[PATCH 4.9 48/87] x86/speculation: Create spec-ctrl.h to avoid include hell

From: Greg Kroah-Hartman
Date: Mon May 21 2018 - 17:33:32 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

commit 28a2775217b17208811fa43a9e96bd1fdf417b86 upstream

Having everything in nospec-branch.h creates a hell of dependencies when
adding the prctl based switching mechanism. Move everything which is not
required in nospec-branch.h to spec-ctrl.h and fix up the includes in the
relevant files.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Reviewed-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/nospec-branch.h | 14 --------------
arch/x86/include/asm/spec-ctrl.h | 21 +++++++++++++++++++++
arch/x86/kernel/cpu/amd.c | 2 +-
arch/x86/kernel/cpu/bugs.c | 2 +-
arch/x86/kvm/svm.c | 2 +-
arch/x86/kvm/vmx.c | 2 +-
6 files changed, 25 insertions(+), 18 deletions(-)
create mode 100644 arch/x86/include/asm/spec-ctrl.h

--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -228,26 +228,12 @@ enum spectre_v2_mitigation {
extern void x86_spec_ctrl_set(u64);
extern u64 x86_spec_ctrl_get_default(void);

-/*
- * On VMENTER we must preserve whatever view of the SPEC_CTRL MSR
- * the guest has, while on VMEXIT we restore the host view. This
- * would be easier if SPEC_CTRL were architecturally maskable or
- * shadowable for guests but this is not (currently) the case.
- * Takes the guest view of SPEC_CTRL MSR as a parameter.
- */
-extern void x86_spec_ctrl_set_guest(u64);
-extern void x86_spec_ctrl_restore_host(u64);
-
/* The Speculative Store Bypass disable variants */
enum ssb_mitigation {
SPEC_STORE_BYPASS_NONE,
SPEC_STORE_BYPASS_DISABLE,
};

-/* AMD specific Speculative Store Bypass MSR data */
-extern u64 x86_amd_ls_cfg_base;
-extern u64 x86_amd_ls_cfg_rds_mask;
-
extern char __indirect_thunk_start[];
extern char __indirect_thunk_end[];

--- /dev/null
+++ b/arch/x86/include/asm/spec-ctrl.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_SPECCTRL_H_
+#define _ASM_X86_SPECCTRL_H_
+
+#include <asm/nospec-branch.h>
+
+/*
+ * On VMENTER we must preserve whatever view of the SPEC_CTRL MSR
+ * the guest has, while on VMEXIT we restore the host view. This
+ * would be easier if SPEC_CTRL were architecturally maskable or
+ * shadowable for guests but this is not (currently) the case.
+ * Takes the guest view of SPEC_CTRL MSR as a parameter.
+ */
+extern void x86_spec_ctrl_set_guest(u64);
+extern void x86_spec_ctrl_restore_host(u64);
+
+/* AMD specific Speculative Store Bypass MSR data */
+extern u64 x86_amd_ls_cfg_base;
+extern u64 x86_amd_ls_cfg_rds_mask;
+
+#endif
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -9,7 +9,7 @@
#include <asm/processor.h>
#include <asm/apic.h>
#include <asm/cpu.h>
-#include <asm/nospec-branch.h>
+#include <asm/spec-ctrl.h>
#include <asm/smp.h>
#include <asm/pci-direct.h>
#include <asm/delay.h>
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -12,7 +12,7 @@
#include <linux/cpu.h>
#include <linux/module.h>

-#include <asm/nospec-branch.h>
+#include <asm/spec-ctrl.h>
#include <asm/cmdline.h>
#include <asm/bugs.h>
#include <asm/processor.h>
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -45,7 +45,7 @@
#include <asm/kvm_para.h>
#include <asm/irq_remapping.h>
#include <asm/microcode.h>
-#include <asm/nospec-branch.h>
+#include <asm/spec-ctrl.h>

#include <asm/virtext.h>
#include "trace.h"
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -50,7 +50,7 @@
#include <asm/apic.h>
#include <asm/irq_remapping.h>
#include <asm/microcode.h>
-#include <asm/nospec-branch.h>
+#include <asm/spec-ctrl.h>

#include "trace.h"
#include "pmu.h"