From: James Morse <james.morse@xxxxxxx> commit aff65393fa1401e034656e349abd655cfe272de0 upstream. kpti is an optional feature, for systems not using kpti a set of vectors for the spectre-bhb mitigations is needed. Add another set of vectors, __bp_harden_el1_vectors, that will be used if a mitigation is needed and kpti is not in use. The EL1 ventries are repeated verbatim as there is no additional work needed for entry from EL1. Reviewed-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx> Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx> Signed-off-by: James Morse <james.morse@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/arm64/kernel/entry.S | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -1025,10 +1025,11 @@ alternative_else_nop_endif .macro tramp_ventry, vector_start, regsize, kpti .align 7 1: - .if \kpti == 1 .if \regsize == 64 msr tpidrro_el0, x30 // Restored in kernel_ventry .endif + + .if \kpti == 1 /* * Defend against branch aliasing attacks by pushing a dummy * entry onto the return stack and using a RET instruction to @@ -1112,6 +1113,37 @@ __entry_tramp_data_start: #endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ /* + * Exception vectors for spectre mitigations on entry from EL1 when + * kpti is not in use. + */ + .macro generate_el1_vector +.Lvector_start\@: + kernel_ventry 1, sync_invalid // Synchronous EL1t + kernel_ventry 1, irq_invalid // IRQ EL1t + kernel_ventry 1, fiq_invalid // FIQ EL1t + kernel_ventry 1, error_invalid // Error EL1t + + kernel_ventry 1, sync // Synchronous EL1h + kernel_ventry 1, irq // IRQ EL1h + kernel_ventry 1, fiq_invalid // FIQ EL1h + kernel_ventry 1, error_invalid // Error EL1h + + .rept 4 + tramp_ventry .Lvector_start\@, 64, kpti=0 + .endr + .rept 4 + tramp_ventry .Lvector_start\@, 32, kpti=0 + .endr + .endm + + .pushsection ".entry.text", "ax" + .align 11 +ENTRY(__bp_harden_el1_vectors) + generate_el1_vector +END(__bp_harden_el1_vectors) + .popsection + +/* * Special system call wrappers. */ ENTRY(sys_rt_sigreturn_wrapper) Patches currently in stable-queue which might be from james.morse@xxxxxxx are queue-4.14/arm64-entry-add-macro-for-reading-symbol-addresses-from-the-trampoline.patch queue-4.14/arm64-use-the-clearbhb-instruction-in-mitigations.patch queue-4.14/arm64-add-percpu-vectors-for-el1.patch queue-4.14/arm64-arch_timer-add-workaround-for-arm-erratum-1188873.patch queue-4.14/arm64-entry-free-up-another-register-on-kpti-s-tramp_exit-path.patch queue-4.14/arm64-entry-don-t-assume-tramp_vectors-is-the-start-of-the-vectors.patch queue-4.14/arm64-entry-make-the-trampoline-cleanup-optional.patch queue-4.14/arm64-add-silicon-errata.txt-entry-for-arm-erratum-1188873.patch queue-4.14/kvm-arm64-add-templates-for-bhb-mitigation-sequences.patch queue-4.14/arm64-entry-add-non-kpti-__bp_harden_el1_vectors-for-mitigations.patch queue-4.14/arm64-add-id_aa64isar2_el1-sys-register.patch queue-4.14/kvm-arm64-allow-smccc_arch_workaround_3-to-be-discovered-and-migrated.patch queue-4.14/arm64-add-neoverse-n2-cortex-a710-cpu-part-definition.patch queue-4.14/arm64-arch_timer-avoid-unused-function-warning.patch queue-4.14/arm64-entry-move-trampoline-macros-out-of-ifdef-d-section.patch queue-4.14/arm64-entry-allow-tramp_alias-to-access-symbols-after-the-4k-boundary.patch queue-4.14/arm64-add-part-number-for-arm-cortex-a77.patch queue-4.14/arm64-entry-move-the-trampoline-data-page-before-the-text-page.patch queue-4.14/arm64-entry.s-add-ventry-overflow-sanity-checks.patch queue-4.14/arm64-add-part-number-for-neoverse-n1.patch queue-4.14/arm64-entry-add-vectors-that-have-the-bhb-mitigation-sequences.patch queue-4.14/arm64-make-arm64_erratum_1188873-depend-on-compat.patch queue-4.14/arm64-mitigate-spectre-style-branch-history-side-channels.patch queue-4.14/arm64-entry-allow-the-trampoline-text-to-occupy-multiple-pages.patch queue-4.14/arm64-proton-pack-report-spectre-bhb-vulnerabilities-as-part-of-spectre-v2.patch queue-4.14/arm64-add-cortex-x2-cpu-part-definition.patch queue-4.14/arm64-entry-make-the-kpti-trampoline-s-kpti-sequence-optional.patch
