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 $
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/linker_set.h>
36 #include <machine/cpu.h>
37 #include <machine/md_var.h>
40 #include <vm/vm_param.h>
42 #include <vm/vm_map.h>
47 #include <ddb/db_access.h>
48 #include <ddb/db_sym.h>
49 #include <ddb/db_variables.h>
61 * Machine register set.
63 struct db_variable db_regs[] = {
64 { "cs", &ddb_regs.tf_cs, NULL },
65 { "ds", &ddb_regs.tf_ds, NULL },
66 { "es", &ddb_regs.tf_es, NULL },
67 { "fs", &ddb_regs.tf_fs, NULL },
68 { "gs", &ddb_regs.tf_gs, NULL },
69 { "ss", &ddb_regs.tf_ss, NULL },
70 { "eax", &ddb_regs.tf_eax, NULL },
71 { "ecx", &ddb_regs.tf_ecx, NULL },
72 { "edx", &ddb_regs.tf_edx, NULL },
73 { "ebx", &ddb_regs.tf_ebx, NULL },
74 { "esp", &ddb_regs.tf_esp, NULL },
75 { "ebp", &ddb_regs.tf_ebp, NULL },
76 { "esi", &ddb_regs.tf_esi, NULL },
77 { "edi", &ddb_regs.tf_edi, NULL },
78 { "eip", &ddb_regs.tf_eip, NULL },
79 { "efl", &ddb_regs.tf_eflags, NULL },
80 { "dr0", NULL, db_dr0 },
81 { "dr1", NULL, db_dr1 },
82 { "dr2", NULL, db_dr2 },
83 { "dr3", NULL, db_dr3 },
84 { "dr4", NULL, db_dr4 },
85 { "dr5", NULL, db_dr5 },
86 { "dr6", NULL, db_dr6 },
87 { "dr7", NULL, db_dr7 },
89 struct db_variable *db_eregs = db_regs + NELEM(db_regs);
94 #define INKERNEL(va) (((vm_offset_t)(va)) >= USRSTACK)
97 struct i386_frame *f_frame;
107 static void db_nextframe(struct i386_frame **, db_addr_t *);
108 static int db_numargs(struct i386_frame *);
109 static void db_print_stack_entry(const char *, int, char **, int *, db_addr_t);
112 static char *watchtype_str(int type);
113 static int ki386_set_watch(int watchnum, unsigned int watchaddr,
114 int size, int access, struct dbreg * d);
115 static int ki386_clr_watch(int watchnum, struct dbreg * d);
116 int db_md_set_watchpoint(db_expr_t addr, db_expr_t size);
117 int db_md_clr_watchpoint(db_expr_t addr, db_expr_t size);
118 void db_md_list_watchpoints(void);
122 * Figure out how many arguments were passed into the frame at "fp".
125 db_numargs(struct i386_frame *fp)
131 argp = (int *)db_get_value((int)&fp->f_retaddr, 4, FALSE);
133 * XXX etext is wrong for LKMs. We should attempt to interpret
134 * the instruction at the return address in all cases. This
135 * may require better fault handling.
137 if (argp < (int *)btext || argp >= (int *)etext) {
140 inst = db_get_value((int)argp, 4, FALSE);
141 if ((inst & 0xff) == 0x59) /* popl %ecx */
143 else if ((inst & 0xffff) == 0xc483) /* addl $Ibs, %esp */
144 args = ((inst >> 16) & 0xff) / 4;
152 db_print_stack_entry(const char *name, int narg, char **argnp, int *argp,
155 db_printf("%s(", name);
158 db_printf("%s=", *argnp++);
159 db_printf("%r", db_get_value((int)argp, 4, FALSE));
165 db_printsym(callpc, DB_STGY_PROC);
166 db_printf(" %p ", (void*) callpc);
171 * Figure out the next frame up in the call stack.
174 db_nextframe(struct i386_frame **fp, db_addr_t *ip)
176 struct trapframe *tf;
180 const char *sym, *name;
182 eip = db_get_value((int) &(*fp)->f_retaddr, 4, FALSE);
183 ebp = db_get_value((int) &(*fp)->f_frame, 4, FALSE);
186 * Figure out frame type.
191 sym = db_search_symbol(eip, DB_STGY_ANY, &offset);
192 db_symbol_values(sym, &name, NULL);
194 if (!strcmp(name, "calltrap")) {
196 } else if (!strncmp(name, "Xresume", 7)) {
197 frame_type = INTERRUPT;
198 } else if (!strcmp(name, "_Xsyscall")) {
199 frame_type = SYSCALL;
204 * Normal frames need no special processing.
206 if (frame_type == NORMAL) {
207 *ip = (db_addr_t) eip;
208 *fp = (struct i386_frame *) ebp;
212 db_print_stack_entry(name, 0, 0, 0, eip);
215 * Point to base of trapframe which is just above the
218 tf = (struct trapframe *) ((int)*fp + 8);
220 esp = (ISPL(tf->tf_cs) == SEL_UPL) ? tf->tf_esp : (int)&tf->tf_esp;
221 switch (frame_type) {
223 if (INKERNEL((int) tf)) {
227 "--- trap %#r, eip = %#r, esp = %#r, ebp = %#r ---\n",
228 tf->tf_trapno, eip, esp, ebp);
232 if (INKERNEL((int) tf)) {
236 "--- syscall %#r, eip = %#r, esp = %#r, ebp = %#r ---\n",
237 tf->tf_eax, eip, esp, ebp);
241 tf = (struct trapframe *)((int)*fp + 16);
242 if (INKERNEL((int) tf)) {
246 "--- interrupt, eip = %#r, esp = %#r, ebp = %#r ---\n",
254 *ip = (db_addr_t) eip;
255 *fp = (struct i386_frame *) ebp;
259 db_stack_trace_cmd(db_expr_t addr, boolean_t have_addr, db_expr_t count,
262 struct i386_frame *frame;
272 frame = (struct i386_frame *)BP_REGS(&ddb_regs);
274 frame = (struct i386_frame *)(SP_REGS(&ddb_regs) - 4);
275 callpc = PC_REGS(&ddb_regs);
276 } else if (!INKERNEL(addr)) {
277 #if 0 /* needswork */
278 pid = (addr % 16) + ((addr >> 4) % 16) * 10 +
279 ((addr >> 8) % 16) * 100 + ((addr >> 12) % 16) * 1000 +
280 ((addr >> 16) % 16) * 10000;
282 * The pcb for curproc is not valid at this point,
283 * so fall back to the default case.
285 if ((curproc != NULL) && (pid == curproc->p_pid)) {
286 frame = (struct i386_frame *)BP_REGS(&ddb_regs);
288 frame = (struct i386_frame *)
289 (SP_REGS(&ddb_regs) - 4);
290 callpc = PC_REGS(&ddb_regs);
298 db_printf("pid %d not found\n", pid);
301 if ((p->p_flags & P_SWAPPEDOUT)) {
302 db_printf("pid %d swapped out\n", pid);
305 pcb = p->p_thread->td_pcb;
306 frame = (struct i386_frame *)pcb->pcb_ebp;
308 frame = (struct i386_frame *)
310 callpc = (db_addr_t)pcb->pcb_eip;
314 db_printf("no kernel stack address\n");
319 * Look for something that might be a frame pointer, just as
322 frame = (struct i386_frame *)addr;
323 for (i = 0; i < 4096; i += 4) {
324 struct i386_frame *check;
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
332 db_printf("%p does not look like a stack frame, skipping\n", (char *)&frame->f_frame + i);
335 db_printf("Unable to find anything that looks like a stack frame\n");
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);
345 struct i386_frame *actframe;
351 char *argnames[MAXNARG], **argnp = NULL;
353 sym = db_search_symbol(callpc, DB_STGY_ANY, &offset);
354 db_symbol_values(sym, &name, NULL);
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).
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 *)
381 if (ddb_regs.tf_ebp == 0) {
382 /* Fake caller's frame better. */
385 } else if ((instr & 0x000000ff) == 0x000000c3) {
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);
394 } else if (name != NULL &&
395 strcmp(name, "fork_trampoline") == 0) {
397 * Don't try to walk back on a stack for a
398 * process that hasn't actually been run yet.
400 db_print_stack_entry(name, 0, 0, 0, callpc);
406 argp = &actframe->f_arg0;
408 if (sym != NULL && db_sym_numargs(sym, &narg, argnames)) {
411 narg = db_numargs(frame);
414 db_print_stack_entry(name, narg, argnp, argp, callpc);
416 if (actframe != frame) {
417 /* `frame' belongs to caller. */
419 db_get_value((int)&actframe->f_retaddr, 4, FALSE);
423 db_nextframe(&frame, &callpc);
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);
431 if (!INKERNEL((int) frame)) {
438 print_backtrace(int count)
442 __asm __volatile("movl %%ebp, %0" : "=r" (ebp));
443 db_stack_trace_cmd(ebp, 1, count, NULL);
446 #define DB_DRX_FUNC(reg) \
448 db_ ## reg (struct db_variable *vp, db_expr_t *valuep, int op) \
450 if (op == DB_VAR_GET) \
451 *valuep = r ## reg (); \
453 load_ ## reg (*valuep); \
468 ki386_set_watch(int watchnum, unsigned int watchaddr, int size, int access,
474 if (watchnum == -1) {
475 for (i = 0, mask = 0x3; i < 4; i++, mask <<= 2)
476 if ((d->dr7 & mask) == 0)
486 size = 1; /* size must be 1 for an execution breakpoint */
488 case DBREG_DR7_WRONLY:
496 * we can watch a 1, 2, or 4 byte sized location
514 /* clear the bits we are about to affect */
515 d->dr7 &= ~((0x3 << (watchnum * 2)) | (0x0f << (watchnum * 4 + 16)));
517 /* set drN register to the address, N=watchnum */
518 DBREG_DRX(d, watchnum) = watchaddr;
520 /* enable the watchpoint */
521 d->dr7 |= (0x2 << (watchnum * 2)) | (mask << (watchnum * 4 + 16));
528 ki386_clr_watch(int watchnum, struct dbreg *d)
530 if (watchnum < 0 || watchnum >= 4)
533 d->dr7 &= ~((0x3 << (watchnum * 2)) | (0x0f << (watchnum * 4 + 16)));
534 DBREG_DRX(d, watchnum) = 0;
541 db_md_set_watchpoint(db_expr_t addr, db_expr_t size)
547 fill_dbregs(NULL, &d);
550 for(i=0; i < 4; i++) {
551 if ((d.dr7 & (3 << (i * 2))) == 0)
555 if (avail * 4 < size)
558 for (i=0; i < 4 && (size != 0); i++) {
559 if ((d.dr7 & (3 << (i * 2))) == 0) {
566 ki386_set_watch(i, addr, wsize, DBREG_DR7_WRONLY, &d);
572 set_dbregs(NULL, &d);
578 db_md_clr_watchpoint(db_expr_t addr, db_expr_t size)
583 fill_dbregs(NULL, &d);
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);
593 set_dbregs(NULL, &d);
599 watchtype_str(int type)
606 case DBREG_DR7_WRONLY:
614 db_md_list_watchpoints(void)
619 fill_dbregs(NULL, &d);
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))) {
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));
633 db_printf(" %-5d disabled\n", i);
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));