?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
kernel - Fix some rare pmap races in i386 and x86_64.
[dragonfly.git] / sys / platform / pc32 / i386 / db_trace.c
blob355be8aea2a499601742bd2102875261067c00cb
1 /*
2 * Mach Operating System
3 * Copyright (c) 1991,1990 Carnegie Mellon University
4 * All Rights Reserved.
5 *
6 * Permission to use, copy, modify and distribute this software and its
7 * documentation is hereby granted, provided that both the copyright
8 * notice and this permission notice appear in all copies of the
9 * software, derivative works or modified versions, and any portions
10 * thereof, and that both notices appear in supporting documentation.
11 *
12 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
13 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
15 *
16 * Carnegie Mellon requests users of this software to return to
17 *
18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
19 * School of Computer Science
20 * Carnegie Mellon University
21 * Pittsburgh PA 15213-3890
22 *
23 * any improvements or extensions that they make and grant Carnegie the
24 * rights to redistribute these changes.
25 *
26 * $FreeBSD: src/sys/i386/i386/db_trace.c,v 1.35.2.3 2002/02/21 22:31:25 silby Exp $
27 * $DragonFly: src/sys/platform/pc32/i386/db_trace.c,v 1.18 2007/02/02 15:57:51 corecode Exp $
28 */
29
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/linker_set.h>
33 #include <sys/lock.h>
34 #include <sys/proc.h>
35 #include <sys/reg.h>
36
37 #include <machine/cpu.h>
38 #include <machine/md_var.h>
39
40 #include <vm/vm.h>
41 #include <vm/vm_param.h>
42 #include <vm/pmap.h>
43 #include <vm/vm_map.h>
44 #include <ddb/ddb.h>
45
46 #include <sys/user.h>
47
48 #include <ddb/db_access.h>
49 #include <ddb/db_sym.h>
50 #include <ddb/db_variables.h>
51
52 db_varfcn_t db_dr0;
53 db_varfcn_t db_dr1;
54 db_varfcn_t db_dr2;
55 db_varfcn_t db_dr3;
56 db_varfcn_t db_dr4;
57 db_varfcn_t db_dr5;
58 db_varfcn_t db_dr6;
59 db_varfcn_t db_dr7;
60
61 /*
62 * Machine register set.
63 */
64 struct db_variable db_regs[] = {
65 { "cs", &ddb_regs.tf_cs, NULL },
66 { "ds", &ddb_regs.tf_ds, NULL },
67 { "es", &ddb_regs.tf_es, NULL },
68 { "fs", &ddb_regs.tf_fs, NULL },
69 { "gs", &ddb_regs.tf_gs, NULL },
70 { "ss", &ddb_regs.tf_ss, NULL },
71 { "eax", &ddb_regs.tf_eax, NULL },
72 { "ecx", &ddb_regs.tf_ecx, NULL },
73 { "edx", &ddb_regs.tf_edx, NULL },
74 { "ebx", &ddb_regs.tf_ebx, NULL },
75 { "esp", &ddb_regs.tf_esp, NULL },
76 { "ebp", &ddb_regs.tf_ebp, NULL },
77 { "esi", &ddb_regs.tf_esi, NULL },
78 { "edi", &ddb_regs.tf_edi, NULL },
79 { "eip", &ddb_regs.tf_eip, NULL },
80 { "efl", &ddb_regs.tf_eflags, NULL },
81 { "dr0", NULL, db_dr0 },
82 { "dr1", NULL, db_dr1 },
83 { "dr2", NULL, db_dr2 },
84 { "dr3", NULL, db_dr3 },
85 { "dr4", NULL, db_dr4 },
86 { "dr5", NULL, db_dr5 },
87 { "dr6", NULL, db_dr6 },
88 { "dr7", NULL, db_dr7 },
89 };
90 struct db_variable *db_eregs = db_regs + sizeof(db_regs)/sizeof(db_regs[0]);
91
92 /*
93 * Stack trace.
94 */
95 #define INKERNEL(va) (((vm_offset_t)(va)) >= USRSTACK)
96
97 struct i386_frame {
98 struct i386_frame *f_frame;
99 int f_retaddr;
100 int f_arg0;
101 };
102
103 #define NORMAL 0
104 #define TRAP 1
105 #define INTERRUPT 2
106 #define SYSCALL 3
107
108 static void db_nextframe(struct i386_frame **, db_addr_t *);
109 static int db_numargs(struct i386_frame *);
110 static void db_print_stack_entry(const char *, int, char **, int *, db_addr_t);
111
112
113 static char *watchtype_str(int type);
114 static int ki386_set_watch(int watchnum, unsigned int watchaddr,
115 int size, int access, struct dbreg * d);
116 static int ki386_clr_watch(int watchnum, struct dbreg * d);
117 int db_md_set_watchpoint(db_expr_t addr, db_expr_t size);
118 int db_md_clr_watchpoint(db_expr_t addr, db_expr_t size);
119 void db_md_list_watchpoints(void);
120
121
122 /*
123 * Figure out how many arguments were passed into the frame at "fp".
124 */
125 static int
126 db_numargs(struct i386_frame *fp)
127 {
128 int *argp;
129 int inst;
130 int args;
131
132 argp = (int *)db_get_value((int)&fp->f_retaddr, 4, FALSE);
133 /*
134 * XXX etext is wrong for LKMs. We should attempt to interpret
135 * the instruction at the return address in all cases. This
136 * may require better fault handling.
137 */
138 if (argp < (int *)btext || argp >= (int *)etext) {
139 args = 5;
140 } else {
141 inst = db_get_value((int)argp, 4, FALSE);
142 if ((inst & 0xff) == 0x59) /* popl %ecx */
143 args = 1;
144 else if ((inst & 0xffff) == 0xc483) /* addl $Ibs, %esp */
145 args = ((inst >> 16) & 0xff) / 4;
146 else
147 args = 5;
148 }
149 return(args);
150 }
151
152 static void
153 db_print_stack_entry(const char *name, int narg, char **argnp, int *argp,
154 db_addr_t callpc)
155 {
156 db_printf("%s(", name);
157 while (narg) {
158 if (argnp)
159 db_printf("%s=", *argnp++);
160 db_printf("%r", db_get_value((int)argp, 4, FALSE));
161 argp++;
162 if (--narg != 0)
163 db_printf(",");
164 }
165 db_printf(") at ");
166 db_printsym(callpc, DB_STGY_PROC);
167 db_printf("\n");
168 }
169
170 /*
171 * Figure out the next frame up in the call stack.
172 */
173 static void
174 db_nextframe(struct i386_frame **fp, db_addr_t *ip)
175 {
176 struct trapframe *tf;
177 int frame_type;
178 int eip, esp, ebp;
179 db_expr_t offset;
180 const char *sym, *name;
181
182 eip = db_get_value((int) &(*fp)->f_retaddr, 4, FALSE);
183 ebp = db_get_value((int) &(*fp)->f_frame, 4, FALSE);
184
185 /*
186 * Figure out frame type.
187 */
188
189 frame_type = NORMAL;
190
191 sym = db_search_symbol(eip, DB_STGY_ANY, &offset);
192 db_symbol_values(sym, &name, NULL);
193 if (name != NULL) {
194 if (!strcmp(name, "calltrap")) {
195 frame_type = TRAP;
196 } else if (!strncmp(name, "Xresume", 7)) {
197 frame_type = INTERRUPT;
198 } else if (!strcmp(name, "_Xsyscall")) {
199 frame_type = SYSCALL;
200 }
201 }
202
203 /*
204 * Normal frames need no special processing.
205 */
206 if (frame_type == NORMAL) {
207 *ip = (db_addr_t) eip;
208 *fp = (struct i386_frame *) ebp;
209 return;
210 }
211
212 db_print_stack_entry(name, 0, 0, 0, eip);
213
214 /*
215 * Point to base of trapframe which is just above the
216 * current frame.
217 */
218 tf = (struct trapframe *) ((int)*fp + 8);
219
220 esp = (ISPL(tf->tf_cs) == SEL_UPL) ? tf->tf_esp : (int)&tf->tf_esp;
221 switch (frame_type) {
222 case TRAP:
223 if (INKERNEL((int) tf)) {
224 eip = tf->tf_eip;
225 ebp = tf->tf_ebp;
226 db_printf(
227 "--- trap %#r, eip = %#r, esp = %#r, ebp = %#r ---\n",
228 tf->tf_trapno, eip, esp, ebp);
229 }
230 break;
231 case SYSCALL:
232 if (INKERNEL((int) tf)) {
233 eip = tf->tf_eip;
234 ebp = tf->tf_ebp;
235 db_printf(
236 "--- syscall %#r, eip = %#r, esp = %#r, ebp = %#r ---\n",
237 tf->tf_eax, eip, esp, ebp);
238 }
239 break;
240 case INTERRUPT:
241 tf = (struct trapframe *)((int)*fp + 16);
242 if (INKERNEL((int) tf)) {
243 eip = tf->tf_eip;
244 ebp = tf->tf_ebp;
245 db_printf(
246 "--- interrupt, eip = %#r, esp = %#r, ebp = %#r ---\n",
247 eip, esp, ebp);
248 }
249 break;
250 default:
251 break;
252 }
253
254 *ip = (db_addr_t) eip;
255 *fp = (struct i386_frame *) ebp;
256 }
257
258 void
259 db_stack_trace_cmd(db_expr_t addr, boolean_t have_addr, db_expr_t count,
260 char *modif)
261 {
262 struct i386_frame *frame;
263 int *argp;
264 db_addr_t callpc;
265 boolean_t first;
266 int i;
267
268 if (count == -1)
269 count = 1024;
270
271 if (!have_addr) {
272 frame = (struct i386_frame *)BP_REGS(&ddb_regs);
273 if (frame == NULL)
274 frame = (struct i386_frame *)(SP_REGS(&ddb_regs) - 4);
275 callpc = PC_REGS(&ddb_regs);
276 } else if (!INKERNEL(addr)) {
277 #if needswork
278 pid = (addr % 16) + ((addr >> 4) % 16) * 10 +
279 ((addr >> 8) % 16) * 100 + ((addr >> 12) % 16) * 1000 +
280 ((addr >> 16) % 16) * 10000;
281 /*
282 * The pcb for curproc is not valid at this point,
283 * so fall back to the default case.
284 */
285 if ((curproc != NULL) && (pid == curproc->p_pid)) {
286 frame = (struct i386_frame *)BP_REGS(&ddb_regs);
287 if (frame == NULL)
288 frame = (struct i386_frame *)
289 (SP_REGS(&ddb_regs) - 4);
290 callpc = PC_REGS(&ddb_regs);
291 } else {
292 pid_t pid;
293 struct proc *p;
294 struct pcb *pcb;
295
296 p = pfind(pid);
297 if (p == NULL) {
298 db_printf("pid %d not found\n", pid);
299 return;
300 }
301 if ((p->p_flag & P_SWAPPEDOUT)) {
302 db_printf("pid %d swapped out\n", pid);
303 return;
304 }
305 pcb = p->p_thread->td_pcb;
306 frame = (struct i386_frame *)pcb->pcb_ebp;
307 if (frame == NULL)
308 frame = (struct i386_frame *)
309 (pcb->pcb_esp - 4);
310 callpc = (db_addr_t)pcb->pcb_eip;
311 }
312 #else
313 /* XXX */
314 db_printf("no kernel stack address\n");
315 return;
316 #endif
317 } else {
318 /*
319 * Look for something that might be a frame pointer, just as
320 * a convenience.
321 */
322 frame = (struct i386_frame *)addr;
323 for (i = 0; i < 4096; i += 4) {
324 struct i386_frame *check;
325
326 check = (struct i386_frame *)db_get_value((int)((char *)&frame->f_frame + i), 4, FALSE);
327 if ((char *)check - (char *)frame >= 0 &&
328 (char *)check - (char *)frame < 4096
329 ) {
330 break;
331 }
332 db_printf("%p does not look like a stack frame, skipping\n", (char *)&frame->f_frame + i);
333 }
334 if (i == 4096) {
335 db_printf("Unable to find anything that looks like a stack frame\n");
336 return;
337 }
338 frame = (void *)((char *)frame + i);
339 db_printf("Trace beginning at frame %p\n", frame);
340 callpc = (db_addr_t)db_get_value((int)&frame->f_retaddr, 4, FALSE);
341 }
342
343 first = TRUE;
344 while (count--) {
345 struct i386_frame *actframe;
346 int narg;
347 const char * name;
348 db_expr_t offset;
349 c_db_sym_t sym;
350 #define MAXNARG 16
351 char *argnames[MAXNARG], **argnp = NULL;
352
353 sym = db_search_symbol(callpc, DB_STGY_ANY, &offset);
354 db_symbol_values(sym, &name, NULL);
355
356 /*
357 * Attempt to determine a (possibly fake) frame that gives
358 * the caller's pc. It may differ from `frame' if the
359 * current function never sets up a standard frame or hasn't
360 * set one up yet or has just discarded one. The last two
361 * cases can be guessed fairly reliably for code generated
362 * by gcc. The first case is too much trouble to handle in
363 * general because the amount of junk on the stack depends
364 * on the pc (the special handling of "calltrap", etc. in
365 * db_nextframe() works because the `next' pc is special).
366 */
367 actframe = frame;
368 if (first) {
369 if (!have_addr) {
370 int instr;
371
372 instr = db_get_value(callpc, 4, FALSE);
373 if ((instr & 0x00ffffff) == 0x00e58955) {
374 /* pushl %ebp; movl %esp, %ebp */
375 actframe = (struct i386_frame *)
376 (SP_REGS(&ddb_regs) - 4);
377 } else if ((instr & 0x0000ffff) == 0x0000e589) {
378 /* movl %esp, %ebp */
379 actframe = (struct i386_frame *)
380 SP_REGS(&ddb_regs);
381 if (ddb_regs.tf_ebp == 0) {
382 /* Fake caller's frame better. */
383 frame = actframe;
384 }
385 } else if ((instr & 0x000000ff) == 0x000000c3) {
386 /* ret */
387 actframe = (struct i386_frame *)
388 (SP_REGS(&ddb_regs) - 4);
389 } else if (offset == 0) {
390 /* Probably a symbol in assembler code. */
391 actframe = (struct i386_frame *)
392 (SP_REGS(&ddb_regs) - 4);
393 }
394 } else if (name != NULL &&
395 strcmp(name, "fork_trampoline") == 0) {
396 /*
397 * Don't try to walk back on a stack for a
398 * process that hasn't actually been run yet.
399 */
400 db_print_stack_entry(name, 0, 0, 0, callpc);
401 break;
402 }
403 first = FALSE;
404 }
405
406 argp = &actframe->f_arg0;
407 narg = MAXNARG;
408 if (sym != NULL && db_sym_numargs(sym, &narg, argnames)) {
409 argnp = argnames;
410 } else {
411 narg = db_numargs(frame);
412 }
413
414 db_print_stack_entry(name, narg, argnp, argp, callpc);
415
416 if (actframe != frame) {
417 /* `frame' belongs to caller. */
418 callpc = (db_addr_t)
419 db_get_value((int)&actframe->f_retaddr, 4, FALSE);
420 continue;
421 }
422
423 db_nextframe(&frame, &callpc);
424
425 if (INKERNEL((int) callpc) && !INKERNEL((int) frame)) {
426 sym = db_search_symbol(callpc, DB_STGY_ANY, &offset);
427 db_symbol_values(sym, &name, NULL);
428 db_print_stack_entry(name, 0, 0, 0, callpc);
429 break;
430 }
431 if (!INKERNEL((int) frame)) {
432 break;
433 }
434 }
435 }
436
437 void
438 print_backtrace(void)
439 {
440 register_t ebp;
441
442 __asm __volatile("movl %%ebp, %0" : "=r" (ebp));
443 db_stack_trace_cmd(ebp, 1, -1, NULL);
444 }
445
446 #define DB_DRX_FUNC(reg) \
447 int \
448 db_ ## reg (struct db_variable *vp, db_expr_t *valuep, int op) \
449 { \
450 if (op == DB_VAR_GET) \
451 *valuep = r ## reg (); \
452 else \
453 load_ ## reg (*valuep); \
454 \
455 return(0); \
456 }
457
458 DB_DRX_FUNC(dr0)
459 DB_DRX_FUNC(dr1)
460 DB_DRX_FUNC(dr2)
461 DB_DRX_FUNC(dr3)
462 DB_DRX_FUNC(dr4)
463 DB_DRX_FUNC(dr5)
464 DB_DRX_FUNC(dr6)
465 DB_DRX_FUNC(dr7)
466
467 static int
468 ki386_set_watch(int watchnum, unsigned int watchaddr, int size, int access,
469 struct dbreg *d)
470 {
471 int i;
472 unsigned int mask;
473
474 if (watchnum == -1) {
475 for (i = 0, mask = 0x3; i < 4; i++, mask <<= 2)
476 if ((d->dr7 & mask) == 0)
477 break;
478 if (i < 4)
479 watchnum = i;
480 else
481 return(-1);
482 }
483
484 switch (access) {
485 case DBREG_DR7_EXEC:
486 size = 1; /* size must be 1 for an execution breakpoint */
487 /* fall through */
488 case DBREG_DR7_WRONLY:
489 case DBREG_DR7_RDWR:
490 break;
491 default:
492 return(-1);
493 }
494
495 /*
496 * we can watch a 1, 2, or 4 byte sized location
497 */
498 switch (size) {
499 case 1:
500 mask = 0x00;
501 break;
502 case 2:
503 mask = 0x01 << 2;
504 break;
505 case 4:
506 mask = 0x03 << 2;
507 break;
508 default:
509 return(-1);
510 }
511
512 mask |= access;
513
514 /* clear the bits we are about to affect */
515 d->dr7 &= ~((0x3 << (watchnum * 2)) | (0x0f << (watchnum * 4 + 16)));
516
517 /* set drN register to the address, N=watchnum */
518 DBREG_DRX(d, watchnum) = watchaddr;
519
520 /* enable the watchpoint */
521 d->dr7 |= (0x2 << (watchnum * 2)) | (mask << (watchnum * 4 + 16));
522
523 return(watchnum);
524 }
525
526
527 int
528 ki386_clr_watch(int watchnum, struct dbreg *d)
529 {
530 if (watchnum < 0 || watchnum >= 4)
531 return(-1);
532
533 d->dr7 &= ~((0x3 << (watchnum * 2)) | (0x0f << (watchnum * 4 + 16)));
534 DBREG_DRX(d, watchnum) = 0;
535
536 return(0);
537 }
538
539
540 int
541 db_md_set_watchpoint(db_expr_t addr, db_expr_t size)
542 {
543 int avail, wsize;
544 int i;
545 struct dbreg d;
546
547 fill_dbregs(NULL, &d);
548
549 avail = 0;
550 for(i=0; i < 4; i++) {
551 if ((d.dr7 & (3 << (i * 2))) == 0)
552 avail++;
553 }
554
555 if (avail * 4 < size)
556 return(-1);
557
558 for (i=0; i < 4 && (size != 0); i++) {
559 if ((d.dr7 & (3 << (i * 2))) == 0) {
560 if (size > 4)
561 wsize = 4;
562 else
563 wsize = size;
564 if (wsize == 3)
565 wsize++;
566 ki386_set_watch(i, addr, wsize, DBREG_DR7_WRONLY, &d);
567 addr += wsize;
568 size -= wsize;
569 }
570 }
571
572 set_dbregs(NULL, &d);
573
574 return(0);
575 }
576
577 int
578 db_md_clr_watchpoint(db_expr_t addr, db_expr_t size)
579 {
580 int i;
581 struct dbreg d;
582
583 fill_dbregs(NULL, &d);
584
585 for(i=0; i<4; i++) {
586 if (d.dr7 & (3 << (i * 2))) {
587 if ((DBREG_DRX((&d), i) >= addr) &&
588 (DBREG_DRX((&d), i) < addr + size))
589 ki386_clr_watch(i, &d);
590 }
591 }
592
593 set_dbregs(NULL, &d);
594
595 return(0);
596 }
597
598 static char *
599 watchtype_str(int type)
600 {
601 switch (type) {
602 case DBREG_DR7_EXEC:
603 return "execute";
604 case DBREG_DR7_RDWR:
605 return "read/write";
606 case DBREG_DR7_WRONLY:
607 return "write";
608 default:
609 return "invalid";
610 }
611 }
612
613 void
614 db_md_list_watchpoints(void)
615 {
616 int i;
617 struct dbreg d;
618
619 fill_dbregs(NULL, &d);
620
621 db_printf("\nhardware watchpoints:\n");
622 db_printf(" watch status type len address\n"
623 " ----- -------- ---------- --- ----------\n");
624 for (i=0; i < 4; i++) {
625 if (d.dr7 & (0x03 << (i * 2))) {
626 unsigned type, len;
627 type = (d.dr7 >> (16 + (i * 4))) & 3;
628 len = (d.dr7 >> (16 + (i * 4) + 2)) & 3;
629 db_printf(" %-5d %-8s %10s %3d 0x%08x\n",
630 i, "enabled", watchtype_str(type),
631 len + 1, DBREG_DRX((&d), i));
632 } else {
633 db_printf(" %-5d disabled\n", i);
634 }
635 }
636
637 db_printf("\ndebug register values:\n");
638 for (i=0; i < 8; i++)
639 db_printf(" dr%d 0x%08x\n", i, DBREG_DRX((&d),i));
640 db_printf("\n");
641 }
DragonFly BSD