From: guenther <guenther@openbsd.org>
Date: Sat, 21 Jul 2018 02:19:54 +0000 (+0000)
Subject: Remove the "got meltdown?" conditional from INTRENTRY by doing it
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=38863611753ab7fd8d696f9c5baf253ebd0014c2;p=openbsd

Remove the "got meltdown?" conditional from INTRENTRY by doing it
 unconditionally and codepatching it out on CPUs that don't need/do
 the mitigation.
Align the from-{kernel,userspace} targets in INTRENTRY with _ALIGN_TRAPS
Align x2apic_eoi using KUENTRY() instead of the artisinal
 segment+label+.globl bits it uses currently
s/testq/testb/ for SEL_RPL checks

ok kettenis@ mlarkin@
---

diff --git a/sys/arch/amd64/amd64/vector.S b/sys/arch/amd64/amd64/vector.S
index e06547f9b92..1f4be77736c 100644
--- a/sys/arch/amd64/amd64/vector.S
+++ b/sys/arch/amd64/amd64/vector.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vector.S,v 1.73 2018/07/12 14:24:54 guenther Exp $	*/
+/*	$OpenBSD: vector.S,v 1.74 2018/07/21 02:19:54 guenther Exp $	*/
 /*	$NetBSD: vector.S,v 1.5 2004/06/28 09:13:11 fvdl Exp $	*/
 
 /*
@@ -472,9 +472,7 @@ KTEXT_PAGE_END
 /* XXX See comment in locore.s */
 #define	XINTR(name,num)		Xintr_##name##num
 
-	KUTEXT
-	.globl _C_LABEL(x2apic_eoi)
-_C_LABEL(x2apic_eoi):
+KUENTRY(x2apic_eoi)
 	pushq   %rax
 	pushq   %rcx
 	pushq   %rdx
diff --git a/sys/arch/amd64/include/frameasm.h b/sys/arch/amd64/include/frameasm.h
index 05a9ecb8b2a..33ab8b4b347 100644
--- a/sys/arch/amd64/include/frameasm.h
+++ b/sys/arch/amd64/include/frameasm.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: frameasm.h,v 1.18 2018/07/10 08:57:44 guenther Exp $	*/
+/*	$OpenBSD: frameasm.h,v 1.19 2018/07/21 02:19:54 guenther Exp $	*/
 /*	$NetBSD: frameasm.h,v 1.1 2003/04/26 18:39:40 fvdl Exp $	*/
 
 #ifndef _AMD64_MACHINE_FRAMEASM_H
@@ -60,20 +60,22 @@
 /* For real interrupt code paths, where we can come from userspace */
 #define INTRENTRY_LABEL(label)	X##label##_untramp
 #define	INTRENTRY(label) \
-	testq	$SEL_RPL,24(%rsp)	; \
+	testb	$SEL_RPL,24(%rsp)	; \
 	je	INTRENTRY_LABEL(label)	; \
 	swapgs				; \
 	movq	%rax,CPUVAR(SCRATCH)	; \
+	CODEPATCH_START			; \
 	movq	CPUVAR(KERN_CR3),%rax	; \
-	testq	%rax,%rax		; \
-	jz	98f			; \
 	movq	%rax,%cr3		; \
+	CODEPATCH_END(CPTAG_MELTDOWN_NOP);\
 	jmp	98f			; \
 	.text				; \
+	_ALIGN_TRAPS			; \
 	.global	INTRENTRY_LABEL(label)	; \
 INTRENTRY_LABEL(label):	/* from kernel */ \
 	INTR_ENTRY_KERN			; \
 	jmp	99f			; \
+	_ALIGN_TRAPS			; \
 98:	/* from userspace */		  \
 	INTR_ENTRY_USER			; \
 99:	INTR_SAVE_MOST_GPRS_NO_ADJ	; \