From patchwork Wed Apr 6 18:26:46 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 558533 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 8F070C433F5 for ; Wed, 6 Apr 2022 20:07:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233908AbiDFUJ0 (ORCPT ); Wed, 6 Apr 2022 16:09:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44378 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233841AbiDFUIm (ORCPT ); Wed, 6 Apr 2022 16:08:42 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 80B3F29C97E; Wed, 6 Apr 2022 11:28:55 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1D56661BCB; Wed, 6 Apr 2022 18:28:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 297C8C385A3; Wed, 6 Apr 2022 18:28:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649269734; bh=zTA/gwxscYLWt3/KQ7o9xr51+1aDngsucM7Pk5mFjtY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sQAOaSZlA0NiexhkvHJZajLSLZSblqsyYFqzE+rw1bCKJsIRv64GO9DLJTo5UZi2z z6bMD9zM/ThQAPXzK606sDQVDC2dIYiQgrlXsJIHmqL24bBqrN1EcAcXmVlf/H958S x0JYQtXvCSrPw3s105g9ov+qhxosJM+ZLZckknhI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Catalin Marinas , James Morse Subject: [PATCH 4.9 37/43] arm64: entry: Add macro for reading symbol addresses from the trampoline Date: Wed, 6 Apr 2022 20:26:46 +0200 Message-Id: <20220406182437.757706906@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220406182436.675069715@linuxfoundation.org> References: <20220406182436.675069715@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: James Morse 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 Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/entry.S | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) --- 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 */