From 43e8849bc29414036ccaef7788de95a07ad32ab5 Mon Sep 17 00:00:00 2001
From: Andrew Turner <andrew@FreeBSD.org>
Date: Mon, 19 Aug 2024 13:59:49 +0100
Subject: [PATCH] conf: Enable BTI checking in the arm64 kernel

To ensure new code has BTI support make it an error to not have the
BTI ELF note when linking the kernel and kernel modules.

Reviewed by:	kib, emaste
Sponsored by:	Arm Ltd
Differential Revision:	https://reviews.freebsd.org/D45469
---
 sys/conf/kern.mk | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sys/conf/kern.mk b/sys/conf/kern.mk
index 93187d93ac6..079bd1173fa 100644
--- a/sys/conf/kern.mk
+++ b/sys/conf/kern.mk
@@ -143,6 +143,9 @@ CFLAGS += -mgeneral-regs-only
 CFLAGS += -ffixed-x18
 # Build with BTI+PAC
 CFLAGS += -mbranch-protection=standard
+.if ${LINKER_TYPE} == "lld"
+LDFLAGS += -Wl,-zbti-report=error
+.endif
 # TODO: support outline atomics
 CFLAGS += -mno-outline-atomics
 INLINE_LIMIT?=	8000