From b69996d1d5d08fd5009ac325ea8e8154efd01b33 Mon Sep 17 00:00:00 2001
From: Warner Losh <imp@FreeBSD.org>
Date: Wed, 29 Jun 2022 08:26:58 -0600
Subject: [PATCH] tty: Default to printing kernel stack traceback only on
 INVARIANT kernels

Change the default from printing a breif kernel thread stack informaton
back to omitting it for non-invariant kernels in response to
SIGINFO/^T. Full and brief stack support can be selected with the
kern.tty_info_kstacks sysctl.

MFC After:		2 weeks
Sponsored by:		Netflix
Reviewed by:		grembo, jhb
Differential Revision:	https://reviews.freebsd.org/D35576
---
 sys/kern/tty_info.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sys/kern/tty_info.c b/sys/kern/tty_info.c
index 237aa47a18da..be6de114bdfd 100644
--- a/sys/kern/tty_info.c
+++ b/sys/kern/tty_info.c
@@ -239,7 +239,11 @@ sbuf_tty_drain(void *a, const char *d, int len)
 }
 
 #ifdef STACK
+#ifdef INVARIANTS
 static int tty_info_kstacks = STACK_SBUF_FMT_COMPACT;
+#else
+static int tty_info_kstacks = STACK_SBUF_FMT_NONE;
+#endif
 
 static int
 sysctl_tty_info_kstacks(SYSCTL_HANDLER_ARGS)