diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/nvhe/host.S')
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/host.S | 32 |
1 files changed, 27 insertions, 5 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S index 727c979b2b69..ea6a397b64a6 100644 --- a/arch/arm64/kvm/hyp/nvhe/host.S +++ b/arch/arm64/kvm/hyp/nvhe/host.S @@ -80,7 +80,7 @@ SYM_FUNC_START(__hyp_do_panic) mov lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\ PSR_MODE_EL1h) msr spsr_el2, lr - ldr lr, =nvhe_hyp_panic_handler + adr_l lr, nvhe_hyp_panic_handler hyp_kimg_va lr, x6 msr elr_el2, lr @@ -125,13 +125,11 @@ alternative_else_nop_endif add sp, sp, #16 /* * Compute the idmap address of __kvm_handle_stub_hvc and - * jump there. Since we use kimage_voffset, do not use the - * HYP VA for __kvm_handle_stub_hvc, but the kernel VA instead - * (by loading it from the constant pool). + * jump there. * * Preserve x0-x4, which may contain stub parameters. */ - ldr x5, =__kvm_handle_stub_hvc + adr_l x5, __kvm_handle_stub_hvc hyp_pa x5, x6 br x5 SYM_FUNC_END(__host_hvc) @@ -153,6 +151,18 @@ 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 +175,18 @@ 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 |