Add logic to trace across/over a trapframe. We have ABI markers in

our unwind information for functions that are entry points into the
kernel. When stepping to the next frame, the unwinder will let us
know when sych a marker was encountered. We use this to stop the
current unwind session, query the trapframe and restart a new
unwind session based on the new trapframe.

The implementation is a bit sloppy, but at this time there are
bigger fish to fry.

3 files changed, 38 insertions, 6 deletions

diff --git a/sys/ia64/ia64/db_trace.c b/sys/ia64/ia64/db_trace.c
index 4e164b2..744c9e2 100644
--- a/sys/ia64/ia64/db_trace.c
+++ b/sys/ia64/ia64/db_trace.c
@@ -49,19 +49,23 @@ db_stack_trace_cmd(db_expr_t addr, boolean_t have_addr, db_expr_t count,
     char *modif)
 {
 	struct unw_regstate rs;
+	struct trapframe *tf;
 	const char *name;
 	db_expr_t offset;
-	uint64_t bsp, cfm, ip, pfs, reg;
+	uint64_t bsp, cfm, ip, pfs, reg, sp;
 	c_db_sym_t sym;
 	int args, error, i;
 
-	error = unw_create(&rs, &ddb_regs);
+	tf = &ddb_regs;
+	error = unw_create(&rs, tf);
 	while (!error && count--) {
 		error = unw_get_cfm(&rs, &cfm);
 		if (!error)
 			error = unw_get_bsp(&rs, &bsp);
 		if (!error)
 			error = unw_get_ip(&rs, &ip);
+		if (!error)
+			error = unw_get_sp(&rs, &sp);
 		if (error)
 			break;
 
@@ -98,6 +102,21 @@ db_stack_trace_cmd(db_expr_t addr, boolean_t have_addr, db_expr_t count,
 
 		db_printsym(ip, DB_STGY_PROC);
 		db_printf("\n");
+
+		if (error != EOVERFLOW)
+			continue;
+		if (sp < IA64_RR_BASE(5))
+			break;
+
+		tf = (struct trapframe *)(sp + 16);
+		if ((tf->tf_flags & FRAME_SYSCALL) != 0 ||
+		    tf->tf_special.iip < IA64_RR_BASE(5))
+			break;
+
+		/* XXX ask if we should unwind across the trapframe. */
+		db_printf("--- trapframe at %p\n", tf);
+		unw_delete(&rs);
+		error = unw_create(&rs, tf);
 	}
 
 	unw_delete(&rs);
diff --git a/sys/ia64/ia64/unwind.c b/sys/ia64/ia64/unwind.c
index cfc5af7..592a773 100644
--- a/sys/ia64/ia64/unwind.c
+++ b/sys/ia64/ia64/unwind.c
@@ -282,16 +282,19 @@ void
 unw_delete(struct unw_regstate *rs)
 {
 
-	uwx_free(rs->env);
+	if (rs->env != NULL)
+		uwx_free(rs->env);
 }
 
 int
 unw_step(struct unw_regstate *rs)
 {
-	int uwxerr;
+	int err;
 
-	uwxerr = uwx_step(rs->env);
-	return ((uwxerr) ? EINVAL : 0);		/* XXX */
+	err = uwx_step(rs->env);
+	if (err == UWX_ABI_FRAME)
+		return (EOVERFLOW);
+	return ((err != 0) ? EINVAL : 0);	/* XXX */
 }
 
 int
@@ -322,6 +325,15 @@ unw_get_ip(struct unw_regstate *s, uint64_t *r)
 }
 
 int
+unw_get_sp(struct unw_regstate *s, uint64_t *r)
+{
+	int uwxerr;
+
+	uwxerr = uwx_get_reg(s->env, UWX_REG_SP, r);
+	return ((uwxerr) ? EINVAL : 0); 	/* XXX */
+}
+
+int
 unw_table_add(uint64_t base, uint64_t start, uint64_t end)
 {
 	struct unw_table *ut;
diff --git a/sys/ia64/include/unwind.h b/sys/ia64/include/unwind.h
index 794a85d..4ae85ec 100644
--- a/sys/ia64/include/unwind.h
+++ b/sys/ia64/include/unwind.h
@@ -44,6 +44,7 @@ int unw_step(struct unw_regstate *s);
 int unw_get_bsp(struct unw_regstate *s, uint64_t *r);
 int unw_get_cfm(struct unw_regstate *s, uint64_t *r);
 int unw_get_ip(struct unw_regstate *s, uint64_t *r);
+int unw_get_sp(struct unw_regstate *s, uint64_t *r);
 
 int unw_table_add(uint64_t, uint64_t, uint64_t);
 void unw_table_remove(uint64_t);