From patchwork Tue Oct 18 11:04:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 616549 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 8CAB3C4332F for ; Tue, 18 Oct 2022 11:05:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230026AbiJRLFQ (ORCPT ); Tue, 18 Oct 2022 07:05:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229846AbiJRLFJ (ORCPT ); Tue, 18 Oct 2022 07:05:09 -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 7F9224CA22 for ; Tue, 18 Oct 2022 04:05:04 -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 8FA0761523 for ; Tue, 18 Oct 2022 11:05:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3709FC43470; Tue, 18 Oct 2022 11:05:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666091104; bh=ajAZKUqLaOvnZYGz9N1ipr/BfWU81j4u/S3wIzL9ky0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tPXcrYiRpc+6OGEB9DCY5ERG2qV3gbhByKGda0loszkEvMKjEOBcGUUAU2GJ+usvw G5FIE8mfd1PswWH6imoDM3+aLwLC0CAT6TjiHGkmG+tSuLb0dcAiD9FGUrUAmczaEu wLiOXno/hv+LEY/d+7OR2NGw2iwQs7Npgan1WW0O3FUk5V7tVGzBXW34qEDsOYZJKG tHqaDvcYS9EJe1cXYbHsQTFGfsGsoBklfzzbZRmGeP/EfazRsDYCGKWwgu8hxwAHc6 rO77oSfzPNf3m7QY5Gw4p2j93gyM8HwBttx2AUrO4N4l/Of8qGtBug1LT75nu0tRjU gojJzD48bx5ZQ== From: Ard Biesheuvel To: linux-arm-kernel@lists.infradead.org Cc: linux-efi@vger.kernel.org, keescook@chromium.org, Ard Biesheuvel , Will Deacon , Catalin Marinas , Marc Zyngier , Mark Rutland Subject: [PATCH v4 6/6] arm64: efi/libstub: enter with the MMU on Date: Tue, 18 Oct 2022 13:04:41 +0200 Message-Id: <20221018110441.3855148-7-ardb@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221018110441.3855148-1-ardb@kernel.org> References: <20221018110441.3855148-1-ardb@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=5695; i=ardb@kernel.org; h=from:subject; bh=ajAZKUqLaOvnZYGz9N1ipr/BfWU81j4u/S3wIzL9ky0=; b=owEB7QES/pANAwAKAcNPIjmS2Y8kAcsmYgBjTohIXzaJn/IlJ+kFr1EYdYg4nuTbXt53uRA+Daku FmMybzSJAbMEAAEKAB0WIQT72WJ8QGnJQhU3VynDTyI5ktmPJAUCY06ISAAKCRDDTyI5ktmPJI/BDA C2Wgvhwat6TNEwsKTKdXKsg0noF3KpdReIyTepvXE8UBG0XgnocFlw6jD1dNkY2lM8Pdmr3xHBjjJF IGJ6jwgtT6vUPlR2r1pQ7/UwD4QWqNdz6O6pR5H37vBRnWL+R2sVEr1XR1r9BLn3nkmaQYtcNHNCum ek1TOBMnDFNYXxMUW4pQYA395zUDv2GJt451/Y2kSTjMG0m2iK/SrSOpC+Ns2a7roDvBNA5h2+l3ot sPg5L+rlWBsWzqUb48Fs8giS9oh+A3df5EXaat7mOMKjc9cIp+UYMJva/VKerTyRHzLRfir+K8wvbH SswaTYcCX8gm8OVikTCAfD8SBJ+wbEKZ2SybzXw89b0nwA/a57v1Fmx7YpBXMqZM+6qHxZ4pkGnRgA pU68xLvz7tBO4tiA10RDplYzE+qcyzlIhBhwWK8ZXwJ5FKvByVEKWIWPYoeYGdvjNDxCL5p0nlcyhc Mm35VGTHNtZtJymkk+Vb+yLCdgBwH7j/HpAV/4E3048z4= X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org Instead of disabling the MMU and caches before jumping to the kernel's entry point, just call it directly, and keep the MMU and caches enabled. This removes the need for any unconditional cache invalidation to the PoC in the entry path (although cache maintenance of the code portion of the image is still necessary for I/D coherency if the image was moved around in memory). It also allows us to get rid of the asm routine, as doing the jump is easily done from C code. Signed-off-by: Ard Biesheuvel --- arch/arm64/kernel/image-vars.h | 5 +- arch/arm64/mm/cache.S | 5 +- drivers/firmware/efi/libstub/arm64-entry.S | 57 -------------------- drivers/firmware/efi/libstub/arm64-stub.c | 17 +++++- 4 files changed, 22 insertions(+), 62 deletions(-) diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h index 74d20835cf91..13e082e946c5 100644 --- a/arch/arm64/kernel/image-vars.h +++ b/arch/arm64/kernel/image-vars.h @@ -10,7 +10,7 @@ #error This file should only be included in vmlinux.lds.S #endif -PROVIDE(__efistub_primary_entry_offset = primary_entry - _text); +PROVIDE(__efistub_primary_entry = primary_entry); /* * The EFI stub has its own symbol namespace prefixed by __efistub_, to @@ -28,10 +28,11 @@ PROVIDE(__efistub_strnlen = __pi_strnlen); PROVIDE(__efistub_strcmp = __pi_strcmp); PROVIDE(__efistub_strncmp = __pi_strncmp); PROVIDE(__efistub_strrchr = __pi_strrchr); -PROVIDE(__efistub_dcache_clean_poc = __pi_dcache_clean_poc); +PROVIDE(__efistub_caches_clean_inval_pou = __pi_caches_clean_inval_pou); PROVIDE(__efistub__text = _text); PROVIDE(__efistub__end = _end); +PROVIDE(__efistub___inittext_end = __inittext_end); PROVIDE(__efistub__edata = _edata); PROVIDE(__efistub_screen_info = screen_info); PROVIDE(__efistub__ctype = _ctype); diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S index 081058d4e436..8c3b3ee9b1d7 100644 --- a/arch/arm64/mm/cache.S +++ b/arch/arm64/mm/cache.S @@ -52,10 +52,11 @@ alternative_else_nop_endif * - start - virtual start address of region * - end - virtual end address of region */ -SYM_FUNC_START(caches_clean_inval_pou) +SYM_FUNC_START(__pi_caches_clean_inval_pou) caches_clean_inval_pou_macro ret -SYM_FUNC_END(caches_clean_inval_pou) +SYM_FUNC_END(__pi_caches_clean_inval_pou) +SYM_FUNC_ALIAS(caches_clean_inval_pou, __pi_caches_clean_inval_pou) /* * caches_clean_inval_user_pou(start,end) diff --git a/drivers/firmware/efi/libstub/arm64-entry.S b/drivers/firmware/efi/libstub/arm64-entry.S deleted file mode 100644 index 4524525ab314..000000000000 --- a/drivers/firmware/efi/libstub/arm64-entry.S +++ /dev/null @@ -1,57 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-only */ -/* - * EFI entry point. - * - * Copyright (C) 2013, 2014 Red Hat, Inc. - * Author: Mark Salter - */ -#include -#include - -SYM_CODE_START(efi_enter_kernel) - /* - * efi_pe_entry() will have copied the kernel image if necessary and we - * end up here with device tree address in x1 and the kernel entry - * point stored in x0. Save those values in registers which are - * callee preserved. - */ - ldr w2, =primary_entry_offset - add x19, x0, x2 // relocated Image entrypoint - - mov x0, x1 // DTB address - mov x1, xzr - mov x2, xzr - mov x3, xzr - - /* - * Clean the remainder of this routine to the PoC - * so that we can safely disable the MMU and caches. - */ - adr x4, 1f - dc cvac, x4 - dsb sy - - /* Turn off Dcache and MMU */ - mrs x4, CurrentEL - cmp x4, #CurrentEL_EL2 - mrs x4, sctlr_el1 - b.ne 0f - mrs x4, sctlr_el2 -0: bic x4, x4, #SCTLR_ELx_M - bic x4, x4, #SCTLR_ELx_C - b.eq 1f - b 2f - - .balign 32 -1: pre_disable_mmu_workaround - msr sctlr_el2, x4 - isb - br x19 // jump to kernel entrypoint - -2: pre_disable_mmu_workaround - msr sctlr_el1, x4 - isb - br x19 // jump to kernel entrypoint - - .org 1b + 32 -SYM_CODE_END(efi_enter_kernel) diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c index 6229f42c797f..9c7e2c1aace2 100644 --- a/drivers/firmware/efi/libstub/arm64-stub.c +++ b/drivers/firmware/efi/libstub/arm64-stub.c @@ -86,7 +86,7 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, efi_handle_t image_handle) { efi_status_t status; - unsigned long kernel_size, kernel_memsize = 0; + unsigned long kernel_size, kernel_codesize, kernel_memsize; u32 phys_seed = 0; /* @@ -130,6 +130,7 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, SEGMENT_ALIGN >> 10); kernel_size = _edata - _text; + kernel_codesize = __inittext_end - _text; kernel_memsize = kernel_size + (_end - _edata); *reserve_size = kernel_memsize; @@ -173,6 +174,7 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, *image_addr = *reserve_addr; memcpy((void *)*image_addr, _text, kernel_size); + caches_clean_inval_pou(*image_addr, *image_addr + kernel_codesize); clean_image_to_poc: /* @@ -184,3 +186,16 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, return EFI_SUCCESS; } + +asmlinkage void primary_entry(void); + +void __noreturn efi_enter_kernel(unsigned long entrypoint, + unsigned long fdt_addr, + unsigned long fdt_size) +{ + void (* __noreturn enter_kernel)(u64, u64, u64, u64); + u64 offset = (char *)primary_entry - _text; + + enter_kernel = (void *)entrypoint + offset; + enter_kernel(fdt_addr, 0, 0, 0); +}