From: kettenis <kettenis@openbsd.org>
Date: Sat, 27 Jul 2024 13:31:26 +0000 (+0000)
Subject: Use ".arch_extension fp" for the signal trampoline since it saves and
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=5ccef5843652c8cb5feaeff7f006be97e32303bc;p=openbsd

Use ".arch_extension fp" for the signal trampoline since it saves and
restores the FPU registers (running in userland).  And add an
".arch_extension nofp" afterwards such that the remaining kernel code
can't touch the FPU.

Needed to build with clang18

ok jsg@
---

diff --git a/sys/arch/arm64/arm64/locore.S b/sys/arch/arm64/arm64/locore.S
index 4781cdbe30f..54cd5922c85 100644
--- a/sys/arch/arm64/arm64/locore.S
+++ b/sys/arch/arm64/arm64/locore.S
@@ -1,4 +1,4 @@
-/* $OpenBSD: locore.S,v 1.46 2024/03/16 20:46:28 kettenis Exp $ */
+/* $OpenBSD: locore.S,v 1.47 2024/07/27 13:31:26 kettenis Exp $ */
 /*-
  * Copyright (c) 2012-2014 Andrew Turner
  * All rights reserved.
@@ -315,6 +315,9 @@ initstack:
 	.globl initstack_end
 initstack_end:
 
+/* The signal trampoline saves and restores the floating-point registers. */
+.arch_extension	fp
+
 	.text
 	.globl	sigcode
 	.type	sigcode,@function
@@ -387,6 +390,9 @@ esigfill:
 sigfillsiz:
 	.word	esigfill - sigfill
 
+/* Back to normal kernel code. */
+.arch_extension	nofp
+
 	.text
 
 #ifdef MULTIPROCESSOR