git: f1f27dfa4ad9 - stable/13 - Work around VNET and DPCPU related panics on aarch64

From: Dimitry Andric <dim_at_FreeBSD.org>
Date: Wed, 26 Jul 2023 18:05:57 UTC
The branch stable/13 has been updated by dim:

URL: https://cgit.FreeBSD.org/src/commit/?id=f1f27dfa4ad9da53fcdfc6aae644fab83bda4e76

commit f1f27dfa4ad9da53fcdfc6aae644fab83bda4e76
Author:     Dimitry Andric <dim@FreeBSD.org>
AuthorDate: 2023-07-23 13:48:36 +0000
Commit:     Dimitry Andric <dim@FreeBSD.org>
CommitDate: 2023-07-26 18:02:37 +0000

    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
    
    (cherry picked from commit 80e4ac2964a11edef456a15b77e43aadeaf273a2)
---
 sys/conf/kmod.mk | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/sys/conf/kmod.mk b/sys/conf/kmod.mk
index a06f6a2555d9..4a0d828f0159 100644
--- a/sys/conf/kmod.mk
+++ b/sys/conf/kmod.mk
@@ -168,6 +168,13 @@ 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