/*
* 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.
*/
int
db_nextframe(long **nextframe, long **retaddr, long **arg0, db_addr_t *ip,
long *argp, int is_trap, void (*pr)(const char *, ...))
{
struct trapframe *tf;
struct x86_64_frame *fp;
struct intrframe *ifp;
int traptype, trapno, err, i;
switch (is_trap) {
case NONE:
*ip = (db_addr_t)
db_get_value((long)*retaddr, 8, false);
fp = (struct x86_64_frame *)
db_get_value((long)*nextframe, 8, false);
if (fp == NULL)
return 0;
*nextframe = (long *)&fp->f_frame;
*retaddr = (long *)&fp->f_retaddr;
*arg0 = (long *)&fp->f_arg0;
break;
case TRAP:
case SYSCALL:
case INTERRUPT:
default:
/* The only argument to trap() or syscall() is the trapframe. */
tf = (struct trapframe *)argp;
switch (is_trap) {
case TRAP:
(*pr)("--- trap (number %"DDB_EXPR_FMT"u) ---\n",
db_get_value((long)&tf->tf_trapno, 8, false));
break;
case SYSCALL:
(*pr)("--- syscall (number %"DDB_EXPR_FMT"u) ---\n",
db_get_value((long)&tf->tf_rax, 8, false));
break;
case INTERRUPT:
(*pr)("--- interrupt ---\n");
break;
}
*ip = (db_addr_t)db_get_value((long)&tf->tf_rip, 8, false);
fp = (struct x86_64_frame *)
db_get_value((long)&tf->tf_rbp, 8, false);
if (fp == NULL)
return 0;
*nextframe = (long *)&fp->f_frame;
*retaddr = (long *)&fp->f_retaddr;
*arg0 = (long *)&fp->f_arg0;
break;
}
/*
* A bit of a hack. Since %rbp may be used in the stub code,
* walk the stack looking for a valid interrupt frame. Such
* a frame can be recognized by always having
* err 0 or IREENT_MAGIC and trapno T_ASTFLT.
*/
if (db_frame_info(*nextframe, (db_addr_t)*ip, NULL, NULL, &traptype,
NULL) != (db_sym_t)0
&& traptype == INTERRUPT) {
for (i = 0; i < 4; i++) {
ifp = (struct intrframe *)(argp + i);
err = db_get_value((long)&ifp->if_tf.tf_err,
sizeof(long), false);
trapno = db_get_value((long)&ifp->if_tf.tf_trapno,
sizeof(long), false);
if ((err == 0 || err == IREENT_MAGIC)
&& trapno == T_ASTFLT) {
*nextframe = (long *)ifp - 1;
break;
}
}
if (i == 4) {
(*pr)("DDB lost frame for ");
db_printsym(*ip, DB_STGY_ANY, pr);
(*pr)(", trying %p\n",argp);
*nextframe = argp;
}
}
return 1;
}
void
db_stack_trace_print(db_expr_t addr, bool have_addr, db_expr_t count,
const char *modif, void (*pr)(const char *, ...))
{
long *frame, *lastframe;
long *retaddr, *arg0;
long *argp;
db_addr_t callpc;
int is_trap;
bool kernel_only = true;
bool trace_thread = false;
bool lwpaddr = false;
#if 0
if (!db_trace_symbols_found)
db_find_trace_symbols();
#endif
{
const char *cp = modif;
char c;
while ((c = *cp++) != 0) {
if (c == 'a') {
lwpaddr = true;
trace_thread = true;
}
if (c == 't')
trace_thread = true;
if (c == 'u')
kernel_only = false;
}
}
if (!have_addr) {
frame = (long *)ddb_regs.tf_rbp;
callpc = (db_addr_t)ddb_regs.tf_rip;
} else {
if (trace_thread) {
struct proc *p;
struct user *u;
struct lwp *l;
if (lwpaddr) {
l = (struct lwp *)addr;
p = l->l_proc;
(*pr)("trace: pid %d ", p->p_pid);
} else {
(*pr)("trace: pid %d ", (int)addr);
p = p_find(addr, PFIND_LOCKED);
if (p == NULL) {
(*pr)("not found\n");
return;
}
l = LIST_FIRST(&p->p_lwps);
KASSERT(l != NULL);
}
(*pr)("lid %d ", l->l_lid);
if (!(l->l_flag & LW_INMEM)) {
(*pr)("swapped out\n");
return;
}
u = l->l_addr;
if (p == curproc && l == curlwp) {
frame = (long *)ddb_regs.tf_rbp;
callpc = (db_addr_t)ddb_regs.tf_rip;
(*pr)("at %p\n", frame);
} else {
frame = (long *)u->u_pcb.pcb_rbp;
callpc = (db_addr_t)
db_get_value((long)(frame + 1), 8, false);
(*pr)("at %p\n", frame);
frame = (long *)*frame; /* XXXfvdl db_get_value? */
}
} else {
frame = (long *)addr;
callpc = (db_addr_t)
db_get_value((long)(frame + 1), 8, false);
frame = (long *)*frame; /* XXXfvdl db_get_value? */
}
}
retaddr = frame + 1;
arg0 = frame + 2;
lastframe = 0;
while (count && frame != 0) {
int narg;
const char * name;
db_expr_t offset;
db_sym_t sym;
char *argnames[16], **argnp = NULL;
db_addr_t lastcallpc;
name = "?";
is_trap = NONE;
offset = 0;
sym = db_frame_info(frame, callpc, &name, &offset, &is_trap,
&narg);
if (lastframe == 0 && sym == (db_sym_t)0) {
/* Symbol not found, peek at code */
u_long instr = db_get_value(callpc, 4, false);
offset = 1;
if (instr == 0xe5894855 ||
/* enter: pushq %rbp, movq %rsp, %rbp */
(instr & 0x00ffffff) == 0x0048e589
/* enter+1: movq %rsp, %rbp */) {
offset = 0;
}
}
if (is_trap == NONE) {
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 %rsp instead
*/
argp = &((struct x86_64_frame *)(ddb_regs.tf_rsp-8))->f_arg0;
} else {
argp = frame + 2;
}
while (narg) {
if (argnp)
(*pr)("%s=", *argnp++);
(*pr)("%lx", db_get_value((long)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 */
struct x86_64_frame *fp = (void *)(ddb_regs.tf_rsp-8);
lastframe = (long *)fp;
callpc = (db_addr_t)
db_get_value((db_addr_t)&fp->f_retaddr, 8, false);
continue;
}
lastframe = frame;
lastcallpc = callpc;
if (!db_nextframe(&frame, &retaddr, &arg0,
&callpc, frame + 2, is_trap, pr))
break;
if (INKERNEL((long)frame)) {
/* staying in kernel */
if (frame < lastframe ||
(frame == lastframe && callpc == lastcallpc)) {
(*pr)("Bad frame pointer: %p\n", frame);
break;
}
} else if (INKERNEL((long)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");
}
}
