debugger

1 files changed, 288 insertions, 0 deletions

diff --git a/src/cmd/db/trcrun.c b/src/cmd/db/trcrun.c
new file mode 100644
index 00000000..807f902e
--- /dev/null
+++ b/src/cmd/db/trcrun.c
@@ -0,0 +1,288 @@
+/*
+ * functions for running the debugged process
+ */
+
+#include "defs.h"
+#include "fns.h"
+
+
+int child;
+int msgfd = -1;
+int notefd = -1;
+int pcspid = -1;
+int pcsactive = 0;
+
+void
+setpcs(void)
+{
+	char buf[128];
+
+	if(pid && pid != pcspid){
+		if(msgfd >= 0){
+			close(msgfd);
+			msgfd = -1;
+		}
+		if(notefd >= 0){
+			close(notefd);
+			notefd = -1;
+		}
+		pcspid = -1;
+		sprint(buf, "/proc/%d/ctl", pid);
+		msgfd = open(buf, OWRITE);
+		if(msgfd < 0)
+			error("can't open control file");
+		sprint(buf, "/proc/%d/note", pid);
+		notefd = open(buf, ORDWR);
+		if(notefd < 0)
+			error("can't open note file");
+		pcspid = pid;
+	}
+}
+
+void
+msgpcs(char *msg)
+{
+	char err[ERRMAX];
+
+	setpcs();
+	if(write(msgfd, msg, strlen(msg)) < 0 && !ending){
+		errstr(err, sizeof err);
+		if(strcmp(err, "interrupted") != 0)
+			endpcs();
+		errors("can't write control file", err);
+	}
+}
+
+/*
+ * empty the note buffer and toss pending breakpoint notes
+ */
+void
+unloadnote(void)
+{
+	char err[ERRMAX];
+
+	setpcs();
+	for(; nnote<NNOTE; nnote++){
+		switch(read(notefd, note[nnote], sizeof note[nnote])){
+		case -1:
+			errstr(err, sizeof err);
+			if(strcmp(err, "interrupted") != 0)
+				endpcs();
+			errors("can't read note file", err);
+		case 0:
+			return;
+		}
+		note[nnote][ERRMAX-1] = '\0';
+		if(strncmp(note[nnote], "sys: breakpoint", 15) == 0)
+			--nnote;
+	}
+}
+
+/*
+ * reload the note buffer
+ */
+void
+loadnote(void)
+{
+	int i;
+	char err[ERRMAX];
+
+	setpcs();
+	for(i=0; i<nnote; i++){
+		if(write(notefd, note[i], strlen(note[i])) < 0){
+			errstr(err, sizeof err);
+			if(strcmp(err, "interrupted") != 0)
+				endpcs();
+			errors("can't write note file", err);
+		}
+	}
+	nnote = 0;
+}
+
+void
+notes(void)
+{
+	int n;
+
+	if(nnote == 0)
+		return;
+	dprint("notes:\n");
+	for(n=0; n<nnote; n++)
+		dprint("%d:\t%s\n", n, note[n]);
+}
+
+void
+killpcs(void)
+{
+	msgpcs("kill");
+}
+
+void
+grab(void)
+{
+	flush();
+	msgpcs("stop");
+	bpwait();
+}
+
+void
+ungrab(void)
+{
+	msgpcs("start");
+}
+
+void
+doexec(void)
+{
+	char *argl[MAXARG];
+	char args[LINSIZ];
+	char *p;
+	char **ap;
+	char *thisarg;
+
+	ap = argl;
+	p = args;
+	*ap++ = symfil;
+	for (rdc(); lastc != EOR;) {
+		thisarg = p;
+		if (lastc == '<' || lastc == '>') {
+			*p++ = lastc;
+			rdc();
+		}
+		while (lastc != EOR && lastc != SPC && lastc != TB) {
+			*p++ = lastc;
+			readchar();
+		}
+		if (lastc == SPC || lastc == TB)
+			rdc();
+		*p++ = 0;
+		if (*thisarg == '<') {
+			close(0);
+			if (open(&thisarg[1], OREAD) < 0) {
+				print("%s: cannot open\n", &thisarg[1]);
+				_exits(0);
+			}
+		}
+		else if (*thisarg == '>') {
+			close(1);
+			if (create(&thisarg[1], OWRITE, 0666) < 0) {
+				print("%s: cannot create\n", &thisarg[1]);
+				_exits(0);
+			}
+		}
+		else
+			*ap++ = thisarg;
+	}
+	*ap = 0;
+	exec(symfil, argl);
+	perror(symfil);
+}
+
+char	procname[100];
+
+void
+startpcs(void)
+{
+	if ((pid = fork()) == 0) {
+		pid = getpid();
+		msgpcs("hang");
+		doexec();
+		exits(0);
+	}
+
+	if (pid == -1)
+		error("can't fork");
+	child++;
+	sprint(procname, "/proc/%d/mem", pid);
+	corfil = procname;
+	msgpcs("waitstop");
+	bpwait();
+	if (adrflg)
+		rput(correg, mach->pc, adrval);
+	while (rdc() != EOR)
+		;
+	reread();
+}
+
+void
+runstep(ulong loc, int keepnote)
+{
+	int nfoll;
+	ulong foll[3];
+	BKPT bkpt[3];
+	int i;
+
+	if(mach->foll == 0){
+		dprint("stepping unimplemented; assuming not a branch\n");
+		nfoll = 1;
+		foll[0] = loc+mach->pcquant;
+	}else {
+		nfoll = mach->foll(cormap, correg, loc, foll);
+		if (nfoll < 0)
+			error("%r");
+	}
+	memset(bkpt, 0, sizeof bkpt);
+	for(i=0; i<nfoll; i++){
+		if(foll[i] == loc)
+			error("can't single step: next instruction is dot");
+		bkpt[i].loc = foll[i];
+		bkput(&bkpt[i], 1);
+	}
+	runrun(keepnote);
+	for(i=0; i<nfoll; i++)
+		bkput(&bkpt[i], 0);
+}
+
+void
+bpwait(void)
+{
+	setcor();
+	unloadnote();
+}
+
+void
+runrun(int keepnote)
+{
+	int on;
+
+	on = nnote;
+	unloadnote();
+	if(on != nnote){
+		notes();
+		error("not running: new notes pending");
+	}
+	if(keepnote)
+		loadnote();
+	else
+		nnote = 0;
+	flush();
+	msgpcs("startstop");
+	bpwait();
+}
+
+void
+bkput(BKPT *bp, int install)
+{
+	char buf[256];
+	ulong loc;
+	int ret;
+
+	errstr(buf, sizeof buf);
+/*
+	if(mach->bpfix)
+		loc = (*mach->bpfix)(bp->loc);
+	else
+*/
+	loc = bp->loc;
+	if(install){
+		ret = get1(cormap, loc, bp->save, mach->bpsize);
+		if (ret > 0)
+			ret = put1(cormap, loc, mach->bpinst, mach->bpsize);
+	}else
+		ret = put1(cormap, loc, bp->save, mach->bpsize);
+	if(ret < 0){
+		sprint(buf, "can't set breakpoint at %#llux: %r", bp->loc);
+		print(buf);
+		read(0, buf, 100);
+	}
+}