From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B3CEC433F5 for ; Fri, 18 Mar 2022 17:50:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239933AbiCRRvk (ORCPT ); Fri, 18 Mar 2022 13:51:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239840AbiCRRvH (ORCPT ); Fri, 18 Mar 2022 13:51:07 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4C02618CD24; Fri, 18 Mar 2022 10:49:43 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2C6571570; Fri, 18 Mar 2022 10:49:43 -0700 (PDT) Received: from eglon.cambridge.arm.com (eglon.cambridge.arm.com [10.1.196.218]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 80D913F7B4; Fri, 18 Mar 2022 10:49:42 -0700 (PDT) From: James Morse To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, james.morse@arm.com, catalin.marinas@arm.com Subject: [stable:PATCH v4.19.235 11/22] arm64: entry: Make the kpti trampoline's kpti sequence optional Date: Fri, 18 Mar 2022 17:48:31 +0000 Message-Id: <20220318174842.2321061-12-james.morse@arm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220318174842.2321061-1-james.morse@arm.com> References: <20220318174842.2321061-1-james.morse@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org commit c47e4d04ba0f1ea17353d85d45f611277507e07a upstream. Spectre-BHB needs to add sequences to the vectors. Having one global set of vectors is a problem for big/little systems where the sequence is costly on cpus that are not vulnerable. Making the vectors per-cpu in the style of KVM's bh_harden_hyp_vecs requires the vectors to be generated by macros. Make the kpti re-mapping of the kernel optional, so the macros can be used without kpti. Reviewed-by: Russell King (Oracle) Reviewed-by: Catalin Marinas Signed-off-by: James Morse --- arch/arm64/kernel/entry.S | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 03c45538a93f..50843161607e 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -970,9 +970,10 @@ alternative_else_nop_endif sub \dst, \dst, PAGE_SIZE .endm - .macro tramp_ventry, vector_start, regsize + .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 @@ -994,8 +995,12 @@ alternative_insn isb, nop, ARM64_WORKAROUND_QCOM_FALKOR_E1003 #endif prfm plil1strm, [x30, #(1b - \vector_start)] msr vbar_el1, x30 + isb + .else + ldr x30, =vectors + .endif // \kpti == 1 + add x30, x30, #(1b - \vector_start + 4) - isb ret .org 1b + 128 // Did we overflow the ventry slot? .endm @@ -1012,15 +1017,15 @@ alternative_insn isb, nop, ARM64_WORKAROUND_QCOM_FALKOR_E1003 eret .endm - .macro generate_tramp_vector + .macro generate_tramp_vector, kpti .Lvector_start\@: .space 0x400 .rept 4 - tramp_ventry .Lvector_start\@, 64 + tramp_ventry .Lvector_start\@, 64, \kpti .endr .rept 4 - tramp_ventry .Lvector_start\@, 32 + tramp_ventry .Lvector_start\@, 32, \kpti .endr .endm @@ -1031,7 +1036,7 @@ alternative_insn isb, nop, ARM64_WORKAROUND_QCOM_FALKOR_E1003 .pushsection ".entry.tramp.text", "ax" .align 11 ENTRY(tramp_vectors) - generate_tramp_vector + generate_tramp_vector kpti=1 END(tramp_vectors) ENTRY(tramp_exit_native) -- 2.30.2