/*
* Find the current stack frame when debugging the kernel.
* If we're looking at a crash dump and this was not a ``clean''
* crash, then we must search the interrupt stack carefully
* looking for a valid frame.
*/
findstackframe()
{
char *panicstr, buf[256];
register struct frame *fp;
caddr_t addr;
register char *cp;
int mask;
if (lookup("_panicstr") == 0)
return;
lseek(fcor, KVTOPH(cursym->n_value), L_SET);
read(fcor, &panicstr, sizeof (panicstr));
if (panicstr == 0)
return;
lseek(fcor, KVTOPH((off_t)panicstr), L_SET);
read(fcor, buf, sizeof (buf));
for (cp = buf; cp < &buf[sizeof (buf)] && *cp; cp++)
if (!isascii(*cp) || (!isprint(*cp) && !isspace(*cp)))
*cp = '?';
if (*cp)
*cp = '\0';
printf("panic: %s\n", buf);
/*
* After a panic, look at the top of the rpb stack to
* find a stack frame. If this was a clean crash,
* i.e. one which left the interrupt and kernel stacks
* in a reasonable state, then we should find a pointer
* to the proper stack frame here (at location scb-4).
* If we don't find a reasonable frame here, then we
* must search down through the interrupt stack.
*/
intstack = lookup("_intstack")->n_value;
#define NISP 3 /* from locore.s */
eintstack = intstack + NISP*NBPG;
rpb = lookup("_rpb")->n_value;
scb = lookup("_scb")->n_value;
lookup("_u");
ustack = cursym->n_value + (int)&((struct user *)0)->u_stack[0];
eustack = cursym->n_value + ctob(UPAGES);
physrw(fcor, KVTOPH((int)scb - sizeof (caddr_t)), &addr, 1);
fp = getframe(fcor, addr);
if (fp == 0)
fp = checkintstack();
/* search kernel stack? */
if (fp == 0) {
printf("can't locate stack frame\n");
return;
}
/* probably shouldn't clobber pcb, but for now this is easy */
pcb.pcb_fp = addr;
pcb.pcb_pc = fp->fr_savpc;
pcb.pcb_ap = addr + sizeof (struct frame) + fp->fr_spa;
for (mask = fp->fr_mask; mask; mask >>= 1)
if (mask & 01)
pcb.pcb_ap += sizeof (caddr_t);
}
getpcb()
{
lseek(fcor, KVTOPH(masterpcbb), L_SET);
read(fcor, &pcb, sizeof (struct pcb));
printf("p0br %X p0lr %X p2br %X p2lr %X\n",
pcb.pcb_p0br, pcb.pcb_p0lr, pcb.pcb_p2br, pcb.pcb_p2lr);
}
getpcb()
{
lseek(fcor, KVTOPH(masterpcbb), L_SET);
read(fcor, &pcb, sizeof (struct pcb));
pcb.pcb_p0lr &= ~AST_CLR;
printf("p0br %x p0lr %x p1br %x p1lr %x\n",
pcb.pcb_p0br, pcb.pcb_p0lr, pcb.pcb_p1br, pcb.pcb_p1lr);
}
setcor()
{
fcor = datmap.ufd = getfile(corfil,2);
if (kernel && fcor != -1 && INKERNEL(filhdr.a_entry)) {
struct stat stb;
kcore = 1;
fstat(fcor, &stb);
datmap.b1 = 0;
datmap.e1 = -1;
if (kernel == 0 && (stb.st_mode & S_IFREG))
datmap.b1 = 0x80000000;
lookup("_Sysmap");
sbr = cursym->n_value;
lookup("_Syssize");
slr = cursym->n_value;
printf("sbr %x slr %x\n", sbr, slr);
lookup("_masterpaddr");
physrw(fcor, KVTOPH(cursym->n_value), &masterpcbb, 1);
masterpcbb = (masterpcbb&PG_PFNUM)*NBPG;
getpcb();
findstackframe();
return;
}
if (read(fcor, (char *)&u, ctob(UPAGES))!=ctob(UPAGES) ||
!INUDOT(u.u_pcb.pcb_ksp) || !INSTACK(u.u_pcb.pcb_usp)) {
datmap.e1 = MAXFILE;
return;
}
signo = u.u_arg[0];
sigcode = u.u_code;
filhdr.a_text = ctob(u.u_tsize);
filhdr.a_data = ctob(u.u_dsize);
stksiz = ctob(u.u_ssize);
switch (filhdr.a_magic) {
case OMAGIC:
datmap.b1 = 0;
datmap.e1 = filhdr.a_text+filhdr.a_data;
datmap.f2 = ctob(UPAGES) + datmap.e1;
break;
case NMAGIC:
case ZMAGIC:
datmap.b1 = round(filhdr.a_text, PAGSIZ);
datmap.e1 = datmap.b1 + filhdr.a_data;
datmap.f2 = ctob(UPAGES) + filhdr.a_data;
break;
}
datbas = datmap.b1;
datmap.f1 = ctob(UPAGES);
datmap.b2 = MAXSTOR - stksiz;
datmap.e2 = MAXSTOR;
}