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BSD 4_4 release
[unix-history] / usr / src / old / adb / adb.tahoe / machdep.c
/*-
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
*
* This module is believed to contain source code proprietary to AT&T.
* Use and redistribution is subject to the Berkeley Software License
* Agreement and your Software Agreement with AT&T (Western Electric).
*/
#ifndef lint
static char sccsid[] = "@(#)machdep.c 5.5 (Berkeley) 4/4/91";
#endif /* not lint */
/*
* adb - miscellaneous machine dependent routines.
*/
#define RLOCALS /* enable alternate $C stack trace */
#include "defs.h"
#include "bkpt.h"
#include <machine/pte.h>
#include <machine/frame.h>
#include <machine/reg.h>
#include <machine/vmparam.h>
#include <sys/ptrace.h>
#include <sys/vmmac.h>
#include <stab.h>
struct pte *sbr;
int slr;
struct pcb pcb;
int masterpcbb;
/*
* Activation records.
*/
/*
* Set up a stack frame based on the registers in the core image
* (or in the kernel core file ... not yet!).
*/
a_init(ap)
register struct activation *ap;
{
ap->a_valid = 1;
if (kcore) {
ap->a_fp = pcb.pcb_fp;
ap->a_pc = pcb.pcb_pc;
} else {
ap->a_fp = u.u_ar0[FP];
ap->a_pc = u.u_ar0[PC];
}
}
/*
* Back up one stack frame in the call stack.
* ap points to the activation record from the previous frame.
* Clear a_valid field if we ran out of frames.
*/
a_back(ap)
register struct activation *ap;
{
struct frame fr;
if (adbread(SP_DATA, ap->a_fp - FRAMEOFF, &fr, sizeof fr) != sizeof fr)
ap->a_valid = 0;
else {
ap->a_fp = fr.fr_savfp;
ap->a_pc = fr.fr_savpc;
if (ap->a_fp == 0)
ap->a_valid = 0;
}
}
/*
* Evaluate a local symbol (N_LSYM or N_PSYM) using the activation
* record pointed to by ap.
*/
addr_t
eval_localsym(sp, ap)
register struct nlist *sp;
struct activation *ap;
{
switch (sp->n_type) {
case N_LSYM:
return (ap->a_fp - sp->n_value);
case N_PSYM:
return (ap->a_fp + sp->n_value);
}
panic("eval_localsym");
/* NOTREACHED */
}
/* true iff address a is in instruction space */
#define ispace(a) ((a) < txtmap.m1.e)
/*
* Delete a (single) breakpoint. Return 0 on success.
*/
int
clr_bpt(b)
struct bkpt *b;
{
addr_t a = b->loc;
return (adbwrite(ispace(a) ? SP_INSTR : SP_DATA, a, &b->ins, 1) != 1);
}
/*
* Set a (single) breakpoint. Return 0 on success.
*/
set_bpt(b)
struct bkpt *b;
{
addr_t a = b->loc;
int space;
char bpt = 0x30; /* breakpoint instruction */
space = ispace(a) ? SP_INSTR : SP_DATA;
return (adbread(space, a, &b->ins, 1) != 1 ||
adbwrite(space, a, &bpt, 1) != 1);
}
/*
* Check a float for `correctness' (reserved patterns, etc). Return
* a pointer to a character string to be printed instead of the float,
* or NULL to print the float as-is.
*
* The string returned, if any, should be no longer than 16 characters.
*
* On the Tahoe, we can simply check the second two bytes. Byte two
* contains one bit of the exponent, and byte 3 has the remaining 7
* exponent bits and the sign bit. If the sign bit is set and the
* exponent is zero, the value is reserved.
*
* PLEASE CHECK THE ABOVE, IT IS PROBABLY WRONG
*/
/* ARGSUSED */
char *
checkfloat(fp, isdouble)
caddr_t fp;
int isdouble;
{
return ((((short *)fp)[1] & 0xff80) == 0x8000 ?
"(reserved oprnd)" : NULL);
}
/*
* Convert a value in `expr_t' format to float or double.
*/
etofloat(e, fp, isdouble)
expr_t e;
caddr_t fp;
int isdouble;
{
if (isdouble)
((int *)fp)[1] = 0;
*(int *)fp = e;
}
mch_init()
{
mkioptab();
}
/* quietly read object obj from address addr */
#define GET(obj, addr) (void) adbread(SP_DATA, addr, &(obj), sizeof(obj))
/* set `current process' pcb */
setpcb(addr)
addr_t addr;
{
int pte;
GET(pte, addr);
masterpcbb = (pte & PG_PFNUM) * NBPG;
}
getpcb()
{
/* maybe use adbread() here ... */
(void) readcore((off_t)masterpcbb & ~KERNBASE,
(char *)&pcb, sizeof(struct pcb));
adbprintf("p0br %R p0lr %R p2br %R p2lr %R\n",
pcb.pcb_p0br, pcb.pcb_p0lr, pcb.pcb_p2br, pcb.pcb_p2lr);
}
/*
* Convert a kernel virtual address to a physical address,
* a la the Tahoe hardware. Set *err if the resulting address
* is invalid.
*/
addr_t
vtophys(addr, err)
addr_t addr;
char **err;
{
register unsigned v = btop(addr & ~KERNBASE);
register addr_t pteaddr;
struct pte pte;
switch ((int)(addr >> 30)) { /* select space */
case 3:
/* system space: get system pte */
if (v >= slr)
goto oor;
pteaddr = (addr_t)(sbr + v) & ~KERNBASE;
goto direct;
case 2:
/* P2 space: must not be in shadow region */
if (v < pcb.pcb_p2lr)
goto oor;
pteaddr = (addr_t)(pcb.pcb_p2br + v);
break;
case 1:
/* P1 space: verboten (for now) */
goto oor;
case 0:
/* P0 space: must not be off end of region */
if (v >= pcb.pcb_p0lr)
goto oor;
pteaddr = (addr_t)(pcb.pcb_p0br + v);
break;
oor:
*err = "address out of segment";
return (0);
}
/* in P0/P1/P2 space, pte should be in kernel virtual space */
if ((pteaddr & KERNBASE) != KERNBASE) {
*err = "bad p0br, p1br, or p2br in pcb";
return (0);
}
pteaddr = vtophys(pteaddr, err);
if (*err)
return (0);
direct:
/*
* Read system pte. If valid or reclaimable,
* physical address is combination of its page number and
* the page offset of the original address.
*/
if (readcore((off_t)pteaddr, (caddr_t)&pte, 4) != 4) {
*err = "page table botch";
return (0);
}
/* SHOULD CHECK NOT I/O ADDRESS; NEED CPU TYPE! */
if (pte.pg_v == 0 && (pte.pg_fod || pte.pg_pfnum == 0)) {
*err = "page not valid/reclaimable";
return (0);
}
return ((addr_t)(ptob(pte.pg_pfnum) + (addr & PGOFSET)));
}
/*
* Print a stack trace ($c, $C). Trace backwards through nback
* frames; if locals is set, print local variables.
*/
printstack(locals, nback)
int locals, nback;
{
register int i;
register addr_t a;
struct nlist *sym;
char *s;
addr_t callpc; /* pc that called this frame */
int narg; /* number of arguments to this frame */
struct activation cur; /* this frame itself */
struct frame fr; /* the frame above this frame */
addr_t dummy; /* a variable to scribble on */
#define UNKNOWN -1
#ifdef RLOCALS
/* if locals variables are broken, use an alternate strategy */
register int r;
addr_t sp, prev_sp;
int regs[13];
static char unknown[] = "<unknown>";
#endif
#ifdef RLOCALS
/* grab registers */
bcopy((caddr_t)(kcore ? &pcb.pcb_r0 : &u.u_ar0[R0]), (caddr_t)regs,
sizeof(regs));
#endif
/* set up the current stack frame */
if (gavedot) {
cur.a_fp = dot;
cur.a_pc = UNKNOWN;
#ifdef RLOCALS
sp = UNKNOWN;
#endif
} else if (kcore) {
cur.a_fp = pcb.pcb_fp;
cur.a_pc = pcb.pcb_pc;
#ifdef RLOCALS
sp = pcb.pcb_ksp;
#endif
} else {
cur.a_fp = u.u_ar0[FP];
cur.a_pc = u.u_ar0[PC];
#ifdef RLOCALS
sp = u.u_ar0[SP];
#endif
}
/* now back up through the stack */
while (nback-- && cur.a_fp != 0) {
/* read this frame, but defer error check */
GET(fr, cur.a_fp - FRAMEOFF);
/* where are we? ... if u. area, signal trampoline code */
if (cur.a_pc >= USRSTACK && cur.a_pc < KERNBASE) {
narg = 0;
GET(callpc, cur.a_fp + 44); /* XXX magic 44 */
s = "sigtramp";
} else {
narg = (fr.fr_removed >> 2) - 1;
callpc = fr.fr_savpc;
if (cur.a_pc != UNKNOWN &&
(sym = findsym(cur.a_pc, SP_INSTR, &dummy)) != 0) {
s = sym->n_un.n_name;
if (eqstr(s, "start")) {
errflag = NULL;
break;
}
} else
s = "?";
}
/* safe at last to check for error reading frame */
checkerr();
/* arguments */
adbprintf("%s(", s);
a = cur.a_fp;
for (i = narg > 20 ? 20 : narg; i;) {
prfrom(a += 4, --i ? ',' : 0);
checkerr();
}
printc(')');
if (cur.a_pc != UNKNOWN) {
prints(" at ");
psymoff("%R", cur.a_pc, SP_INSTR, -(addr_t)1, "");
}
printc('\n');
/* local variables */
if (locals) {
#ifdef busted
if (cur.a_pc != UNKNOWN) {
sym = findsym(cur.a_pc, SP_INSTR, &dummy);
while ((sym = nextlocal(sym)) != NULL) {
adbprintf("%8t");
printlsym(sym->n_un.n_name);
adbprintf(":%12t");
prfrom(eval_localsym(sym, &cur), '\n');
}
}
#endif
#ifdef RLOCALS
adbprintf("\
fp: %R\%16tsp: %?s%?R%32tpc: %?s%?R%48tr0: %R\n\
r1: %R\%16tr2: %R\%32tr3: %R\%48tr4: %R\n\
r5: %R\%16tr6: %R\%32tr7: %R\%48tr8: %R\n\
r9: %R\%16tr10: %R\%32tr11: %R\%48tr12: %R\n",
#define q(s) s == UNKNOWN, unknown, s != UNKNOWN, s
cur.a_fp, q(sp), q(cur.a_pc), regs[0],
#undef q
regs[1], regs[2], regs[3], regs[4],
regs[5], regs[6], regs[7], regs[8],
regs[9], regs[10], regs[11], regs[12]);
/* update registers, and find previous frame's sp */
a = cur.a_fp + 4;
for (r = 0, i = fr.fr_mask; i != 0; r++, i >>= 1)
if (i & 1)
GET(regs[r], a += 4);
a += narg * 4;
prev_sp = a;
/* now print automatics */
if (sp != UNKNOWN) {
#define MAXPRINT 30 /* max # words to print */
/* XXX should be settable */
i = (cur.a_fp - sp) >> 2;
if (i > MAXPRINT)
i = MAXPRINT;
for (a = cur.a_fp; --i >= 0;) {
a -= 4;
adbprintf("%R: %V(fp):%24t",
a, a - cur.a_fp);
prfrom(a, '\n');
}
if (a > sp)
adbprintf("\
%R: %V(fp) .. %R: %V(fp) not displayed\n",
a, a - cur.a_fp,
sp, sp - cur.a_fp);
}
#endif /* RLOCALS */
}
errflag = NULL; /* clobber any read errors */
/* back up one frame */
if (fr.fr_savfp == 0)
break;
cur.a_fp = fr.fr_savfp;
#ifdef RLOCALS
sp = prev_sp;
#endif
cur.a_pc = callpc;
if (!gavedot && !INSTACK(cur.a_fp) && !kcore)
break;
/* make sure we returned somewhere... */
(void) adbread(kcore ? SP_DATA : SP_INSTR, cur.a_pc, &dummy, 1);
checkerr();
}
}
/*
* Register offset to u. pointer, and register offset to ptrace value
*/
#define otoua(o) \
((int *)(((o) < 0 ? (int)u.u_ar0 : (int)&u.u_pcb) + (o)))
#define otopt(o) \
((int *)((o) < 0 ? (o) + ctob(UPAGES) : (o)))
/*
* Return the value of some register.
*/
expr_t
getreg(reg)
register struct reglist *reg;
{
return (kcore ? *reg->r_pcbaddr : *otoua(reg->r_offset));
}
/*
* Set the value of some register. Return 0 if all goes well.
*/
setreg(reg, val)
register struct reglist *reg;
expr_t val;
{
if (kcore)
*reg->r_pcbaddr = val;
else {
*otoua(reg->r_offset) = val;
if (pid) {
errno = 0;
if (ptrace(PT_WRITE_U, pid, otopt(reg->r_offset),
(int)val) == -1 && errno)
return (-1);
}
}
return (0);
}
/*
* Read registers from current process.
*/
readregs()
{
register struct reglist *reg;
extern struct reglist reglist[];
for (reg = reglist; reg->r_name != NULL; reg++)
*otoua(reg->r_offset) =
ptrace(PT_READ_U, pid, otopt(reg->r_offset), 0);
}
addr_t
getpc()
{
return (kcore ? pcb.pcb_pc : u.u_ar0[PC]);
}
setpc(where)
addr_t where;
{
if (kcore)
pcb.pcb_pc = where;
else
u.u_ar0[PC] = where;
}
/*
* udot returns true if u.u_pcb appears correct. More extensive
* checking is possible....
*/
udot()
{
/* user stack should be in stack segment */
if (!INSTACK(u.u_pcb.pcb_usp))
return (0);
/* kernel stack should be in u. area */
if (u.u_pcb.pcb_ksp < USRSTACK || u.u_pcb.pcb_ksp >= KERNBASE)
return (0);
/* looks good to us... */
return (1);
}
sigprint()
{
extern char *sys_siglist[];
extern char *illinames[], *fpenames[];
extern int nillinames, nfpenames;
if ((u_int)signo - 1 < NSIG - 1)
prints(sys_siglist[signo]);
switch (signo) {
case SIGFPE:
if ((u_int)sigcode < nfpenames)
prints(fpenames[sigcode]);
break;
case SIGILL:
if ((u_int)sigcode < nillinames)
prints(illinames[sigcode]);
break;
}
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.