2 * Mach Operating System
3 * Copyright (c) 1991,1990 Carnegie Mellon University
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.
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.
16 * Carnegie Mellon requests users of this software to return to
18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
19 * School of Computer Science
20 * Carnegie Mellon University
21 * Pittsburgh PA 15213-3890
23 * any improvements or extensions that they make and grant Carnegie the
24 * rights to redistribute these changes.
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/vkernel/i386/db_trace.c,v 1.6 2007/02/02 15:57:51 corecode Exp $
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/linker_set.h>
37 #include <machine/cpu.h>
38 #include <machine/md_var.h>
41 #include <vm/vm_param.h>
43 #include <vm/vm_map.h>
48 #include <ddb/db_access.h>
49 #include <ddb/db_sym.h>
50 #include <ddb/db_variables.h>
62 * Machine register set.
64 struct db_variable db_regs[] = {
65 { "cs", &ddb_regs.tf_cs, FCN_NULL },
66 { "ds", &ddb_regs.tf_ds, FCN_NULL },
67 { "es", &ddb_regs.tf_es, FCN_NULL },
68 { "fs", &ddb_regs.tf_fs, FCN_NULL },
69 { "gs", &ddb_regs.tf_gs, FCN_NULL },
70 { "ss", &ddb_regs.tf_ss, FCN_NULL },
71 { "eax", &ddb_regs.tf_eax, FCN_NULL },
72 { "ecx", &ddb_regs.tf_ecx, FCN_NULL },
73 { "edx", &ddb_regs.tf_edx, FCN_NULL },
74 { "ebx", &ddb_regs.tf_ebx, FCN_NULL },
75 { "esp", &ddb_regs.tf_esp, FCN_NULL },
76 { "ebp", &ddb_regs.tf_ebp, FCN_NULL },
77 { "esi", &ddb_regs.tf_esi, FCN_NULL },
78 { "edi", &ddb_regs.tf_edi, FCN_NULL },
79 { "eip", &ddb_regs.tf_eip, FCN_NULL },
80 { "efl", &ddb_regs.tf_eflags, FCN_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 },
90 struct db_variable *db_eregs = db_regs + sizeof(db_regs)/sizeof(db_regs[0]);
95 #define INKERNEL(va) (((vm_offset_t)(va)) >= USRSTACK)
98 struct i386_frame *f_frame;
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);
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);
123 * Figure out how many arguments were passed into the frame at "fp".
126 db_numargs(struct i386_frame *fp)
133 argp = (int *)db_get_value((int)&fp->f_retaddr, 4, FALSE);
135 * XXX etext is wrong for LKMs. We should attempt to interpret
136 * the instruction at the return address in all cases. This
137 * may require better fault handling.
139 if (argp < (int *)btext || argp >= (int *)etext) {
142 inst = db_get_value((int)argp, 4, FALSE);
143 if ((inst & 0xff) == 0x59) /* popl %ecx */
145 else if ((inst & 0xffff) == 0xc483) /* addl $Ibs, %esp */
146 args = ((inst >> 16) & 0xff) / 4;
156 db_print_stack_entry(const char *name, int narg, char **argnp, int *argp,
159 db_printf("%s(", name);
162 db_printf("%s=", *argnp++);
163 db_printf("%r", db_get_value((int)argp, 4, FALSE));
169 db_printsym(callpc, DB_STGY_PROC);
174 * Figure out the next frame up in the call stack.
177 db_nextframe(struct i386_frame **fp, db_addr_t *ip)
179 struct trapframe *tf;
183 const char *sym, *name;
185 eip = db_get_value((int) &(*fp)->f_retaddr, 4, FALSE);
186 ebp = db_get_value((int) &(*fp)->f_frame, 4, FALSE);
189 * Figure out frame type.
194 sym = db_search_symbol(eip, DB_STGY_ANY, &offset);
195 db_symbol_values(sym, &name, NULL);
197 if (!strcmp(name, "calltrap")) {
199 } else if (!strncmp(name, "Xresume", 7)) {
200 frame_type = INTERRUPT;
201 } else if (!strcmp(name, "_Xsyscall")) {
202 frame_type = SYSCALL;
207 * Normal frames need no special processing.
209 if (frame_type == NORMAL) {
210 *ip = (db_addr_t) eip;
211 *fp = (struct i386_frame *) ebp;
215 db_print_stack_entry(name, 0, 0, 0, eip);
218 * Point to base of trapframe which is just above the
221 tf = (struct trapframe *) ((int)*fp + 8);
224 esp = (ISPL(tf->tf_cs) == SEL_UPL) ? tf->tf_esp : (int)&tf->tf_esp;
226 esp = (int)&tf->tf_esp;
228 switch (frame_type) {
234 "--- trap %#r, eip = %#r, esp = %#r, ebp = %#r ---\n",
235 tf->tf_trapno, eip, esp, ebp);
243 "--- syscall %#r, eip = %#r, esp = %#r, ebp = %#r ---\n",
244 tf->tf_eax, eip, esp, ebp);
248 tf = (struct trapframe *)((int)*fp + 16);
253 "--- interrupt, eip = %#r, esp = %#r, ebp = %#r ---\n",
261 *ip = (db_addr_t) eip;
262 *fp = (struct i386_frame *) ebp;
266 db_stack_trace_cmd(db_expr_t addr, boolean_t have_addr, db_expr_t count,
269 struct i386_frame *frame;
279 frame = (struct i386_frame *)BP_REGS(&ddb_regs);
281 frame = (struct i386_frame *)(SP_REGS(&ddb_regs) - 4);
282 callpc = PC_REGS(&ddb_regs);
285 * Look for something that might be a frame pointer, just as
288 frame = (struct i386_frame *)addr;
289 for (i = 0; i < 4096; i += 4) {
290 struct i386_frame *check;
292 check = (struct i386_frame *)db_get_value((int)((char *)&frame->f_frame + i), 4, FALSE);
293 if ((char *)check - (char *)frame >= 0 &&
294 (char *)check - (char *)frame < 4096
298 db_printf("%p does not look like a stack frame, skipping\n", (char *)&frame->f_frame + i);
301 db_printf("Unable to find anything that looks like a stack frame\n");
304 frame = (void *)((char *)frame + i);
305 db_printf("Trace beginning at frame %p\n", frame);
306 callpc = (db_addr_t)db_get_value((int)&frame->f_retaddr, 4, FALSE);
311 struct i386_frame *actframe;
317 char *argnames[MAXNARG], **argnp = NULL;
319 sym = db_search_symbol(callpc, DB_STGY_ANY, &offset);
320 db_symbol_values(sym, &name, NULL);
323 * Attempt to determine a (possibly fake) frame that gives
324 * the caller's pc. It may differ from `frame' if the
325 * current function never sets up a standard frame or hasn't
326 * set one up yet or has just discarded one. The last two
327 * cases can be guessed fairly reliably for code generated
328 * by gcc. The first case is too much trouble to handle in
329 * general because the amount of junk on the stack depends
330 * on the pc (the special handling of "calltrap", etc. in
331 * db_nextframe() works because the `next' pc is special).
338 instr = db_get_value(callpc, 4, FALSE);
339 if ((instr & 0x00ffffff) == 0x00e58955) {
340 /* pushl %ebp; movl %esp, %ebp */
341 actframe = (struct i386_frame *)
342 (SP_REGS(&ddb_regs) - 4);
343 } else if ((instr & 0x0000ffff) == 0x0000e589) {
344 /* movl %esp, %ebp */
345 actframe = (struct i386_frame *)
347 if (ddb_regs.tf_ebp == 0) {
348 /* Fake caller's frame better. */
351 } else if ((instr & 0x000000ff) == 0x000000c3) {
353 actframe = (struct i386_frame *)
354 (SP_REGS(&ddb_regs) - 4);
355 } else if (offset == 0) {
356 /* Probably a symbol in assembler code. */
357 actframe = (struct i386_frame *)
358 (SP_REGS(&ddb_regs) - 4);
360 } else if (name != NULL &&
361 strcmp(name, "fork_trampoline") == 0) {
363 * Don't try to walk back on a stack for a
364 * process that hasn't actually been run yet.
366 db_print_stack_entry(name, 0, 0, 0, callpc);
372 argp = &actframe->f_arg0;
374 if (sym != NULL && db_sym_numargs(sym, &narg, argnames)) {
377 narg = db_numargs(frame);
380 db_print_stack_entry(name, narg, argnp, argp, callpc);
382 if (actframe != frame) {
383 /* `frame' belongs to caller. */
385 db_get_value((int)&actframe->f_retaddr, 4, FALSE);
389 db_nextframe(&frame, &callpc);
392 sym = db_search_symbol(callpc, DB_STGY_ANY, &offset);
393 db_symbol_values(sym, &name, NULL);
394 db_print_stack_entry(name, 0, 0, 0, callpc);
403 db_print_backtrace(void)
407 __asm __volatile("movl %%ebp, %0" : "=r" (ebp));
408 db_stack_trace_cmd(ebp, 1, -1, NULL);
411 #define DB_DRX_FUNC(reg) \
413 db_ ## reg (struct db_variable *vp, db_expr_t *valuep, int op) \
415 if (op == DB_VAR_GET) \
416 *valuep = r ## reg (); \
418 load_ ## reg (*valuep); \
433 ki386_set_watch(int watchnum, unsigned int watchaddr, int size, int access,
439 if (watchnum == -1) {
440 for (i = 0, mask = 0x3; i < 4; i++, mask <<= 2)
441 if ((d->dr7 & mask) == 0)
451 size = 1; /* size must be 1 for an execution breakpoint */
453 case DBREG_DR7_WRONLY:
461 * we can watch a 1, 2, or 4 byte sized location
479 /* clear the bits we are about to affect */
480 d->dr7 &= ~((0x3 << (watchnum * 2)) | (0x0f << (watchnum * 4 + 16)));
482 /* set drN register to the address, N=watchnum */
483 DBREG_DRX(d, watchnum) = watchaddr;
485 /* enable the watchpoint */
486 d->dr7 |= (0x2 << (watchnum * 2)) | (mask << (watchnum * 4 + 16));
493 ki386_clr_watch(int watchnum, struct dbreg *d)
495 if (watchnum < 0 || watchnum >= 4)
498 d->dr7 &= ~((0x3 << (watchnum * 2)) | (0x0f << (watchnum * 4 + 16)));
499 DBREG_DRX(d, watchnum) = 0;
506 db_md_set_watchpoint(db_expr_t addr, db_expr_t size)
512 fill_dbregs(NULL, &d);
515 for(i=0; i < 4; i++) {
516 if ((d.dr7 & (3 << (i * 2))) == 0)
520 if (avail * 4 < size)
523 for (i=0; i < 4 && (size != 0); i++) {
524 if ((d.dr7 & (3 << (i * 2))) == 0) {
531 ki386_set_watch(i, addr, wsize, DBREG_DR7_WRONLY, &d);
537 set_dbregs(NULL, &d);
543 db_md_clr_watchpoint(db_expr_t addr, db_expr_t size)
548 fill_dbregs(NULL, &d);
551 if (d.dr7 & (3 << (i * 2))) {
552 if ((DBREG_DRX((&d), i) >= addr) &&
553 (DBREG_DRX((&d), i) < addr + size))
554 ki386_clr_watch(i, &d);
558 set_dbregs(NULL, &d);
564 watchtype_str(int type)
571 case DBREG_DR7_WRONLY:
579 db_md_list_watchpoints(void)
584 fill_dbregs(NULL, &d);
586 db_printf("\nhardware watchpoints:\n");
587 db_printf(" watch status type len address\n"
588 " ----- -------- ---------- --- ----------\n");
589 for (i=0; i < 4; i++) {
590 if (d.dr7 & (0x03 << (i * 2))) {
592 type = (d.dr7 >> (16 + (i * 4))) & 3;
593 len = (d.dr7 >> (16 + (i * 4) + 2)) & 3;
594 db_printf(" %-5d %-8s %10s %3d 0x%08x\n",
595 i, "enabled", watchtype_str(type),
596 len + 1, DBREG_DRX((&d), i));
598 db_printf(" %-5d disabled\n", i);
602 db_printf("\ndebug register values:\n");
603 for (i=0; i < 8; i++)
604 db_printf(" dr%d 0x%08x\n", i, DBREG_DRX((&d),i));