Module Name: src
Committed By: ryo
Date: Fri Dec 20 07:16:43 UTC 2019
Modified Files:
src/sys/arch/aarch64/aarch64: cpuswitch.S
src/sys/arch/aarch64/include: asm.h
Log Message:
Add a speculation barrier after the 'eret'.
Some aarch64 cpus speculatively execute instructions after 'eret',
and this potentiates side-channel attack.
from
https://github.com/torvalds/linux/commit/679db70801da9fda91d26caf13bf5b5ccc74e8e8
To generate a diff of this commit:
cvs rdiff -u -r1.12 -r1.13 src/sys/arch/aarch64/aarch64/cpuswitch.S
cvs rdiff -u -r1.4 -r1.5 src/sys/arch/aarch64/include/asm.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/aarch64/aarch64/cpuswitch.S
diff -u src/sys/arch/aarch64/aarch64/cpuswitch.S:1.12 src/sys/arch/aarch64/aarch64/cpuswitch.S:1.13
--- src/sys/arch/aarch64/aarch64/cpuswitch.S:1.12 Sun Sep 15 07:13:37 2019
+++ src/sys/arch/aarch64/aarch64/cpuswitch.S Fri Dec 20 07:16:43 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: cpuswitch.S,v 1.12 2019/09/15 07:13:37 skrll Exp $ */
+/* $NetBSD: cpuswitch.S,v 1.13 2019/12/20 07:16:43 ryo Exp $ */
/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -37,7 +37,7 @@
#include "opt_ddb.h"
#include "opt_kasan.h"
-RCSID("$NetBSD: cpuswitch.S,v 1.12 2019/09/15 07:13:37 skrll Exp $")
+RCSID("$NetBSD: cpuswitch.S,v 1.13 2019/12/20 07:16:43 ryo Exp $")
/*
* At IPL_SCHED:
@@ -268,7 +268,7 @@ ENTRY_NP(el1_trap_exit)
ldp x1, x2, [x0, #TF_X1]
ldr x0, [x0, #TF_X0]
- eret
+ ERET
END(el1_trap_exit)
#ifdef DDB
END(el1_trap)
@@ -339,7 +339,7 @@ ENTRY_NP(el0_trap_exit)
unwind_x0_x2
/* leave sp at l_md.md_utf, return back to EL0 user process */
- eret
+ ERET
END(el0_trap_exit)
#ifdef DDB
END(el0_trap)
Index: src/sys/arch/aarch64/include/asm.h
diff -u src/sys/arch/aarch64/include/asm.h:1.4 src/sys/arch/aarch64/include/asm.h:1.5
--- src/sys/arch/aarch64/include/asm.h:1.4 Mon Aug 5 16:24:48 2019
+++ src/sys/arch/aarch64/include/asm.h Fri Dec 20 07:16:43 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: asm.h,v 1.4 2019/08/05 16:24:48 joerg Exp $ */
+/* $NetBSD: asm.h,v 1.5 2019/12/20 07:16:43 ryo Exp $ */
#ifndef _AARCH64_ASM_H_
#define _AARCH64_ASM_H_
@@ -8,6 +8,15 @@
#ifdef __aarch64__
#define fp x29
#define lr x30
+
+/*
+ * Add a speculation barrier after the 'eret'.
+ * Some aarch64 cpus speculatively execute instructions after 'eret',
+ * and this potentiates side-channel attacks.
+ */
+#define ERET \
+ eret; dsb sy; isb
+
#endif
#endif /* !_AARCH64_ASM_H_ */
