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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
commitb4b7ff4b08e691656c9d77c758fc355833128ac0 (patch)
tree82fcb00e6b918026dc9f2d1f05ed8eee83874cc0 /arch/arm64/kvm/hyp.S
parent35acfa0fc609f2a2cd95cef4a6a9c3a5c38f1778 (diff)
Linux-libre 4.4-gnupck-4.4-gnu
Diffstat (limited to 'arch/arm64/kvm/hyp.S')
-rw-r--r--arch/arm64/kvm/hyp.S22
1 files changed, 20 insertions, 2 deletions
diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
index e5836138e..86c289832 100644
--- a/arch/arm64/kvm/hyp.S
+++ b/arch/arm64/kvm/hyp.S
@@ -864,6 +864,10 @@ ENTRY(__kvm_flush_vm_context)
ENDPROC(__kvm_flush_vm_context)
__kvm_hyp_panic:
+ // Stash PAR_EL1 before corrupting it in __restore_sysregs
+ mrs x0, par_el1
+ push x0, xzr
+
// Guess the context by looking at VTTBR:
// If zero, then we're already a host.
// Otherwise restore a minimal host context before panicing.
@@ -880,6 +884,14 @@ __kvm_hyp_panic:
bl __restore_sysregs
+ /*
+ * Make sure we have a valid host stack, and don't leave junk in the
+ * frame pointer that will give us a misleading host stack unwinding.
+ */
+ ldr x22, [x2, #CPU_GP_REG_OFFSET(CPU_SP_EL1)]
+ msr sp_el1, x22
+ mov x29, xzr
+
1: adr x0, __hyp_panic_str
adr x1, 2f
ldp x2, x3, [x1]
@@ -890,7 +902,7 @@ __kvm_hyp_panic:
mrs x3, esr_el2
mrs x4, far_el2
mrs x5, hpfar_el2
- mrs x6, par_el1
+ pop x6, xzr // active context PAR_EL1
mrs x7, tpidr_el2
mov lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\
@@ -906,7 +918,7 @@ __kvm_hyp_panic:
ENDPROC(__kvm_hyp_panic)
__hyp_panic_str:
- .ascii "HYP panic:\nPS:%08x PC:%p ESR:%p\nFAR:%p HPFAR:%p PAR:%p\nVCPU:%p\n\0"
+ .ascii "HYP panic:\nPS:%08x PC:%016x ESR:%08x\nFAR:%016x HPFAR:%016x PAR:%016x\nVCPU:%p\n\0"
.align 2
@@ -1007,9 +1019,15 @@ el1_trap:
b.ne 1f // Not an abort we care about
/* This is an abort. Check for permission fault */
+alternative_if_not ARM64_WORKAROUND_834220
and x2, x1, #ESR_ELx_FSC_TYPE
cmp x2, #FSC_PERM
b.ne 1f // Not a permission fault
+alternative_else
+ nop // Use the permission fault path to
+ nop // check for a valid S1 translation,
+ nop // regardless of the ESR value.
+alternative_endif
/*
* Check for Stage-1 page table walk, which is guaranteed