/* $OpenBSD: db_trace.c,v 1.4 2007/01/15 23:19:05 jsg Exp $ */
/* $NetBSD: db_trace.c,v 1.1 2003/04/26 18:39:27 fvdl 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 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 <machine/frame.h>
#include <machine/trap.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>
#if 1
#define dbreg(xx) (long *)offsetof(db_regs_t, tf_ ## xx)
#else
#define dbreg(xx) (long *)&ddb_regs.tf_ ## xx
#endif
static int db_x86_64_regop(struct db_variable *, db_expr_t *, int);
/*
* Machine register set.
*/
struct db_variable db_regs[] = {
{ "ds", dbreg(ds), db_x86_64_regop },
{ "es", dbreg(es), db_x86_64_regop },
{ "fs", dbreg(fs), db_x86_64_regop },
{ "gs", dbreg(gs), db_x86_64_regop },
{ "rdi", dbreg(rdi), db_x86_64_regop },
{ "rsi", dbreg(rsi), db_x86_64_regop },
{ "rbp", dbreg(rbp), db_x86_64_regop },
{ "rbx", dbreg(rbx), db_x86_64_regop },
{ "rdx", dbreg(rdx), db_x86_64_regop },
{ "rcx", dbreg(rcx), db_x86_64_regop },
{ "rax", dbreg(rax), db_x86_64_regop },
{ "r8", dbreg(r8), db_x86_64_regop },
{ "r9", dbreg(r9), db_x86_64_regop },
{ "r10", dbreg(r10), db_x86_64_regop },
{ "r11", dbreg(r11), db_x86_64_regop },
{ "r12", dbreg(r12), db_x86_64_regop },
{ "r13", dbreg(r13), db_x86_64_regop },
{ "r14", dbreg(r14), db_x86_64_regop },
{ "r15", dbreg(r15), db_x86_64_regop },
{ "rip", dbreg(rip), db_x86_64_regop },
{ "cs", dbreg(cs), db_x86_64_regop },
{ "rflags", dbreg(rflags), db_x86_64_regop },
{ "rsp", dbreg(rsp), db_x86_64_regop },
{ "ss", dbreg(ss), db_x86_64_regop },
};
struct db_variable * db_eregs =
db_regs + sizeof(db_regs)/sizeof(db_regs[0]);
static int
db_x86_64_regop(struct db_variable *vp, db_expr_t *val, int opcode)
{
db_expr_t *regaddr =
(db_expr_t *)(((uint8_t *)DDB_REGS) + ((size_t)vp->valuep));
switch (opcode) {
case DB_VAR_GET:
*val = *regaddr;
break;
case DB_VAR_SET:
*regaddr = *val;
break;
default:
panic("db_x86_64_regop: unknown op %d", opcode);
}
return 0;
}
/*
* Stack trace.
*/
#define INKERNEL(va) (((vaddr_t)(va)) >= VM_MIN_KERNEL_ADDRESS)
struct x86_64_frame {
struct x86_64_frame *f_frame;
long f_retaddr;
long 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 x86_64_frame *);
void db_nextframe(struct x86_64_frame **, db_addr_t *, long *, int,
int (*) (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".
* We can probably figure out how many arguments where passed above
* the first 6 (which are in registers), but since we can't
* reliably determine the values currently, just return 0.
*/
int
db_numargs(struct x86_64_frame *fp)
{
return 0;
}
/*
* 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 x86_64_frame **fp, db_addr_t *ip, long *argp, int is_trap,
int (*pr)(const char *, ...))
{
switch (is_trap) {
case NONE:
*ip = (db_addr_t)
db_get_value((db_addr_t)&(*fp)->f_retaddr, 8, FALSE);
*fp = (struct x86_64_frame *)
db_get_value((db_addr_t)&(*fp)->f_frame, 8, 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 %ld) ---\n", tf->tf_rax);
break;
case INTERRUPT:
(*pr)("--- interrupt ---\n");
break;
}
*fp = (struct x86_64_frame *)tf->tf_rbp;
*ip = (db_addr_t)tf->tf_rip;
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 x86_64_frame *frame, *lastframe;
long *argp;
db_addr_t callpc;
int is_trap = 0;
boolean_t kernel_only = TRUE;
boolean_t trace_thread = 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 == 'u')
kernel_only = FALSE;
}
}
if (!have_addr) {
frame = (struct x86_64_frame *)ddb_regs.tf_rbp;
callpc = (db_addr_t)ddb_regs.tf_rip;
} else {
#if 0
if (trace_thread) {
struct proc *p;
struct user *u;
struct lwp *l;
(*pr)("trace: pid %d ", (int)addr);
p = pfind(addr);
if (p == NULL) {
(*pr)("not found\n");
return;
}
l = proc_representative_lwp(p);
if (!(l->l_flag&L_INMEM)) {
(*pr)("swapped out\n");
return;
}
u = l->l_addr;
frame = (struct x86_64_frame *) u->u_pcb.pcb_rbp;
(*pr)("at %p\n", frame);
} else
#endif
frame = (struct x86_64_frame *)addr;
callpc = (db_addr_t)
db_get_value((db_addr_t)&frame->f_retaddr, 8, FALSE);
frame = (struct x86_64_frame *)frame->f_frame;
}
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 */
long instr = db_get_value(callpc, 8, 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(frame) && name) {
#ifdef __ELF__
if (!strcmp(name, "trap")) {
is_trap = TRAP;
} else if (!strcmp(name, "syscall")) {
is_trap = SYSCALL;
} else if (name[0] == 'X') {
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;
} else
goto normal;
narg = 0;
#else
if (!strcmp(name, "_trap")) {
is_trap = TRAP;
} else if (!strcmp(name, "_syscall")) {
is_trap = SYSCALL;
} else if (name[0] == '_' && name[1] == 'X') {
if (!strncmp(name, "_Xintr", 6) ||
!strncmp(name, "_Xresume", 8) ||
!strncmp(name, "_Xstray", 7) ||
!strncmp(name, "_Xhold", 6) ||
!strncmp(name, "_Xrecurse", 9) ||
!strcmp(name, "_Xdoreti") ||
!strncmp(name, "_Xsoft", 6)) {
is_trap = INTERRUPT;
} else
goto normal;
} else
goto normal;
narg = 0;
#endif /* __ELF__ */
} 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 x86_64_frame *)(ddb_regs.tf_rsp-8))->f_arg0;
} else {
argp = &frame->f_arg0;
}
while (narg) {
if (argnp)
(*pr)("%s=", *argnp++);
(*pr)("%lx", db_get_value((db_addr_t)argp, 8, 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 x86_64_frame *)(ddb_regs.tf_rsp-8);
callpc = (db_addr_t)
db_get_value((db_addr_t)&lastframe->f_retaddr,
8, FALSE);
continue;
}
lastframe = frame;
db_nextframe(&frame, &callpc, &frame->f_arg0, is_trap, pr);
if (frame == 0) {
/* end of chain */
break;
}
if (INKERNEL(frame)) {
/* staying in kernel */
if (frame <= lastframe) {
(*pr)("Bad frame pointer: %p\n", frame);
break;
}
} else if (INKERNEL(lastframe)) {
/* switch from user to kernel */
if (kernel_only) {
(*pr)("end of kernel\n");
break; /* kernel stack only */
}
} else {
/* in user */
if (frame <= lastframe) {
(*pr)("Bad user frame pointer: %p\n",
frame);
break;
}
}
--count;
}
(*pr)("end trace frame: 0x%lx, count: %d\n", frame, count);
if (count && is_trap != NONE) {
db_printsym(callpc, DB_STGY_XTRN, pr);
(*pr)(":\n");
}
}