
40 
41 #include <vm/vm.h>
42 #include <vm/vm_param.h>
43 #include <vm/pmap.h>
44 
45 #include "regset.h"
46 
47 extern uintptr_t kernbase;
48 uintptr_t kernelbase = (uintptr_t) &kernbase;
49 
50 uint8_t dtrace_fuword8_nocheck(void *);
51 uint16_t dtrace_fuword16_nocheck(void *);
52 uint32_t dtrace_fuword32_nocheck(void *);
53 uint64_t dtrace_fuword64_nocheck(void *);
54 
55 int	dtrace_ustackdepth_max = 2048;
56 
57 void
58 dtrace_getpcstack(pc_t *pcstack, int pcstack_limit, int aframes,
59     uint32_t *intrpc)
60 {
61 	int depth = 0;
62 	register_t ebp;
63 	struct i386_frame *frame;
64 	vm_offset_t callpc;
65 	pc_t caller = (pc_t) solaris_cpu[curcpu].cpu_dtrace_caller;
66 
67 	if (intrpc != 0)
68 		pcstack[depth++] = (pc_t) intrpc;
69 
70 	aframes++;
71 
72 	__asm __volatile("movl %%ebp,%0" : "=r" (ebp));
73 
74 	frame = (struct i386_frame *)ebp;
75 	while (depth < pcstack_limit) {
76 		if (!kstack_contains(curthread, (vm_offset_t)frame,
77 		    sizeof(*frame)))
78 			break;
79 
80 		callpc = frame->f_retaddr;
81 
82 		if (!INKERNEL(callpc))
83 			break;
84 
85 		if (aframes > 0) {
86 			aframes--;
87 			if ((aframes == 0) && (caller != 0)) {
88 				pcstack[depth++] = caller;
89 			}
90 		}
91 		else {
92 			pcstack[depth++] = callpc;
93 		}
94 
95 		if (frame->f_frame <= frame)
96 			break;
97 		frame = frame->f_frame;
98 	}
99 
100 	for (; depth < pcstack_limit; depth++) {
101 		pcstack[depth] = 0;
102 	}
103 }
104 
105 static int
106 dtrace_getustack_common(uint64_t *pcstack, int pcstack_limit, uintptr_t pc,
107     uintptr_t sp)
108 {
109 #ifdef notyet
110 	proc_t *p = curproc;
111 	uintptr_t oldcontext = lwp->lwp_oldcontext; /* XXX signal stack. */
112 	size_t s1, s2;
113 #endif
114 	uintptr_t oldsp;
115 	volatile uint16_t *flags =
116 	    (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
117 	int ret = 0;
118 
119 	ASSERT(pcstack == NULL || pcstack_limit > 0);
120 	ASSERT(dtrace_ustackdepth_max > 0);
121 
122 #ifdef notyet /* XXX signal stack. */
123 	if (p->p_model == DATAMODEL_NATIVE) {
124 		s1 = sizeof (struct frame) + 2 * sizeof (long);
125 		s2 = s1 + sizeof (siginfo_t);
126 	} else {
127 		s1 = sizeof (struct frame32) + 3 * sizeof (int);
128 		s2 = s1 + sizeof (siginfo32_t);
129 	}
130 #endif
131 
132 	while (pc != 0) {
133 		/*
134 		 * We limit the number of times we can go around this
135 		 * loop to account for a circular stack.
136 		 */
137 		if (ret++ >= dtrace_ustackdepth_max) {
138 			*flags |= CPU_DTRACE_BADSTACK;
139 			cpu_core[curcpu].cpuc_dtrace_illval = sp;
140 			break;
141 		}
142 
143 		if (pcstack != NULL) {
144 			*pcstack++ = (uint64_t)pc;
145 			pcstack_limit--;
146 			if (pcstack_limit <= 0)
147 				break;
148 		}
149 
150 		if (sp == 0)
151 			break;
152 
153 		oldsp = sp;
154 
155 #ifdef notyet /* XXX signal stack. */
156 		if (oldcontext == sp + s1 || oldcontext == sp + s2) {
157 			if (p->p_model == DATAMODEL_NATIVE) {
158 				ucontext_t *ucp = (ucontext_t *)oldcontext;
159 				greg_t *gregs = ucp->uc_mcontext.gregs;
160 
161 				sp = dtrace_fulword(&gregs[REG_FP]);
162 				pc = dtrace_fulword(&gregs[REG_PC]);
163 
164 				oldcontext = dtrace_fulword(&ucp->uc_link);
165 			} else {
166 				ucontext32_t *ucp = (ucontext32_t *)oldcontext;
167 				greg32_t *gregs = ucp->uc_mcontext.gregs;
168 
169 				sp = dtrace_fuword32(&gregs[EBP]);
170 				pc = dtrace_fuword32(&gregs[EIP]);
171 
172 				oldcontext = dtrace_fuword32(&ucp->uc_link);
173 			}
174 		} else {
175 			if (p->p_model == DATAMODEL_NATIVE) {
176 				struct frame *fr = (struct frame *)sp;
177 
178 				pc = dtrace_fulword(&fr->fr_savpc);
179 				sp = dtrace_fulword(&fr->fr_savfp);
180 			} else {
181 				struct frame32 *fr = (struct frame32 *)sp;
182 
183 				pc = dtrace_fuword32(&fr->fr_savpc);
184 				sp = dtrace_fuword32(&fr->fr_savfp);
185 			}
186 		}
187 #else
188 		pc = dtrace_fuword32((void *)(sp +
189 			offsetof(struct i386_frame, f_retaddr)));
190 		sp = dtrace_fuword32((void *)sp);
191 #endif /* ! notyet */
192 
193 		if (sp == oldsp) {
194 			*flags |= CPU_DTRACE_BADSTACK;
195 			cpu_core[curcpu].cpuc_dtrace_illval = sp;
196 			break;
197 		}
198 
199 		/*
200 		 * This is totally bogus:  if we faulted, we're going to clear
201 		 * the fault and break.  This is to deal with the apparently
202 		 * broken Java stacks on x86.
203 		 */
204 		if (*flags & CPU_DTRACE_FAULT) {
205 			*flags &= ~CPU_DTRACE_FAULT;
206 			break;
207 		}
208 	}
209 
210 	return (ret);
211 }
212 
213 void
214 dtrace_getupcstack(uint64_t *pcstack, int pcstack_limit)
215 {
216 	proc_t *p = curproc;
217 	struct trapframe *tf;
218 	uintptr_t pc, sp, fp;
219 	volatile uint16_t *flags =
220 	    (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
221 	int n;
222 
223 	if (*flags & CPU_DTRACE_FAULT)
224 		return;
225 
226 	if (pcstack_limit <= 0)
227 		return;
228 
229 	/*
230 	 * If there's no user context we still need to zero the stack.
231 	 */
232 	if (p == NULL || (tf = curthread->td_frame) == NULL)
233 		goto zero;
234 
235 	*pcstack++ = (uint64_t)p->p_pid;
236 	pcstack_limit--;
237 
238 	if (pcstack_limit <= 0)
239 		return;
240 
241 	pc = tf->tf_eip;
242 	fp = tf->tf_ebp;
243 	sp = tf->tf_esp;
244 
245 	if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) {
246 		/*
247 		 * In an entry probe.  The frame pointer has not yet been
248 		 * pushed (that happens in the function prologue).  The
249 		 * best approach is to add the current pc as a missing top
250 		 * of stack and back the pc up to the caller, which is stored
251 		 * at the current stack pointer address since the call
252 		 * instruction puts it there right before the branch.
253 		 */
254 
255 		*pcstack++ = (uint64_t)pc;
256 		pcstack_limit--;
257 		if (pcstack_limit <= 0)
258 			return;
259 
260 		pc = dtrace_fuword32((void *) sp);
261 	}
262 
263 	n = dtrace_getustack_common(pcstack, pcstack_limit, pc, sp);
264 	ASSERT(n >= 0);
265 	ASSERT(n <= pcstack_limit);
266 
267 	pcstack += n;
268 	pcstack_limit -= n;
269 
270 zero:
271 	while (pcstack_limit-- > 0)
272 		*pcstack++ = 0;
273 }
274 
275 int
276 dtrace_getustackdepth(void)
277 {
278 	proc_t *p = curproc;
279 	struct trapframe *tf;
280 	uintptr_t pc, fp, sp;
281 	int n = 0;
282 
283 	if (p == NULL || (tf = curthread->td_frame) == NULL)
284 		return (0);
285 
286 	if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_FAULT))
287 		return (-1);
288 
289 	pc = tf->tf_eip;
290 	fp = tf->tf_ebp;
291 	sp = tf->tf_esp;
292 
293 	if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) {
294 		/*
295 		 * In an entry probe.  The frame pointer has not yet been
296 		 * pushed (that happens in the function prologue).  The
297 		 * best approach is to add the current pc as a missing top
298 		 * of stack and back the pc up to the caller, which is stored
299 		 * at the current stack pointer address since the call
300 		 * instruction puts it there right before the branch.
301 		 */
302 
303 		pc = dtrace_fuword32((void *) sp);
304 		n++;
305 	}
306 
307 	n += dtrace_getustack_common(NULL, 0, pc, fp);
308 
309 	return (n);
310 }
311 
312 void
313 dtrace_getufpstack(uint64_t *pcstack, uint64_t *fpstack, int pcstack_limit)
314 {
315 	proc_t *p = curproc;
316 	struct trapframe *tf;
317 	uintptr_t pc, sp, fp;
318 	volatile uint16_t *flags =
319 	    (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
320 #ifdef notyet /* XXX signal stack */
321 	uintptr_t oldcontext;
322 	size_t s1, s2;
323 #endif
324 
325 	if (*flags & CPU_DTRACE_FAULT)
326 		return;
327 
328 	if (pcstack_limit <= 0)
329 		return;
330 
331 	/*
332 	 * If there's no user context we still need to zero the stack.
333 	 */
334 	if (p == NULL || (tf = curthread->td_frame) == NULL)
335 		goto zero;
336 
337 	*pcstack++ = (uint64_t)p->p_pid;
338 	pcstack_limit--;
339 
340 	if (pcstack_limit <= 0)
341 		return;
342 
343 	pc = tf->tf_eip;
344 	fp = tf->tf_ebp;
345 	sp = tf->tf_esp;
346 
347 #ifdef notyet /* XXX signal stack */
348 	oldcontext = lwp->lwp_oldcontext;
349 
350 	if (p->p_model == DATAMODEL_NATIVE) {
351 		s1 = sizeof (struct frame) + 2 * sizeof (long);
352 		s2 = s1 + sizeof (siginfo_t);
353 	} else {
354 		s1 = sizeof (struct frame32) + 3 * sizeof (int);
355 		s2 = s1 + sizeof (siginfo32_t);
356 	}
357 #endif
358 
359 	if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) {
360 		*pcstack++ = (uint64_t)pc;
361 		*fpstack++ = 0;
362 		pcstack_limit--;
363 		if (pcstack_limit <= 0)
364 			return;
365 
366 		pc = dtrace_fuword32((void *)sp);
367 	}
368 
369 	while (pc != 0) {
370 		*pcstack++ = (uint64_t)pc;
371 		*fpstack++ = fp;
372 		pcstack_limit--;
373 		if (pcstack_limit <= 0)
374 			break;
375 
376 		if (fp == 0)
377 			break;
378 
379 #ifdef notyet /* XXX signal stack */
380 		if (oldcontext == sp + s1 || oldcontext == sp + s2) {
381 			if (p->p_model == DATAMODEL_NATIVE) {
382 				ucontext_t *ucp = (ucontext_t *)oldcontext;
383 				greg_t *gregs = ucp->uc_mcontext.gregs;
384 
385 				sp = dtrace_fulword(&gregs[REG_FP]);
386 				pc = dtrace_fulword(&gregs[REG_PC]);
387 
388 				oldcontext = dtrace_fulword(&ucp->uc_link);
389 			} else {
390 				ucontext_t *ucp = (ucontext_t *)oldcontext;
391 				greg_t *gregs = ucp->uc_mcontext.gregs;
392 
393 				sp = dtrace_fuword32(&gregs[EBP]);
394 				pc = dtrace_fuword32(&gregs[EIP]);
395 
396 				oldcontext = dtrace_fuword32(&ucp->uc_link);
397 			}
398 		} else
399 #endif /* XXX */
400 		{
401 			pc = dtrace_fuword32((void *)(fp +
402 				offsetof(struct i386_frame, f_retaddr)));
403 			fp = dtrace_fuword32((void *)fp);
404 		}
405 
406 		/*
407 		 * This is totally bogus:  if we faulted, we're going to clear
408 		 * the fault and break.  This is to deal with the apparently
409 		 * broken Java stacks on x86.
410 		 */
411 		if (*flags & CPU_DTRACE_FAULT) {
412 			*flags &= ~CPU_DTRACE_FAULT;
413 			break;
414 		}
415 	}
416 
417 zero:
418 	while (pcstack_limit-- > 0)
419 		*pcstack++ = 0;
420 }
421 
422 uint64_t
423 dtrace_getarg(int arg, int aframes)
424 {
425 	struct trapframe *frame;
426 	struct i386_frame *fp = (struct i386_frame *)dtrace_getfp();
427 	uintptr_t *stack, val;
428 	int i;
429 
430 	for (i = 1; i <= aframes; i++) {
431 		fp = fp->f_frame;
432 
433 		if (P2ROUNDUP(fp->f_retaddr, 4) ==
434 		    (long)dtrace_invop_callsite) {
435 			/*
436 			 * If we pass through the invalid op handler, we will
437 			 * use the trap frame pointer that it pushed on the
438 			 * stack as the second argument to dtrace_invop() as
439 			 * the pointer to the stack.  When using this stack, we
440 			 * must skip the third argument to dtrace_invop(),
441 			 * which is included in the i386_frame.
442 			 */
443 			frame = (struct trapframe *)(((uintptr_t **)&fp[1])[0]);
444 			/*
445 			 * Skip the three hardware-saved registers and the
446 			 * return address.
447 			 */
448 			stack = (uintptr_t *)frame->tf_isp + 4;
449 			goto load;
450 		}
451 
452 	}
453 
454 	/*
455 	 * We know that we did not come through a trap to get into
456 	 * dtrace_probe() -- the provider simply called dtrace_probe()
457 	 * directly.  As this is the case, we need to shift the argument
458 	 * that we're looking for:  the probe ID is the first argument to
459 	 * dtrace_probe(), so the argument n will actually be found where
460 	 * one would expect to find argument (n + 1).
461 	 */
462 	arg++;
463 
464 	stack = (uintptr_t *)fp + 2;
465 
466 load:
467 	DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
468 	val = stack[arg];
469 	DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
470 
471 	return (val);
472 }
473 
474 int
475 dtrace_getstackdepth(int aframes)
476 {
477 	int depth = 0;
478 	struct i386_frame *frame;
479 	vm_offset_t ebp;
480 
481 	aframes++;
482 	ebp = dtrace_getfp();
483 	frame = (struct i386_frame *)ebp;
484 	depth++;
485 	for(;;) {
486 		if (!kstack_contains(curthread, (vm_offset_t)frame,
487 		    sizeof(*frame)))
488 			break;
489 		depth++;
490 		if (frame->f_frame <= frame)
491 			break;
492 		frame = frame->f_frame;
493 	}
494 	if (depth < aframes)
495 		return 0;
496 	else
497 		return depth - aframes;
498 }
499 
500 ulong_t
501 dtrace_getreg(struct trapframe *frame, uint_t reg)
502 {
503 	struct pcb *pcb;
504 	int regmap[] = {  /* Order is dependent on reg.d */
505 		REG_GS,		/* 0  GS */
506 		REG_FS,		/* 1  FS */
507 		REG_ES,		/* 2  ES */
508 		REG_DS,		/* 3  DS */
509 		REG_RDI,	/* 4  EDI */
510 		REG_RSI,	/* 5  ESI */
511 		REG_RBP,	/* 6  EBP, REG_FP */
512 		REG_RSP,	/* 7  ESP */
513 		REG_RBX,	/* 8  EBX */
514 		REG_RDX,	/* 9  EDX, REG_R1 */
515 		REG_RCX,	/* 10 ECX */
516 		REG_RAX,	/* 11 EAX, REG_R0 */
517 		REG_TRAPNO,	/* 12 TRAPNO */
518 		REG_ERR,	/* 13 ERR */
519 		REG_RIP,	/* 14 EIP, REG_PC */
520 		REG_CS,		/* 15 CS */
521 		REG_RFL,	/* 16 EFL, REG_PS */
522 		REG_RSP,	/* 17 UESP, REG_SP */
523 		REG_SS		/* 18 SS */
524 	};
525 
526 	if (reg > SS) {
527 		DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
528 		return (0);
529 	}
530 
531 	if (reg >= sizeof (regmap) / sizeof (int)) {
532 		DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
533 		return (0);
534 	}
535 
536 	reg = regmap[reg];
537 
538 	switch(reg) {
539 	case REG_GS:
540 		if ((pcb = curthread->td_pcb) == NULL) {
541 			DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
542 			return (0);
543 		}
544 		return (pcb->pcb_gs);
545 	case REG_FS:
546 		return (frame->tf_fs);
547 	case REG_ES:
548 		return (frame->tf_es);
549 	case REG_DS:
550 		return (frame->tf_ds);
551 	case REG_RDI:
552 		return (frame->tf_edi);
553 	case REG_RSI:
554 		return (frame->tf_esi);
555 	case REG_RBP:
556 		return (frame->tf_ebp);
557 	case REG_RSP:
558 		return (frame->tf_isp);
559 	case REG_RBX:
560 		return (frame->tf_ebx);
561 	case REG_RCX:
562 		return (frame->tf_ecx);
563 	case REG_RAX:
564 		return (frame->tf_eax);
565 	case REG_TRAPNO:
566 		return (frame->tf_trapno);
567 	case REG_ERR:
568 		return (frame->tf_err);
569 	case REG_RIP:
570 		return (frame->tf_eip);
571 	case REG_CS:
572 		return (frame->tf_cs);
573 	case REG_RFL:
574 		return (frame->tf_eflags);
575 #if 0
576 	case REG_RSP:
577 		return (frame->tf_esp);
578 #endif
579 	case REG_SS:
580 		return (frame->tf_ss);
581 	default:
582 		DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
583 		return (0);
584 	}
585 }
586 
587 static int
588 dtrace_copycheck(uintptr_t uaddr, uintptr_t kaddr, size_t size)
589 {
590 	ASSERT(kaddr >= kernelbase && kaddr + size >= kaddr);
591 
592 	if (uaddr + size >= kernelbase || uaddr + size < uaddr) {
593 		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
594 		cpu_core[curcpu].cpuc_dtrace_illval = uaddr;
595 		return (0);
596 	}
597 
598 	return (1);
599 }
600 
601 void
602 dtrace_copyin(uintptr_t uaddr, uintptr_t kaddr, size_t size,
603     volatile uint16_t *flags)
604 {
605 	if (dtrace_copycheck(uaddr, kaddr, size))
606 		dtrace_copy(uaddr, kaddr, size);
607 }
608 
609 void
610 dtrace_copyout(uintptr_t kaddr, uintptr_t uaddr, size_t size,
611     volatile uint16_t *flags)
612 {
613 	if (dtrace_copycheck(uaddr, kaddr, size))
614 		dtrace_copy(kaddr, uaddr, size);
615 }
616 
617 void
618 dtrace_copyinstr(uintptr_t uaddr, uintptr_t kaddr, size_t size,
619     volatile uint16_t *flags)
620 {
621 	if (dtrace_copycheck(uaddr, kaddr, size))
622 		dtrace_copystr(uaddr, kaddr, size, flags);
623 }
624 
625 void
626 dtrace_copyoutstr(uintptr_t kaddr, uintptr_t uaddr, size_t size,
627     volatile uint16_t *flags)
628 {
629 	if (dtrace_copycheck(uaddr, kaddr, size))
630 		dtrace_copystr(kaddr, uaddr, size, flags);
631 }
632 
633 uint8_t
634 dtrace_fuword8(void *uaddr)
635 {
636 	if ((uintptr_t)uaddr >= kernelbase) {
637 		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
638 		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
639 		return (0);
640 	}
641 	return (dtrace_fuword8_nocheck(uaddr));
642 }
643 
644 uint16_t
645 dtrace_fuword16(void *uaddr)
646 {
647 	if ((uintptr_t)uaddr >= kernelbase) {
648 		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
649 		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
650 		return (0);
651 	}
652 	return (dtrace_fuword16_nocheck(uaddr));
653 }
654 
655 uint32_t
656 dtrace_fuword32(void *uaddr)
657 {
658 	if ((uintptr_t)uaddr >= kernelbase) {
659 		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
660 		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
661 		return (0);
662 	}
663 	return (dtrace_fuword32_nocheck(uaddr));
664 }
665 
666 uint64_t
667 dtrace_fuword64(void *uaddr)
668 {
669 	if ((uintptr_t)uaddr >= kernelbase) {
670 		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
671 		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
672 		return (0);
673 	}
674 	return (dtrace_fuword64_nocheck(uaddr));
675 }
676