KVM: arm64: Avoid unnecessary absolute addressing via literals

There are a few cases in the nVHE code where we take the absolute
address of a symbol via a literal pool entry, and subsequently translate
it to another address space (PA, kimg VA, kernel linear VA, etc).
Originally, this literal was needed because we relied on a different
translation for absolute references, but this is no longer the case, so
we can simply use relative addressing instead. This removes a couple of
RELA entries pointing into the .text segment.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220428140350.3303481-1-ardb@kernel.org

diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S
index 3d613e721a75d00b8e253574e632277b01c3d4b8..366551594417a02f4d9a4cd12b8e6c4d299df484 100644 (file)
--- 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
        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
 
        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
        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.
         */
         *
         * 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)
        hyp_pa  x5, x6
        br      x5
 SYM_FUNC_END(__host_hvc)