From b54c389fbcd6f000e9fdf0ef87dd2df4992c8e1c Mon Sep 17 00:00:00 2001
From: Ian Lepore <ian@FreeBSD.org>
Date: Fri, 2 Jan 2015 03:20:13 +0000
Subject: Put in a workaround for bug 196407 (arm modules cause crashes &
 panics).

When we started compiling the kernel with -march=armv7 the compiler
started emitting new types of relocation info which are incompatible with
the shared-lib file format used by .ko modules.  This workaround prevents
the compiler from emitting the instruction sequences that require the
new relocs.  This amounts to using an undocumented internal compiler
flag, so this is just a temporary workaround while we look for a good fix.

PR:		196407
---
 sys/conf/kmod.mk | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'sys/conf')

diff --git a/sys/conf/kmod.mk b/sys/conf/kmod.mk
index f97578fb6cae..3b1f3054acd3 100644
--- a/sys/conf/kmod.mk
+++ b/sys/conf/kmod.mk
@@ -118,6 +118,11 @@ CFLAGS+=	${DEBUG_FLAGS}
 CFLAGS+=	-fno-omit-frame-pointer -mno-omit-leaf-frame-pointer
 .endif
 
+# Temporary workaround for PR 196407, which contains the fascinating details.
+.if ${MACHINE_CPUARCH} == arm
+CFLAGS.clang+=	-mllvm -arm-use-movt=0
+.endif
+
 .if ${MACHINE_CPUARCH} == powerpc
 CFLAGS+=	-mlongcall -fno-omit-frame-pointer
 .endif
-- 
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