xref: /freebsd/sys/cddl/dev/dtrace/i386/dtrace_isa.c (revision 580744621f33383027108364dcadad718df46ffe)
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 (!INKERNEL(frame))
77 			break;
78 
79 		callpc = frame->f_retaddr;
80 
81 		if (!INKERNEL(callpc))
82 			break;
83 
84 		if (aframes > 0) {
85 			aframes--;
86 			if ((aframes == 0) && (caller != 0)) {
87 				pcstack[depth++] = caller;
88 			}
89 		}
90 		else {
91 			pcstack[depth++] = callpc;
92 		}
93 
94 		if (frame->f_frame <= frame ||
95 		    (vm_offset_t)frame->f_frame >= curthread->td_kstack +
96 		    curthread->td_kstack_pages * PAGE_SIZE)
97 			break;
98 		frame = frame->f_frame;
99 	}
100 
101 	for (; depth < pcstack_limit; depth++) {
102 		pcstack[depth] = 0;
103 	}
104 }
105 
106 static int
107 dtrace_getustack_common(uint64_t *pcstack, int pcstack_limit, uintptr_t pc,
108     uintptr_t sp)
109 {
110 #ifdef notyet
111 	proc_t *p = curproc;
112 	uintptr_t oldcontext = lwp->lwp_oldcontext; /* XXX signal stack. */
113 	size_t s1, s2;
114 #endif
115 	uintptr_t oldsp;
116 	volatile uint16_t *flags =
117 	    (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
118 	int ret = 0;
119 
120 	ASSERT(pcstack == NULL || pcstack_limit > 0);
121 	ASSERT(dtrace_ustackdepth_max > 0);
122 
123 #ifdef notyet /* XXX signal stack. */
124 	if (p->p_model == DATAMODEL_NATIVE) {
125 		s1 = sizeof (struct frame) + 2 * sizeof (long);
126 		s2 = s1 + sizeof (siginfo_t);
127 	} else {
128 		s1 = sizeof (struct frame32) + 3 * sizeof (int);
129 		s2 = s1 + sizeof (siginfo32_t);
130 	}
131 #endif
132 
133 	while (pc != 0) {
134 		/*
135 		 * We limit the number of times we can go around this
136 		 * loop to account for a circular stack.
137 		 */
138 		if (ret++ >= dtrace_ustackdepth_max) {
139 			*flags |= CPU_DTRACE_BADSTACK;
140 			cpu_core[curcpu].cpuc_dtrace_illval = sp;
141 			break;
142 		}
143 
144 		if (pcstack != NULL) {
145 			*pcstack++ = (uint64_t)pc;
146 			pcstack_limit--;
147 			if (pcstack_limit <= 0)
148 				break;
149 		}
150 
151 		if (sp == 0)
152 			break;
153 
154 		oldsp = sp;
155 
156 #ifdef notyet /* XXX signal stack. */
157 		if (oldcontext == sp + s1 || oldcontext == sp + s2) {
158 			if (p->p_model == DATAMODEL_NATIVE) {
159 				ucontext_t *ucp = (ucontext_t *)oldcontext;
160 				greg_t *gregs = ucp->uc_mcontext.gregs;
161 
162 				sp = dtrace_fulword(&gregs[REG_FP]);
163 				pc = dtrace_fulword(&gregs[REG_PC]);
164 
165 				oldcontext = dtrace_fulword(&ucp->uc_link);
166 			} else {
167 				ucontext32_t *ucp = (ucontext32_t *)oldcontext;
168 				greg32_t *gregs = ucp->uc_mcontext.gregs;
169 
170 				sp = dtrace_fuword32(&gregs[EBP]);
171 				pc = dtrace_fuword32(&gregs[EIP]);
172 
173 				oldcontext = dtrace_fuword32(&ucp->uc_link);
174 			}
175 		} else {
176 			if (p->p_model == DATAMODEL_NATIVE) {
177 				struct frame *fr = (struct frame *)sp;
178 
179 				pc = dtrace_fulword(&fr->fr_savpc);
180 				sp = dtrace_fulword(&fr->fr_savfp);
181 			} else {
182 				struct frame32 *fr = (struct frame32 *)sp;
183 
184 				pc = dtrace_fuword32(&fr->fr_savpc);
185 				sp = dtrace_fuword32(&fr->fr_savfp);
186 			}
187 		}
188 #else
189 		pc = dtrace_fuword32((void *)(sp +
190 			offsetof(struct i386_frame, f_retaddr)));
191 		sp = dtrace_fuword32((void *)sp);
192 #endif /* ! notyet */
193 
194 		if (sp == oldsp) {
195 			*flags |= CPU_DTRACE_BADSTACK;
196 			cpu_core[curcpu].cpuc_dtrace_illval = sp;
197 			break;
198 		}
199 
200 		/*
201 		 * This is totally bogus:  if we faulted, we're going to clear
202 		 * the fault and break.  This is to deal with the apparently
203 		 * broken Java stacks on x86.
204 		 */
205 		if (*flags & CPU_DTRACE_FAULT) {
206 			*flags &= ~CPU_DTRACE_FAULT;
207 			break;
208 		}
209 	}
210 
211 	return (ret);
212 }
213 
214 void
215 dtrace_getupcstack(uint64_t *pcstack, int pcstack_limit)
216 {
217 	proc_t *p = curproc;
218 	struct trapframe *tf;
219 	uintptr_t pc, sp, fp;
220 	volatile uint16_t *flags =
221 	    (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
222 	int n;
223 
224 	if (*flags & CPU_DTRACE_FAULT)
225 		return;
226 
227 	if (pcstack_limit <= 0)
228 		return;
229 
230 	/*
231 	 * If there's no user context we still need to zero the stack.
232 	 */
233 	if (p == NULL || (tf = curthread->td_frame) == NULL)
234 		goto zero;
235 
236 	*pcstack++ = (uint64_t)p->p_pid;
237 	pcstack_limit--;
238 
239 	if (pcstack_limit <= 0)
240 		return;
241 
242 	pc = tf->tf_eip;
243 	fp = tf->tf_ebp;
244 	sp = tf->tf_esp;
245 
246 	if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) {
247 		/*
248 		 * In an entry probe.  The frame pointer has not yet been
249 		 * pushed (that happens in the function prologue).  The
250 		 * best approach is to add the current pc as a missing top
251 		 * of stack and back the pc up to the caller, which is stored
252 		 * at the current stack pointer address since the call
253 		 * instruction puts it there right before the branch.
254 		 */
255 
256 		*pcstack++ = (uint64_t)pc;
257 		pcstack_limit--;
258 		if (pcstack_limit <= 0)
259 			return;
260 
261 		pc = dtrace_fuword32((void *) sp);
262 	}
263 
264 	n = dtrace_getustack_common(pcstack, pcstack_limit, pc, sp);
265 	ASSERT(n >= 0);
266 	ASSERT(n <= pcstack_limit);
267 
268 	pcstack += n;
269 	pcstack_limit -= n;
270 
271 zero:
272 	while (pcstack_limit-- > 0)
273 		*pcstack++ = 0;
274 }
275 
276 int
277 dtrace_getustackdepth(void)
278 {
279 	proc_t *p = curproc;
280 	struct trapframe *tf;
281 	uintptr_t pc, fp, sp;
282 	int n = 0;
283 
284 	if (p == NULL || (tf = curthread->td_frame) == NULL)
285 		return (0);
286 
287 	if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_FAULT))
288 		return (-1);
289 
290 	pc = tf->tf_eip;
291 	fp = tf->tf_ebp;
292 	sp = tf->tf_esp;
293 
294 	if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) {
295 		/*
296 		 * In an entry probe.  The frame pointer has not yet been
297 		 * pushed (that happens in the function prologue).  The
298 		 * best approach is to add the current pc as a missing top
299 		 * of stack and back the pc up to the caller, which is stored
300 		 * at the current stack pointer address since the call
301 		 * instruction puts it there right before the branch.
302 		 */
303 
304 		pc = dtrace_fuword32((void *) sp);
305 		n++;
306 	}
307 
308 	n += dtrace_getustack_common(NULL, 0, pc, fp);
309 
310 	return (n);
311 }
312 
313 void
314 dtrace_getufpstack(uint64_t *pcstack, uint64_t *fpstack, int pcstack_limit)
315 {
316 	proc_t *p = curproc;
317 	struct trapframe *tf;
318 	uintptr_t pc, sp, fp;
319 	volatile uint16_t *flags =
320 	    (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
321 #ifdef notyet /* XXX signal stack */
322 	uintptr_t oldcontext;
323 	size_t s1, s2;
324 #endif
325 
326 	if (*flags & CPU_DTRACE_FAULT)
327 		return;
328 
329 	if (pcstack_limit <= 0)
330 		return;
331 
332 	/*
333 	 * If there's no user context we still need to zero the stack.
334 	 */
335 	if (p == NULL || (tf = curthread->td_frame) == NULL)
336 		goto zero;
337 
338 	*pcstack++ = (uint64_t)p->p_pid;
339 	pcstack_limit--;
340 
341 	if (pcstack_limit <= 0)
342 		return;
343 
344 	pc = tf->tf_eip;
345 	fp = tf->tf_ebp;
346 	sp = tf->tf_esp;
347 
348 #ifdef notyet /* XXX signal stack */
349 	oldcontext = lwp->lwp_oldcontext;
350 
351 	if (p->p_model == DATAMODEL_NATIVE) {
352 		s1 = sizeof (struct frame) + 2 * sizeof (long);
353 		s2 = s1 + sizeof (siginfo_t);
354 	} else {
355 		s1 = sizeof (struct frame32) + 3 * sizeof (int);
356 		s2 = s1 + sizeof (siginfo32_t);
357 	}
358 #endif
359 
360 	if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) {
361 		*pcstack++ = (uint64_t)pc;
362 		*fpstack++ = 0;
363 		pcstack_limit--;
364 		if (pcstack_limit <= 0)
365 			return;
366 
367 		pc = dtrace_fuword32((void *)sp);
368 	}
369 
370 	while (pc != 0) {
371 		*pcstack++ = (uint64_t)pc;
372 		*fpstack++ = fp;
373 		pcstack_limit--;
374 		if (pcstack_limit <= 0)
375 			break;
376 
377 		if (fp == 0)
378 			break;
379 
380 #ifdef notyet /* XXX signal stack */
381 		if (oldcontext == sp + s1 || oldcontext == sp + s2) {
382 			if (p->p_model == DATAMODEL_NATIVE) {
383 				ucontext_t *ucp = (ucontext_t *)oldcontext;
384 				greg_t *gregs = ucp->uc_mcontext.gregs;
385 
386 				sp = dtrace_fulword(&gregs[REG_FP]);
387 				pc = dtrace_fulword(&gregs[REG_PC]);
388 
389 				oldcontext = dtrace_fulword(&ucp->uc_link);
390 			} else {
391 				ucontext_t *ucp = (ucontext_t *)oldcontext;
392 				greg_t *gregs = ucp->uc_mcontext.gregs;
393 
394 				sp = dtrace_fuword32(&gregs[EBP]);
395 				pc = dtrace_fuword32(&gregs[EIP]);
396 
397 				oldcontext = dtrace_fuword32(&ucp->uc_link);
398 			}
399 		} else
400 #endif /* XXX */
401 		{
402 			pc = dtrace_fuword32((void *)(fp +
403 				offsetof(struct i386_frame, f_retaddr)));
404 			fp = dtrace_fuword32((void *)fp);
405 		}
406 
407 		/*
408 		 * This is totally bogus:  if we faulted, we're going to clear
409 		 * the fault and break.  This is to deal with the apparently
410 		 * broken Java stacks on x86.
411 		 */
412 		if (*flags & CPU_DTRACE_FAULT) {
413 			*flags &= ~CPU_DTRACE_FAULT;
414 			break;
415 		}
416 	}
417 
418 zero:
419 	while (pcstack_limit-- > 0)
420 		*pcstack++ = 0;
421 }
422 
423 uint64_t
424 dtrace_getarg(int arg, int aframes)
425 {
426 	struct trapframe *frame;
427 	struct i386_frame *fp = (struct i386_frame *)dtrace_getfp();
428 	uintptr_t *stack, val;
429 	int i;
430 
431 	for (i = 1; i <= aframes; i++) {
432 		fp = fp->f_frame;
433 
434 		if (P2ROUNDUP(fp->f_retaddr, 4) ==
435 		    (long)dtrace_invop_callsite) {
436 			/*
437 			 * If we pass through the invalid op handler, we will
438 			 * use the trap frame pointer that it pushed on the
439 			 * stack as the second argument to dtrace_invop() as
440 			 * the pointer to the stack.  When using this stack, we
441 			 * must skip the third argument to dtrace_invop(),
442 			 * which is included in the i386_frame.
443 			 */
444 			frame = (struct trapframe *)(((uintptr_t **)&fp[1])[0]);
445 			/*
446 			 * Skip the three hardware-saved registers and the
447 			 * return address.
448 			 */
449 			stack = (uintptr_t *)frame->tf_isp + 4;
450 			goto load;
451 		}
452 
453 	}
454 
455 	/*
456 	 * We know that we did not come through a trap to get into
457 	 * dtrace_probe() -- the provider simply called dtrace_probe()
458 	 * directly.  As this is the case, we need to shift the argument
459 	 * that we're looking for:  the probe ID is the first argument to
460 	 * dtrace_probe(), so the argument n will actually be found where
461 	 * one would expect to find argument (n + 1).
462 	 */
463 	arg++;
464 
465 	stack = (uintptr_t *)fp + 2;
466 
467 load:
468 	DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
469 	val = stack[arg];
470 	DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
471 
472 	return (val);
473 }
474 
475 int
476 dtrace_getstackdepth(int aframes)
477 {
478 	int depth = 0;
479 	struct i386_frame *frame;
480 	vm_offset_t ebp;
481 
482 	aframes++;
483 	ebp = dtrace_getfp();
484 	frame = (struct i386_frame *)ebp;
485 	depth++;
486 	for(;;) {
487 		if (!INKERNEL((long) frame))
488 			break;
489 		if (!INKERNEL((long) frame->f_frame))
490 			break;
491 		depth++;
492 		if (frame->f_frame <= frame ||
493 		    (vm_offset_t)frame->f_frame >= curthread->td_kstack +
494 		    curthread->td_kstack_pages * PAGE_SIZE)
495 			break;
496 		frame = frame->f_frame;
497 	}
498 	if (depth < aframes)
499 		return 0;
500 	else
501 		return depth - aframes;
502 }
503 
504 ulong_t
505 dtrace_getreg(struct trapframe *rp, uint_t reg)
506 {
507 	struct pcb *pcb;
508 	int regmap[] = {  /* Order is dependent on reg.d */
509 		REG_GS,		/* 0  GS */
510 		REG_FS,		/* 1  FS */
511 		REG_ES,		/* 2  ES */
512 		REG_DS,		/* 3  DS */
513 		REG_RDI,	/* 4  EDI */
514 		REG_RSI,	/* 5  ESI */
515 		REG_RBP,	/* 6  EBP, REG_FP */
516 		REG_RSP,	/* 7  ESP */
517 		REG_RBX,	/* 8  EBX */
518 		REG_RDX,	/* 9  EDX, REG_R1 */
519 		REG_RCX,	/* 10 ECX */
520 		REG_RAX,	/* 11 EAX, REG_R0 */
521 		REG_TRAPNO,	/* 12 TRAPNO */
522 		REG_ERR,	/* 13 ERR */
523 		REG_RIP,	/* 14 EIP, REG_PC */
524 		REG_CS,		/* 15 CS */
525 		REG_RFL,	/* 16 EFL, REG_PS */
526 		REG_RSP,	/* 17 UESP, REG_SP */
527 		REG_SS		/* 18 SS */
528 	};
529 
530 	if (reg > SS) {
531 		DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
532 		return (0);
533 	}
534 
535 	if (reg >= sizeof (regmap) / sizeof (int)) {
536 		DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
537 		return (0);
538 	}
539 
540 	reg = regmap[reg];
541 
542 	switch(reg) {
543 	case REG_GS:
544 		if ((pcb = curthread->td_pcb) == NULL) {
545 			DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
546 			return (0);
547 		}
548 		return (pcb->pcb_gs);
549 	case REG_FS:
550 		return (rp->tf_fs);
551 	case REG_ES:
552 		return (rp->tf_es);
553 	case REG_DS:
554 		return (rp->tf_ds);
555 	case REG_RDI:
556 		return (rp->tf_edi);
557 	case REG_RSI:
558 		return (rp->tf_esi);
559 	case REG_RBP:
560 		return (rp->tf_ebp);
561 	case REG_RSP:
562 		return (rp->tf_isp);
563 	case REG_RBX:
564 		return (rp->tf_ebx);
565 	case REG_RCX:
566 		return (rp->tf_ecx);
567 	case REG_RAX:
568 		return (rp->tf_eax);
569 	case REG_TRAPNO:
570 		return (rp->tf_trapno);
571 	case REG_ERR:
572 		return (rp->tf_err);
573 	case REG_RIP:
574 		return (rp->tf_eip);
575 	case REG_CS:
576 		return (rp->tf_cs);
577 	case REG_RFL:
578 		return (rp->tf_eflags);
579 #if 0
580 	case REG_RSP:
581 		return (rp->tf_esp);
582 #endif
583 	case REG_SS:
584 		return (rp->tf_ss);
585 	default:
586 		DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
587 		return (0);
588 	}
589 }
590 
591 static int
592 dtrace_copycheck(uintptr_t uaddr, uintptr_t kaddr, size_t size)
593 {
594 	ASSERT(kaddr >= kernelbase && kaddr + size >= kaddr);
595 
596 	if (uaddr + size >= kernelbase || uaddr + size < uaddr) {
597 		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
598 		cpu_core[curcpu].cpuc_dtrace_illval = uaddr;
599 		return (0);
600 	}
601 
602 	return (1);
603 }
604 
605 void
606 dtrace_copyin(uintptr_t uaddr, uintptr_t kaddr, size_t size,
607     volatile uint16_t *flags)
608 {
609 	if (dtrace_copycheck(uaddr, kaddr, size))
610 		dtrace_copy(uaddr, kaddr, size);
611 }
612 
613 void
614 dtrace_copyout(uintptr_t kaddr, uintptr_t uaddr, size_t size,
615     volatile uint16_t *flags)
616 {
617 	if (dtrace_copycheck(uaddr, kaddr, size))
618 		dtrace_copy(kaddr, uaddr, size);
619 }
620 
621 void
622 dtrace_copyinstr(uintptr_t uaddr, uintptr_t kaddr, size_t size,
623     volatile uint16_t *flags)
624 {
625 	if (dtrace_copycheck(uaddr, kaddr, size))
626 		dtrace_copystr(uaddr, kaddr, size, flags);
627 }
628 
629 void
630 dtrace_copyoutstr(uintptr_t kaddr, uintptr_t uaddr, size_t size,
631     volatile uint16_t *flags)
632 {
633 	if (dtrace_copycheck(uaddr, kaddr, size))
634 		dtrace_copystr(kaddr, uaddr, size, flags);
635 }
636 
637 uint8_t
638 dtrace_fuword8(void *uaddr)
639 {
640 	if ((uintptr_t)uaddr >= kernelbase) {
641 		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
642 		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
643 		return (0);
644 	}
645 	return (dtrace_fuword8_nocheck(uaddr));
646 }
647 
648 uint16_t
649 dtrace_fuword16(void *uaddr)
650 {
651 	if ((uintptr_t)uaddr >= kernelbase) {
652 		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
653 		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
654 		return (0);
655 	}
656 	return (dtrace_fuword16_nocheck(uaddr));
657 }
658 
659 uint32_t
660 dtrace_fuword32(void *uaddr)
661 {
662 	if ((uintptr_t)uaddr >= kernelbase) {
663 		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
664 		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
665 		return (0);
666 	}
667 	return (dtrace_fuword32_nocheck(uaddr));
668 }
669 
670 uint64_t
671 dtrace_fuword64(void *uaddr)
672 {
673 	if ((uintptr_t)uaddr >= kernelbase) {
674 		DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
675 		cpu_core[curcpu].cpuc_dtrace_illval = (uintptr_t)uaddr;
676 		return (0);
677 	}
678 	return (dtrace_fuword64_nocheck(uaddr));
679 }
680