/* $OpenBSD: db_trace.c,v 1.13 2006/11/28 18:56:17 uwe Exp $ */
/* $NetBSD: db_trace.c,v 1.18 1996/05/03 19:42:01 christos Exp $ */
/*
* Mach Operating System
* Copyright (c) 1991,1990 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <machine/db_machdep.h>
#include <ddb/db_sym.h>
#include <ddb/db_access.h>
#include <ddb/db_variables.h>
#include <ddb/db_output.h>
#include <ddb/db_interface.h>
/*
* Machine register set.
*/
struct db_variable db_regs[] = {
{ "ds", (long *)&ddb_regs.tf_ds, FCN_NULL },
{ "es", (long *)&ddb_regs.tf_es, FCN_NULL },
{ "fs", (long *)&ddb_regs.tf_fs, FCN_NULL },
{ "gs", (long *)&ddb_regs.tf_gs, FCN_NULL },
{ "edi", (long *)&ddb_regs.tf_edi, FCN_NULL },
{ "esi", (long *)&ddb_regs.tf_esi, FCN_NULL },
{ "ebp", (long *)&ddb_regs.tf_ebp, FCN_NULL },
{ "ebx", (long *)&ddb_regs.tf_ebx, FCN_NULL },
{ "edx", (long *)&ddb_regs.tf_edx, FCN_NULL },
{ "ecx", (long *)&ddb_regs.tf_ecx, FCN_NULL },
{ "eax", (long *)&ddb_regs.tf_eax, FCN_NULL },
{ "eip", (long *)&ddb_regs.tf_eip, FCN_NULL },
{ "cs", (long *)&ddb_regs.tf_cs, FCN_NULL },
{ "eflags", (long *)&ddb_regs.tf_eflags, FCN_NULL },
{ "esp", (long *)&ddb_regs.tf_esp, FCN_NULL },
{ "ss", (long *)&ddb_regs.tf_ss, FCN_NULL },
};
struct db_variable *db_eregs = db_regs + sizeof(db_regs)/sizeof(db_regs[0]);
/*
* Stack trace.
*/
#define INKERNEL(va) (((vaddr_t)(va)) >= VM_MIN_KERNEL_ADDRESS)
struct i386_frame {
struct i386_frame *f_frame;
int f_retaddr;
int f_arg0;
};
#define NONE 0
#define TRAP 1
#define SYSCALL 2
#define INTERRUPT 3
db_addr_t db_trap_symbol_value = 0;
db_addr_t db_syscall_symbol_value = 0;
db_addr_t db_kdintr_symbol_value = 0;
boolean_t db_trace_symbols_found = FALSE;
void db_find_trace_symbols(void);
int db_numargs(struct i386_frame *);
void db_nextframe(struct i386_frame **, db_addr_t *, int *, int,
int (*pr)(const char *, ...));
void
db_find_trace_symbols(void)
{
db_expr_t value;
if (db_value_of_name("trap", &value))
db_trap_symbol_value = (db_addr_t) value;
if (db_value_of_name("kdintr", &value))
db_kdintr_symbol_value = (db_addr_t) value;
if (db_value_of_name("syscall", &value))
db_syscall_symbol_value = (db_addr_t) value;
db_trace_symbols_found = TRUE;
}
/*
* Figure out how many arguments were passed into the frame at "fp".
*/
int
db_numargs(struct i386_frame *fp)
{
int *argp;
int inst;
int args;
extern char etext[];
argp = (int *)db_get_value((int)&fp->f_retaddr, 4, FALSE);
if (argp < (int *)VM_MIN_KERNEL_ADDRESS || argp > (int *)etext) {
args = 5;
} else {
inst = db_get_value((int)argp, 4, FALSE);
if ((inst & 0xff) == 0x59) /* popl %ecx */
args = 1;
else if ((inst & 0xffff) == 0xc483) /* addl %n, %esp */
args = ((inst >> 16) & 0xff) / 4;
else
args = 5;
}
return (args);
}
/*
* Figure out the next frame up in the call stack.
* For trap(), we print the address of the faulting instruction and
* proceed with the calling frame. We return the ip that faulted.
* If the trap was caused by jumping through a bogus pointer, then
* the next line in the backtrace will list some random function as
* being called. It should get the argument list correct, though.
* It might be possible to dig out from the next frame up the name
* of the function that faulted, but that could get hairy.
*/
void
db_nextframe(struct i386_frame **fp, db_addr_t *ip, int *argp, int is_trap,
int (*pr)(const char *, ...))
{
switch (is_trap) {
case NONE:
*ip = (db_addr_t)
db_get_value((int) &(*fp)->f_retaddr, 4, FALSE);
*fp = (struct i386_frame *)
db_get_value((int) &(*fp)->f_frame, 4, FALSE);
break;
default: {
struct trapframe *tf;
/* The only argument to trap() or syscall() is the trapframe. */
tf = (struct trapframe *)argp;
switch (is_trap) {
case TRAP:
(*pr)("--- trap (number %d) ---\n", tf->tf_trapno);
break;
case SYSCALL:
(*pr)("--- syscall (number %d) ---\n", tf->tf_eax);
break;
case INTERRUPT:
(*pr)("--- interrupt ---\n");
break;
}
*fp = (struct i386_frame *)tf->tf_ebp;
*ip = (db_addr_t)tf->tf_eip;
break;
}
}
}
void
db_stack_trace_print(db_expr_t addr, boolean_t have_addr, db_expr_t count,
char *modif, int (*pr)(const char *, ...))
{
struct i386_frame *frame, *lastframe;
int *argp;
db_addr_t callpc;
int is_trap = 0;
boolean_t kernel_only = TRUE;
boolean_t trace_thread = FALSE;
boolean_t trace_proc = FALSE;
#if 0
if (!db_trace_symbols_found)
db_find_trace_symbols();
#endif
{
char *cp = modif;
char c;
while ((c = *cp++) != 0) {
if (c == 't')
trace_thread = TRUE;
if (c == 'p')
trace_proc = TRUE;
if (c == 'u')
kernel_only = FALSE;
}
}
if (count == -1)
count = 65535;
if (!have_addr) {
frame = (struct i386_frame *)ddb_regs.tf_ebp;
callpc = (db_addr_t)ddb_regs.tf_eip;
} else if (trace_thread) {
(*pr) ("db_trace.c: can't trace thread\n");
} else if (trace_proc) {
struct proc *p = pfind((pid_t)addr);
if (p == NULL) {
(*pr) ("db_trace.c: process not found\n");
return;
}
frame = (struct i386_frame *)p->p_addr->u_pcb.pcb_ebp;
callpc = (db_addr_t)
db_get_value((int)&frame->f_retaddr, 4, FALSE);
} else {
frame = (struct i386_frame *)addr;
callpc = (db_addr_t)
db_get_value((int)&frame->f_retaddr, 4, FALSE);
}
lastframe = 0;
while (count && frame != 0) {
int narg;
char * name;
db_expr_t offset;
db_sym_t sym;
#define MAXNARG 16
char *argnames[MAXNARG], **argnp = NULL;
sym = db_search_symbol(callpc, DB_STGY_ANY, &offset);
db_symbol_values(sym, &name, NULL);
if (lastframe == 0 && sym == NULL) {
/* Symbol not found, peek at code */
int instr = db_get_value(callpc, 4, FALSE);
offset = 1;
if ((instr & 0x00ffffff) == 0x00e58955 ||
/* enter: pushl %ebp, movl %esp, %ebp */
(instr & 0x0000ffff) == 0x0000e589
/* enter+1: movl %esp, %ebp */) {
offset = 0;
}
}
if (INKERNEL((int)frame) && name) {
if (!strcmp(name, "trap")) {
is_trap = TRAP;
} else if (!strcmp(name, "syscall")) {
is_trap = SYSCALL;
} else if (!strncmp(name, "Xintr", 5) ||
!strncmp(name, "Xresume", 7) ||
!strncmp(name, "Xstray", 6) ||
!strncmp(name, "Xhold", 5) ||
!strncmp(name, "Xrecurse", 8) ||
!strcmp(name, "Xdoreti") ||
!strncmp(name, "Xsoft", 5)) {
is_trap = INTERRUPT;
} else
goto normal;
narg = 0;
} else {
normal:
is_trap = NONE;
narg = MAXNARG;
if (db_sym_numargs(sym, &narg, argnames))
argnp = argnames;
else
narg = db_numargs(frame);
}
(*pr)("%s(", name);
if (lastframe == 0 && offset == 0 && !have_addr) {
/*
* We have a breakpoint before the frame is set up
* Use %esp instead
*/
argp = &((struct i386_frame *)(ddb_regs.tf_esp-4))->f_arg0;
} else {
argp = &frame->f_arg0;
}
while (narg) {
if (argnp)
(*pr)("%s=", *argnp++);
(*pr)("%x", db_get_value((int)argp, 4, FALSE));
argp++;
if (--narg != 0)
(*pr)(",");
}
(*pr)(") at ");
db_printsym(callpc, DB_STGY_PROC, pr);
(*pr)("\n");
if (lastframe == 0 && offset == 0 && !have_addr) {
/* Frame really belongs to next callpc */
lastframe = (struct i386_frame *)(ddb_regs.tf_esp-4);
callpc = (db_addr_t)
db_get_value((int)&lastframe->f_retaddr, 4, FALSE);
continue;
}
lastframe = frame;
db_nextframe(&frame, &callpc, &frame->f_arg0, is_trap, pr);
if (frame == 0) {
/* end of chain */
break;
}
if (INKERNEL((int)frame)) {
/* staying in kernel */
if (frame <= lastframe) {
(*pr)("Bad frame pointer: %p\n", frame);
break;
}
} else if (INKERNEL((int)lastframe)) {
/* switch from user to kernel */
if (kernel_only)
break; /* kernel stack only */
} else {
/* in user */
if (frame <= lastframe) {
(*pr)("Bad user frame pointer: %p\n",
frame);
break;
}
}
--count;
}
if (count && is_trap != NONE) {
db_printsym(callpc, DB_STGY_XTRN, pr);
(*pr)(":\n");
}
}