From patchwork Wed Apr 6 16:45:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 558554 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 19673C43219 for ; Wed, 6 Apr 2022 18:08:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240169AbiDFSJ6 (ORCPT ); Wed, 6 Apr 2022 14:09:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34678 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240109AbiDFSIW (ORCPT ); Wed, 6 Apr 2022 14:08:22 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 303FB1FCF7; Wed, 6 Apr 2022 09:46:35 -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 1754923A; Wed, 6 Apr 2022 09:46:35 -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 6A3FD3F73B; Wed, 6 Apr 2022 09:46:34 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: James Morse , Catalin Marinas Subject: [stable:PATCH v4.9.309 37/43] arm64: entry: Add macro for reading symbol addresses from the trampoline Date: Wed, 6 Apr 2022 17:45:40 +0100 Message-Id: <20220406164546.1888528-37-james.morse@arm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220406164546.1888528-1-james.morse@arm.com> References: <0220406164217.1888053-1-james.morse@arm.com> <20220406164546.1888528-1-james.morse@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org commit b28a8eebe81c186fdb1a0078263b30576c8e1f42 upstream. The trampoline code needs to use the address of symbols in the wider kernel, e.g. vectors. PC-relative addressing wouldn't work as the trampoline code doesn't run at the address the linker expected. tramp_ventry uses a literal pool, unless CONFIG_RANDOMIZE_BASE is set, in which case it uses the data page as a literal pool because the data page can be unmapped when running in user-space, which is required for CPUs vulnerable to meltdown. Pull this logic out as a macro, instead of adding a third copy of it. Reviewed-by: Catalin Marinas [ Removed SDEI for stable backport ] Signed-off-by: James Morse --- arch/arm64/kernel/entry.S | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 6e637315fd80..ec46c89759a8 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -921,6 +921,15 @@ __ni_sys_trace: sub \dst, \dst, PAGE_SIZE .endm + .macro tramp_data_read_var dst, var +#ifdef CONFIG_RANDOMIZE_BASE + tramp_data_page \dst + add \dst, \dst, #:lo12:__entry_tramp_data_\var + ldr \dst, [\dst] +#else + ldr \dst, =\var +#endif + .endm #define BHB_MITIGATION_NONE 0 #define BHB_MITIGATION_LOOP 1 @@ -951,13 +960,7 @@ __ni_sys_trace: b . 2: tramp_map_kernel x30 -#ifdef CONFIG_RANDOMIZE_BASE - tramp_data_page x30 - isb - ldr x30, [x30] -#else - ldr x30, =vectors -#endif + tramp_data_read_var x30, vectors prfm plil1strm, [x30, #(1b - \vector_start)] msr vbar_el1, x30 isb @@ -1037,7 +1040,12 @@ END(tramp_exit_compat) .align PAGE_SHIFT .globl __entry_tramp_data_start __entry_tramp_data_start: +__entry_tramp_data_vectors: .quad vectors +#ifdef CONFIG_ARM_SDE_INTERFACE +__entry_tramp_data___sdei_asm_trampoline_next_handler: + .quad __sdei_asm_handler +#endif /* CONFIG_ARM_SDE_INTERFACE */ .popsection // .rodata #endif /* CONFIG_RANDOMIZE_BASE */ #endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */