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authorLinus Torvalds <torvalds@linux-foundation.org>2018-06-06 13:49:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-06-06 13:49:25 -0700
commit311da4975894aab7a4bb94aa83f38f052d7ffda4 (patch)
tree4de18b9cbeac4f21ed2aa7c8ec0ae515a56f368c /arch/arm/kvm
parentca95bf62fcf528a0d8069731d39303ba43fb9af4 (diff)
parent0ac000e86703dedea1000513dbb8a64d02930668 (diff)
downloadlinux-311da4975894aab7a4bb94aa83f38f052d7ffda4.tar.bz2
Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm
Pull ARM updates from Russell King: - Initial round of Spectre variant 1 and variant 2 fixes for 32-bit ARM - Clang support improvements - nommu updates for v8 MPU - enable ARM_MODULE_PLTS by default to avoid problems loading modules with larger kernels - vmlinux.lds and dma-mapping cleanups * 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (31 commits) ARM: spectre-v1: fix syscall entry ARM: spectre-v1: add array_index_mask_nospec() implementation ARM: spectre-v1: add speculation barrier (csdb) macros ARM: KVM: report support for SMCCC_ARCH_WORKAROUND_1 ARM: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling ARM: spectre-v2: KVM: invalidate icache on guest exit for Brahma B15 ARM: KVM: invalidate icache on guest exit for Cortex-A15 ARM: KVM: invalidate BTB on guest exit for Cortex-A12/A17 ARM: spectre-v2: warn about incorrect context switching functions ARM: spectre-v2: add firmware based hardening ARM: spectre-v2: harden user aborts in kernel space ARM: spectre-v2: add Cortex A8 and A15 validation of the IBE bit ARM: spectre-v2: harden branch predictor on context switches ARM: spectre: add Kconfig symbol for CPUs vulnerable to Spectre ARM: bugs: add support for per-processor bug checking ARM: bugs: hook processor bug checking into SMP and suspend paths ARM: bugs: prepare processor bug infrastructure ARM: add more CPU part numbers for Cortex and Brahma B15 CPUs ARM: 8774/1: remove no-op macro VMLINUX_SYMBOL() ARM: 8773/1: amba: Export amba_bustype ...
Diffstat (limited to 'arch/arm/kvm')
-rw-r--r--arch/arm/kvm/hyp/hyp-entry.S112
1 files changed, 109 insertions, 3 deletions
diff --git a/arch/arm/kvm/hyp/hyp-entry.S b/arch/arm/kvm/hyp/hyp-entry.S
index 95a2faefc070..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>
@@ -71,6 +72,90 @@ __kvm_hyp_vector:
W(b) hyp_irq
W(b) hyp_fiq
+#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
+
+ /*
+ * 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
+
+decode_vectors:
+
+#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
@@ -118,7 +203,7 @@ hyp_hvc:
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
@@ -149,7 +234,14 @@ hyp_hvc:
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 +251,21 @@ hyp_hvc:
THUMB( orr lr, #1)
blx lr @ Call the HYP function
- pop {lr}
+ 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: