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| author | Marc Zyngier <maz@kernel.org> | 2022-05-04 09:42:37 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2022-05-04 09:42:37 +0100 |
| commit | 904cabf4712426fdcb902b149b97c62ac0fbc8f6 (patch) | |
| tree | 5eec3b136099513bd8bb8221c2a5170adbea43d9 /arch/arm64/kvm/hyp/nvhe/host.S | |
| parent | b2c4caf3316ce535af333bbd2cd99ad96f991074 (diff) | |
| parent | 6ccf9cb557bd32073b0d68baed97f1bd8a40ff1d (diff) | |
| download | linux-stable-904cabf4712426fdcb902b149b97c62ac0fbc8f6.tar.gz linux-stable-904cabf4712426fdcb902b149b97c62ac0fbc8f6.tar.bz2 linux-stable-904cabf4712426fdcb902b149b97c62ac0fbc8f6.zip | |
Merge branch kvm-arm64/hyp-stack-guard into kvmarm-master/next
* kvm-arm64/hyp-stack-guard:
: .
: Harden the EL2 stack by providing stack guards, courtesy of
: Kalesh Singh.
: .
KVM: arm64: Symbolize the nVHE HYP addresses
KVM: arm64: Detect and handle hypervisor stack overflows
KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
KVM: arm64: Add guard pages for KVM nVHE hypervisor stack
KVM: arm64: Introduce pkvm_alloc_private_va_range()
KVM: arm64: Introduce hyp_alloc_private_va_range()
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'arch/arm64/kvm/hyp/nvhe/host.S')
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/host.S | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S index 727c979b2b69..20bf1327e6b9 100644 --- a/arch/arm64/kvm/hyp/nvhe/host.S +++ b/arch/arm64/kvm/hyp/nvhe/host.S @@ -153,6 +153,18 @@ SYM_FUNC_END(__host_hvc) .macro invalid_host_el2_vect .align 7 + + /* + * Test whether the SP has overflowed, without corrupting a GPR. + * nVHE hypervisor stacks are aligned so that the PAGE_SHIFT bit + * of SP should always be 1. + */ + add sp, sp, x0 // sp' = sp + x0 + sub x0, sp, x0 // x0' = sp' - x0 = (sp + x0) - x0 = sp + tbz x0, #PAGE_SHIFT, .L__hyp_sp_overflow\@ + sub x0, sp, x0 // x0'' = sp' - x0' = (sp + x0) - sp = x0 + sub sp, sp, x0 // sp'' = sp' - x0 = (sp + x0) - x0 = sp + /* If a guest is loaded, panic out of it. */ stp x0, x1, [sp, #-16]! get_loaded_vcpu x0, x1 @@ -165,6 +177,18 @@ SYM_FUNC_END(__host_hvc) * been partially clobbered by __host_enter. */ b hyp_panic + +.L__hyp_sp_overflow\@: + /* + * Reset SP to the top of the stack, to allow handling the hyp_panic. + * This corrupts the stack but is ok, since we won't be attempting + * any unwinding here. + */ + ldr_this_cpu x0, kvm_init_params + NVHE_INIT_STACK_HYP_VA, x1 + mov sp, x0 + + b hyp_panic_bad_stack + ASM_BUG() .endm .macro invalid_host_el1_vect |