ref: 9f76a7f6819ac04552b4fb6588156f3e4089d1d7
dir: /os/port/devdbg.c/
#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "ureg.h"
#include "../port/error.h"
#include "rdbg.h"
#include <kernel.h>
#include <interp.h>
/*
* The following should be set in the config file to override
* the defaults.
*/
int dbgstart;
char *dbgdata;
char *dbgctl;
char *dbgctlstart;
char *dbgctlstop;
char *dbgctlflush;
//
// Error messages sent to the remote debugger
//
static uchar Ereset[9] = { 'r', 'e', 's', 'e', 't' };
static uchar Ecount[9] = { 'c', 'o', 'u', 'n', 't' };
static uchar Eunk[9] = { 'u', 'n', 'k' };
static uchar Einval[9] = { 'i', 'n', 'v', 'a', 'l' };
static uchar Ebadpid[9] = {'p', 'i', 'd'};
static uchar Eunsup[9] = { 'u', 'n', 's', 'u', 'p' };
static uchar Enotstop[9] = { 'n', 'o', 't', 's', 't', 'o', 'p' };
//
// Error messages raised via call to error()
//
static char Erunning[] = "Not allowed while debugger is running";
static char Enumarg[] = "Not enough args";
static char Ebadcmd[] = "Unknown command";
static int PROCREG;
static struct {
Rendez;
Bkpt *b;
} brk;
static Queue *logq;
int dbgchat = 0;
typedef struct Debugger Debugger;
struct Debugger {
RWlock;
int running;
char data[PRINTSIZE];
char ctl[PRINTSIZE];
char ctlstart[PRINTSIZE];
char ctlstop[PRINTSIZE];
char ctlflush[PRINTSIZE];
};
static Debugger debugger = {
.data= "#t/eia0",
.ctl= "#t/eia0ctl",
.ctlstart= "b19200",
.ctlstop= "h",
.ctlflush= "f",
};
enum {
BkptStackSize= 256,
};
typedef struct SkipArg SkipArg;
struct SkipArg
{
Bkpt *b;
Proc *p;
};
Bkpt *breakpoints;
void freecondlist(BkptCond *l);
static int
getbreaks(ulong addr, Bkpt **a, int nb)
{
Bkpt *b;
int n;
n = 0;
for(b = breakpoints; b != nil; b = b->next){
if(b->addr == addr){
a[n++] = b;
if(n == nb)
break;
}
}
return n;
}
Bkpt*
newbreak(int id, ulong addr, BkptCond *conds, void(*handler)(Bkpt*), void *aux)
{
Bkpt *b;
b = malloc(sizeof(*b));
if(b == nil)
error(Enomem);
b->id = id;
b->conditions = conds;
b->addr = addr;
b->handler = handler;
b->aux = aux;
b->next = nil;
return b;
}
void
freebreak(Bkpt *b)
{
freecondlist(b->conditions);
free(b);
}
BkptCond*
newcondition(uchar cmd, ulong val)
{
BkptCond *c;
c = mallocz(sizeof(*c), 0);
if(c == nil)
error(Enomem);
c->op = cmd;
c->val = val;
c->next = nil;
return c;
}
void
freecondlist(BkptCond *l)
{
BkptCond *next;
while(l != nil){
next = l->next;
free(l);
l = next;
}
}
void
breakset(Bkpt *b)
{
Bkpt *e[1];
if(getbreaks(b->addr, e, 1) != 0){
b->instr = e[0]->instr;
} else {
b->instr = machinstr(b->addr);
machbreakset(b->addr);
}
b->next = breakpoints;
breakpoints = b;
}
void
breakrestore(Bkpt *b)
{
b->next = breakpoints;
breakpoints = b;
machbreakset(b->addr);
}
Bkpt*
breakclear(int id)
{
Bkpt *b, *e, *p;
for(b=breakpoints, p=nil; b != nil && b->id != id; p = b, b = b->next)
;
if(b != nil){
if(p == nil)
breakpoints = b->next;
else
p->next = b->next;
if(getbreaks(b->addr, &e, 1) == 0)
machbreakclear(b->addr, b->instr);
}
return b;
}
void
breaknotify(Bkpt *b, Proc *p)
{
p->dbgstop = 1; // stop running this process.
b->handler(b);
}
int
breakmatch(BkptCond *cond, Ureg *ur, Proc *p)
{
ulong a, b;
int pos;
ulong s[BkptStackSize];
memset(s, 0, sizeof(s));
pos = 0;
for(;cond != nil; cond = cond->next){
switch(cond->op){
default:
panic("breakmatch: unknown operator %c", cond->op);
break;
case 'k':
if(p == nil || p->pid != cond->val)
return 0;
s[pos++] = 1;
break;
case 'b':
if(ur->pc != cond->val)
return 0;
s[pos++] = 1;
break;
case 'p': s[pos++] = cond->val; break;
case '*': a = *(ulong*)s[--pos]; s[pos++] = a; break;
case '&': a = s[--pos]; b = s[--pos]; s[pos++] = a & b; break;
case '=': a = s[--pos]; b = s[--pos]; s[pos++] = a == b; break;
case '!': a = s[--pos]; b = s[--pos]; s[pos++] = a != b; break;
case 'a': a = s[--pos]; b = s[--pos]; s[pos++] = a && b; break;
case 'o': a = s[--pos]; b = s[--pos]; s[pos++] = a || b; break;
}
}
if(pos && s[pos-1])
return 1;
return 0;
}
void
breakinit(void)
{
machbreakinit();
}
static void
dbglog(char *fmt, ...)
{
int n;
va_list arg;
char buf[PRINTSIZE];
va_start(arg, fmt);
n = vseprint(buf, buf+sizeof(buf), fmt, arg) - buf;
va_end(arg);
qwrite(logq, buf, n);
}
static int
get(int dbgfd, uchar *b)
{
int i;
uchar c;
if(kread(dbgfd, &c, 1) < 0)
error(Eio);
for(i=0; i<9; i++){
if(kread(dbgfd, b++, 1) < 0)
error(Eio);
}
return c;
}
static void
mesg(int dbgfd, int m, uchar *buf)
{
int i;
uchar c;
c = m;
if(kwrite(dbgfd, &c, 1) < 0)
error(Eio);
for(i=0; i<9; i++){
if(kwrite(dbgfd, buf+i, 1) < 0)
error(Eio);
}
}
static ulong
dbglong(uchar *s)
{
return (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]<<0);
}
static Proc *
dbgproc(ulong pid, int dbgok)
{
int i;
Proc *p;
if(!dbgok && pid == up->pid)
return 0;
p = proctab(0);
for(i = 0; i < conf.nproc; i++){
if(p->pid == pid)
return p;
p++;
}
return 0;
}
static void*
addr(uchar *s)
{
ulong a;
Proc *p;
static Ureg ureg;
a = ((s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]<<0));
if(a < sizeof(Ureg)){
p = dbgproc(PROCREG, 0);
if(p == 0){
dbglog("dbg: invalid pid\n");
return 0;
}
if(p->dbgreg){
/* in trap(), registers are all on stack */
memmove(&ureg, p->dbgreg, sizeof(ureg));
}
else {
/* not in trap, only pc and sp are available */
memset(&ureg, 0, sizeof(ureg));
ureg.sp = p->sched.sp;
ureg.pc = p->sched.pc;
}
return (uchar*)&ureg+a;
}
return (void*)a;
}
static void
dumpcmd(uchar cmd, uchar *min)
{
char *s;
int n;
switch(cmd){
case Terr: s = "Terr"; break;
case Tmget: s = "Tmget"; break;
case Tmput: s = "Tmput"; break;
case Tspid: s = "Tspid"; break;
case Tproc: s = "Tproc"; break;
case Tstatus: s = "Tstatus"; break;
case Trnote: s = "Trnote"; break;
case Tstartstop: s = "Tstartstop"; break;
case Twaitstop: s = "Twaitstop"; break;
case Tstart: s = "Tstart"; break;
case Tstop: s = "Tstop"; break;
case Tkill: s = "Tkill"; break;
case Tcondbreak: s = "Tcondbreak"; break;
default: s = "<Unknown>"; break;
}
dbglog("%s: [%2.2ux]: ", s, cmd);
for(n = 0; n < 9; n++)
dbglog("%2.2ux", min[n]);
dbglog("\n");
}
static int
brkpending(void *a)
{
Proc *p;
p = a;
if(brk.b != nil) return 1;
p->dbgstop = 0; /* atomic */
if(p->state == Stopped)
ready(p);
return 0;
}
static void
gotbreak(Bkpt *b)
{
Bkpt *cur, *prev;
b->link = nil;
for(prev = nil, cur = brk.b; cur != nil; prev = cur, cur = cur->link)
;
if(prev == nil)
brk.b = b;
else
prev->link = b;
wakeup(&brk);
}
static int
startstop(Proc *p)
{
int id;
int s;
Bkpt *b;
sleep(&brk, brkpending, p);
s = splhi();
b = brk.b;
brk.b = b->link;
splx(s);
id = b->id;
return id;
}
static int
condbreak(char cmd, ulong val)
{
BkptCond *c;
static BkptCond *head = nil;
static BkptCond *tail = nil;
static Proc *p = nil;
static int id = -1;
int s;
if(waserror()){
dbglog(up->env->errstr);
freecondlist(head);
head = tail = nil;
p = nil;
id = -1;
return 0;
}
switch(cmd){
case 'b': case 'p':
case '*': case '&': case '=':
case '!': case 'a': case 'o':
break;
case 'n':
id = val;
poperror();
return 1;
case 'k':
p = dbgproc(val, 0);
if(p == nil)
error("k: unknown pid");
break;
case 'd': {
Bkpt *b;
s = splhi();
b = breakclear(val);
if(b != nil){
Bkpt *cur, *prev;
prev = nil;
cur = brk.b;
while(cur != nil){
if(cur->id == b->id){
if(prev == nil)
brk.b = cur->link;
else
prev->link = cur->link;
break;
}
cur = cur->link;
}
freebreak(b);
}
splx(s);
poperror();
return 1;
}
default:
dbglog("condbreak(): unknown op %c %lux\n", cmd, val);
error("unknown op");
}
c = newcondition(cmd, val);
//
// the 'b' command comes last, (so we know we have reached the end
// of the condition list), but it should be the first thing
// checked, so put it at the head.
//
if(cmd == 'b'){
if(p == nil) error("no pid");
if(id == -1) error("no id");
c->next = head;
s = splhi();
breakset(newbreak(id, val, c, gotbreak, p));
splx(s);
head = tail = nil;
p = nil;
id = -1;
} else if(tail != nil){
tail->next = c;
tail = c;
} else
head = tail = c;
poperror();
return 1;
}
static void
dbg(void*)
{
Proc *p;
ulong val;
int n, cfd, dfd;
uchar cmd, *a, min[RDBMSGLEN-1], mout[RDBMSGLEN-1];
rlock(&debugger);
setpri(PriRealtime);
closefgrp(up->env->fgrp);
up->env->fgrp = newfgrp(nil);
if(waserror()){
dbglog("dbg: quits: %s\n", up->env->errstr);
runlock(&debugger);
wlock(&debugger);
debugger.running = 0;
wunlock(&debugger);
pexit("", 0);
}
dfd = kopen(debugger.data, ORDWR);
if(dfd < 0){
dbglog("dbg: can't open %s: %s\n",debugger.data, up->env->errstr);
error(Eio);
}
if(waserror()){
kclose(dfd);
nexterror();
}
if(debugger.ctl[0] != 0){
cfd = kopen(debugger.ctl, ORDWR);
if(cfd < 0){
dbglog("dbg: can't open %s: %s\n", debugger.ctl, up->env->errstr);
error(Eio);
}
if(kwrite(cfd, debugger.ctlstart, strlen(debugger.ctlstart)) < 0){
dbglog("dbg: write %s: %s\n", debugger.ctl, up->env->errstr);
error(Eio);
}
}else
cfd = -1;
if(waserror()){
if(cfd != -1){
kwrite(cfd, debugger.ctlflush, strlen(debugger.ctlflush));
kclose(cfd);
}
nexterror();
}
mesg(dfd, Rerr, Ereset);
for(;;){
memset(mout, 0, sizeof(mout));
cmd = get(dfd, min);
if(dbgchat)
dumpcmd(cmd, min);
switch(cmd){
case Tmget:
n = min[4];
if(n > 9){
mesg(dfd, Rerr, Ecount);
break;
}
a = addr(min+0);
if(!isvalid_va(a)){
mesg(dfd, Rerr, Einval);
break;
}
memmove(mout, a, n);
mesg(dfd, Rmget, mout);
break;
case Tmput:
n = min[4];
if(n > 4){
mesg(dfd, Rerr, Ecount);
break;
}
a = addr(min+0);
if(!isvalid_va(a)){
mesg(dfd, Rerr, Einval);
break;
}
memmove(a, min+5, n);
segflush(a, n);
mesg(dfd, Rmput, mout);
break;
case Tproc:
p = dbgproc(dbglong(min+0), 0);
if(p == 0){
mesg(dfd, Rerr, Ebadpid);
break;
}
PROCREG = p->pid; /* try this instead of Tspid */
sprint((char*)mout, "%8.8lux", p);
mesg(dfd, Rproc, mout);
break;
case Tstatus:
p = dbgproc(dbglong(min+0), 1);
if(p == 0){
mesg(dfd, Rerr, Ebadpid);
break;
}
if(p->state > Rendezvous || p->state < Dead)
sprint((char*)mout, "%8.8ux", p->state);
else if(p->dbgstop == 1)
strncpy((char*)mout, statename[Stopped], sizeof(mout));
else
strncpy((char*)mout, statename[p->state], sizeof(mout));
mesg(dfd, Rstatus, mout);
break;
case Trnote:
p = dbgproc(dbglong(min+0), 0);
if(p == 0){
mesg(dfd, Rerr, Ebadpid);
break;
}
mout[0] = 0; /* should be trap status, if any */
mesg(dfd, Rrnote, mout);
break;
case Tstop:
p = dbgproc(dbglong(min+0), 0);
if(p == 0){
mesg(dfd, Rerr, Ebadpid);
break;
}
p->dbgstop = 1; /* atomic */
mout[0] = 0;
mesg(dfd, Rstop, mout);
break;
case Tstart:
p = dbgproc(dbglong(min+0), 0);
if(p == 0){
mesg(dfd, Rerr, Ebadpid);
break;
}
p->dbgstop = 0; /* atomic */
if(p->state == Stopped)
ready(p);
mout[0] = 0;
mesg(dfd, Rstart, mout);
break;
case Tstartstop:
p = dbgproc(dbglong(min+0), 0);
if(p == 0){
mesg(dfd, Rerr, Ebadpid);
break;
}
if(!p->dbgstop){
mesg(dfd, Rerr, Enotstop);
break;
}
mout[0] = startstop(p);
mesg(dfd, Rstartstop, mout);
break;
case Tcondbreak:
val = dbglong(min+0);
if(!condbreak(min[4], val)){
mesg(dfd, Rerr, Eunk);
break;
}
mout[0] = 0;
mesg(dfd, Rcondbreak, mout);
break;
default:
dumpcmd(cmd, min);
mesg(dfd, Rerr, Eunk);
break;
}
}
}
static void
dbgnote(Proc *p, Ureg *ur)
{
if(p){
p->dbgreg = ur;
PROCREG = p->pid; /* acid can get the trap info from regs */
}
}
enum {
Qdir,
Qdbgctl,
Qdbglog,
DBGrun = 1,
DBGstop = 2,
Loglimit = 4096,
};
static Dirtab dbgdir[]=
{
".", {Qdir, 0, QTDIR}, 0, 0555,
"dbgctl", {Qdbgctl}, 0, 0660,
"dbglog", {Qdbglog}, 0, 0440,
};
static void
start_debugger(void)
{
breakinit();
dbglog("starting debugger\n");
debugger.running++;
kproc("dbg", dbg, 0, KPDUPPG);
}
static void
dbginit(void)
{
logq = qopen(Loglimit, 0, 0, 0);
if(logq == nil)
error(Enomem);
qnoblock(logq, 1);
wlock(&debugger);
if(waserror()){
wunlock(&debugger);
qfree(logq);
logq = nil;
nexterror();
}
if(dbgdata != nil){
strncpy(debugger.data, dbgdata, sizeof(debugger.data));
debugger.data[sizeof(debugger.data)-1] = 0;
}
if(dbgctl != nil){
strncpy(debugger.ctl, dbgctl, sizeof(debugger.ctl));
debugger.ctl[sizeof(debugger.ctl)-1] = 0;
}
if(dbgctlstart != nil){
strncpy(debugger.ctlstart, dbgctlstart, sizeof(debugger.ctlstart));
debugger.ctlstart[sizeof(debugger.ctlstart)-1] = 0;
}
if(dbgctlstop != nil){
strncpy(debugger.ctlstop, dbgctlstop, sizeof(debugger.ctlstop));
debugger.ctlstop[sizeof(debugger.ctlstop)-1] = 0;
}
if(dbgctlflush != nil){
strncpy(debugger.ctlflush, dbgctlflush, sizeof(debugger.ctlflush));
debugger.ctlflush[sizeof(debugger.ctlflush)-1] = 0;
}
if(dbgstart)
start_debugger();
poperror();
wunlock(&debugger);
}
static Chan*
dbgattach(char *spec)
{
return devattach('b', spec);
}
static Walkqid*
dbgwalk(Chan *c, Chan *nc, char **name, int nname)
{
return devwalk(c, nc, name, nname, dbgdir, nelem(dbgdir), devgen);
}
static int
dbgstat(Chan *c, uchar *dp, int n)
{
return devstat(c, dp, n, dbgdir, nelem(dbgdir), devgen);
}
static Chan*
dbgopen(Chan *c, int omode)
{
return devopen(c, omode, dbgdir, nelem(dbgdir), devgen);
}
static long
dbgread(Chan *c, void *buf, long n, vlong offset)
{
char *ctlstate;
switch((ulong)c->qid.path){
case Qdir:
return devdirread(c, buf, n, dbgdir, nelem(dbgdir), devgen);
case Qdbgctl:
rlock(&debugger);
ctlstate = smprint("%s data %s ctl %s ctlstart %s ctlstop %s ctlflush %s\n",
debugger.running ? "running" : "stopped",
debugger.data, debugger.ctl,
debugger.ctlstart, debugger.ctlstop, debugger.ctlflush);
runlock(&debugger);
if(ctlstate == nil)
error(Enomem);
if(waserror()){
free(ctlstate);
nexterror();
}
n = readstr(offset, buf, n, ctlstate);
poperror();
free(ctlstate);
return n;
case Qdbglog:
return qread(logq, buf, n);
default:
error(Egreg);
}
return -1; /* never reached */
}
static void
ctl(Cmdbuf *cb)
{
Debugger d;
int dbgstate = 0;
int i;
char *df;
int dfsize;
int setval;
memset(&d, 0, sizeof(d));
for(i=0; i < cb->nf; i++){
setval = 0;
df = nil;
dfsize = 0;
switch(cb->f[i][0]){
case 'd':
df = d.data;
dfsize = sizeof(d.data);
setval=1;
break;
case 'c':
df = d.ctl;
dfsize = sizeof(d.ctl);
setval=1;
break;
case 'i':
df = d.ctlstart;
dfsize = sizeof(d.ctlstart);
setval=1;
break;
case 'h':
df = d.ctlstop;
dfsize = sizeof(d.ctlstop);
setval=1;
break;
case 'f':
df = d.ctlflush;
dfsize = sizeof(d.ctlflush);
setval=1;
break;
case 'r':
dbgstate = DBGrun;
break;
case 's':
dbgstate = DBGstop;
break;
default:
error(Ebadcmd);
}
if(setval){
if(i+1 >= cb->nf)
cmderror(cb, Enumarg);
strncpy(df, cb->f[i+1], dfsize-1);
df[dfsize-1] = 0;
++d.running;
++i;
}
}
if(d.running){
wlock(&debugger);
if(debugger.running){
wunlock(&debugger);
error(Erunning);
}
if(d.data[0] != 0){
strcpy(debugger.data, d.data);
dbglog("data %s\n",debugger.data);
}
if(d.ctl[0] != 0){
strcpy(debugger.ctl, d.ctl);
dbglog("ctl %s\n",debugger.ctl);
}
if(d.ctlstart[0] != 0){
strcpy(debugger.ctlstart, d.ctlstart);
dbglog("ctlstart %s\n",debugger.ctlstart);
}
if(d.ctlstop[0] != 0){
strcpy(debugger.ctlstop, d.ctlstop);
dbglog("ctlstop %s\n",debugger.ctlstop);
}
wunlock(&debugger);
}
if(dbgstate == DBGrun){
if(!debugger.running){
wlock(&debugger);
if(waserror()){
wunlock(&debugger);
nexterror();
}
if(!debugger.running)
start_debugger();
else
dbglog("debugger already running\n");
poperror();
wunlock(&debugger);
} else
dbglog("debugger already running\n");
} else if(dbgstate == DBGstop){
if(debugger.running){
/* force hangup to stop the dbg process */
int cfd;
if(debugger.ctl[0] == 0)
return;
cfd = kopen(debugger.ctl, OWRITE);
if(cfd == -1)
error(up->env->errstr);
dbglog("stopping debugger\n");
if(kwrite(cfd, debugger.ctlstop, strlen(debugger.ctlstop)) == -1)
error(up->env->errstr);
kclose(cfd);
} else
dbglog("debugger not running\n");
}
}
static long
dbgwrite(Chan *c, void *va, long n, vlong)
{
Cmdbuf *cb;
switch((ulong)c->qid.path){
default:
error(Egreg);
break;
case Qdbgctl:
cb = parsecmd(va, n);
if(waserror()){
free(cb);
nexterror();
}
ctl(cb);
poperror();
break;
}
return n;
}
static void
dbgclose(Chan*)
{
}
Dev dbgdevtab = {
'b',
"dbg",
devreset,
dbginit,
devshutdown,
dbgattach,
dbgwalk,
dbgstat,
dbgopen,
devcreate,
dbgclose,
dbgread,
devbread,
dbgwrite,
devbwrite,
devremove,
devwstat,
};