i386/i386/db_trace.c Source
/*
* 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
* 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 the
* rights to redistribute these changes.
*
* $Id: db_trace.c,v 1.2 1993/10/16 14:14:56 rgrimes Exp $
*/
#include "param.h"
#include "proc.h"
#include
#include
#include
#include
/*
* Machine register set.
*/
struct db_variable db_regs[] = {
"cs", (int *)&ddb_regs.tf_cs, FCN_NULL,
"ds", (int *)&ddb_regs.tf_ds, FCN_NULL,
"es", (int *)&ddb_regs.tf_es, FCN_NULL,
#if 0
"fs", (int *)&ddb_regs.tf_fs, FCN_NULL,
"gs", (int *)&ddb_regs.tf_gs, FCN_NULL,
#endif
"ss", (int *)&ddb_regs.tf_ss, FCN_NULL,
"eax", (int *)&ddb_regs.tf_eax, FCN_NULL,
"ecx", (int *)&ddb_regs.tf_ecx, FCN_NULL,
"edx", (int *)&ddb_regs.tf_edx, FCN_NULL,
"ebx", (int *)&ddb_regs.tf_ebx, FCN_NULL,
"esp", (int *)&ddb_regs.tf_esp,FCN_NULL,
"ebp", (int *)&ddb_regs.tf_ebp, FCN_NULL,
"esi", (int *)&ddb_regs.tf_esi, FCN_NULL,
"edi", (int *)&ddb_regs.tf_edi, FCN_NULL,
"eip", (int *)&ddb_regs.tf_eip, FCN_NULL,
"efl", (int *)&ddb_regs.tf_eflags, FCN_NULL,
};
struct db_variable *db_eregs = db_regs + sizeof(db_regs)/sizeof(db_regs[0]);
/*
* Stack trace.
*/
#define INKERNEL(va) (((vm_offset_t)(va)) >= VM_MIN_KERNEL_ADDRESS)
struct i386_frame {
struct i386_frame *f_frame;
int f_retaddr;
int f_arg0;
};
#define TRAP 1
#define INTERRUPT 2
db_addr_t db_trap_symbol_value = 0;
db_addr_t db_kdintr_symbol_value = 0;
boolean_t db_trace_symbols_found = FALSE;
void
db_find_trace_symbols()
{
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;
db_trace_symbols_found = TRUE;
}
/*
* Figure out how many arguments were passed into the frame at "fp".
*/
int
db_numargs(fp)
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(fp, ip, argp, is_trap)
struct i386_frame **fp; /* in/out */
db_addr_t *ip; /* out */
int *argp; /* in */
int is_trap; /* in */
{
struct i386_saved_state *saved_regs;
if (is_trap == 0) {
*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);
} else {
/*
* We know that trap() has 1 argument and we know that
* it is an (int *).
*/
saved_regs = (struct i386_saved_state *)
db_get_value((int)argp, 4, FALSE);
db_printf("--- trap (number %d) ---\n",
saved_regs->tf_trapno & 0xffff);
db_printsym(saved_regs->tf_eip, DB_STGY_XTRN);
db_printf(":\n");
*fp = (struct i386_frame *)saved_regs->tf_ebp;
*ip = (db_addr_t)saved_regs->tf_eip;
}
}
void
db_stack_trace_cmd(addr, have_addr, count, modif)
db_expr_t addr;
boolean_t have_addr;
db_expr_t count;
char *modif;
{
struct i386_frame *frame, *lastframe;
int *argp;
db_addr_t callpc;
int is_trap;
boolean_t kernel_only = TRUE;
boolean_t trace_thread = FALSE;
if (!db_trace_symbols_found)
db_find_trace_symbols();
{
register char *cp = modif;
register char c;
while ((c = *cp++) != 0) {
if (c == 't')
trace_thread = 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) {
printf ("db_trace.c: can't trace thread\n");
}
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) {
register int narg;
char * name;
db_expr_t offset;
if (INKERNEL((int)frame) && callpc == db_trap_symbol_value) {
narg = 1;
is_trap = TRAP;
}
else
if (INKERNEL((int)frame) && callpc == db_kdintr_symbol_value) {
is_trap = INTERRUPT;
narg = 0;
}
else {
is_trap = 0;
narg = db_numargs(frame);
}
db_find_sym_and_offset(callpc, &name, &offset);
db_printf("%s(", name);
argp = &frame->f_arg0;
while (narg) {
db_printf("%x", db_get_value((int)argp, 4, FALSE));
argp++;
if (--narg != 0)
db_printf(",");
}
db_printf(") at ");
db_printsym(callpc, DB_STGY_XTRN);
db_printf("\n");
lastframe = frame;
db_nextframe(&frame, &callpc, &frame->f_arg0, is_trap);
if (frame == 0) {
/* end of chain */
break;
}
if (INKERNEL((int)frame)) {
/* staying in kernel */
if (frame <= lastframe) {
db_printf("Bad frame pointer: 0x%x\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) {
db_printf("Bad frame pointer: 0x%x\n", frame);
break;
}
}
}
}