xref: /freebsd/sys/cddl/dev/dtrace/i386/dtrace_isa.c (revision b78ee15e9f04ae15c3e1200df974473167524d17)
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 #define INKERNEL(va) (((vm_offset_t)(va)) >= USRSTACK && \
51 	 ((vm_offset_t)(va)) < VM_MAX_KERNEL_ADDRESS)
52 
53 uint8_t dtrace_fuword8_nocheck(void *);
54 uint16_t dtrace_fuword16_nocheck(void *);
55 uint32_t dtrace_fuword32_nocheck(void *);
56 uint64_t dtrace_fuword64_nocheck(void *);
57 
58 int	dtrace_ustackdepth_max = 2048;
59 
60 void
61 dtrace_getpcstack(pc_t *pcstack, int pcstack_limit, int aframes,
62     uint32_t *intrpc)
63 {
64 	int depth = 0;
65 	register_t ebp;
66 	struct i386_frame *frame;
67 	vm_offset_t callpc;
68 	pc_t caller = (pc_t) solaris_cpu[curcpu].cpu_dtrace_caller;
69 
70 	if (intrpc != 0)
71 		pcstack[depth++] = (pc_t) intrpc;
72 
73 	aframes++;
74 
75 	__asm __volatile("movl %%ebp,%0" : "=r" (ebp));
76 
77 	frame = (struct i386_frame *)ebp;
78 	while (depth < pcstack_limit) {
79 		if (!INKERNEL(frame))
80 			break;
81 
82 		callpc = frame->f_retaddr;
83 
84 		if (!INKERNEL(callpc))
85 			break;
86 
87 		if (aframes > 0) {
88 			aframes--;
89 			if ((aframes == 0) && (caller != 0)) {
90 				pcstack[depth++] = caller;
91 			}
92 		}
93 		else {
94 			pcstack[depth++] = callpc;
95 		}
96 
97 		if (frame->f_frame <= frame ||
98 		    (vm_offset_t)frame->f_frame >=
99 		    (vm_offset_t)ebp + KSTACK_PAGES * PAGE_SIZE)
100 			break;
101 		frame = frame->f_frame;
102 	}
103 
104 	for (; depth < pcstack_limit; depth++) {
105 		pcstack[depth] = 0;
106 	}
107 }
108 
109 static int
110 dtrace_getustack_common(uint64_t *pcstack, int pcstack_limit, uintptr_t pc,
111     uintptr_t sp)
112 {
113 #ifdef notyet
114 	proc_t *p = curproc;
115 	uintptr_t oldcontext = lwp->lwp_oldcontext; /* XXX signal stack. */
116 	size_t s1, s2;
117 #endif
118 	uintptr_t oldsp;
119 	volatile uint16_t *flags =
120 	    (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
121 	int ret = 0;
122 
123 	ASSERT(pcstack == NULL || pcstack_limit > 0);
124 	ASSERT(dtrace_ustackdepth_max > 0);
125 
126 #ifdef notyet /* XXX signal stack. */
127 	if (p->p_model == DATAMODEL_NATIVE) {
128 		s1 = sizeof (struct frame) + 2 * sizeof (long);
129 		s2 = s1 + sizeof (siginfo_t);
130 	} else {
131 		s1 = sizeof (struct frame32) + 3 * sizeof (int);
132 		s2 = s1 + sizeof (siginfo32_t);
133 	}
134 #endif
135 
136 	while (pc != 0) {
137 		/*
138 		 * We limit the number of times we can go around this
139 		 * loop to account for a circular stack.
140 		 */
141 		if (ret++ >= dtrace_ustackdepth_max) {
142 			*flags |= CPU_DTRACE_BADSTACK;
143 			cpu_core[curcpu].cpuc_dtrace_illval = sp;
144 			break;
145 		}
146 
147 		if (pcstack != NULL) {
148 			*pcstack++ = (uint64_t)pc;
149 			pcstack_limit--;
150 			if (pcstack_limit <= 0)
151 				break;
152 		}
153 
154 		if (sp == 0)
155 			break;
156 
157 		oldsp = sp;
158 
159 #ifdef notyet /* XXX signal stack. */
160 		if (oldcontext == sp + s1 || oldcontext == sp + s2) {
161 			if (p->p_model == DATAMODEL_NATIVE) {
162 				ucontext_t *ucp = (ucontext_t *)oldcontext;
163 				greg_t *gregs = ucp->uc_mcontext.gregs;
164 
165 				sp = dtrace_fulword(&gregs[REG_FP]);
166 				pc = dtrace_fulword(&gregs[REG_PC]);
167 
168 				oldcontext = dtrace_fulword(&ucp->uc_link);
169 			} else {
170 				ucontext32_t *ucp = (ucontext32_t *)oldcontext;
171 				greg32_t *gregs = ucp->uc_mcontext.gregs;
172 
173 				sp = dtrace_fuword32(&gregs[EBP]);
174 				pc = dtrace_fuword32(&gregs[EIP]);
175 
176 				oldcontext = dtrace_fuword32(&ucp->uc_link);
177 			}
178 		} else {
179 			if (p->p_model == DATAMODEL_NATIVE) {
180 				struct frame *fr = (struct frame *)sp;
181 
182 				pc = dtrace_fulword(&fr->fr_savpc);
183 				sp = dtrace_fulword(&fr->fr_savfp);
184 			} else {
185 				struct frame32 *fr = (struct frame32 *)sp;
186 
187 				pc = dtrace_fuword32(&fr->fr_savpc);
188 				sp = dtrace_fuword32(&fr->fr_savfp);
189 			}
190 		}
191 #else
192 		pc = dtrace_fuword32((void *)(sp +
193 			offsetof(struct i386_frame, f_retaddr)));
194 		sp = dtrace_fuword32((void *)sp);
195 #endif /* ! notyet */
196 
197 		if (sp == oldsp) {
198 			*flags |= CPU_DTRACE_BADSTACK;
199 			cpu_core[curcpu].cpuc_dtrace_illval = sp;
200 			break;
201 		}
202 
203 		/*
204 		 * This is totally bogus:  if we faulted, we're going to clear
205 		 * the fault and break.  This is to deal with the apparently
206 		 * broken Java stacks on x86.
207 		 */
208 		if (*flags & CPU_DTRACE_FAULT) {
209 			*flags &= ~CPU_DTRACE_FAULT;
210 			break;
211 		}
212 	}
213 
214 	return (ret);
215 }
216 
217 void
218 dtrace_getupcstack(uint64_t *pcstack, int pcstack_limit)
219 {
220 	proc_t *p = curproc;
221 	struct trapframe *tf;
222 	uintptr_t pc, sp, fp;
223 	volatile uint16_t *flags =
224 	    (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
225 	int n;
226 
227 	if (*flags & CPU_DTRACE_FAULT)
228 		return;
229 
230 	if (pcstack_limit <= 0)
231 		return;
232 
233 	/*
234 	 * If there's no user context we still need to zero the stack.
235 	 */
236 	if (p == NULL || (tf = curthread->td_frame) == NULL)
237 		goto zero;
238 
239 	*pcstack++ = (uint64_t)p->p_pid;
240 	pcstack_limit--;
241 
242 	if (pcstack_limit <= 0)
243 		return;
244 
245 	pc = tf->tf_eip;
246 	fp = tf->tf_ebp;
247 	sp = tf->tf_esp;
248 
249 	if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) {
250 		/*
251 		 * In an entry probe.  The frame pointer has not yet been
252 		 * pushed (that happens in the function prologue).  The
253 		 * best approach is to add the current pc as a missing top
254 		 * of stack and back the pc up to the caller, which is stored
255 		 * at the current stack pointer address since the call
256 		 * instruction puts it there right before the branch.
257 		 */
258 
259 		*pcstack++ = (uint64_t)pc;
260 		pcstack_limit--;
261 		if (pcstack_limit <= 0)
262 			return;
263 
264 		pc = dtrace_fuword32((void *) sp);
265 	}
266 
267 	n = dtrace_getustack_common(pcstack, pcstack_limit, pc, sp);
268 	ASSERT(n >= 0);
269 	ASSERT(n <= pcstack_limit);
270 
271 	pcstack += n;
272 	pcstack_limit -= n;
273 
274 zero:
275 	while (pcstack_limit-- > 0)
276 		*pcstack++ = 0;
277 }
278 
279 int
280 dtrace_getustackdepth(void)
281 {
282 	proc_t *p = curproc;
283 	struct trapframe *tf;
284 	uintptr_t pc, fp, sp;
285 	int n = 0;
286 
287 	if (p == NULL || (tf = curthread->td_frame) == NULL)
288 		return (0);
289 
290 	if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_FAULT))
291 		return (-1);
292 
293 	pc = tf->tf_eip;
294 	fp = tf->tf_ebp;
295 	sp = tf->tf_esp;
296 
297 	if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) {
298 		/*
299 		 * In an entry probe.  The frame pointer has not yet been
300 		 * pushed (that happens in the function prologue).  The
301 		 * best approach is to add the current pc as a missing top
302 		 * of stack and back the pc up to the caller, which is stored
303 		 * at the current stack pointer address since the call
304 		 * instruction puts it there right before the branch.
305 		 */
306 
307 		pc = dtrace_fuword32((void *) sp);
308 		n++;
309 	}
310 
311 	n += dtrace_getustack_common(NULL, 0, pc, fp);
312 
313 	return (n);
314 }
315 
316 void
317 dtrace_getufpstack(uint64_t *pcstack, uint64_t *fpstack, int pcstack_limit)
318 {
319 	proc_t *p = curproc;
320 	struct trapframe *tf;
321 	uintptr_t pc, sp, fp;
322 	volatile uint16_t *flags =
323 	    (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
324 #ifdef notyet /* XXX signal stack */
325 	uintptr_t oldcontext;
326 	size_t s1, s2;
327 #endif
328 
329 	if (*flags & CPU_DTRACE_FAULT)
330 		return;
331 
332 	if (pcstack_limit <= 0)
333 		return;
334 
335 	/*
336 	 * If there's no user context we still need to zero the stack.
337 	 */
338 	if (p == NULL || (tf = curthread->td_frame) == NULL)
339 		goto zero;
340 
341 	*pcstack++ = (uint64_t)p->p_pid;
342 	pcstack_limit--;
343 
344 	if (pcstack_limit <= 0)
345 		return;
346 
347 	pc = tf->tf_eip;
348 	fp = tf->tf_ebp;
349 	sp = tf->tf_esp;
350 
351 #ifdef notyet /* XXX signal stack */
352 	oldcontext = lwp->lwp_oldcontext;
353 
354 	if (p->p_model == DATAMODEL_NATIVE) {
355 		s1 = sizeof (struct frame) + 2 * sizeof (long);
356 		s2 = s1 + sizeof (siginfo_t);
357 	} else {
358 		s1 = sizeof (struct frame32) + 3 * sizeof (int);
359 		s2 = s1 + sizeof (siginfo32_t);
360 	}
361 #endif
362 
363 	if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) {
364 		*pcstack++ = (uint64_t)pc;
365 		*fpstack++ = 0;
366 		pcstack_limit--;
367 		if (pcstack_limit <= 0)
368 			return;
369 
370 		pc = dtrace_fuword32((void *)sp);
371 	}
372 
373 	while (pc != 0) {
374 		*pcstack++ = (uint64_t)pc;
375 		*fpstack++ = fp;
376 		pcstack_limit--;
377 		if (pcstack_limit <= 0)
378 			break;
379 
380 		if (fp == 0)
381 			break;
382 
383 #ifdef notyet /* XXX signal stack */
384 		if (oldcontext == sp + s1 || oldcontext == sp + s2) {
385 			if (p->p_model == DATAMODEL_NATIVE) {
386 				ucontext_t *ucp = (ucontext_t *)oldcontext;
387 				greg_t *gregs = ucp->uc_mcontext.gregs;
388 
389 				sp = dtrace_fulword(&gregs[REG_FP]);
390 				pc = dtrace_fulword(&gregs[REG_PC]);
391 
392 				oldcontext = dtrace_fulword(&ucp->uc_link);
393 			} else {
394 				ucontext_t *ucp = (ucontext_t *)oldcontext;
395 				greg_t *gregs = ucp->uc_mcontext.gregs;
396 
397 				sp = dtrace_fuword32(&gregs[EBP]);
398 				pc = dtrace_fuword32(&gregs[EIP]);
399 
400 				oldcontext = dtrace_fuword32(&ucp->uc_link);
401 			}
402 		} else
403 #endif /* XXX */
404 		{
405 			pc = dtrace_fuword32((void *)(fp +
406 				offsetof(struct i386_frame, f_retaddr)));
407 			fp = dtrace_fuword32((void *)fp);
408 		}
409 
410 		/*
411 		 * This is totally bogus:  if we faulted, we're going to clear
412 		 * the fault and break.  This is to deal with the apparently
413 		 * broken Java stacks on x86.
414 		 */
415 		if (*flags & CPU_DTRACE_FAULT) {
416 			*flags &= ~CPU_DTRACE_FAULT;
417 			break;
418 		}
419 	}
420 
421 zero:
422 	while (pcstack_limit-- > 0)
423 		*pcstack++ = 0;
424 }
425 
426 uint64_t
427 dtrace_getarg(int arg, int aframes)
428 {
429 	uintptr_t val;
430 	struct i386_frame *fp = (struct i386_frame *)dtrace_getfp();
431 	uintptr_t *stack;
432 	int i;
433 
434 	for (i = 1; i <= aframes; i++) {
435 		fp = fp->f_frame;
436 
437 		if (P2ROUNDUP(fp->f_retaddr, 4) ==
438 		    (long)dtrace_invop_callsite) {
439 			/*
440 			 * If we pass through the invalid op handler, we will
441 			 * use the pointer that it passed to the stack as the
442 			 * second argument to dtrace_invop() as the pointer to
443 			 * the stack.  When using this stack, we must step
444 			 * beyond the EIP/RIP that was pushed when the trap was
445 			 * taken -- hence the "+ 1" below.
446 			 */
447 			stack = ((uintptr_t **)&fp[1])[0] + 1;
448 			goto load;
449 		}
450 
451 	}
452 
453 	/*
454 	 * We know that we did not come through a trap to get into
455 	 * dtrace_probe() -- the provider simply called dtrace_probe()
456 	 * directly.  As this is the case, we need to shift the argument
457 	 * that we're looking for:  the probe ID is the first argument to
458 	 * dtrace_probe(), so the argument n will actually be found where
459 	 * one would expect to find argument (n + 1).
460 	 */
461 	arg++;
462 
463 	stack = (uintptr_t *)fp + 2;
464 
465 load:
466 	DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
467 	val = stack[arg];
468 	DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
469 
470 	return (val);
471 }
472 
473 int
474 dtrace_getstackdepth(int aframes)
475 {
476 	int depth = 0;
477 	struct i386_frame *frame;
478 	vm_offset_t ebp;
479 
480 	aframes++;
481 	ebp = dtrace_getfp();
482 	frame = (struct i386_frame *)ebp;
483 	depth++;
484 	for(;;) {
485 		if (!INKERNEL((long) frame))
486 			break;
487 		if (!INKERNEL((long) frame->f_frame))
488 			break;
489 		depth++;
490 		if (frame->f_frame <= frame ||
491 		    (vm_offset_t)frame->f_frame >=
492 		    (vm_offset_t)ebp + KSTACK_PAGES * PAGE_SIZE)
493 			break;
494 		frame = frame->f_frame;
495 	}
496 	if (depth < aframes)
497 		return 0;
498 	else
499 		return depth - aframes;
500 }
501 
502 ulong_t
503 dtrace_getreg(struct trapframe *rp, uint_t reg)
504 {
505 	struct pcb *pcb;
506 	int regmap[] = {  /* Order is dependent on reg.d */
507 		REG_GS,		/* 0  GS */
508 		REG_FS,		/* 1  FS */
509 		REG_ES,		/* 2  ES */
510 		REG_DS,		/* 3  DS */
511 		REG_RDI,	/* 4  EDI */
512 		REG_RSI,	/* 5  ESI */
513 		REG_RBP,	/* 6  EBP, REG_FP */
514 		REG_RSP,	/* 7  ESP */
515 		REG_RBX,	/* 8  EBX */
516 		REG_RDX,	/* 9  EDX, REG_R1 */
517 		REG_RCX,	/* 10 ECX */
518 		REG_RAX,	/* 11 EAX, REG_R0 */
519 		REG_TRAPNO,	/* 12 TRAPNO */
520 		REG_ERR,	/* 13 ERR */
521 		REG_RIP,	/* 14 EIP, REG_PC */
522 		REG_CS,		/* 15 CS */
523 		REG_RFL,	/* 16 EFL, REG_PS */
524 		REG_RSP,	/* 17 UESP, REG_SP */
525 		REG_SS		/* 18 SS */
526 	};
527 
528 	if (reg > SS) {
529 		DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
530 		return (0);
531 	}
532 
533 	if (reg >= sizeof (regmap) / sizeof (int)) {
534 		DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
535 		return (0);
536 	}
537 
538 	reg = regmap[reg];
539 
540 	switch(reg) {
541 	case REG_GS:
542 		if ((pcb = curthread->td_pcb) == NULL) {
543 			DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
544 			return (0);
545 		}
546 		return (pcb->pcb_gs);
547 	case REG_FS:
548 		return (rp->tf_fs);
549 	case REG_ES:
550 		return (rp->tf_es);
551 	case REG_DS:
552 		return (rp->tf_ds);
553 	case REG_RDI:
554 		return (rp->tf_edi);
555 	case REG_RSI:
556 		return (rp->tf_esi);
557 	case REG_RBP:
558 		return (rp->tf_ebp);
559 	case REG_RSP:
560 		return (rp->tf_isp);
561 	case REG_RBX:
562 		return (rp->tf_ebx);
563 	case REG_RCX:
564 		return (rp->tf_ecx);
565 	case REG_RAX:
566 		return (rp->tf_eax);
567 	case REG_TRAPNO:
568 		return (rp->tf_trapno);
569 	case REG_ERR:
570 		return (rp->tf_err);
571 	case REG_RIP:
572 		return (rp->tf_eip);
573 	case REG_CS:
574 		return (rp->tf_cs);
575 	case REG_RFL:
576 		return (rp->tf_eflags);
577 #if 0
578 	case REG_RSP:
579 		return (rp->tf_esp);
580 #endif
581 	case REG_SS:
582 		return (rp->tf_ss);
583 	default:
584 		DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
585 		return (0);
586 	}
587 }
588 
589 static int
590 dtrace_copycheck(uintptr_t uaddr, uintptr_t kaddr, size_t size)
591 {
592 	ASSERT(kaddr >= kernelbase && kaddr + size >= kaddr);
593 
594 	if (uaddr + size >= kernelbase || uaddr + size < uaddr) {
595 		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
596 		cpu_core[curcpu].cpuc_dtrace_illval = uaddr;
597 		return (0);
598 	}
599 
600 	return (1);
601 }
602 
603 void
604 dtrace_copyin(uintptr_t uaddr, uintptr_t kaddr, size_t size,
605     volatile uint16_t *flags)
606 {
607 	if (dtrace_copycheck(uaddr, kaddr, size))
608 		dtrace_copy(uaddr, kaddr, size);
609 }
610 
611 void
612 dtrace_copyout(uintptr_t kaddr, uintptr_t uaddr, size_t size,
613     volatile uint16_t *flags)
614 {
615 	if (dtrace_copycheck(uaddr, kaddr, size))
616 		dtrace_copy(kaddr, uaddr, size);
617 }
618 
619 void
620 dtrace_copyinstr(uintptr_t uaddr, uintptr_t kaddr, size_t size,
621     volatile uint16_t *flags)
622 {
623 	if (dtrace_copycheck(uaddr, kaddr, size))
624 		dtrace_copystr(uaddr, kaddr, size, flags);
625 }
626 
627 void
628 dtrace_copyoutstr(uintptr_t kaddr, uintptr_t uaddr, size_t size,
629     volatile uint16_t *flags)
630 {
631 	if (dtrace_copycheck(uaddr, kaddr, size))
632 		dtrace_copystr(kaddr, uaddr, size, flags);
633 }
634 
635 uint8_t
636 dtrace_fuword8(void *uaddr)
637 {
638 	if ((uintptr_t)uaddr >= kernelbase) {
639 		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
640 		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
641 		return (0);
642 	}
643 	return (dtrace_fuword8_nocheck(uaddr));
644 }
645 
646 uint16_t
647 dtrace_fuword16(void *uaddr)
648 {
649 	if ((uintptr_t)uaddr >= kernelbase) {
650 		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
651 		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
652 		return (0);
653 	}
654 	return (dtrace_fuword16_nocheck(uaddr));
655 }
656 
657 uint32_t
658 dtrace_fuword32(void *uaddr)
659 {
660 	if ((uintptr_t)uaddr >= kernelbase) {
661 		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
662 		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
663 		return (0);
664 	}
665 	return (dtrace_fuword32_nocheck(uaddr));
666 }
667 
668 uint64_t
669 dtrace_fuword64(void *uaddr)
670 {
671 	if ((uintptr_t)uaddr >= kernelbase) {
672 		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
673 		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
674 		return (0);
675 	}
676 	return (dtrace_fuword64_nocheck(uaddr));
677 }
678