* [PATCH v3 00/15] ARM Spectre variant 2 fixes
@ 2018-05-25 13:59 ` Russell King - ARM Linux
0 siblings, 0 replies; 42+ messages in thread
From: Russell King - ARM Linux @ 2018-05-25 13:59 UTC (permalink / raw)
To: linux-arm-kernel
Third version:
- Remove "PSCI" from the SMC version of the workaround as well.
- Avoid reporting active workaround if the IBE bit is not set.
- Only probe for workaround_1 on Cortex A57 and A72, or non-ARM CPUs.
- Require features probe for workaround_1 to return zero.
- Validation that all CPUs in the system have the same workaround status.
- Avoid corrupting r12 in workaround_1 KVM hypervisor implementation.
arch/arm/include/asm/bugs.h | 6 +-
arch/arm/include/asm/cp15.h | 3 +
arch/arm/include/asm/cputype.h | 8 ++
arch/arm/include/asm/kvm_asm.h | 2 -
arch/arm/include/asm/kvm_host.h | 14 ++-
arch/arm/include/asm/kvm_mmu.h | 23 ++++-
arch/arm/include/asm/proc-fns.h | 4 +
arch/arm/include/asm/system_misc.h | 15 ++++
arch/arm/kernel/Makefile | 1 +
arch/arm/kernel/bugs.c | 18 ++++
arch/arm/kernel/smp.c | 4 +
arch/arm/kernel/suspend.c | 2 +
arch/arm/kvm/hyp/hyp-entry.S | 112 +++++++++++++++++++++++-
arch/arm/mm/Kconfig | 23 +++++
arch/arm/mm/Makefile | 2 +-
arch/arm/mm/fault.c | 3 +
arch/arm/mm/proc-macros.S | 3 +-
arch/arm/mm/proc-v7-2level.S | 6 --
arch/arm/mm/proc-v7-bugs.c | 170 +++++++++++++++++++++++++++++++++++++
arch/arm/mm/proc-v7.S | 154 ++++++++++++++++++++++++++-------
20 files changed, 523 insertions(+), 50 deletions(-)
create mode 100644 arch/arm/kernel/bugs.c
create mode 100644 arch/arm/mm/proc-v7-bugs.c
On Mon, May 21, 2018 at 12:42:38PM +0100, Russell King - ARM Linux wrote:
> This is the second posting - the original cover note is below. Comments
> from previous series addresesd:
> - Drop R7 and R8 changes.
> - Remove "PSCI" from the hypervisor version of the workaround.
>
> arch/arm/include/asm/bugs.h | 6 +-
> arch/arm/include/asm/cp15.h | 3 +
> arch/arm/include/asm/cputype.h | 5 ++
> arch/arm/include/asm/kvm_asm.h | 2 -
> arch/arm/include/asm/kvm_host.h | 14 +++-
> arch/arm/include/asm/kvm_mmu.h | 23 +++++-
> arch/arm/include/asm/proc-fns.h | 4 +
> arch/arm/include/asm/system_misc.h | 8 ++
> arch/arm/kernel/Makefile | 1 +
> arch/arm/kernel/bugs.c | 18 +++++
> arch/arm/kernel/smp.c | 4 +
> arch/arm/kernel/suspend.c | 2 +
> arch/arm/kvm/hyp/hyp-entry.S | 108 +++++++++++++++++++++++++-
> arch/arm/mm/Kconfig | 23 ++++++
> arch/arm/mm/Makefile | 2 +-
> arch/arm/mm/fault.c | 3 +
> arch/arm/mm/proc-macros.S | 3 +-
> arch/arm/mm/proc-v7-2level.S | 6 --
> arch/arm/mm/proc-v7-bugs.c | 130 +++++++++++++++++++++++++++++++
> arch/arm/mm/proc-v7.S | 154 +++++++++++++++++++++++++++++--------
> 20 files changed, 469 insertions(+), 50 deletions(-)
> create mode 100644 arch/arm/kernel/bugs.c
> create mode 100644 arch/arm/mm/proc-v7-bugs.c
>
> On Wed, May 16, 2018 at 11:59:49AM +0100, Russell King - ARM Linux wrote:
> > This series addresses the Spectre variant 2 issues on ARM Cortex and
> > Broadcom Brahma B15 CPUs. Due to the complexity of the bug, it is not
> > possible to verify that this series fixes any of the bugs, since it
> > has not been able to reproduce these exact scenarios using test
> > programs.
> >
> > I believe that this covers the entire extent of the Spectre variant 2
> > issues, with the exception of Cortex A53 and Cortex A72 processors as
> > these require a substantially more complex solution (except where the
> > workaround is implemented in PSCI firmware.)
> >
> > Spectre variant 1 is not covered by this series.
> >
> > The patch series is based partly on Marc Zyngier's work from February -
> > two of the KVM patches are from Marc's work.
> >
> > The main differences are:
> > - Inclusion of more processors as per current ARM Ltd security update
> > documentation.
> > - Extension of "bugs" infrastructure to detect Cortex A8 and Cortex A15
> > CPUs missing out on the IBE bit being set on (re-)entry to the kernel
> > through all paths.
> > - Handle all suspect userspace-touching-kernelspace aborts irrespective
> > of mapping type.
> >
> > The first patch will trivially conflict with the Broadcom Brahma
> > updates already in arm-soc - it has been necessary to independently
> > add the ID definitions for the B15 CPU.
> >
> > Having worked through this series, I'm of the opinion that the
> > define_processor_functions macro in proc-v7 are probably more hassle
> > than they're worth - here, we don't need the global equivalent symbols,
> > because we never refer to them from the kernel code for any V7
> > processor (MULTI_CPU is always defined.)
> >
> > This series is currently in my "spectre" branch (along with some
> > Spectre variant 1 patches.)
> >
> > Please carefully review.
> >
> > arch/arm/include/asm/bugs.h | 6 +-
> > arch/arm/include/asm/cp15.h | 3 +
> > arch/arm/include/asm/cputype.h | 5 ++
> > arch/arm/include/asm/kvm_asm.h | 2 -
> > arch/arm/include/asm/kvm_host.h | 14 +++-
> > arch/arm/include/asm/kvm_mmu.h | 23 +++++-
> > arch/arm/include/asm/proc-fns.h | 4 +
> > arch/arm/include/asm/system_misc.h | 8 ++
> > arch/arm/kernel/Makefile | 1 +
> > arch/arm/kernel/bugs.c | 18 +++++
> > arch/arm/kernel/smp.c | 4 +
> > arch/arm/kernel/suspend.c | 2 +
> > arch/arm/kvm/hyp/hyp-entry.S | 108 ++++++++++++++++++++++++-
> > arch/arm/mm/Kconfig | 23 ++++++
> > arch/arm/mm/Makefile | 2 +-
> > arch/arm/mm/fault.c | 3 +
> > arch/arm/mm/proc-macros.S | 3 +-
> > arch/arm/mm/proc-v7-2level.S | 6 --
> > arch/arm/mm/proc-v7-bugs.c | 130 ++++++++++++++++++++++++++++++
> > arch/arm/mm/proc-v7.S | 158 +++++++++++++++++++++++++++++--------
> > 20 files changed, 471 insertions(+), 52 deletions(-)
> >
> > --
> > RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
> > FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up
> > According to speedtest.net: 8.21Mbps down 510kbps up
> >
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel at lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
> --
> RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
> FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up
> According to speedtest.net: 8.21Mbps down 510kbps up
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
--
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up
According to speedtest.net: 8.21Mbps down 510kbps up
^ permalink raw reply [flat|nested] 42+ messages in thread
* [PATCH v3 01/15] ARM: add more CPU part numbers for Cortex and Brahma B15 CPUs
2018-05-25 13:59 ` Russell King - ARM Linux
@ 2018-05-25 14:00 ` Russell King
-1 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:00 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: Marc Zyngier, Florian Fainelli, Christoffer Dall, kvmarm
Add CPU part numbers for Cortex A53, A57, A72, A73, A75 and the
Broadcom Brahma B15 CPU.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
---
arch/arm/include/asm/cputype.h | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h
index cb546425da8a..26021980504d 100644
--- a/arch/arm/include/asm/cputype.h
+++ b/arch/arm/include/asm/cputype.h
@@ -77,8 +77,16 @@
#define ARM_CPU_PART_CORTEX_A12 0x4100c0d0
#define ARM_CPU_PART_CORTEX_A17 0x4100c0e0
#define ARM_CPU_PART_CORTEX_A15 0x4100c0f0
+#define ARM_CPU_PART_CORTEX_A53 0x4100d030
+#define ARM_CPU_PART_CORTEX_A57 0x4100d070
+#define ARM_CPU_PART_CORTEX_A72 0x4100d080
+#define ARM_CPU_PART_CORTEX_A73 0x4100d090
+#define ARM_CPU_PART_CORTEX_A75 0x4100d0a0
#define ARM_CPU_PART_MASK 0xff00fff0
+/* Broadcom cores */
+#define ARM_CPU_PART_BRAHMA_B15 0x420000f0
+
/* DEC implemented cores */
#define ARM_CPU_PART_SA1100 0x4400a110
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v3 01/15] ARM: add more CPU part numbers for Cortex and Brahma B15 CPUs
@ 2018-05-25 14:00 ` Russell King
0 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:00 UTC (permalink / raw)
To: linux-arm-kernel
Add CPU part numbers for Cortex A53, A57, A72, A73, A75 and the
Broadcom Brahma B15 CPU.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
---
arch/arm/include/asm/cputype.h | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h
index cb546425da8a..26021980504d 100644
--- a/arch/arm/include/asm/cputype.h
+++ b/arch/arm/include/asm/cputype.h
@@ -77,8 +77,16 @@
#define ARM_CPU_PART_CORTEX_A12 0x4100c0d0
#define ARM_CPU_PART_CORTEX_A17 0x4100c0e0
#define ARM_CPU_PART_CORTEX_A15 0x4100c0f0
+#define ARM_CPU_PART_CORTEX_A53 0x4100d030
+#define ARM_CPU_PART_CORTEX_A57 0x4100d070
+#define ARM_CPU_PART_CORTEX_A72 0x4100d080
+#define ARM_CPU_PART_CORTEX_A73 0x4100d090
+#define ARM_CPU_PART_CORTEX_A75 0x4100d0a0
#define ARM_CPU_PART_MASK 0xff00fff0
+/* Broadcom cores */
+#define ARM_CPU_PART_BRAHMA_B15 0x420000f0
+
/* DEC implemented cores */
#define ARM_CPU_PART_SA1100 0x4400a110
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v3 02/15] ARM: bugs: prepare processor bug infrastructure
2018-05-25 13:59 ` Russell King - ARM Linux
@ 2018-05-25 14:00 ` Russell King
-1 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:00 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: Marc Zyngier, Florian Fainelli, kvmarm
Prepare the processor bug infrastructure so that it can be expanded to
check for per-processor bugs.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
arch/arm/include/asm/bugs.h | 4 ++--
arch/arm/kernel/Makefile | 1 +
arch/arm/kernel/bugs.c | 9 +++++++++
3 files changed, 12 insertions(+), 2 deletions(-)
create mode 100644 arch/arm/kernel/bugs.c
diff --git a/arch/arm/include/asm/bugs.h b/arch/arm/include/asm/bugs.h
index a97f1ea708d1..ed122d294f3f 100644
--- a/arch/arm/include/asm/bugs.h
+++ b/arch/arm/include/asm/bugs.h
@@ -10,10 +10,10 @@
#ifndef __ASM_BUGS_H
#define __ASM_BUGS_H
-#ifdef CONFIG_MMU
extern void check_writebuffer_bugs(void);
-#define check_bugs() check_writebuffer_bugs()
+#ifdef CONFIG_MMU
+extern void check_bugs(void);
#else
#define check_bugs() do { } while (0)
#endif
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index b59ac4bf82b8..8cad59465af3 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -31,6 +31,7 @@ else
obj-y += entry-armv.o
endif
+obj-$(CONFIG_MMU) += bugs.o
obj-$(CONFIG_CPU_IDLE) += cpuidle.o
obj-$(CONFIG_ISA_DMA_API) += dma.o
obj-$(CONFIG_FIQ) += fiq.o fiqasm.o
diff --git a/arch/arm/kernel/bugs.c b/arch/arm/kernel/bugs.c
new file mode 100644
index 000000000000..88024028bb70
--- /dev/null
+++ b/arch/arm/kernel/bugs.c
@@ -0,0 +1,9 @@
+// SPDX-Identifier: GPL-2.0
+#include <linux/init.h>
+#include <asm/bugs.h>
+#include <asm/proc-fns.h>
+
+void __init check_bugs(void)
+{
+ check_writebuffer_bugs();
+}
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread* [PATCH v3 02/15] ARM: bugs: prepare processor bug infrastructure
@ 2018-05-25 14:00 ` Russell King
0 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:00 UTC (permalink / raw)
To: linux-arm-kernel
Prepare the processor bug infrastructure so that it can be expanded to
check for per-processor bugs.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
arch/arm/include/asm/bugs.h | 4 ++--
arch/arm/kernel/Makefile | 1 +
arch/arm/kernel/bugs.c | 9 +++++++++
3 files changed, 12 insertions(+), 2 deletions(-)
create mode 100644 arch/arm/kernel/bugs.c
diff --git a/arch/arm/include/asm/bugs.h b/arch/arm/include/asm/bugs.h
index a97f1ea708d1..ed122d294f3f 100644
--- a/arch/arm/include/asm/bugs.h
+++ b/arch/arm/include/asm/bugs.h
@@ -10,10 +10,10 @@
#ifndef __ASM_BUGS_H
#define __ASM_BUGS_H
-#ifdef CONFIG_MMU
extern void check_writebuffer_bugs(void);
-#define check_bugs() check_writebuffer_bugs()
+#ifdef CONFIG_MMU
+extern void check_bugs(void);
#else
#define check_bugs() do { } while (0)
#endif
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index b59ac4bf82b8..8cad59465af3 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -31,6 +31,7 @@ else
obj-y += entry-armv.o
endif
+obj-$(CONFIG_MMU) += bugs.o
obj-$(CONFIG_CPU_IDLE) += cpuidle.o
obj-$(CONFIG_ISA_DMA_API) += dma.o
obj-$(CONFIG_FIQ) += fiq.o fiqasm.o
diff --git a/arch/arm/kernel/bugs.c b/arch/arm/kernel/bugs.c
new file mode 100644
index 000000000000..88024028bb70
--- /dev/null
+++ b/arch/arm/kernel/bugs.c
@@ -0,0 +1,9 @@
+// SPDX-Identifier: GPL-2.0
+#include <linux/init.h>
+#include <asm/bugs.h>
+#include <asm/proc-fns.h>
+
+void __init check_bugs(void)
+{
+ check_writebuffer_bugs();
+}
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v3 03/15] ARM: bugs: hook processor bug checking into SMP and suspend paths
2018-05-25 13:59 ` Russell King - ARM Linux
@ 2018-05-25 14:00 ` Russell King
-1 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:00 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: Marc Zyngier, Florian Fainelli, kvmarm
Check for CPU bugs when secondary processors are being brought online,
and also when CPUs are resuming from a low power mode. This gives an
opportunity to check that processor specific bug workarounds are
correctly enabled for all paths that a CPU re-enters the kernel.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
arch/arm/include/asm/bugs.h | 2 ++
arch/arm/kernel/bugs.c | 5 +++++
arch/arm/kernel/smp.c | 4 ++++
arch/arm/kernel/suspend.c | 2 ++
4 files changed, 13 insertions(+)
diff --git a/arch/arm/include/asm/bugs.h b/arch/arm/include/asm/bugs.h
index ed122d294f3f..73a99c72a930 100644
--- a/arch/arm/include/asm/bugs.h
+++ b/arch/arm/include/asm/bugs.h
@@ -14,8 +14,10 @@ extern void check_writebuffer_bugs(void);
#ifdef CONFIG_MMU
extern void check_bugs(void);
+extern void check_other_bugs(void);
#else
#define check_bugs() do { } while (0)
+#define check_other_bugs() do { } while (0)
#endif
#endif
diff --git a/arch/arm/kernel/bugs.c b/arch/arm/kernel/bugs.c
index 88024028bb70..16e7ba2a9cc4 100644
--- a/arch/arm/kernel/bugs.c
+++ b/arch/arm/kernel/bugs.c
@@ -3,7 +3,12 @@
#include <asm/bugs.h>
#include <asm/proc-fns.h>
+void check_other_bugs(void)
+{
+}
+
void __init check_bugs(void)
{
check_writebuffer_bugs();
+ check_other_bugs();
}
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 2da087926ebe..5ad0b67b9e33 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -31,6 +31,7 @@
#include <linux/irq_work.h>
#include <linux/atomic.h>
+#include <asm/bugs.h>
#include <asm/smp.h>
#include <asm/cacheflush.h>
#include <asm/cpu.h>
@@ -405,6 +406,9 @@ asmlinkage void secondary_start_kernel(void)
* before we continue - which happens after __cpu_up returns.
*/
set_cpu_online(cpu, true);
+
+ check_other_bugs();
+
complete(&cpu_running);
local_irq_enable();
diff --git a/arch/arm/kernel/suspend.c b/arch/arm/kernel/suspend.c
index a40ebb7c0896..d08099269e35 100644
--- a/arch/arm/kernel/suspend.c
+++ b/arch/arm/kernel/suspend.c
@@ -3,6 +3,7 @@
#include <linux/slab.h>
#include <linux/mm_types.h>
+#include <asm/bugs.h>
#include <asm/cacheflush.h>
#include <asm/idmap.h>
#include <asm/pgalloc.h>
@@ -36,6 +37,7 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
cpu_switch_mm(mm->pgd, mm);
local_flush_bp_all();
local_flush_tlb_all();
+ check_other_bugs();
}
return ret;
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread* [PATCH v3 03/15] ARM: bugs: hook processor bug checking into SMP and suspend paths
@ 2018-05-25 14:00 ` Russell King
0 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:00 UTC (permalink / raw)
To: linux-arm-kernel
Check for CPU bugs when secondary processors are being brought online,
and also when CPUs are resuming from a low power mode. This gives an
opportunity to check that processor specific bug workarounds are
correctly enabled for all paths that a CPU re-enters the kernel.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
arch/arm/include/asm/bugs.h | 2 ++
arch/arm/kernel/bugs.c | 5 +++++
arch/arm/kernel/smp.c | 4 ++++
arch/arm/kernel/suspend.c | 2 ++
4 files changed, 13 insertions(+)
diff --git a/arch/arm/include/asm/bugs.h b/arch/arm/include/asm/bugs.h
index ed122d294f3f..73a99c72a930 100644
--- a/arch/arm/include/asm/bugs.h
+++ b/arch/arm/include/asm/bugs.h
@@ -14,8 +14,10 @@ extern void check_writebuffer_bugs(void);
#ifdef CONFIG_MMU
extern void check_bugs(void);
+extern void check_other_bugs(void);
#else
#define check_bugs() do { } while (0)
+#define check_other_bugs() do { } while (0)
#endif
#endif
diff --git a/arch/arm/kernel/bugs.c b/arch/arm/kernel/bugs.c
index 88024028bb70..16e7ba2a9cc4 100644
--- a/arch/arm/kernel/bugs.c
+++ b/arch/arm/kernel/bugs.c
@@ -3,7 +3,12 @@
#include <asm/bugs.h>
#include <asm/proc-fns.h>
+void check_other_bugs(void)
+{
+}
+
void __init check_bugs(void)
{
check_writebuffer_bugs();
+ check_other_bugs();
}
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 2da087926ebe..5ad0b67b9e33 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -31,6 +31,7 @@
#include <linux/irq_work.h>
#include <linux/atomic.h>
+#include <asm/bugs.h>
#include <asm/smp.h>
#include <asm/cacheflush.h>
#include <asm/cpu.h>
@@ -405,6 +406,9 @@ asmlinkage void secondary_start_kernel(void)
* before we continue - which happens after __cpu_up returns.
*/
set_cpu_online(cpu, true);
+
+ check_other_bugs();
+
complete(&cpu_running);
local_irq_enable();
diff --git a/arch/arm/kernel/suspend.c b/arch/arm/kernel/suspend.c
index a40ebb7c0896..d08099269e35 100644
--- a/arch/arm/kernel/suspend.c
+++ b/arch/arm/kernel/suspend.c
@@ -3,6 +3,7 @@
#include <linux/slab.h>
#include <linux/mm_types.h>
+#include <asm/bugs.h>
#include <asm/cacheflush.h>
#include <asm/idmap.h>
#include <asm/pgalloc.h>
@@ -36,6 +37,7 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
cpu_switch_mm(mm->pgd, mm);
local_flush_bp_all();
local_flush_tlb_all();
+ check_other_bugs();
}
return ret;
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v3 04/15] ARM: bugs: add support for per-processor bug checking
2018-05-25 13:59 ` Russell King - ARM Linux
@ 2018-05-25 14:00 ` Russell King
-1 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:00 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: Marc Zyngier, Florian Fainelli, Christoffer Dall, kvmarm
Add support for per-processor bug checking - each processor function
descriptor gains a function pointer for this check, which must not be
an __init function. If non-NULL, this will be called whenever a CPU
enters the kernel via which ever path (boot CPU, secondary CPU startup,
CPU resuming, etc.)
This allows processor specific bug checks to validate that workaround
bits are properly enabled by firmware via all entry paths to the kernel.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
arch/arm/include/asm/proc-fns.h | 4 ++++
arch/arm/kernel/bugs.c | 4 ++++
arch/arm/mm/proc-macros.S | 3 ++-
3 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/arch/arm/include/asm/proc-fns.h b/arch/arm/include/asm/proc-fns.h
index f2e1af45bd6f..e25f4392e1b2 100644
--- a/arch/arm/include/asm/proc-fns.h
+++ b/arch/arm/include/asm/proc-fns.h
@@ -37,6 +37,10 @@ extern struct processor {
*/
void (*_proc_init)(void);
/*
+ * Check for processor bugs
+ */
+ void (*check_bugs)(void);
+ /*
* Disable any processor specifics
*/
void (*_proc_fin)(void);
diff --git a/arch/arm/kernel/bugs.c b/arch/arm/kernel/bugs.c
index 16e7ba2a9cc4..7be511310191 100644
--- a/arch/arm/kernel/bugs.c
+++ b/arch/arm/kernel/bugs.c
@@ -5,6 +5,10 @@
void check_other_bugs(void)
{
+#ifdef MULTI_CPU
+ if (processor.check_bugs)
+ processor.check_bugs();
+#endif
}
void __init check_bugs(void)
diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S
index f10e31d0730a..81d0efb055c6 100644
--- a/arch/arm/mm/proc-macros.S
+++ b/arch/arm/mm/proc-macros.S
@@ -273,13 +273,14 @@
mcr p15, 0, ip, c7, c10, 4 @ data write barrier
.endm
-.macro define_processor_functions name:req, dabort:req, pabort:req, nommu=0, suspend=0
+.macro define_processor_functions name:req, dabort:req, pabort:req, nommu=0, suspend=0, bugs=0
.type \name\()_processor_functions, #object
.align 2
ENTRY(\name\()_processor_functions)
.word \dabort
.word \pabort
.word cpu_\name\()_proc_init
+ .word \bugs
.word cpu_\name\()_proc_fin
.word cpu_\name\()_reset
.word cpu_\name\()_do_idle
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread* [PATCH v3 04/15] ARM: bugs: add support for per-processor bug checking
@ 2018-05-25 14:00 ` Russell King
0 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:00 UTC (permalink / raw)
To: linux-arm-kernel
Add support for per-processor bug checking - each processor function
descriptor gains a function pointer for this check, which must not be
an __init function. If non-NULL, this will be called whenever a CPU
enters the kernel via which ever path (boot CPU, secondary CPU startup,
CPU resuming, etc.)
This allows processor specific bug checks to validate that workaround
bits are properly enabled by firmware via all entry paths to the kernel.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
arch/arm/include/asm/proc-fns.h | 4 ++++
arch/arm/kernel/bugs.c | 4 ++++
arch/arm/mm/proc-macros.S | 3 ++-
3 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/arch/arm/include/asm/proc-fns.h b/arch/arm/include/asm/proc-fns.h
index f2e1af45bd6f..e25f4392e1b2 100644
--- a/arch/arm/include/asm/proc-fns.h
+++ b/arch/arm/include/asm/proc-fns.h
@@ -37,6 +37,10 @@ extern struct processor {
*/
void (*_proc_init)(void);
/*
+ * Check for processor bugs
+ */
+ void (*check_bugs)(void);
+ /*
* Disable any processor specifics
*/
void (*_proc_fin)(void);
diff --git a/arch/arm/kernel/bugs.c b/arch/arm/kernel/bugs.c
index 16e7ba2a9cc4..7be511310191 100644
--- a/arch/arm/kernel/bugs.c
+++ b/arch/arm/kernel/bugs.c
@@ -5,6 +5,10 @@
void check_other_bugs(void)
{
+#ifdef MULTI_CPU
+ if (processor.check_bugs)
+ processor.check_bugs();
+#endif
}
void __init check_bugs(void)
diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S
index f10e31d0730a..81d0efb055c6 100644
--- a/arch/arm/mm/proc-macros.S
+++ b/arch/arm/mm/proc-macros.S
@@ -273,13 +273,14 @@
mcr p15, 0, ip, c7, c10, 4 @ data write barrier
.endm
-.macro define_processor_functions name:req, dabort:req, pabort:req, nommu=0, suspend=0
+.macro define_processor_functions name:req, dabort:req, pabort:req, nommu=0, suspend=0, bugs=0
.type \name\()_processor_functions, #object
.align 2
ENTRY(\name\()_processor_functions)
.word \dabort
.word \pabort
.word cpu_\name\()_proc_init
+ .word \bugs
.word cpu_\name\()_proc_fin
.word cpu_\name\()_reset
.word cpu_\name\()_do_idle
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v3 05/15] ARM: spectre: add Kconfig symbol for CPUs vulnerable to Spectre
2018-05-25 13:59 ` Russell King - ARM Linux
@ 2018-05-25 14:00 ` Russell King
-1 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:00 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: Marc Zyngier, Florian Fainelli, Christoffer Dall, kvmarm
Add a Kconfig symbol for CPUs which are vulnerable to the Spectre
attacks.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
arch/arm/mm/Kconfig | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 7f14acf67caf..6f3ef86b4cb7 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -415,6 +415,7 @@ config CPU_V7
select CPU_CP15_MPU if !MMU
select CPU_HAS_ASID if MMU
select CPU_PABRT_V7
+ select CPU_SPECTRE if MMU
select CPU_THUMB_CAPABLE
select CPU_TLB_V7 if MMU
@@ -826,6 +827,9 @@ config CPU_BPREDICT_DISABLE
help
Say Y here to disable branch prediction. If unsure, say N.
+config CPU_SPECTRE
+ bool
+
config TLS_REG_EMUL
bool
select NEED_KUSER_HELPERS
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v3 05/15] ARM: spectre: add Kconfig symbol for CPUs vulnerable to Spectre
@ 2018-05-25 14:00 ` Russell King
0 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:00 UTC (permalink / raw)
To: linux-arm-kernel
Add a Kconfig symbol for CPUs which are vulnerable to the Spectre
attacks.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
arch/arm/mm/Kconfig | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 7f14acf67caf..6f3ef86b4cb7 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -415,6 +415,7 @@ config CPU_V7
select CPU_CP15_MPU if !MMU
select CPU_HAS_ASID if MMU
select CPU_PABRT_V7
+ select CPU_SPECTRE if MMU
select CPU_THUMB_CAPABLE
select CPU_TLB_V7 if MMU
@@ -826,6 +827,9 @@ config CPU_BPREDICT_DISABLE
help
Say Y here to disable branch prediction. If unsure, say N.
+config CPU_SPECTRE
+ bool
+
config TLS_REG_EMUL
bool
select NEED_KUSER_HELPERS
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v3 06/15] ARM: spectre-v2: harden branch predictor on context switches
2018-05-25 13:59 ` Russell King - ARM Linux
@ 2018-05-25 14:00 ` Russell King
-1 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:00 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: Marc Zyngier, Florian Fainelli, kvmarm
Harden the branch predictor against Spectre v2 attacks on context
switches for ARMv7 and later CPUs. We do this by:
Cortex A9, A12, A17, A73, A75: invalidating the BTB.
Cortex A15, Brahma B15: invalidating the instruction cache.
Cortex A57 and Cortex A72 are not addressed in this patch.
Cortex R7 and Cortex R8 are also not addressed as we do not enforce
memory protection on these cores.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/mm/Kconfig | 19 +++++++
arch/arm/mm/proc-v7-2level.S | 6 ---
arch/arm/mm/proc-v7.S | 125 +++++++++++++++++++++++++++++++++----------
3 files changed, 115 insertions(+), 35 deletions(-)
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 6f3ef86b4cb7..9357ff52c221 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -830,6 +830,25 @@ config CPU_BPREDICT_DISABLE
config CPU_SPECTRE
bool
+config HARDEN_BRANCH_PREDICTOR
+ bool "Harden the branch predictor against aliasing attacks" if EXPERT
+ depends on CPU_SPECTRE
+ default y
+ help
+ Speculation attacks against some high-performance processors rely
+ on being able to manipulate the branch predictor for a victim
+ context by executing aliasing branches in the attacker context.
+ Such attacks can be partially mitigated against by clearing
+ internal branch predictor state and limiting the prediction
+ logic in some situations.
+
+ This config option will take CPU-specific actions to harden
+ the branch predictor against aliasing attacks and may rely on
+ specific instruction sequences or control bits being set by
+ the system firmware.
+
+ If unsure, say Y.
+
config TLS_REG_EMUL
bool
select NEED_KUSER_HELPERS
diff --git a/arch/arm/mm/proc-v7-2level.S b/arch/arm/mm/proc-v7-2level.S
index c6141a5435c3..f8d45ad2a515 100644
--- a/arch/arm/mm/proc-v7-2level.S
+++ b/arch/arm/mm/proc-v7-2level.S
@@ -41,11 +41,6 @@
* even on Cortex-A8 revisions not affected by 430973.
* If IBE is not set, the flush BTAC/BTB won't do anything.
*/
-ENTRY(cpu_ca8_switch_mm)
-#ifdef CONFIG_MMU
- mov r2, #0
- mcr p15, 0, r2, c7, c5, 6 @ flush BTAC/BTB
-#endif
ENTRY(cpu_v7_switch_mm)
#ifdef CONFIG_MMU
mmid r1, r1 @ get mm->context.id
@@ -66,7 +61,6 @@ ENTRY(cpu_v7_switch_mm)
#endif
bx lr
ENDPROC(cpu_v7_switch_mm)
-ENDPROC(cpu_ca8_switch_mm)
/*
* cpu_v7_set_pte_ext(ptep, pte)
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index d55d493f9a1e..a2d433d59848 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -93,6 +93,17 @@ ENTRY(cpu_v7_dcache_clean_area)
ret lr
ENDPROC(cpu_v7_dcache_clean_area)
+ENTRY(cpu_v7_iciallu_switch_mm)
+ mov r3, #0
+ mcr p15, 0, r3, c7, c5, 0 @ ICIALLU
+ b cpu_v7_switch_mm
+ENDPROC(cpu_v7_iciallu_switch_mm)
+ENTRY(cpu_v7_bpiall_switch_mm)
+ mov r3, #0
+ mcr p15, 0, r3, c7, c5, 6 @ flush BTAC/BTB
+ b cpu_v7_switch_mm
+ENDPROC(cpu_v7_bpiall_switch_mm)
+
string cpu_v7_name, "ARMv7 Processor"
.align
@@ -158,31 +169,6 @@ ENTRY(cpu_v7_do_resume)
ENDPROC(cpu_v7_do_resume)
#endif
-/*
- * Cortex-A8
- */
- globl_equ cpu_ca8_proc_init, cpu_v7_proc_init
- globl_equ cpu_ca8_proc_fin, cpu_v7_proc_fin
- globl_equ cpu_ca8_reset, cpu_v7_reset
- globl_equ cpu_ca8_do_idle, cpu_v7_do_idle
- globl_equ cpu_ca8_dcache_clean_area, cpu_v7_dcache_clean_area
- globl_equ cpu_ca8_set_pte_ext, cpu_v7_set_pte_ext
- globl_equ cpu_ca8_suspend_size, cpu_v7_suspend_size
-#ifdef CONFIG_ARM_CPU_SUSPEND
- globl_equ cpu_ca8_do_suspend, cpu_v7_do_suspend
- globl_equ cpu_ca8_do_resume, cpu_v7_do_resume
-#endif
-
-/*
- * Cortex-A9 processor functions
- */
- globl_equ cpu_ca9mp_proc_init, cpu_v7_proc_init
- globl_equ cpu_ca9mp_proc_fin, cpu_v7_proc_fin
- globl_equ cpu_ca9mp_reset, cpu_v7_reset
- globl_equ cpu_ca9mp_do_idle, cpu_v7_do_idle
- globl_equ cpu_ca9mp_dcache_clean_area, cpu_v7_dcache_clean_area
- globl_equ cpu_ca9mp_switch_mm, cpu_v7_switch_mm
- globl_equ cpu_ca9mp_set_pte_ext, cpu_v7_set_pte_ext
.globl cpu_ca9mp_suspend_size
.equ cpu_ca9mp_suspend_size, cpu_v7_suspend_size + 4 * 2
#ifdef CONFIG_ARM_CPU_SUSPEND
@@ -548,10 +534,75 @@ ENDPROC(__v7_setup)
@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
define_processor_functions v7, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+ @ generic v7 bpiall on context switch
+ globl_equ cpu_v7_bpiall_proc_init, cpu_v7_proc_init
+ globl_equ cpu_v7_bpiall_proc_fin, cpu_v7_proc_fin
+ globl_equ cpu_v7_bpiall_reset, cpu_v7_reset
+ globl_equ cpu_v7_bpiall_do_idle, cpu_v7_do_idle
+ globl_equ cpu_v7_bpiall_dcache_clean_area, cpu_v7_dcache_clean_area
+ globl_equ cpu_v7_bpiall_set_pte_ext, cpu_v7_set_pte_ext
+ globl_equ cpu_v7_bpiall_suspend_size, cpu_v7_suspend_size
+#ifdef CONFIG_ARM_CPU_SUSPEND
+ globl_equ cpu_v7_bpiall_do_suspend, cpu_v7_do_suspend
+ globl_equ cpu_v7_bpiall_do_resume, cpu_v7_do_resume
+#endif
+ define_processor_functions v7_bpiall, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+
+#define HARDENED_BPIALL_PROCESSOR_FUNCTIONS v7_bpiall_processor_functions
+#else
+#define HARDENED_BPIALL_PROCESSOR_FUNCTIONS v7_processor_functions
+#endif
+
#ifndef CONFIG_ARM_LPAE
+ @ Cortex-A8 - always needs bpiall switch_mm implementation
+ globl_equ cpu_ca8_proc_init, cpu_v7_proc_init
+ globl_equ cpu_ca8_proc_fin, cpu_v7_proc_fin
+ globl_equ cpu_ca8_reset, cpu_v7_reset
+ globl_equ cpu_ca8_do_idle, cpu_v7_do_idle
+ globl_equ cpu_ca8_dcache_clean_area, cpu_v7_dcache_clean_area
+ globl_equ cpu_ca8_set_pte_ext, cpu_v7_set_pte_ext
+ globl_equ cpu_ca8_switch_mm, cpu_v7_bpiall_switch_mm
+ globl_equ cpu_ca8_suspend_size, cpu_v7_suspend_size
+#ifdef CONFIG_ARM_CPU_SUSPEND
+ globl_equ cpu_ca8_do_suspend, cpu_v7_do_suspend
+ globl_equ cpu_ca8_do_resume, cpu_v7_do_resume
+#endif
define_processor_functions ca8, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+
+ @ Cortex-A9 - needs more registers preserved across suspend/resume
+ @ and bpiall switch_mm for hardening
+ globl_equ cpu_ca9mp_proc_init, cpu_v7_proc_init
+ globl_equ cpu_ca9mp_proc_fin, cpu_v7_proc_fin
+ globl_equ cpu_ca9mp_reset, cpu_v7_reset
+ globl_equ cpu_ca9mp_do_idle, cpu_v7_do_idle
+ globl_equ cpu_ca9mp_dcache_clean_area, cpu_v7_dcache_clean_area
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+ globl_equ cpu_ca9mp_switch_mm, cpu_v7_bpiall_switch_mm
+#else
+ globl_equ cpu_ca9mp_switch_mm, cpu_v7_switch_mm
+#endif
+ globl_equ cpu_ca9mp_set_pte_ext, cpu_v7_set_pte_ext
define_processor_functions ca9mp, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
#endif
+
+ @ Cortex-A15 - needs iciallu switch_mm for hardening
+ globl_equ cpu_ca15_proc_init, cpu_v7_proc_init
+ globl_equ cpu_ca15_proc_fin, cpu_v7_proc_fin
+ globl_equ cpu_ca15_reset, cpu_v7_reset
+ globl_equ cpu_ca15_do_idle, cpu_v7_do_idle
+ globl_equ cpu_ca15_dcache_clean_area, cpu_v7_dcache_clean_area
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+ globl_equ cpu_ca15_switch_mm, cpu_v7_iciallu_switch_mm
+#else
+ globl_equ cpu_ca15_switch_mm, cpu_v7_switch_mm
+#endif
+ globl_equ cpu_ca15_set_pte_ext, cpu_v7_set_pte_ext
+ globl_equ cpu_ca15_suspend_size, cpu_v7_suspend_size
+ globl_equ cpu_ca15_do_suspend, cpu_v7_do_suspend
+ globl_equ cpu_ca15_do_resume, cpu_v7_do_resume
+ define_processor_functions ca15, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
#ifdef CONFIG_CPU_PJ4B
define_processor_functions pj4b, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
#endif
@@ -658,7 +709,7 @@ ENDPROC(__v7_setup)
__v7_ca12mp_proc_info:
.long 0x410fc0d0
.long 0xff0ffff0
- __v7_proc __v7_ca12mp_proc_info, __v7_ca12mp_setup
+ __v7_proc __v7_ca12mp_proc_info, __v7_ca12mp_setup, proc_fns = HARDENED_BPIALL_PROCESSOR_FUNCTIONS
.size __v7_ca12mp_proc_info, . - __v7_ca12mp_proc_info
/*
@@ -668,7 +719,7 @@ ENDPROC(__v7_setup)
__v7_ca15mp_proc_info:
.long 0x410fc0f0
.long 0xff0ffff0
- __v7_proc __v7_ca15mp_proc_info, __v7_ca15mp_setup
+ __v7_proc __v7_ca15mp_proc_info, __v7_ca15mp_setup, proc_fns = ca15_processor_functions
.size __v7_ca15mp_proc_info, . - __v7_ca15mp_proc_info
/*
@@ -678,7 +729,7 @@ ENDPROC(__v7_setup)
__v7_b15mp_proc_info:
.long 0x420f00f0
.long 0xff0ffff0
- __v7_proc __v7_b15mp_proc_info, __v7_b15mp_setup, cache_fns = b15_cache_fns
+ __v7_proc __v7_b15mp_proc_info, __v7_b15mp_setup, proc_fns = ca15_processor_functions, cache_fns = b15_cache_fns
.size __v7_b15mp_proc_info, . - __v7_b15mp_proc_info
/*
@@ -688,9 +739,25 @@ ENDPROC(__v7_setup)
__v7_ca17mp_proc_info:
.long 0x410fc0e0
.long 0xff0ffff0
- __v7_proc __v7_ca17mp_proc_info, __v7_ca17mp_setup
+ __v7_proc __v7_ca17mp_proc_info, __v7_ca17mp_setup, proc_fns = HARDENED_BPIALL_PROCESSOR_FUNCTIONS
.size __v7_ca17mp_proc_info, . - __v7_ca17mp_proc_info
+ /* ARM Ltd. Cortex A73 processor */
+ .type __v7_ca73_proc_info, #object
+__v7_ca73_proc_info:
+ .long 0x410fd090
+ .long 0xff0ffff0
+ __v7_proc __v7_ca73_proc_info, __v7_setup, proc_fns = HARDENED_BPIALL_PROCESSOR_FUNCTIONS
+ .size __v7_ca73_proc_info, . - __v7_ca73_proc_info
+
+ /* ARM Ltd. Cortex A75 processor */
+ .type __v7_ca75_proc_info, #object
+__v7_ca75_proc_info:
+ .long 0x410fd0a0
+ .long 0xff0ffff0
+ __v7_proc __v7_ca75_proc_info, __v7_setup, proc_fns = HARDENED_BPIALL_PROCESSOR_FUNCTIONS
+ .size __v7_ca75_proc_info, . - __v7_ca75_proc_info
+
/*
* Qualcomm Inc. Krait processors.
*/
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v3 06/15] ARM: spectre-v2: harden branch predictor on context switches
@ 2018-05-25 14:00 ` Russell King
0 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:00 UTC (permalink / raw)
To: linux-arm-kernel
Harden the branch predictor against Spectre v2 attacks on context
switches for ARMv7 and later CPUs. We do this by:
Cortex A9, A12, A17, A73, A75: invalidating the BTB.
Cortex A15, Brahma B15: invalidating the instruction cache.
Cortex A57 and Cortex A72 are not addressed in this patch.
Cortex R7 and Cortex R8 are also not addressed as we do not enforce
memory protection on these cores.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/mm/Kconfig | 19 +++++++
arch/arm/mm/proc-v7-2level.S | 6 ---
arch/arm/mm/proc-v7.S | 125 +++++++++++++++++++++++++++++++++----------
3 files changed, 115 insertions(+), 35 deletions(-)
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 6f3ef86b4cb7..9357ff52c221 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -830,6 +830,25 @@ config CPU_BPREDICT_DISABLE
config CPU_SPECTRE
bool
+config HARDEN_BRANCH_PREDICTOR
+ bool "Harden the branch predictor against aliasing attacks" if EXPERT
+ depends on CPU_SPECTRE
+ default y
+ help
+ Speculation attacks against some high-performance processors rely
+ on being able to manipulate the branch predictor for a victim
+ context by executing aliasing branches in the attacker context.
+ Such attacks can be partially mitigated against by clearing
+ internal branch predictor state and limiting the prediction
+ logic in some situations.
+
+ This config option will take CPU-specific actions to harden
+ the branch predictor against aliasing attacks and may rely on
+ specific instruction sequences or control bits being set by
+ the system firmware.
+
+ If unsure, say Y.
+
config TLS_REG_EMUL
bool
select NEED_KUSER_HELPERS
diff --git a/arch/arm/mm/proc-v7-2level.S b/arch/arm/mm/proc-v7-2level.S
index c6141a5435c3..f8d45ad2a515 100644
--- a/arch/arm/mm/proc-v7-2level.S
+++ b/arch/arm/mm/proc-v7-2level.S
@@ -41,11 +41,6 @@
* even on Cortex-A8 revisions not affected by 430973.
* If IBE is not set, the flush BTAC/BTB won't do anything.
*/
-ENTRY(cpu_ca8_switch_mm)
-#ifdef CONFIG_MMU
- mov r2, #0
- mcr p15, 0, r2, c7, c5, 6 @ flush BTAC/BTB
-#endif
ENTRY(cpu_v7_switch_mm)
#ifdef CONFIG_MMU
mmid r1, r1 @ get mm->context.id
@@ -66,7 +61,6 @@ ENTRY(cpu_v7_switch_mm)
#endif
bx lr
ENDPROC(cpu_v7_switch_mm)
-ENDPROC(cpu_ca8_switch_mm)
/*
* cpu_v7_set_pte_ext(ptep, pte)
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index d55d493f9a1e..a2d433d59848 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -93,6 +93,17 @@ ENTRY(cpu_v7_dcache_clean_area)
ret lr
ENDPROC(cpu_v7_dcache_clean_area)
+ENTRY(cpu_v7_iciallu_switch_mm)
+ mov r3, #0
+ mcr p15, 0, r3, c7, c5, 0 @ ICIALLU
+ b cpu_v7_switch_mm
+ENDPROC(cpu_v7_iciallu_switch_mm)
+ENTRY(cpu_v7_bpiall_switch_mm)
+ mov r3, #0
+ mcr p15, 0, r3, c7, c5, 6 @ flush BTAC/BTB
+ b cpu_v7_switch_mm
+ENDPROC(cpu_v7_bpiall_switch_mm)
+
string cpu_v7_name, "ARMv7 Processor"
.align
@@ -158,31 +169,6 @@ ENTRY(cpu_v7_do_resume)
ENDPROC(cpu_v7_do_resume)
#endif
-/*
- * Cortex-A8
- */
- globl_equ cpu_ca8_proc_init, cpu_v7_proc_init
- globl_equ cpu_ca8_proc_fin, cpu_v7_proc_fin
- globl_equ cpu_ca8_reset, cpu_v7_reset
- globl_equ cpu_ca8_do_idle, cpu_v7_do_idle
- globl_equ cpu_ca8_dcache_clean_area, cpu_v7_dcache_clean_area
- globl_equ cpu_ca8_set_pte_ext, cpu_v7_set_pte_ext
- globl_equ cpu_ca8_suspend_size, cpu_v7_suspend_size
-#ifdef CONFIG_ARM_CPU_SUSPEND
- globl_equ cpu_ca8_do_suspend, cpu_v7_do_suspend
- globl_equ cpu_ca8_do_resume, cpu_v7_do_resume
-#endif
-
-/*
- * Cortex-A9 processor functions
- */
- globl_equ cpu_ca9mp_proc_init, cpu_v7_proc_init
- globl_equ cpu_ca9mp_proc_fin, cpu_v7_proc_fin
- globl_equ cpu_ca9mp_reset, cpu_v7_reset
- globl_equ cpu_ca9mp_do_idle, cpu_v7_do_idle
- globl_equ cpu_ca9mp_dcache_clean_area, cpu_v7_dcache_clean_area
- globl_equ cpu_ca9mp_switch_mm, cpu_v7_switch_mm
- globl_equ cpu_ca9mp_set_pte_ext, cpu_v7_set_pte_ext
.globl cpu_ca9mp_suspend_size
.equ cpu_ca9mp_suspend_size, cpu_v7_suspend_size + 4 * 2
#ifdef CONFIG_ARM_CPU_SUSPEND
@@ -548,10 +534,75 @@ ENDPROC(__v7_setup)
@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
define_processor_functions v7, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+ @ generic v7 bpiall on context switch
+ globl_equ cpu_v7_bpiall_proc_init, cpu_v7_proc_init
+ globl_equ cpu_v7_bpiall_proc_fin, cpu_v7_proc_fin
+ globl_equ cpu_v7_bpiall_reset, cpu_v7_reset
+ globl_equ cpu_v7_bpiall_do_idle, cpu_v7_do_idle
+ globl_equ cpu_v7_bpiall_dcache_clean_area, cpu_v7_dcache_clean_area
+ globl_equ cpu_v7_bpiall_set_pte_ext, cpu_v7_set_pte_ext
+ globl_equ cpu_v7_bpiall_suspend_size, cpu_v7_suspend_size
+#ifdef CONFIG_ARM_CPU_SUSPEND
+ globl_equ cpu_v7_bpiall_do_suspend, cpu_v7_do_suspend
+ globl_equ cpu_v7_bpiall_do_resume, cpu_v7_do_resume
+#endif
+ define_processor_functions v7_bpiall, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+
+#define HARDENED_BPIALL_PROCESSOR_FUNCTIONS v7_bpiall_processor_functions
+#else
+#define HARDENED_BPIALL_PROCESSOR_FUNCTIONS v7_processor_functions
+#endif
+
#ifndef CONFIG_ARM_LPAE
+ @ Cortex-A8 - always needs bpiall switch_mm implementation
+ globl_equ cpu_ca8_proc_init, cpu_v7_proc_init
+ globl_equ cpu_ca8_proc_fin, cpu_v7_proc_fin
+ globl_equ cpu_ca8_reset, cpu_v7_reset
+ globl_equ cpu_ca8_do_idle, cpu_v7_do_idle
+ globl_equ cpu_ca8_dcache_clean_area, cpu_v7_dcache_clean_area
+ globl_equ cpu_ca8_set_pte_ext, cpu_v7_set_pte_ext
+ globl_equ cpu_ca8_switch_mm, cpu_v7_bpiall_switch_mm
+ globl_equ cpu_ca8_suspend_size, cpu_v7_suspend_size
+#ifdef CONFIG_ARM_CPU_SUSPEND
+ globl_equ cpu_ca8_do_suspend, cpu_v7_do_suspend
+ globl_equ cpu_ca8_do_resume, cpu_v7_do_resume
+#endif
define_processor_functions ca8, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+
+ @ Cortex-A9 - needs more registers preserved across suspend/resume
+ @ and bpiall switch_mm for hardening
+ globl_equ cpu_ca9mp_proc_init, cpu_v7_proc_init
+ globl_equ cpu_ca9mp_proc_fin, cpu_v7_proc_fin
+ globl_equ cpu_ca9mp_reset, cpu_v7_reset
+ globl_equ cpu_ca9mp_do_idle, cpu_v7_do_idle
+ globl_equ cpu_ca9mp_dcache_clean_area, cpu_v7_dcache_clean_area
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+ globl_equ cpu_ca9mp_switch_mm, cpu_v7_bpiall_switch_mm
+#else
+ globl_equ cpu_ca9mp_switch_mm, cpu_v7_switch_mm
+#endif
+ globl_equ cpu_ca9mp_set_pte_ext, cpu_v7_set_pte_ext
define_processor_functions ca9mp, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
#endif
+
+ @ Cortex-A15 - needs iciallu switch_mm for hardening
+ globl_equ cpu_ca15_proc_init, cpu_v7_proc_init
+ globl_equ cpu_ca15_proc_fin, cpu_v7_proc_fin
+ globl_equ cpu_ca15_reset, cpu_v7_reset
+ globl_equ cpu_ca15_do_idle, cpu_v7_do_idle
+ globl_equ cpu_ca15_dcache_clean_area, cpu_v7_dcache_clean_area
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+ globl_equ cpu_ca15_switch_mm, cpu_v7_iciallu_switch_mm
+#else
+ globl_equ cpu_ca15_switch_mm, cpu_v7_switch_mm
+#endif
+ globl_equ cpu_ca15_set_pte_ext, cpu_v7_set_pte_ext
+ globl_equ cpu_ca15_suspend_size, cpu_v7_suspend_size
+ globl_equ cpu_ca15_do_suspend, cpu_v7_do_suspend
+ globl_equ cpu_ca15_do_resume, cpu_v7_do_resume
+ define_processor_functions ca15, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
#ifdef CONFIG_CPU_PJ4B
define_processor_functions pj4b, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
#endif
@@ -658,7 +709,7 @@ ENDPROC(__v7_setup)
__v7_ca12mp_proc_info:
.long 0x410fc0d0
.long 0xff0ffff0
- __v7_proc __v7_ca12mp_proc_info, __v7_ca12mp_setup
+ __v7_proc __v7_ca12mp_proc_info, __v7_ca12mp_setup, proc_fns = HARDENED_BPIALL_PROCESSOR_FUNCTIONS
.size __v7_ca12mp_proc_info, . - __v7_ca12mp_proc_info
/*
@@ -668,7 +719,7 @@ ENDPROC(__v7_setup)
__v7_ca15mp_proc_info:
.long 0x410fc0f0
.long 0xff0ffff0
- __v7_proc __v7_ca15mp_proc_info, __v7_ca15mp_setup
+ __v7_proc __v7_ca15mp_proc_info, __v7_ca15mp_setup, proc_fns = ca15_processor_functions
.size __v7_ca15mp_proc_info, . - __v7_ca15mp_proc_info
/*
@@ -678,7 +729,7 @@ ENDPROC(__v7_setup)
__v7_b15mp_proc_info:
.long 0x420f00f0
.long 0xff0ffff0
- __v7_proc __v7_b15mp_proc_info, __v7_b15mp_setup, cache_fns = b15_cache_fns
+ __v7_proc __v7_b15mp_proc_info, __v7_b15mp_setup, proc_fns = ca15_processor_functions, cache_fns = b15_cache_fns
.size __v7_b15mp_proc_info, . - __v7_b15mp_proc_info
/*
@@ -688,9 +739,25 @@ ENDPROC(__v7_setup)
__v7_ca17mp_proc_info:
.long 0x410fc0e0
.long 0xff0ffff0
- __v7_proc __v7_ca17mp_proc_info, __v7_ca17mp_setup
+ __v7_proc __v7_ca17mp_proc_info, __v7_ca17mp_setup, proc_fns = HARDENED_BPIALL_PROCESSOR_FUNCTIONS
.size __v7_ca17mp_proc_info, . - __v7_ca17mp_proc_info
+ /* ARM Ltd. Cortex A73 processor */
+ .type __v7_ca73_proc_info, #object
+__v7_ca73_proc_info:
+ .long 0x410fd090
+ .long 0xff0ffff0
+ __v7_proc __v7_ca73_proc_info, __v7_setup, proc_fns = HARDENED_BPIALL_PROCESSOR_FUNCTIONS
+ .size __v7_ca73_proc_info, . - __v7_ca73_proc_info
+
+ /* ARM Ltd. Cortex A75 processor */
+ .type __v7_ca75_proc_info, #object
+__v7_ca75_proc_info:
+ .long 0x410fd0a0
+ .long 0xff0ffff0
+ __v7_proc __v7_ca75_proc_info, __v7_setup, proc_fns = HARDENED_BPIALL_PROCESSOR_FUNCTIONS
+ .size __v7_ca75_proc_info, . - __v7_ca75_proc_info
+
/*
* Qualcomm Inc. Krait processors.
*/
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v3 07/15] ARM: spectre-v2: add Cortex A8 and A15 validation of the IBE bit
2018-05-25 13:59 ` Russell King - ARM Linux
@ 2018-05-25 14:00 ` Russell King
-1 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:00 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: Marc Zyngier, Florian Fainelli, kvmarm
When the branch predictor hardening is enabled, firmware must have set
the IBE bit in the auxiliary control register. If this bit has not
been set, the Spectre workarounds will not be functional.
Add validation that this bit is set, and print a warning at alert level
if this is not the case.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
arch/arm/mm/Makefile | 2 +-
arch/arm/mm/proc-v7-bugs.c | 29 +++++++++++++++++++++++++++++
arch/arm/mm/proc-v7.S | 4 ++--
3 files changed, 32 insertions(+), 3 deletions(-)
create mode 100644 arch/arm/mm/proc-v7-bugs.c
diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index 9dbb84923e12..a0c40610210c 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -97,7 +97,7 @@ obj-$(CONFIG_CPU_MOHAWK) += proc-mohawk.o
obj-$(CONFIG_CPU_FEROCEON) += proc-feroceon.o
obj-$(CONFIG_CPU_V6) += proc-v6.o
obj-$(CONFIG_CPU_V6K) += proc-v6.o
-obj-$(CONFIG_CPU_V7) += proc-v7.o
+obj-$(CONFIG_CPU_V7) += proc-v7.o proc-v7-bugs.o
obj-$(CONFIG_CPU_V7M) += proc-v7m.o
AFLAGS_proc-v6.o :=-Wa,-march=armv6
diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c
new file mode 100644
index 000000000000..a32ce13479d9
--- /dev/null
+++ b/arch/arm/mm/proc-v7-bugs.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/smp.h>
+
+static __maybe_unused void cpu_v7_check_auxcr_set(u32 mask, const char *msg)
+{
+ u32 aux_cr;
+
+ asm("mrc p15, 0, %0, c1, c0, 1" : "=r" (aux_cr));
+
+ if ((aux_cr & mask) != mask)
+ pr_err("CPU%u: %s", smp_processor_id(), msg);
+}
+
+static void check_spectre_auxcr(u32 bit)
+{
+ if (IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR))
+ cpu_v7_check_auxcr_set(bit, "Spectre v2: firmware did not set auxiliary control register IBE bit, system vulnerable\n");
+}
+
+void cpu_v7_ca8_ibe(void)
+{
+ check_spectre_auxcr(BIT(6));
+}
+
+void cpu_v7_ca15_ibe(void)
+{
+ check_spectre_auxcr(BIT(0));
+}
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index a2d433d59848..fa9214036fb3 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -569,7 +569,7 @@ ENDPROC(__v7_setup)
globl_equ cpu_ca8_do_suspend, cpu_v7_do_suspend
globl_equ cpu_ca8_do_resume, cpu_v7_do_resume
#endif
- define_processor_functions ca8, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+ define_processor_functions ca8, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_ca8_ibe
@ Cortex-A9 - needs more registers preserved across suspend/resume
@ and bpiall switch_mm for hardening
@@ -602,7 +602,7 @@ ENDPROC(__v7_setup)
globl_equ cpu_ca15_suspend_size, cpu_v7_suspend_size
globl_equ cpu_ca15_do_suspend, cpu_v7_do_suspend
globl_equ cpu_ca15_do_resume, cpu_v7_do_resume
- define_processor_functions ca15, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+ define_processor_functions ca15, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_ca15_ibe
#ifdef CONFIG_CPU_PJ4B
define_processor_functions pj4b, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
#endif
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread* [PATCH v3 07/15] ARM: spectre-v2: add Cortex A8 and A15 validation of the IBE bit
@ 2018-05-25 14:00 ` Russell King
0 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:00 UTC (permalink / raw)
To: linux-arm-kernel
When the branch predictor hardening is enabled, firmware must have set
the IBE bit in the auxiliary control register. If this bit has not
been set, the Spectre workarounds will not be functional.
Add validation that this bit is set, and print a warning at alert level
if this is not the case.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
arch/arm/mm/Makefile | 2 +-
arch/arm/mm/proc-v7-bugs.c | 29 +++++++++++++++++++++++++++++
arch/arm/mm/proc-v7.S | 4 ++--
3 files changed, 32 insertions(+), 3 deletions(-)
create mode 100644 arch/arm/mm/proc-v7-bugs.c
diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index 9dbb84923e12..a0c40610210c 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -97,7 +97,7 @@ obj-$(CONFIG_CPU_MOHAWK) += proc-mohawk.o
obj-$(CONFIG_CPU_FEROCEON) += proc-feroceon.o
obj-$(CONFIG_CPU_V6) += proc-v6.o
obj-$(CONFIG_CPU_V6K) += proc-v6.o
-obj-$(CONFIG_CPU_V7) += proc-v7.o
+obj-$(CONFIG_CPU_V7) += proc-v7.o proc-v7-bugs.o
obj-$(CONFIG_CPU_V7M) += proc-v7m.o
AFLAGS_proc-v6.o :=-Wa,-march=armv6
diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c
new file mode 100644
index 000000000000..a32ce13479d9
--- /dev/null
+++ b/arch/arm/mm/proc-v7-bugs.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/smp.h>
+
+static __maybe_unused void cpu_v7_check_auxcr_set(u32 mask, const char *msg)
+{
+ u32 aux_cr;
+
+ asm("mrc p15, 0, %0, c1, c0, 1" : "=r" (aux_cr));
+
+ if ((aux_cr & mask) != mask)
+ pr_err("CPU%u: %s", smp_processor_id(), msg);
+}
+
+static void check_spectre_auxcr(u32 bit)
+{
+ if (IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR))
+ cpu_v7_check_auxcr_set(bit, "Spectre v2: firmware did not set auxiliary control register IBE bit, system vulnerable\n");
+}
+
+void cpu_v7_ca8_ibe(void)
+{
+ check_spectre_auxcr(BIT(6));
+}
+
+void cpu_v7_ca15_ibe(void)
+{
+ check_spectre_auxcr(BIT(0));
+}
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index a2d433d59848..fa9214036fb3 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -569,7 +569,7 @@ ENDPROC(__v7_setup)
globl_equ cpu_ca8_do_suspend, cpu_v7_do_suspend
globl_equ cpu_ca8_do_resume, cpu_v7_do_resume
#endif
- define_processor_functions ca8, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+ define_processor_functions ca8, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_ca8_ibe
@ Cortex-A9 - needs more registers preserved across suspend/resume
@ and bpiall switch_mm for hardening
@@ -602,7 +602,7 @@ ENDPROC(__v7_setup)
globl_equ cpu_ca15_suspend_size, cpu_v7_suspend_size
globl_equ cpu_ca15_do_suspend, cpu_v7_do_suspend
globl_equ cpu_ca15_do_resume, cpu_v7_do_resume
- define_processor_functions ca15, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+ define_processor_functions ca15, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_ca15_ibe
#ifdef CONFIG_CPU_PJ4B
define_processor_functions pj4b, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
#endif
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v3 08/15] ARM: spectre-v2: harden user aborts in kernel space
2018-05-25 13:59 ` Russell King - ARM Linux
@ 2018-05-25 14:01 ` Russell King
-1 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:01 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: Marc Zyngier, Florian Fainelli, kvmarm
In order to prevent aliasing attacks on the branch predictor,
invalidate the BTB or instruction cache on CPUs that are known to be
affected when taking an abort on a address that is outside of a user
task limit:
Cortex A8, A9, A12, A17, A73, A75: flush BTB.
Cortex A15, Brahma B15: invalidate icache.
If the IBE bit is not set, then there is little point to enabling the
workaround.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/include/asm/cp15.h | 3 ++
arch/arm/include/asm/system_misc.h | 15 ++++++++
arch/arm/mm/fault.c | 3 ++
arch/arm/mm/proc-v7-bugs.c | 76 +++++++++++++++++++++++++++++++++++---
arch/arm/mm/proc-v7.S | 8 ++--
5 files changed, 96 insertions(+), 9 deletions(-)
diff --git a/arch/arm/include/asm/cp15.h b/arch/arm/include/asm/cp15.h
index 4c9fa72b59f5..07e27f212dc7 100644
--- a/arch/arm/include/asm/cp15.h
+++ b/arch/arm/include/asm/cp15.h
@@ -65,6 +65,9 @@
#define __write_sysreg(v, r, w, c, t) asm volatile(w " " c : : "r" ((t)(v)))
#define write_sysreg(v, ...) __write_sysreg(v, __VA_ARGS__)
+#define BPIALL __ACCESS_CP15(c7, 0, c5, 6)
+#define ICIALLU __ACCESS_CP15(c7, 0, c5, 0)
+
extern unsigned long cr_alignment; /* defined in entry-armv.S */
static inline unsigned long get_cr(void)
diff --git a/arch/arm/include/asm/system_misc.h b/arch/arm/include/asm/system_misc.h
index 78f6db114faf..8e76db83c498 100644
--- a/arch/arm/include/asm/system_misc.h
+++ b/arch/arm/include/asm/system_misc.h
@@ -8,6 +8,7 @@
#include <linux/linkage.h>
#include <linux/irqflags.h>
#include <linux/reboot.h>
+#include <linux/percpu.h>
extern void cpu_init(void);
@@ -15,6 +16,20 @@ void soft_restart(unsigned long);
extern void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
extern void (*arm_pm_idle)(void);
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+typedef void (*harden_branch_predictor_fn_t)(void);
+DECLARE_PER_CPU(harden_branch_predictor_fn_t, harden_branch_predictor_fn);
+static inline void harden_branch_predictor(void)
+{
+ harden_branch_predictor_fn_t fn = per_cpu(harden_branch_predictor_fn,
+ smp_processor_id());
+ if (fn)
+ fn();
+}
+#else
+#define harden_branch_predictor() do { } while (0)
+#endif
+
#define UDBG_UNDEFINED (1 << 0)
#define UDBG_SYSCALL (1 << 1)
#define UDBG_BADABORT (1 << 2)
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index b75eada23d0a..3b1ba003c4f9 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -163,6 +163,9 @@ __do_user_fault(struct task_struct *tsk, unsigned long addr,
{
struct siginfo si;
+ if (addr > TASK_SIZE)
+ harden_branch_predictor();
+
#ifdef CONFIG_DEBUG_USER
if (((user_debug & UDBG_SEGV) && (sig == SIGSEGV)) ||
((user_debug & UDBG_BUS) && (sig == SIGBUS))) {
diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c
index a32ce13479d9..585b2b61d7d3 100644
--- a/arch/arm/mm/proc-v7-bugs.c
+++ b/arch/arm/mm/proc-v7-bugs.c
@@ -2,28 +2,92 @@
#include <linux/kernel.h>
#include <linux/smp.h>
-static __maybe_unused void cpu_v7_check_auxcr_set(u32 mask, const char *msg)
+#include <asm/cp15.h>
+#include <asm/cputype.h>
+#include <asm/system_misc.h>
+
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+DEFINE_PER_CPU(harden_branch_predictor_fn_t, harden_branch_predictor_fn);
+
+static void harden_branch_predictor_bpiall(void)
+{
+ write_sysreg(0, BPIALL);
+}
+
+static void harden_branch_predictor_iciallu(void)
+{
+ write_sysreg(0, ICIALLU);
+}
+
+static void cpu_v7_spectre_init(void)
+{
+ const char *spectre_v2_method = NULL;
+ int cpu = smp_processor_id();
+
+ if (per_cpu(harden_branch_predictor_fn, cpu))
+ return;
+
+ switch (read_cpuid_part()) {
+ case ARM_CPU_PART_CORTEX_A8:
+ case ARM_CPU_PART_CORTEX_A9:
+ case ARM_CPU_PART_CORTEX_A12:
+ case ARM_CPU_PART_CORTEX_A17:
+ case ARM_CPU_PART_CORTEX_A73:
+ case ARM_CPU_PART_CORTEX_A75:
+ per_cpu(harden_branch_predictor_fn, cpu) =
+ harden_branch_predictor_bpiall;
+ spectre_v2_method = "BPIALL";
+ break;
+
+ case ARM_CPU_PART_CORTEX_A15:
+ case ARM_CPU_PART_BRAHMA_B15:
+ per_cpu(harden_branch_predictor_fn, cpu) =
+ harden_branch_predictor_iciallu;
+ spectre_v2_method = "ICIALLU";
+ break;
+ }
+ if (spectre_v2_method)
+ pr_info("CPU%u: Spectre v2: using %s workaround\n",
+ smp_processor_id(), spectre_v2_method);
+}
+#else
+static void cpu_v7_spectre_init(void)
+{
+}
+#endif
+
+static __maybe_unused bool cpu_v7_check_auxcr_set(u32 mask, const char *msg)
{
u32 aux_cr;
asm("mrc p15, 0, %0, c1, c0, 1" : "=r" (aux_cr));
- if ((aux_cr & mask) != mask)
+ if ((aux_cr & mask) != mask) {
pr_err("CPU%u: %s", smp_processor_id(), msg);
+ return false;
+ }
+ return true;
}
-static void check_spectre_auxcr(u32 bit)
+static bool check_spectre_auxcr(u32 bit)
{
- if (IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR))
+ return IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR) &&
cpu_v7_check_auxcr_set(bit, "Spectre v2: firmware did not set auxiliary control register IBE bit, system vulnerable\n");
}
void cpu_v7_ca8_ibe(void)
{
- check_spectre_auxcr(BIT(6));
+ if (check_spectre_auxcr(BIT(6)))
+ cpu_v7_spectre_init();
}
void cpu_v7_ca15_ibe(void)
{
- check_spectre_auxcr(BIT(0));
+ if (check_spectre_auxcr(BIT(0)))
+ cpu_v7_spectre_init();
+}
+
+void cpu_v7_bugs_init(void)
+{
+ cpu_v7_spectre_init();
}
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index fa9214036fb3..79510011e7eb 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -532,8 +532,10 @@ ENDPROC(__v7_setup)
__INITDATA
+ .weak cpu_v7_bugs_init
+
@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
- define_processor_functions v7, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+ define_processor_functions v7, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_bugs_init
#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
@ generic v7 bpiall on context switch
@@ -548,7 +550,7 @@ ENDPROC(__v7_setup)
globl_equ cpu_v7_bpiall_do_suspend, cpu_v7_do_suspend
globl_equ cpu_v7_bpiall_do_resume, cpu_v7_do_resume
#endif
- define_processor_functions v7_bpiall, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+ define_processor_functions v7_bpiall, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_bugs_init
#define HARDENED_BPIALL_PROCESSOR_FUNCTIONS v7_bpiall_processor_functions
#else
@@ -584,7 +586,7 @@ ENDPROC(__v7_setup)
globl_equ cpu_ca9mp_switch_mm, cpu_v7_switch_mm
#endif
globl_equ cpu_ca9mp_set_pte_ext, cpu_v7_set_pte_ext
- define_processor_functions ca9mp, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+ define_processor_functions ca9mp, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_bugs_init
#endif
@ Cortex-A15 - needs iciallu switch_mm for hardening
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread* [PATCH v3 08/15] ARM: spectre-v2: harden user aborts in kernel space
@ 2018-05-25 14:01 ` Russell King
0 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:01 UTC (permalink / raw)
To: linux-arm-kernel
In order to prevent aliasing attacks on the branch predictor,
invalidate the BTB or instruction cache on CPUs that are known to be
affected when taking an abort on a address that is outside of a user
task limit:
Cortex A8, A9, A12, A17, A73, A75: flush BTB.
Cortex A15, Brahma B15: invalidate icache.
If the IBE bit is not set, then there is little point to enabling the
workaround.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/include/asm/cp15.h | 3 ++
arch/arm/include/asm/system_misc.h | 15 ++++++++
arch/arm/mm/fault.c | 3 ++
arch/arm/mm/proc-v7-bugs.c | 76 +++++++++++++++++++++++++++++++++++---
arch/arm/mm/proc-v7.S | 8 ++--
5 files changed, 96 insertions(+), 9 deletions(-)
diff --git a/arch/arm/include/asm/cp15.h b/arch/arm/include/asm/cp15.h
index 4c9fa72b59f5..07e27f212dc7 100644
--- a/arch/arm/include/asm/cp15.h
+++ b/arch/arm/include/asm/cp15.h
@@ -65,6 +65,9 @@
#define __write_sysreg(v, r, w, c, t) asm volatile(w " " c : : "r" ((t)(v)))
#define write_sysreg(v, ...) __write_sysreg(v, __VA_ARGS__)
+#define BPIALL __ACCESS_CP15(c7, 0, c5, 6)
+#define ICIALLU __ACCESS_CP15(c7, 0, c5, 0)
+
extern unsigned long cr_alignment; /* defined in entry-armv.S */
static inline unsigned long get_cr(void)
diff --git a/arch/arm/include/asm/system_misc.h b/arch/arm/include/asm/system_misc.h
index 78f6db114faf..8e76db83c498 100644
--- a/arch/arm/include/asm/system_misc.h
+++ b/arch/arm/include/asm/system_misc.h
@@ -8,6 +8,7 @@
#include <linux/linkage.h>
#include <linux/irqflags.h>
#include <linux/reboot.h>
+#include <linux/percpu.h>
extern void cpu_init(void);
@@ -15,6 +16,20 @@ void soft_restart(unsigned long);
extern void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
extern void (*arm_pm_idle)(void);
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+typedef void (*harden_branch_predictor_fn_t)(void);
+DECLARE_PER_CPU(harden_branch_predictor_fn_t, harden_branch_predictor_fn);
+static inline void harden_branch_predictor(void)
+{
+ harden_branch_predictor_fn_t fn = per_cpu(harden_branch_predictor_fn,
+ smp_processor_id());
+ if (fn)
+ fn();
+}
+#else
+#define harden_branch_predictor() do { } while (0)
+#endif
+
#define UDBG_UNDEFINED (1 << 0)
#define UDBG_SYSCALL (1 << 1)
#define UDBG_BADABORT (1 << 2)
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index b75eada23d0a..3b1ba003c4f9 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -163,6 +163,9 @@ __do_user_fault(struct task_struct *tsk, unsigned long addr,
{
struct siginfo si;
+ if (addr > TASK_SIZE)
+ harden_branch_predictor();
+
#ifdef CONFIG_DEBUG_USER
if (((user_debug & UDBG_SEGV) && (sig == SIGSEGV)) ||
((user_debug & UDBG_BUS) && (sig == SIGBUS))) {
diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c
index a32ce13479d9..585b2b61d7d3 100644
--- a/arch/arm/mm/proc-v7-bugs.c
+++ b/arch/arm/mm/proc-v7-bugs.c
@@ -2,28 +2,92 @@
#include <linux/kernel.h>
#include <linux/smp.h>
-static __maybe_unused void cpu_v7_check_auxcr_set(u32 mask, const char *msg)
+#include <asm/cp15.h>
+#include <asm/cputype.h>
+#include <asm/system_misc.h>
+
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+DEFINE_PER_CPU(harden_branch_predictor_fn_t, harden_branch_predictor_fn);
+
+static void harden_branch_predictor_bpiall(void)
+{
+ write_sysreg(0, BPIALL);
+}
+
+static void harden_branch_predictor_iciallu(void)
+{
+ write_sysreg(0, ICIALLU);
+}
+
+static void cpu_v7_spectre_init(void)
+{
+ const char *spectre_v2_method = NULL;
+ int cpu = smp_processor_id();
+
+ if (per_cpu(harden_branch_predictor_fn, cpu))
+ return;
+
+ switch (read_cpuid_part()) {
+ case ARM_CPU_PART_CORTEX_A8:
+ case ARM_CPU_PART_CORTEX_A9:
+ case ARM_CPU_PART_CORTEX_A12:
+ case ARM_CPU_PART_CORTEX_A17:
+ case ARM_CPU_PART_CORTEX_A73:
+ case ARM_CPU_PART_CORTEX_A75:
+ per_cpu(harden_branch_predictor_fn, cpu) =
+ harden_branch_predictor_bpiall;
+ spectre_v2_method = "BPIALL";
+ break;
+
+ case ARM_CPU_PART_CORTEX_A15:
+ case ARM_CPU_PART_BRAHMA_B15:
+ per_cpu(harden_branch_predictor_fn, cpu) =
+ harden_branch_predictor_iciallu;
+ spectre_v2_method = "ICIALLU";
+ break;
+ }
+ if (spectre_v2_method)
+ pr_info("CPU%u: Spectre v2: using %s workaround\n",
+ smp_processor_id(), spectre_v2_method);
+}
+#else
+static void cpu_v7_spectre_init(void)
+{
+}
+#endif
+
+static __maybe_unused bool cpu_v7_check_auxcr_set(u32 mask, const char *msg)
{
u32 aux_cr;
asm("mrc p15, 0, %0, c1, c0, 1" : "=r" (aux_cr));
- if ((aux_cr & mask) != mask)
+ if ((aux_cr & mask) != mask) {
pr_err("CPU%u: %s", smp_processor_id(), msg);
+ return false;
+ }
+ return true;
}
-static void check_spectre_auxcr(u32 bit)
+static bool check_spectre_auxcr(u32 bit)
{
- if (IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR))
+ return IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR) &&
cpu_v7_check_auxcr_set(bit, "Spectre v2: firmware did not set auxiliary control register IBE bit, system vulnerable\n");
}
void cpu_v7_ca8_ibe(void)
{
- check_spectre_auxcr(BIT(6));
+ if (check_spectre_auxcr(BIT(6)))
+ cpu_v7_spectre_init();
}
void cpu_v7_ca15_ibe(void)
{
- check_spectre_auxcr(BIT(0));
+ if (check_spectre_auxcr(BIT(0)))
+ cpu_v7_spectre_init();
+}
+
+void cpu_v7_bugs_init(void)
+{
+ cpu_v7_spectre_init();
}
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index fa9214036fb3..79510011e7eb 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -532,8 +532,10 @@ ENDPROC(__v7_setup)
__INITDATA
+ .weak cpu_v7_bugs_init
+
@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
- define_processor_functions v7, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+ define_processor_functions v7, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_bugs_init
#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
@ generic v7 bpiall on context switch
@@ -548,7 +550,7 @@ ENDPROC(__v7_setup)
globl_equ cpu_v7_bpiall_do_suspend, cpu_v7_do_suspend
globl_equ cpu_v7_bpiall_do_resume, cpu_v7_do_resume
#endif
- define_processor_functions v7_bpiall, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+ define_processor_functions v7_bpiall, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_bugs_init
#define HARDENED_BPIALL_PROCESSOR_FUNCTIONS v7_bpiall_processor_functions
#else
@@ -584,7 +586,7 @@ ENDPROC(__v7_setup)
globl_equ cpu_ca9mp_switch_mm, cpu_v7_switch_mm
#endif
globl_equ cpu_ca9mp_set_pte_ext, cpu_v7_set_pte_ext
- define_processor_functions ca9mp, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+ define_processor_functions ca9mp, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_bugs_init
#endif
@ Cortex-A15 - needs iciallu switch_mm for hardening
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread* Re: [PATCH v3 08/15] ARM: spectre-v2: harden user aborts in kernel space
2018-05-25 14:01 ` Russell King
@ 2018-05-25 15:47 ` Tony Lindgren
-1 siblings, 0 replies; 42+ messages in thread
From: Tony Lindgren @ 2018-05-25 15:47 UTC (permalink / raw)
To: Russell King
Cc: Marc Zyngier, Florian Fainelli, Christoffer Dall,
linux-arm-kernel, kvmarm
* Russell King <rmk+kernel@armlinux.org.uk> [180525 15:10]:
> +static void cpu_v7_spectre_init(void)
> +{
> + const char *spectre_v2_method = NULL;
> + int cpu = smp_processor_id();
> +
> + if (per_cpu(harden_branch_predictor_fn, cpu))
> + return;
> +
> + switch (read_cpuid_part()) {
> + case ARM_CPU_PART_CORTEX_A8:
> + case ARM_CPU_PART_CORTEX_A9:
> + case ARM_CPU_PART_CORTEX_A12:
> + case ARM_CPU_PART_CORTEX_A17:
> + case ARM_CPU_PART_CORTEX_A73:
> + case ARM_CPU_PART_CORTEX_A75:
> + per_cpu(harden_branch_predictor_fn, cpu) =
> + harden_branch_predictor_bpiall;
> + spectre_v2_method = "BPIALL";
> + break;
> +
> + case ARM_CPU_PART_CORTEX_A15:
> + case ARM_CPU_PART_BRAHMA_B15:
> + per_cpu(harden_branch_predictor_fn, cpu) =
> + harden_branch_predictor_iciallu;
> + spectre_v2_method = "ICIALLU";
> + break;
> + }
> + if (spectre_v2_method)
> + pr_info("CPU%u: Spectre v2: using %s workaround\n",
> + smp_processor_id(), spectre_v2_method);
> +}
We can now get this with the whole series applied:
CPU0: Spectre v2: firmware did not set auxiliary control register
IBE bit, system vulnerable
CPU: Spectre v2: using ICIALLU workaround
So maybe change the wording from "using %s workaround" to
"chosen workaround %s"?
Or I guess disabling the pr_info when not functional can
be done in the later patches based on some variable set
by check_spectre_auxcr() would be doable too.
Regards,
Tony
^ permalink raw reply [flat|nested] 42+ messages in thread* [PATCH v3 08/15] ARM: spectre-v2: harden user aborts in kernel space
@ 2018-05-25 15:47 ` Tony Lindgren
0 siblings, 0 replies; 42+ messages in thread
From: Tony Lindgren @ 2018-05-25 15:47 UTC (permalink / raw)
To: linux-arm-kernel
* Russell King <rmk+kernel@armlinux.org.uk> [180525 15:10]:
> +static void cpu_v7_spectre_init(void)
> +{
> + const char *spectre_v2_method = NULL;
> + int cpu = smp_processor_id();
> +
> + if (per_cpu(harden_branch_predictor_fn, cpu))
> + return;
> +
> + switch (read_cpuid_part()) {
> + case ARM_CPU_PART_CORTEX_A8:
> + case ARM_CPU_PART_CORTEX_A9:
> + case ARM_CPU_PART_CORTEX_A12:
> + case ARM_CPU_PART_CORTEX_A17:
> + case ARM_CPU_PART_CORTEX_A73:
> + case ARM_CPU_PART_CORTEX_A75:
> + per_cpu(harden_branch_predictor_fn, cpu) =
> + harden_branch_predictor_bpiall;
> + spectre_v2_method = "BPIALL";
> + break;
> +
> + case ARM_CPU_PART_CORTEX_A15:
> + case ARM_CPU_PART_BRAHMA_B15:
> + per_cpu(harden_branch_predictor_fn, cpu) =
> + harden_branch_predictor_iciallu;
> + spectre_v2_method = "ICIALLU";
> + break;
> + }
> + if (spectre_v2_method)
> + pr_info("CPU%u: Spectre v2: using %s workaround\n",
> + smp_processor_id(), spectre_v2_method);
> +}
We can now get this with the whole series applied:
CPU0: Spectre v2: firmware did not set auxiliary control register
IBE bit, system vulnerable
CPU: Spectre v2: using ICIALLU workaround
So maybe change the wording from "using %s workaround" to
"chosen workaround %s"?
Or I guess disabling the pr_info when not functional can
be done in the later patches based on some variable set
by check_spectre_auxcr() would be doable too.
Regards,
Tony
^ permalink raw reply [flat|nested] 42+ messages in thread* Re: [PATCH v3 08/15] ARM: spectre-v2: harden user aborts in kernel space
2018-05-25 15:47 ` Tony Lindgren
@ 2018-05-25 15:52 ` Russell King - ARM Linux
-1 siblings, 0 replies; 42+ messages in thread
From: Russell King - ARM Linux @ 2018-05-25 15:52 UTC (permalink / raw)
To: Tony Lindgren; +Cc: Marc Zyngier, Florian Fainelli, linux-arm-kernel, kvmarm
On Fri, May 25, 2018 at 08:47:42AM -0700, Tony Lindgren wrote:
> * Russell King <rmk+kernel@armlinux.org.uk> [180525 15:10]:
> > +static void cpu_v7_spectre_init(void)
> > +{
> > + const char *spectre_v2_method = NULL;
> > + int cpu = smp_processor_id();
> > +
> > + if (per_cpu(harden_branch_predictor_fn, cpu))
> > + return;
> > +
> > + switch (read_cpuid_part()) {
> > + case ARM_CPU_PART_CORTEX_A8:
> > + case ARM_CPU_PART_CORTEX_A9:
> > + case ARM_CPU_PART_CORTEX_A12:
> > + case ARM_CPU_PART_CORTEX_A17:
> > + case ARM_CPU_PART_CORTEX_A73:
> > + case ARM_CPU_PART_CORTEX_A75:
> > + per_cpu(harden_branch_predictor_fn, cpu) =
> > + harden_branch_predictor_bpiall;
> > + spectre_v2_method = "BPIALL";
> > + break;
> > +
> > + case ARM_CPU_PART_CORTEX_A15:
> > + case ARM_CPU_PART_BRAHMA_B15:
> > + per_cpu(harden_branch_predictor_fn, cpu) =
> > + harden_branch_predictor_iciallu;
> > + spectre_v2_method = "ICIALLU";
> > + break;
> > + }
> > + if (spectre_v2_method)
> > + pr_info("CPU%u: Spectre v2: using %s workaround\n",
> > + smp_processor_id(), spectre_v2_method);
> > +}
>
> We can now get this with the whole series applied:
>
> CPU0: Spectre v2: firmware did not set auxiliary control register
> IBE bit, system vulnerable
> CPU: Spectre v2: using ICIALLU workaround
>
> So maybe change the wording from "using %s workaround" to
> "chosen workaround %s"?
>
> Or I guess disabling the pr_info when not functional can
> be done in the later patches based on some variable set
> by check_spectre_auxcr() would be doable too.
You should not be getting both messages. It looks like you're using
an older series - I assumed you pulled my git tree rather than the
patches? The public git tree isn't up to date with these changes.
--
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up
According to speedtest.net: 8.21Mbps down 510kbps up
^ permalink raw reply [flat|nested] 42+ messages in thread* [PATCH v3 08/15] ARM: spectre-v2: harden user aborts in kernel space
@ 2018-05-25 15:52 ` Russell King - ARM Linux
0 siblings, 0 replies; 42+ messages in thread
From: Russell King - ARM Linux @ 2018-05-25 15:52 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, May 25, 2018 at 08:47:42AM -0700, Tony Lindgren wrote:
> * Russell King <rmk+kernel@armlinux.org.uk> [180525 15:10]:
> > +static void cpu_v7_spectre_init(void)
> > +{
> > + const char *spectre_v2_method = NULL;
> > + int cpu = smp_processor_id();
> > +
> > + if (per_cpu(harden_branch_predictor_fn, cpu))
> > + return;
> > +
> > + switch (read_cpuid_part()) {
> > + case ARM_CPU_PART_CORTEX_A8:
> > + case ARM_CPU_PART_CORTEX_A9:
> > + case ARM_CPU_PART_CORTEX_A12:
> > + case ARM_CPU_PART_CORTEX_A17:
> > + case ARM_CPU_PART_CORTEX_A73:
> > + case ARM_CPU_PART_CORTEX_A75:
> > + per_cpu(harden_branch_predictor_fn, cpu) =
> > + harden_branch_predictor_bpiall;
> > + spectre_v2_method = "BPIALL";
> > + break;
> > +
> > + case ARM_CPU_PART_CORTEX_A15:
> > + case ARM_CPU_PART_BRAHMA_B15:
> > + per_cpu(harden_branch_predictor_fn, cpu) =
> > + harden_branch_predictor_iciallu;
> > + spectre_v2_method = "ICIALLU";
> > + break;
> > + }
> > + if (spectre_v2_method)
> > + pr_info("CPU%u: Spectre v2: using %s workaround\n",
> > + smp_processor_id(), spectre_v2_method);
> > +}
>
> We can now get this with the whole series applied:
>
> CPU0: Spectre v2: firmware did not set auxiliary control register
> IBE bit, system vulnerable
> CPU: Spectre v2: using ICIALLU workaround
>
> So maybe change the wording from "using %s workaround" to
> "chosen workaround %s"?
>
> Or I guess disabling the pr_info when not functional can
> be done in the later patches based on some variable set
> by check_spectre_auxcr() would be doable too.
You should not be getting both messages. It looks like you're using
an older series - I assumed you pulled my git tree rather than the
patches? The public git tree isn't up to date with these changes.
--
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up
According to speedtest.net: 8.21Mbps down 510kbps up
^ permalink raw reply [flat|nested] 42+ messages in thread* Re: [PATCH v3 08/15] ARM: spectre-v2: harden user aborts in kernel space
2018-05-25 15:52 ` Russell King - ARM Linux
@ 2018-05-25 16:01 ` Tony Lindgren
-1 siblings, 0 replies; 42+ messages in thread
From: Tony Lindgren @ 2018-05-25 16:01 UTC (permalink / raw)
To: Russell King - ARM Linux
Cc: Marc Zyngier, Florian Fainelli, Christoffer Dall,
linux-arm-kernel, kvmarm
* Russell King - ARM Linux <linux@armlinux.org.uk> [180525 15:54]:
> On Fri, May 25, 2018 at 08:47:42AM -0700, Tony Lindgren wrote:
> > We can now get this with the whole series applied:
> >
> > CPU0: Spectre v2: firmware did not set auxiliary control register
> > IBE bit, system vulnerable
> > CPU: Spectre v2: using ICIALLU workaround
> >
> > So maybe change the wording from "using %s workaround" to
> > "chosen workaround %s"?
> >
> > Or I guess disabling the pr_info when not functional can
> > be done in the later patches based on some variable set
> > by check_spectre_auxcr() would be doable too.
>
> You should not be getting both messages. It looks like you're using
> an older series - I assumed you pulled my git tree rather than the
> patches? The public git tree isn't up to date with these changes.
Yes I just fetched your git tree because it allows using
git mergetool because of the conflicts with next. I'll apply
manually and test again.
Thanks,
Tony
^ permalink raw reply [flat|nested] 42+ messages in thread
* [PATCH v3 08/15] ARM: spectre-v2: harden user aborts in kernel space
@ 2018-05-25 16:01 ` Tony Lindgren
0 siblings, 0 replies; 42+ messages in thread
From: Tony Lindgren @ 2018-05-25 16:01 UTC (permalink / raw)
To: linux-arm-kernel
* Russell King - ARM Linux <linux@armlinux.org.uk> [180525 15:54]:
> On Fri, May 25, 2018 at 08:47:42AM -0700, Tony Lindgren wrote:
> > We can now get this with the whole series applied:
> >
> > CPU0: Spectre v2: firmware did not set auxiliary control register
> > IBE bit, system vulnerable
> > CPU: Spectre v2: using ICIALLU workaround
> >
> > So maybe change the wording from "using %s workaround" to
> > "chosen workaround %s"?
> >
> > Or I guess disabling the pr_info when not functional can
> > be done in the later patches based on some variable set
> > by check_spectre_auxcr() would be doable too.
>
> You should not be getting both messages. It looks like you're using
> an older series - I assumed you pulled my git tree rather than the
> patches? The public git tree isn't up to date with these changes.
Yes I just fetched your git tree because it allows using
git mergetool because of the conflicts with next. I'll apply
manually and test again.
Thanks,
Tony
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v3 08/15] ARM: spectre-v2: harden user aborts in kernel space
2018-05-25 16:01 ` Tony Lindgren
@ 2018-05-25 16:15 ` Tony Lindgren
-1 siblings, 0 replies; 42+ messages in thread
From: Tony Lindgren @ 2018-05-25 16:15 UTC (permalink / raw)
To: Russell King - ARM Linux
Cc: Marc Zyngier, Florian Fainelli, Christoffer Dall,
linux-arm-kernel, kvmarm
* Tony Lindgren <tony@atomide.com> [180525 16:04]:
> * Russell King - ARM Linux <linux@armlinux.org.uk> [180525 15:54]:
> > On Fri, May 25, 2018 at 08:47:42AM -0700, Tony Lindgren wrote:
> > > We can now get this with the whole series applied:
> > >
> > > CPU0: Spectre v2: firmware did not set auxiliary control register
> > > IBE bit, system vulnerable
> > > CPU: Spectre v2: using ICIALLU workaround
> > >
> > > So maybe change the wording from "using %s workaround" to
> > > "chosen workaround %s"?
> > >
> > > Or I guess disabling the pr_info when not functional can
> > > be done in the later patches based on some variable set
> > > by check_spectre_auxcr() would be doable too.
> >
> > You should not be getting both messages. It looks like you're using
> > an older series - I assumed you pulled my git tree rather than the
> > patches? The public git tree isn't up to date with these changes.
>
> Yes I just fetched your git tree because it allows using
> git mergetool because of the conflicts with next. I'll apply
> manually and test again.
And testing with the correct patches in the $subject series
makes the issue go away.
Regards,
Tony
^ permalink raw reply [flat|nested] 42+ messages in thread
* [PATCH v3 08/15] ARM: spectre-v2: harden user aborts in kernel space
@ 2018-05-25 16:15 ` Tony Lindgren
0 siblings, 0 replies; 42+ messages in thread
From: Tony Lindgren @ 2018-05-25 16:15 UTC (permalink / raw)
To: linux-arm-kernel
* Tony Lindgren <tony@atomide.com> [180525 16:04]:
> * Russell King - ARM Linux <linux@armlinux.org.uk> [180525 15:54]:
> > On Fri, May 25, 2018 at 08:47:42AM -0700, Tony Lindgren wrote:
> > > We can now get this with the whole series applied:
> > >
> > > CPU0: Spectre v2: firmware did not set auxiliary control register
> > > IBE bit, system vulnerable
> > > CPU: Spectre v2: using ICIALLU workaround
> > >
> > > So maybe change the wording from "using %s workaround" to
> > > "chosen workaround %s"?
> > >
> > > Or I guess disabling the pr_info when not functional can
> > > be done in the later patches based on some variable set
> > > by check_spectre_auxcr() would be doable too.
> >
> > You should not be getting both messages. It looks like you're using
> > an older series - I assumed you pulled my git tree rather than the
> > patches? The public git tree isn't up to date with these changes.
>
> Yes I just fetched your git tree because it allows using
> git mergetool because of the conflicts with next. I'll apply
> manually and test again.
And testing with the correct patches in the $subject series
makes the issue go away.
Regards,
Tony
^ permalink raw reply [flat|nested] 42+ messages in thread
* [PATCH v3 09/15] ARM: spectre-v2: add firmware based hardening
2018-05-25 13:59 ` Russell King - ARM Linux
@ 2018-05-25 14:01 ` Russell King
-1 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:01 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: Marc Zyngier, Florian Fainelli, kvmarm
Add firmware based hardening for cores that require more complex
handling in firmware.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/mm/proc-v7-bugs.c | 64 +++++++++++++++++++++++++++++++++++++++++++++-
arch/arm/mm/proc-v7.S | 21 +++++++++++++++
2 files changed, 84 insertions(+), 1 deletion(-)
diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c
index 585b2b61d7d3..5e50b0d9354c 100644
--- a/arch/arm/mm/proc-v7-bugs.c
+++ b/arch/arm/mm/proc-v7-bugs.c
@@ -1,14 +1,20 @@
// SPDX-License-Identifier: GPL-2.0
+#include <linux/arm-smccc.h>
#include <linux/kernel.h>
+#include <linux/psci.h>
#include <linux/smp.h>
#include <asm/cp15.h>
#include <asm/cputype.h>
+#include <asm/proc-fns.h>
#include <asm/system_misc.h>
#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
DEFINE_PER_CPU(harden_branch_predictor_fn_t, harden_branch_predictor_fn);
+extern void cpu_v7_smc_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
+extern void cpu_v7_hvc_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
+
static void harden_branch_predictor_bpiall(void)
{
write_sysreg(0, BPIALL);
@@ -19,15 +25,27 @@ static void harden_branch_predictor_iciallu(void)
write_sysreg(0, ICIALLU);
}
+static void __maybe_unused call_smc_arch_workaround_1(void)
+{
+ arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL);
+}
+
+static void __maybe_unused call_hvc_arch_workaround_1(void)
+{
+ arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL);
+}
+
static void cpu_v7_spectre_init(void)
{
const char *spectre_v2_method = NULL;
int cpu = smp_processor_id();
+ u32 cpuid;
if (per_cpu(harden_branch_predictor_fn, cpu))
return;
- switch (read_cpuid_part()) {
+ cpuid = read_cpuid_part();
+ switch (cpuid) {
case ARM_CPU_PART_CORTEX_A8:
case ARM_CPU_PART_CORTEX_A9:
case ARM_CPU_PART_CORTEX_A12:
@@ -45,7 +63,51 @@ static void cpu_v7_spectre_init(void)
harden_branch_predictor_iciallu;
spectre_v2_method = "ICIALLU";
break;
+
+#ifdef CONFIG_ARM_PSCI
+ default:
+ /* Other ARM CPUs require no workaround */
+ if (cpuid >> 24 == ARM_CPU_IMP_ARM)
+ break;
+ /* fallthrough */
+ /* Cortex A57/A72 require firmware workaround */
+ case ARM_CPU_PART_CORTEX_A57:
+ case ARM_CPU_PART_CORTEX_A72: {
+ struct arm_smccc_res res;
+
+ if (psci_ops.smccc_version == SMCCC_VERSION_1_0)
+ break;
+
+ switch (psci_ops.conduit) {
+ case PSCI_CONDUIT_HVC:
+ arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
+ ARM_SMCCC_ARCH_WORKAROUND_1, &res);
+ if ((int)res.a0 != 0)
+ break;
+ per_cpu(harden_branch_predictor_fn, cpu) =
+ call_hvc_arch_workaround_1;
+ processor.switch_mm = cpu_v7_hvc_switch_mm;
+ spectre_v2_method = "hypervisor";
+ break;
+
+ case PSCI_CONDUIT_SMC:
+ arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
+ ARM_SMCCC_ARCH_WORKAROUND_1, &res);
+ if ((int)res.a0 != 0)
+ break;
+ per_cpu(harden_branch_predictor_fn, cpu) =
+ call_smc_arch_workaround_1;
+ processor.switch_mm = cpu_v7_smc_switch_mm;
+ spectre_v2_method = "firmware";
+ break;
+
+ default:
+ break;
+ }
}
+#endif
+ }
+
if (spectre_v2_method)
pr_info("CPU%u: Spectre v2: using %s workaround\n",
smp_processor_id(), spectre_v2_method);
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 79510011e7eb..b78d59a1cc05 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -9,6 +9,7 @@
*
* This is the "shell" of the ARMv7 processor support.
*/
+#include <linux/arm-smccc.h>
#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/assembler.h>
@@ -93,6 +94,26 @@ ENTRY(cpu_v7_dcache_clean_area)
ret lr
ENDPROC(cpu_v7_dcache_clean_area)
+#ifdef CONFIG_ARM_PSCI
+ .arch_extension sec
+ENTRY(cpu_v7_smc_switch_mm)
+ stmfd sp!, {r0 - r3}
+ movw r0, #:lower16:ARM_SMCCC_ARCH_WORKAROUND_1
+ movt r0, #:upper16:ARM_SMCCC_ARCH_WORKAROUND_1
+ smc #0
+ ldmfd sp!, {r0 - r3}
+ b cpu_v7_switch_mm
+ENDPROC(cpu_v7_smc_switch_mm)
+ .arch_extension virt
+ENTRY(cpu_v7_hvc_switch_mm)
+ stmfd sp!, {r0 - r3}
+ movw r0, #:lower16:ARM_SMCCC_ARCH_WORKAROUND_1
+ movt r0, #:upper16:ARM_SMCCC_ARCH_WORKAROUND_1
+ hvc #0
+ ldmfd sp!, {r0 - r3}
+ b cpu_v7_switch_mm
+ENDPROC(cpu_v7_smc_switch_mm)
+#endif
ENTRY(cpu_v7_iciallu_switch_mm)
mov r3, #0
mcr p15, 0, r3, c7, c5, 0 @ ICIALLU
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread* [PATCH v3 09/15] ARM: spectre-v2: add firmware based hardening
@ 2018-05-25 14:01 ` Russell King
0 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:01 UTC (permalink / raw)
To: linux-arm-kernel
Add firmware based hardening for cores that require more complex
handling in firmware.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/mm/proc-v7-bugs.c | 64 +++++++++++++++++++++++++++++++++++++++++++++-
arch/arm/mm/proc-v7.S | 21 +++++++++++++++
2 files changed, 84 insertions(+), 1 deletion(-)
diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c
index 585b2b61d7d3..5e50b0d9354c 100644
--- a/arch/arm/mm/proc-v7-bugs.c
+++ b/arch/arm/mm/proc-v7-bugs.c
@@ -1,14 +1,20 @@
// SPDX-License-Identifier: GPL-2.0
+#include <linux/arm-smccc.h>
#include <linux/kernel.h>
+#include <linux/psci.h>
#include <linux/smp.h>
#include <asm/cp15.h>
#include <asm/cputype.h>
+#include <asm/proc-fns.h>
#include <asm/system_misc.h>
#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
DEFINE_PER_CPU(harden_branch_predictor_fn_t, harden_branch_predictor_fn);
+extern void cpu_v7_smc_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
+extern void cpu_v7_hvc_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
+
static void harden_branch_predictor_bpiall(void)
{
write_sysreg(0, BPIALL);
@@ -19,15 +25,27 @@ static void harden_branch_predictor_iciallu(void)
write_sysreg(0, ICIALLU);
}
+static void __maybe_unused call_smc_arch_workaround_1(void)
+{
+ arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL);
+}
+
+static void __maybe_unused call_hvc_arch_workaround_1(void)
+{
+ arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL);
+}
+
static void cpu_v7_spectre_init(void)
{
const char *spectre_v2_method = NULL;
int cpu = smp_processor_id();
+ u32 cpuid;
if (per_cpu(harden_branch_predictor_fn, cpu))
return;
- switch (read_cpuid_part()) {
+ cpuid = read_cpuid_part();
+ switch (cpuid) {
case ARM_CPU_PART_CORTEX_A8:
case ARM_CPU_PART_CORTEX_A9:
case ARM_CPU_PART_CORTEX_A12:
@@ -45,7 +63,51 @@ static void cpu_v7_spectre_init(void)
harden_branch_predictor_iciallu;
spectre_v2_method = "ICIALLU";
break;
+
+#ifdef CONFIG_ARM_PSCI
+ default:
+ /* Other ARM CPUs require no workaround */
+ if (cpuid >> 24 == ARM_CPU_IMP_ARM)
+ break;
+ /* fallthrough */
+ /* Cortex A57/A72 require firmware workaround */
+ case ARM_CPU_PART_CORTEX_A57:
+ case ARM_CPU_PART_CORTEX_A72: {
+ struct arm_smccc_res res;
+
+ if (psci_ops.smccc_version == SMCCC_VERSION_1_0)
+ break;
+
+ switch (psci_ops.conduit) {
+ case PSCI_CONDUIT_HVC:
+ arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
+ ARM_SMCCC_ARCH_WORKAROUND_1, &res);
+ if ((int)res.a0 != 0)
+ break;
+ per_cpu(harden_branch_predictor_fn, cpu) =
+ call_hvc_arch_workaround_1;
+ processor.switch_mm = cpu_v7_hvc_switch_mm;
+ spectre_v2_method = "hypervisor";
+ break;
+
+ case PSCI_CONDUIT_SMC:
+ arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
+ ARM_SMCCC_ARCH_WORKAROUND_1, &res);
+ if ((int)res.a0 != 0)
+ break;
+ per_cpu(harden_branch_predictor_fn, cpu) =
+ call_smc_arch_workaround_1;
+ processor.switch_mm = cpu_v7_smc_switch_mm;
+ spectre_v2_method = "firmware";
+ break;
+
+ default:
+ break;
+ }
}
+#endif
+ }
+
if (spectre_v2_method)
pr_info("CPU%u: Spectre v2: using %s workaround\n",
smp_processor_id(), spectre_v2_method);
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 79510011e7eb..b78d59a1cc05 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -9,6 +9,7 @@
*
* This is the "shell" of the ARMv7 processor support.
*/
+#include <linux/arm-smccc.h>
#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/assembler.h>
@@ -93,6 +94,26 @@ ENTRY(cpu_v7_dcache_clean_area)
ret lr
ENDPROC(cpu_v7_dcache_clean_area)
+#ifdef CONFIG_ARM_PSCI
+ .arch_extension sec
+ENTRY(cpu_v7_smc_switch_mm)
+ stmfd sp!, {r0 - r3}
+ movw r0, #:lower16:ARM_SMCCC_ARCH_WORKAROUND_1
+ movt r0, #:upper16:ARM_SMCCC_ARCH_WORKAROUND_1
+ smc #0
+ ldmfd sp!, {r0 - r3}
+ b cpu_v7_switch_mm
+ENDPROC(cpu_v7_smc_switch_mm)
+ .arch_extension virt
+ENTRY(cpu_v7_hvc_switch_mm)
+ stmfd sp!, {r0 - r3}
+ movw r0, #:lower16:ARM_SMCCC_ARCH_WORKAROUND_1
+ movt r0, #:upper16:ARM_SMCCC_ARCH_WORKAROUND_1
+ hvc #0
+ ldmfd sp!, {r0 - r3}
+ b cpu_v7_switch_mm
+ENDPROC(cpu_v7_smc_switch_mm)
+#endif
ENTRY(cpu_v7_iciallu_switch_mm)
mov r3, #0
mcr p15, 0, r3, c7, c5, 0 @ ICIALLU
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v3 10/15] ARM: spectre-v2: warn about incorrect context switching functions
2018-05-25 13:59 ` Russell King - ARM Linux
@ 2018-05-25 14:01 ` Russell King
-1 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:01 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: Marc Zyngier, Florian Fainelli, Christoffer Dall, kvmarm
Warn at error level if the context switching function is not what we
are expecting. This can happen with big.Little systems, which we
currently do not support.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/mm/proc-v7-bugs.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c
index 5e50b0d9354c..615ff233641d 100644
--- a/arch/arm/mm/proc-v7-bugs.c
+++ b/arch/arm/mm/proc-v7-bugs.c
@@ -12,6 +12,8 @@
#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
DEFINE_PER_CPU(harden_branch_predictor_fn_t, harden_branch_predictor_fn);
+extern void cpu_v7_iciallu_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
+extern void cpu_v7_bpiall_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
extern void cpu_v7_smc_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
extern void cpu_v7_hvc_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
@@ -52,6 +54,8 @@ static void cpu_v7_spectre_init(void)
case ARM_CPU_PART_CORTEX_A17:
case ARM_CPU_PART_CORTEX_A73:
case ARM_CPU_PART_CORTEX_A75:
+ if (processor.switch_mm != cpu_v7_bpiall_switch_mm)
+ goto bl_error;
per_cpu(harden_branch_predictor_fn, cpu) =
harden_branch_predictor_bpiall;
spectre_v2_method = "BPIALL";
@@ -59,6 +63,8 @@ static void cpu_v7_spectre_init(void)
case ARM_CPU_PART_CORTEX_A15:
case ARM_CPU_PART_BRAHMA_B15:
+ if (processor.switch_mm != cpu_v7_iciallu_switch_mm)
+ goto bl_error;
per_cpu(harden_branch_predictor_fn, cpu) =
harden_branch_predictor_iciallu;
spectre_v2_method = "ICIALLU";
@@ -84,6 +90,8 @@ static void cpu_v7_spectre_init(void)
ARM_SMCCC_ARCH_WORKAROUND_1, &res);
if ((int)res.a0 != 0)
break;
+ if (processor.switch_mm != cpu_v7_hvc_switch_mm && cpu)
+ goto bl_error;
per_cpu(harden_branch_predictor_fn, cpu) =
call_hvc_arch_workaround_1;
processor.switch_mm = cpu_v7_hvc_switch_mm;
@@ -95,6 +103,8 @@ static void cpu_v7_spectre_init(void)
ARM_SMCCC_ARCH_WORKAROUND_1, &res);
if ((int)res.a0 != 0)
break;
+ if (processor.switch_mm != cpu_v7_smc_switch_mm && cpu)
+ goto bl_error;
per_cpu(harden_branch_predictor_fn, cpu) =
call_smc_arch_workaround_1;
processor.switch_mm = cpu_v7_smc_switch_mm;
@@ -111,6 +121,11 @@ static void cpu_v7_spectre_init(void)
if (spectre_v2_method)
pr_info("CPU%u: Spectre v2: using %s workaround\n",
smp_processor_id(), spectre_v2_method);
+ return;
+
+bl_error:
+ pr_err("CPU%u: Spectre v2: incorrect context switching function, system vulnerable\n",
+ cpu);
}
#else
static void cpu_v7_spectre_init(void)
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread* [PATCH v3 10/15] ARM: spectre-v2: warn about incorrect context switching functions
@ 2018-05-25 14:01 ` Russell King
0 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:01 UTC (permalink / raw)
To: linux-arm-kernel
Warn at error level if the context switching function is not what we
are expecting. This can happen with big.Little systems, which we
currently do not support.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/mm/proc-v7-bugs.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c
index 5e50b0d9354c..615ff233641d 100644
--- a/arch/arm/mm/proc-v7-bugs.c
+++ b/arch/arm/mm/proc-v7-bugs.c
@@ -12,6 +12,8 @@
#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
DEFINE_PER_CPU(harden_branch_predictor_fn_t, harden_branch_predictor_fn);
+extern void cpu_v7_iciallu_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
+extern void cpu_v7_bpiall_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
extern void cpu_v7_smc_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
extern void cpu_v7_hvc_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
@@ -52,6 +54,8 @@ static void cpu_v7_spectre_init(void)
case ARM_CPU_PART_CORTEX_A17:
case ARM_CPU_PART_CORTEX_A73:
case ARM_CPU_PART_CORTEX_A75:
+ if (processor.switch_mm != cpu_v7_bpiall_switch_mm)
+ goto bl_error;
per_cpu(harden_branch_predictor_fn, cpu) =
harden_branch_predictor_bpiall;
spectre_v2_method = "BPIALL";
@@ -59,6 +63,8 @@ static void cpu_v7_spectre_init(void)
case ARM_CPU_PART_CORTEX_A15:
case ARM_CPU_PART_BRAHMA_B15:
+ if (processor.switch_mm != cpu_v7_iciallu_switch_mm)
+ goto bl_error;
per_cpu(harden_branch_predictor_fn, cpu) =
harden_branch_predictor_iciallu;
spectre_v2_method = "ICIALLU";
@@ -84,6 +90,8 @@ static void cpu_v7_spectre_init(void)
ARM_SMCCC_ARCH_WORKAROUND_1, &res);
if ((int)res.a0 != 0)
break;
+ if (processor.switch_mm != cpu_v7_hvc_switch_mm && cpu)
+ goto bl_error;
per_cpu(harden_branch_predictor_fn, cpu) =
call_hvc_arch_workaround_1;
processor.switch_mm = cpu_v7_hvc_switch_mm;
@@ -95,6 +103,8 @@ static void cpu_v7_spectre_init(void)
ARM_SMCCC_ARCH_WORKAROUND_1, &res);
if ((int)res.a0 != 0)
break;
+ if (processor.switch_mm != cpu_v7_smc_switch_mm && cpu)
+ goto bl_error;
per_cpu(harden_branch_predictor_fn, cpu) =
call_smc_arch_workaround_1;
processor.switch_mm = cpu_v7_smc_switch_mm;
@@ -111,6 +121,11 @@ static void cpu_v7_spectre_init(void)
if (spectre_v2_method)
pr_info("CPU%u: Spectre v2: using %s workaround\n",
smp_processor_id(), spectre_v2_method);
+ return;
+
+bl_error:
+ pr_err("CPU%u: Spectre v2: incorrect context switching function, system vulnerable\n",
+ cpu);
}
#else
static void cpu_v7_spectre_init(void)
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v3 11/15] ARM: KVM: invalidate BTB on guest exit for Cortex-A12/A17
2018-05-25 13:59 ` Russell King - ARM Linux
@ 2018-05-25 14:01 ` Russell King
-1 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:01 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: Marc Zyngier, Florian Fainelli, Christoffer Dall, kvmarm
From: Marc Zyngier <marc.zyngier@arm.com>
In order to avoid aliasing attacks against the branch predictor,
let's invalidate the BTB on guest exit. This is made complicated
by the fact that we cannot take a branch before invalidating the
BTB.
We only apply this to A12 and A17, which are the only two ARM
cores on which this useful.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/include/asm/kvm_asm.h | 2 --
arch/arm/include/asm/kvm_mmu.h | 17 +++++++++-
arch/arm/kvm/hyp/hyp-entry.S | 71 ++++++++++++++++++++++++++++++++++++++++--
3 files changed, 85 insertions(+), 5 deletions(-)
diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h
index 36dd2962a42d..df24ed48977d 100644
--- a/arch/arm/include/asm/kvm_asm.h
+++ b/arch/arm/include/asm/kvm_asm.h
@@ -61,8 +61,6 @@ struct kvm_vcpu;
extern char __kvm_hyp_init[];
extern char __kvm_hyp_init_end[];
-extern char __kvm_hyp_vector[];
-
extern void __kvm_flush_vm_context(void);
extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);
extern void __kvm_tlb_flush_vmid(struct kvm *kvm);
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index de1b919404e4..d08ce9c41df4 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -297,7 +297,22 @@ static inline unsigned int kvm_get_vmid_bits(void)
static inline void *kvm_get_hyp_vector(void)
{
- return kvm_ksym_ref(__kvm_hyp_vector);
+ switch(read_cpuid_part()) {
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+ case ARM_CPU_PART_CORTEX_A12:
+ case ARM_CPU_PART_CORTEX_A17:
+ {
+ extern char __kvm_hyp_vector_bp_inv[];
+ return kvm_ksym_ref(__kvm_hyp_vector_bp_inv);
+ }
+
+#endif
+ default:
+ {
+ extern char __kvm_hyp_vector[];
+ return kvm_ksym_ref(__kvm_hyp_vector);
+ }
+ }
}
static inline int kvm_map_vectors(void)
diff --git a/arch/arm/kvm/hyp/hyp-entry.S b/arch/arm/kvm/hyp/hyp-entry.S
index 95a2faefc070..e789f52a5129 100644
--- a/arch/arm/kvm/hyp/hyp-entry.S
+++ b/arch/arm/kvm/hyp/hyp-entry.S
@@ -71,6 +71,66 @@
W(b) hyp_irq
W(b) hyp_fiq
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+ .align 5
+__kvm_hyp_vector_bp_inv:
+ .global __kvm_hyp_vector_bp_inv
+
+ /*
+ * We encode the exception entry in the bottom 3 bits of
+ * SP, and we have to guarantee to be 8 bytes aligned.
+ */
+ W(add) sp, sp, #1 /* Reset 7 */
+ W(add) sp, sp, #1 /* Undef 6 */
+ W(add) sp, sp, #1 /* Syscall 5 */
+ W(add) sp, sp, #1 /* Prefetch abort 4 */
+ W(add) sp, sp, #1 /* Data abort 3 */
+ W(add) sp, sp, #1 /* HVC 2 */
+ W(add) sp, sp, #1 /* IRQ 1 */
+ W(nop) /* FIQ 0 */
+
+ mcr p15, 0, r0, c7, c5, 6 /* BPIALL */
+ isb
+
+#ifdef CONFIG_THUMB2_KERNEL
+ /*
+ * Yet another silly hack: Use VPIDR as a temp register.
+ * Thumb2 is really a pain, as SP cannot be used with most
+ * of the bitwise instructions. The vect_br macro ensures
+ * things gets cleaned-up.
+ */
+ mcr p15, 4, r0, c0, c0, 0 /* VPIDR */
+ mov r0, sp
+ and r0, r0, #7
+ sub sp, sp, r0
+ push {r1, r2}
+ mov r1, r0
+ mrc p15, 4, r0, c0, c0, 0 /* VPIDR */
+ mrc p15, 0, r2, c0, c0, 0 /* MIDR */
+ mcr p15, 4, r2, c0, c0, 0 /* VPIDR */
+#endif
+
+.macro vect_br val, targ
+ARM( eor sp, sp, #\val )
+ARM( tst sp, #7 )
+ARM( eorne sp, sp, #\val )
+
+THUMB( cmp r1, #\val )
+THUMB( popeq {r1, r2} )
+
+ beq \targ
+.endm
+
+ vect_br 0, hyp_fiq
+ vect_br 1, hyp_irq
+ vect_br 2, hyp_hvc
+ vect_br 3, hyp_dabt
+ vect_br 4, hyp_pabt
+ vect_br 5, hyp_svc
+ vect_br 6, hyp_undef
+ vect_br 7, hyp_reset
+#endif
+
.macro invalid_vector label, cause
.align
\label: mov r0, #\cause
@@ -149,7 +209,14 @@ ENDPROC(__hyp_do_panic)
bx ip
1:
- push {lr}
+ /*
+ * Pushing r2 here is just a way of keeping the stack aligned to
+ * 8 bytes on any path that can trigger a HYP exception. Here,
+ * we may well be about to jump into the guest, and the guest
+ * exit would otherwise be badly decoded by our fancy
+ * "decode-exception-without-a-branch" code...
+ */
+ push {r2, lr}
mov lr, r0
mov r0, r1
@@ -159,7 +226,7 @@ ENDPROC(__hyp_do_panic)
THUMB( orr lr, #1)
blx lr @ Call the HYP function
- pop {lr}
+ pop {r2, lr}
eret
guest_trap:
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread* [PATCH v3 11/15] ARM: KVM: invalidate BTB on guest exit for Cortex-A12/A17
@ 2018-05-25 14:01 ` Russell King
0 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:01 UTC (permalink / raw)
To: linux-arm-kernel
From: Marc Zyngier <marc.zyngier@arm.com>
In order to avoid aliasing attacks against the branch predictor,
let's invalidate the BTB on guest exit. This is made complicated
by the fact that we cannot take a branch before invalidating the
BTB.
We only apply this to A12 and A17, which are the only two ARM
cores on which this useful.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/include/asm/kvm_asm.h | 2 --
arch/arm/include/asm/kvm_mmu.h | 17 +++++++++-
arch/arm/kvm/hyp/hyp-entry.S | 71 ++++++++++++++++++++++++++++++++++++++++--
3 files changed, 85 insertions(+), 5 deletions(-)
diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h
index 36dd2962a42d..df24ed48977d 100644
--- a/arch/arm/include/asm/kvm_asm.h
+++ b/arch/arm/include/asm/kvm_asm.h
@@ -61,8 +61,6 @@ struct kvm_vcpu;
extern char __kvm_hyp_init[];
extern char __kvm_hyp_init_end[];
-extern char __kvm_hyp_vector[];
-
extern void __kvm_flush_vm_context(void);
extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);
extern void __kvm_tlb_flush_vmid(struct kvm *kvm);
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index de1b919404e4..d08ce9c41df4 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -297,7 +297,22 @@ static inline unsigned int kvm_get_vmid_bits(void)
static inline void *kvm_get_hyp_vector(void)
{
- return kvm_ksym_ref(__kvm_hyp_vector);
+ switch(read_cpuid_part()) {
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+ case ARM_CPU_PART_CORTEX_A12:
+ case ARM_CPU_PART_CORTEX_A17:
+ {
+ extern char __kvm_hyp_vector_bp_inv[];
+ return kvm_ksym_ref(__kvm_hyp_vector_bp_inv);
+ }
+
+#endif
+ default:
+ {
+ extern char __kvm_hyp_vector[];
+ return kvm_ksym_ref(__kvm_hyp_vector);
+ }
+ }
}
static inline int kvm_map_vectors(void)
diff --git a/arch/arm/kvm/hyp/hyp-entry.S b/arch/arm/kvm/hyp/hyp-entry.S
index 95a2faefc070..e789f52a5129 100644
--- a/arch/arm/kvm/hyp/hyp-entry.S
+++ b/arch/arm/kvm/hyp/hyp-entry.S
@@ -71,6 +71,66 @@
W(b) hyp_irq
W(b) hyp_fiq
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+ .align 5
+__kvm_hyp_vector_bp_inv:
+ .global __kvm_hyp_vector_bp_inv
+
+ /*
+ * We encode the exception entry in the bottom 3 bits of
+ * SP, and we have to guarantee to be 8 bytes aligned.
+ */
+ W(add) sp, sp, #1 /* Reset 7 */
+ W(add) sp, sp, #1 /* Undef 6 */
+ W(add) sp, sp, #1 /* Syscall 5 */
+ W(add) sp, sp, #1 /* Prefetch abort 4 */
+ W(add) sp, sp, #1 /* Data abort 3 */
+ W(add) sp, sp, #1 /* HVC 2 */
+ W(add) sp, sp, #1 /* IRQ 1 */
+ W(nop) /* FIQ 0 */
+
+ mcr p15, 0, r0, c7, c5, 6 /* BPIALL */
+ isb
+
+#ifdef CONFIG_THUMB2_KERNEL
+ /*
+ * Yet another silly hack: Use VPIDR as a temp register.
+ * Thumb2 is really a pain, as SP cannot be used with most
+ * of the bitwise instructions. The vect_br macro ensures
+ * things gets cleaned-up.
+ */
+ mcr p15, 4, r0, c0, c0, 0 /* VPIDR */
+ mov r0, sp
+ and r0, r0, #7
+ sub sp, sp, r0
+ push {r1, r2}
+ mov r1, r0
+ mrc p15, 4, r0, c0, c0, 0 /* VPIDR */
+ mrc p15, 0, r2, c0, c0, 0 /* MIDR */
+ mcr p15, 4, r2, c0, c0, 0 /* VPIDR */
+#endif
+
+.macro vect_br val, targ
+ARM( eor sp, sp, #\val )
+ARM( tst sp, #7 )
+ARM( eorne sp, sp, #\val )
+
+THUMB( cmp r1, #\val )
+THUMB( popeq {r1, r2} )
+
+ beq \targ
+.endm
+
+ vect_br 0, hyp_fiq
+ vect_br 1, hyp_irq
+ vect_br 2, hyp_hvc
+ vect_br 3, hyp_dabt
+ vect_br 4, hyp_pabt
+ vect_br 5, hyp_svc
+ vect_br 6, hyp_undef
+ vect_br 7, hyp_reset
+#endif
+
.macro invalid_vector label, cause
.align
\label: mov r0, #\cause
@@ -149,7 +209,14 @@ ENDPROC(__hyp_do_panic)
bx ip
1:
- push {lr}
+ /*
+ * Pushing r2 here is just a way of keeping the stack aligned to
+ * 8 bytes on any path that can trigger a HYP exception. Here,
+ * we may well be about to jump into the guest, and the guest
+ * exit would otherwise be badly decoded by our fancy
+ * "decode-exception-without-a-branch" code...
+ */
+ push {r2, lr}
mov lr, r0
mov r0, r1
@@ -159,7 +226,7 @@ ENDPROC(__hyp_do_panic)
THUMB( orr lr, #1)
blx lr @ Call the HYP function
- pop {lr}
+ pop {r2, lr}
eret
guest_trap:
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v3 12/15] ARM: KVM: invalidate icache on guest exit for Cortex-A15
2018-05-25 13:59 ` Russell King - ARM Linux
@ 2018-05-25 14:01 ` Russell King
-1 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:01 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: Marc Zyngier, Florian Fainelli, Christoffer Dall, kvmarm
From: Marc Zyngier <marc.zyngier@arm.com>
In order to avoid aliasing attacks against the branch predictor
on Cortex-A15, let's invalidate the BTB on guest exit, which can
only be done by invalidating the icache (with ACTLR[0] being set).
We use the same hack as for A12/A17 to perform the vector decoding.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/include/asm/kvm_mmu.h | 5 +++++
arch/arm/kvm/hyp/hyp-entry.S | 24 ++++++++++++++++++++++++
2 files changed, 29 insertions(+)
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index d08ce9c41df4..48edb1f4ced4 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -306,6 +306,11 @@ static inline void *kvm_get_hyp_vector(void)
return kvm_ksym_ref(__kvm_hyp_vector_bp_inv);
}
+ case ARM_CPU_PART_CORTEX_A15:
+ {
+ extern char __kvm_hyp_vector_ic_inv[];
+ return kvm_ksym_ref(__kvm_hyp_vector_ic_inv);
+ }
#endif
default:
{
diff --git a/arch/arm/kvm/hyp/hyp-entry.S b/arch/arm/kvm/hyp/hyp-entry.S
index e789f52a5129..918a05dd2d63 100644
--- a/arch/arm/kvm/hyp/hyp-entry.S
+++ b/arch/arm/kvm/hyp/hyp-entry.S
@@ -73,6 +73,28 @@
#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
.align 5
+__kvm_hyp_vector_ic_inv:
+ .global __kvm_hyp_vector_ic_inv
+
+ /*
+ * We encode the exception entry in the bottom 3 bits of
+ * SP, and we have to guarantee to be 8 bytes aligned.
+ */
+ W(add) sp, sp, #1 /* Reset 7 */
+ W(add) sp, sp, #1 /* Undef 6 */
+ W(add) sp, sp, #1 /* Syscall 5 */
+ W(add) sp, sp, #1 /* Prefetch abort 4 */
+ W(add) sp, sp, #1 /* Data abort 3 */
+ W(add) sp, sp, #1 /* HVC 2 */
+ W(add) sp, sp, #1 /* IRQ 1 */
+ W(nop) /* FIQ 0 */
+
+ mcr p15, 0, r0, c7, c5, 0 /* ICIALLU */
+ isb
+
+ b decode_vectors
+
+ .align 5
__kvm_hyp_vector_bp_inv:
.global __kvm_hyp_vector_bp_inv
@@ -92,6 +114,8 @@
mcr p15, 0, r0, c7, c5, 6 /* BPIALL */
isb
+decode_vectors:
+
#ifdef CONFIG_THUMB2_KERNEL
/*
* Yet another silly hack: Use VPIDR as a temp register.
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread* [PATCH v3 12/15] ARM: KVM: invalidate icache on guest exit for Cortex-A15
@ 2018-05-25 14:01 ` Russell King
0 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:01 UTC (permalink / raw)
To: linux-arm-kernel
From: Marc Zyngier <marc.zyngier@arm.com>
In order to avoid aliasing attacks against the branch predictor
on Cortex-A15, let's invalidate the BTB on guest exit, which can
only be done by invalidating the icache (with ACTLR[0] being set).
We use the same hack as for A12/A17 to perform the vector decoding.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/include/asm/kvm_mmu.h | 5 +++++
arch/arm/kvm/hyp/hyp-entry.S | 24 ++++++++++++++++++++++++
2 files changed, 29 insertions(+)
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index d08ce9c41df4..48edb1f4ced4 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -306,6 +306,11 @@ static inline void *kvm_get_hyp_vector(void)
return kvm_ksym_ref(__kvm_hyp_vector_bp_inv);
}
+ case ARM_CPU_PART_CORTEX_A15:
+ {
+ extern char __kvm_hyp_vector_ic_inv[];
+ return kvm_ksym_ref(__kvm_hyp_vector_ic_inv);
+ }
#endif
default:
{
diff --git a/arch/arm/kvm/hyp/hyp-entry.S b/arch/arm/kvm/hyp/hyp-entry.S
index e789f52a5129..918a05dd2d63 100644
--- a/arch/arm/kvm/hyp/hyp-entry.S
+++ b/arch/arm/kvm/hyp/hyp-entry.S
@@ -73,6 +73,28 @@
#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
.align 5
+__kvm_hyp_vector_ic_inv:
+ .global __kvm_hyp_vector_ic_inv
+
+ /*
+ * We encode the exception entry in the bottom 3 bits of
+ * SP, and we have to guarantee to be 8 bytes aligned.
+ */
+ W(add) sp, sp, #1 /* Reset 7 */
+ W(add) sp, sp, #1 /* Undef 6 */
+ W(add) sp, sp, #1 /* Syscall 5 */
+ W(add) sp, sp, #1 /* Prefetch abort 4 */
+ W(add) sp, sp, #1 /* Data abort 3 */
+ W(add) sp, sp, #1 /* HVC 2 */
+ W(add) sp, sp, #1 /* IRQ 1 */
+ W(nop) /* FIQ 0 */
+
+ mcr p15, 0, r0, c7, c5, 0 /* ICIALLU */
+ isb
+
+ b decode_vectors
+
+ .align 5
__kvm_hyp_vector_bp_inv:
.global __kvm_hyp_vector_bp_inv
@@ -92,6 +114,8 @@
mcr p15, 0, r0, c7, c5, 6 /* BPIALL */
isb
+decode_vectors:
+
#ifdef CONFIG_THUMB2_KERNEL
/*
* Yet another silly hack: Use VPIDR as a temp register.
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v3 13/15] ARM: spectre-v2: KVM: invalidate icache on guest exit for Brahma B15
2018-05-25 13:59 ` Russell King - ARM Linux
@ 2018-05-25 14:01 ` Russell King
-1 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:01 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: Marc Zyngier, Florian Fainelli, Christoffer Dall, kvmarm
Include Brahma B15 in the Spectre v2 KVM workarounds.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
---
arch/arm/include/asm/kvm_mmu.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index 48edb1f4ced4..fea770f78144 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -306,6 +306,7 @@ static inline void *kvm_get_hyp_vector(void)
return kvm_ksym_ref(__kvm_hyp_vector_bp_inv);
}
+ case ARM_CPU_PART_BRAHMA_B15:
case ARM_CPU_PART_CORTEX_A15:
{
extern char __kvm_hyp_vector_ic_inv[];
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread* [PATCH v3 13/15] ARM: spectre-v2: KVM: invalidate icache on guest exit for Brahma B15
@ 2018-05-25 14:01 ` Russell King
0 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:01 UTC (permalink / raw)
To: linux-arm-kernel
Include Brahma B15 in the Spectre v2 KVM workarounds.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
---
arch/arm/include/asm/kvm_mmu.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index 48edb1f4ced4..fea770f78144 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -306,6 +306,7 @@ static inline void *kvm_get_hyp_vector(void)
return kvm_ksym_ref(__kvm_hyp_vector_bp_inv);
}
+ case ARM_CPU_PART_BRAHMA_B15:
case ARM_CPU_PART_CORTEX_A15:
{
extern char __kvm_hyp_vector_ic_inv[];
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v3 14/15] ARM: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling
2018-05-25 13:59 ` Russell King - ARM Linux
@ 2018-05-25 14:01 ` Russell King
-1 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:01 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: Marc Zyngier, Florian Fainelli, kvmarm
We want SMCCC_ARCH_WORKAROUND_1 to be fast. As fast as possible.
So let's intercept it as early as we can by testing for the
function call number as soon as we've identified a HVC call
coming from the guest.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/kvm/hyp/hyp-entry.S | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kvm/hyp/hyp-entry.S b/arch/arm/kvm/hyp/hyp-entry.S
index 918a05dd2d63..aa3f9a9837ac 100644
--- a/arch/arm/kvm/hyp/hyp-entry.S
+++ b/arch/arm/kvm/hyp/hyp-entry.S
@@ -16,6 +16,7 @@
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
+#include <linux/arm-smccc.h>
#include <linux/linkage.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_asm.h>
@@ -202,7 +203,7 @@ ENDPROC(__hyp_do_panic)
lsr r2, r2, #16
and r2, r2, #0xff
cmp r2, #0
- bne guest_trap @ Guest called HVC
+ bne guest_hvc_trap @ Guest called HVC
/*
* Getting here means host called HVC, we shift parameters and branch
@@ -253,6 +254,20 @@ THUMB( orr lr, #1)
pop {r2, lr}
eret
+guest_hvc_trap:
+ movw r2, #:lower16:ARM_SMCCC_ARCH_WORKAROUND_1
+ movt r2, #:upper16:ARM_SMCCC_ARCH_WORKAROUND_1
+ ldr r0, [sp] @ Guest's r0
+ teq r0, r2
+ bne guest_trap
+ add sp, sp, #12
+ @ Returns:
+ @ r0 = 0
+ @ r1 = HSR value (perfectly predictable)
+ @ r2 = ARM_SMCCC_ARCH_WORKAROUND_1
+ mov r0, #0
+ eret
+
guest_trap:
load_vcpu r0 @ Load VCPU pointer to r0
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread* [PATCH v3 14/15] ARM: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling
@ 2018-05-25 14:01 ` Russell King
0 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:01 UTC (permalink / raw)
To: linux-arm-kernel
We want SMCCC_ARCH_WORKAROUND_1 to be fast. As fast as possible.
So let's intercept it as early as we can by testing for the
function call number as soon as we've identified a HVC call
coming from the guest.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/kvm/hyp/hyp-entry.S | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kvm/hyp/hyp-entry.S b/arch/arm/kvm/hyp/hyp-entry.S
index 918a05dd2d63..aa3f9a9837ac 100644
--- a/arch/arm/kvm/hyp/hyp-entry.S
+++ b/arch/arm/kvm/hyp/hyp-entry.S
@@ -16,6 +16,7 @@
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
+#include <linux/arm-smccc.h>
#include <linux/linkage.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_asm.h>
@@ -202,7 +203,7 @@ ENDPROC(__hyp_do_panic)
lsr r2, r2, #16
and r2, r2, #0xff
cmp r2, #0
- bne guest_trap @ Guest called HVC
+ bne guest_hvc_trap @ Guest called HVC
/*
* Getting here means host called HVC, we shift parameters and branch
@@ -253,6 +254,20 @@ THUMB( orr lr, #1)
pop {r2, lr}
eret
+guest_hvc_trap:
+ movw r2, #:lower16:ARM_SMCCC_ARCH_WORKAROUND_1
+ movt r2, #:upper16:ARM_SMCCC_ARCH_WORKAROUND_1
+ ldr r0, [sp] @ Guest's r0
+ teq r0, r2
+ bne guest_trap
+ add sp, sp, #12
+ @ Returns:
+ @ r0 = 0
+ @ r1 = HSR value (perfectly predictable)
+ @ r2 = ARM_SMCCC_ARCH_WORKAROUND_1
+ mov r0, #0
+ eret
+
guest_trap:
load_vcpu r0 @ Load VCPU pointer to r0
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v3 15/15] ARM: KVM: report support for SMCCC_ARCH_WORKAROUND_1
2018-05-25 13:59 ` Russell King - ARM Linux
@ 2018-05-25 14:01 ` Russell King
-1 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:01 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: Marc Zyngier, Florian Fainelli, kvmarm
Report support for SMCCC_ARCH_WORKAROUND_1 to KVM guests for affected
CPUs.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/include/asm/kvm_host.h | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 248b930563e5..11f91744ffb0 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -21,6 +21,7 @@
#include <linux/types.h>
#include <linux/kvm_types.h>
+#include <asm/cputype.h>
#include <asm/kvm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_mmio.h>
@@ -311,8 +312,17 @@ static inline void kvm_arm_vhe_guest_exit(void) {}
static inline bool kvm_arm_harden_branch_predictor(void)
{
- /* No way to detect it yet, pretend it is not there. */
- return false;
+ switch(read_cpuid_part()) {
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+ case ARM_CPU_PART_BRAHMA_B15:
+ case ARM_CPU_PART_CORTEX_A12:
+ case ARM_CPU_PART_CORTEX_A15:
+ case ARM_CPU_PART_CORTEX_A17:
+ return true;
+#endif
+ default:
+ return false;
+ }
}
#endif /* __ARM_KVM_HOST_H__ */
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread* [PATCH v3 15/15] ARM: KVM: report support for SMCCC_ARCH_WORKAROUND_1
@ 2018-05-25 14:01 ` Russell King
0 siblings, 0 replies; 42+ messages in thread
From: Russell King @ 2018-05-25 14:01 UTC (permalink / raw)
To: linux-arm-kernel
Report support for SMCCC_ARCH_WORKAROUND_1 to KVM guests for affected
CPUs.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/include/asm/kvm_host.h | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 248b930563e5..11f91744ffb0 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -21,6 +21,7 @@
#include <linux/types.h>
#include <linux/kvm_types.h>
+#include <asm/cputype.h>
#include <asm/kvm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_mmio.h>
@@ -311,8 +312,17 @@ static inline void kvm_arm_vhe_guest_exit(void) {}
static inline bool kvm_arm_harden_branch_predictor(void)
{
- /* No way to detect it yet, pretend it is not there. */
- return false;
+ switch(read_cpuid_part()) {
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+ case ARM_CPU_PART_BRAHMA_B15:
+ case ARM_CPU_PART_CORTEX_A12:
+ case ARM_CPU_PART_CORTEX_A15:
+ case ARM_CPU_PART_CORTEX_A17:
+ return true;
+#endif
+ default:
+ return false;
+ }
}
#endif /* __ARM_KVM_HOST_H__ */
--
2.7.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* Re: [PATCH v3 00/15] ARM Spectre variant 2 fixes
2018-05-25 13:59 ` Russell King - ARM Linux
@ 2018-05-25 16:25 ` Tony Lindgren
-1 siblings, 0 replies; 42+ messages in thread
From: Tony Lindgren @ 2018-05-25 16:25 UTC (permalink / raw)
To: Russell King - ARM Linux
Cc: Marc Zyngier, Florian Fainelli, kvmarm, linux-arm-kernel
* Russell King - ARM Linux <linux@armlinux.org.uk> [180525 07:02]:
> Third version:
> - Remove "PSCI" from the SMC version of the workaround as well.
> - Avoid reporting active workaround if the IBE bit is not set.
> - Only probe for workaround_1 on Cortex A57 and A72, or non-ARM CPUs.
> - Require features probe for workaround_1 to return zero.
> - Validation that all CPUs in the system have the same workaround status.
> - Avoid corrupting r12 in workaround_1 KVM hypervisor implementation.
Looks good to me and things still work for me. I don't really
want to count that as Tested-by though :) But feel free to add:
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
^ permalink raw reply [flat|nested] 42+ messages in thread
* [PATCH v3 00/15] ARM Spectre variant 2 fixes
@ 2018-05-25 16:25 ` Tony Lindgren
0 siblings, 0 replies; 42+ messages in thread
From: Tony Lindgren @ 2018-05-25 16:25 UTC (permalink / raw)
To: linux-arm-kernel
* Russell King - ARM Linux <linux@armlinux.org.uk> [180525 07:02]:
> Third version:
> - Remove "PSCI" from the SMC version of the workaround as well.
> - Avoid reporting active workaround if the IBE bit is not set.
> - Only probe for workaround_1 on Cortex A57 and A72, or non-ARM CPUs.
> - Require features probe for workaround_1 to return zero.
> - Validation that all CPUs in the system have the same workaround status.
> - Avoid corrupting r12 in workaround_1 KVM hypervisor implementation.
Looks good to me and things still work for me. I don't really
want to count that as Tested-by though :) But feel free to add:
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
^ permalink raw reply [flat|nested] 42+ messages in thread