Unify db_stack_trace_cmd(). All it did was look up the thread given

the thread ID and call db_trace_thread().
Since arm has all the logic in db_stack_trace_cmd(), rename the
new DB_COMMAND function to db_stack_trace to avoid conflicts on
arm.
While here, have db_stack_trace parse its own arguments so that
we can use a more natural radix for IDs. If the ID is not a thread
ID, or more precisely when no thread exists with the ID, try if
there's a process with that ID and return the first thread in it.
This makes it easier to print stack traces from the ps output.

requested by: rwatson@
tested on: amd64, i386, ia64

2 files changed, 43 insertions, 3 deletions

diff --git a/sys/ddb/db_command.c b/sys/ddb/db_command.c
index 30740ab..03fd662 100644
--- a/sys/ddb/db_command.c
+++ b/sys/ddb/db_command.c
@@ -70,6 +70,7 @@ static db_cmdfcn_t	db_fncall;
 static db_cmdfcn_t	db_gdb;
 static db_cmdfcn_t	db_kill;
 static db_cmdfcn_t	db_reset;
+static db_cmdfcn_t	db_stack_trace;
 static db_cmdfcn_t	db_watchdog;
 
 /* XXX this is actually forward-static. */
@@ -410,8 +411,8 @@ static struct command db_command_table[] = {
 	{ "until",	db_trace_until_call_cmd,0,	0 },
 	{ "next",	db_trace_until_matching_cmd,0,	0 },
 	{ "match",	db_trace_until_matching_cmd,0,	0 },
-	{ "trace",	db_stack_trace_cmd,	0,	0 },
-	{ "where",	db_stack_trace_cmd,	0,	0 },
+	{ "trace",	db_stack_trace,		0,	0 },
+	{ "where",	db_stack_trace,		0,	0 },
 	{ "call",	db_fncall,		CS_OWN,	0 },
 	{ "show",	0,			0,	db_show_cmds },
 	{ "ps",		db_ps,			0,	0 },
@@ -623,3 +624,43 @@ db_gdb(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
 	else
 		db_printf("Step to enter the remote GDB backend.\n");
 }
+
+static void
+db_stack_trace(db_expr_t tid, boolean_t hastid, db_expr_t count, char *modif)
+{
+	struct thread *td;
+	db_expr_t radix;
+	int t;
+
+	/*
+	 * We parse our own arguments. We don't like the default radix.
+	 */
+	radix = db_radix;
+	db_radix = 10;
+	hastid = db_expression(&tid);
+	t = db_read_token();
+	if (t == tCOMMA) {
+		if (!db_expression(&count)) {
+			db_printf("Count missing\n");
+			db_flush_lex();
+			return;
+		}
+	} else {
+		db_unread_token(t);
+		count = -1;
+	}
+	db_skip_to_eol();
+	db_radix = radix;
+
+	if (hastid) {
+		td = kdb_thr_lookup((lwpid_t)tid);
+		if (td == NULL)
+			td = kdb_thr_from_pid((pid_t)tid);
+		if (td == NULL) {
+			db_printf("Thread %d not found\n", (int)tid);
+			return;
+		}
+	} else
+		td = kdb_thread;
+	db_trace_thread(td, count);
+}
diff --git a/sys/ddb/ddb.h b/sys/ddb/ddb.h
index c1ffff9..97d332e 100644
--- a/sys/ddb/ddb.h
+++ b/sys/ddb/ddb.h
@@ -128,7 +128,6 @@ db_cmdfcn_t	db_set_thread;
 db_cmdfcn_t	db_show_regs;
 db_cmdfcn_t	db_show_threads;
 db_cmdfcn_t	db_single_step_cmd;
-db_cmdfcn_t	db_stack_trace_cmd;
 db_cmdfcn_t	db_trace_until_call_cmd;
 db_cmdfcn_t	db_trace_until_matching_cmd;
 db_cmdfcn_t	db_watchpoint_cmd;