Work around VNET and DPCPU related panics on aarch64

lld >= 14 and recent GNU ld can relax adrp+add and adrp+ldr
instructions, which breaks VNET and DPCPU when used in modules.

Until VNET and DPCPU can be fixed to deal with these relaxed
instructions, disable linker relaxation for now.

PR:		264094
Reviewed by:	markj
MFC after:	3 days
Differential Revision: https://reviews.freebsd.org/D41156

This commit is contained in:

Dimitry Andric

2023-07-23 15:48:36 +02:00

parent 058d1722b0

commit 80e4ac2964

1 changed files with 7 additions and 0 deletions

									
										sys/conf/kmod.mk
									
		+7
		
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				@@ -170,6 +170,13 @@ CFLAGS+=	-fno-omit-frame-pointer -mno-omit-leaf-frame-pointer

				CFLAGS+=	-fPIC

				.endif

				.if ${MACHINE_CPUARCH} == "aarch64"

				# https://bugs.freebsd.org/264094

				# lld >= 14 and recent GNU ld can relax adrp+add and adrp+ldr instructions,

				# which breaks VNET.

				LDFLAGS+=	--no-relax

				.endif

				# Temporary workaround for PR 196407, which contains the fascinating details.

				# Don't allow clang to use fpu instructions or registers in kernel modules.

				.if ${MACHINE_CPUARCH} == arm