From patchwork Sat Apr 2 13:35:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guo Ren X-Patchwork-Id: 12799174 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 C9E60C3527B for ; Sat, 2 Apr 2022 13:38:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355790AbiDBNjx (ORCPT ); Sat, 2 Apr 2022 09:39:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58944 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355654AbiDBNjf (ORCPT ); Sat, 2 Apr 2022 09:39:35 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F1473100E37; Sat, 2 Apr 2022 06:37:26 -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 85A7161481; Sat, 2 Apr 2022 13:37:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 605D6C34110; Sat, 2 Apr 2022 13:37:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1648906646; bh=UEwTRlZAy4kLlmbBNaeoYiWupFPI5fJMOID0/hv13uY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QTnIZy0YhYFXQ9utl0bKoNuLWtbPgY+e5FekJ0ZuB8OA1oah/wyqrw/RhQ/6JhrxX hHR5t1Ycmd2XwH8vu1d6ryDvl9hdMhee4pUbFH8UZafMPmhtw2XovNZkgjG988WRee m6SgYyBcWC7bn0CnkVX9NMJjyabByjixe1JbxD/S/pDiUm6OOqgzyxJJnak6Cp5bXY ljTOodtzHT9HbhP1WkV0zJy34qXnC+wHf75rmkCBcCV4e4U9DrBjCd6a2PNSTfwioV ByuYHArHmLZuuJQSA9NRhncEB8qZMIbYigG3PhtfJiWSJY8q1s/v+xNaQ3e6FRrQhA d6GiN9xj4fqYQ== From: guoren@kernel.org To: guoren@kernel.org, palmer@dabbelt.com, arnd@arndb.de, gregkh@linuxfoundation.org, hch@lst.de Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, linux-csky@vger.kernel.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-parisc@vger.kernel.org, linux-mips@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, heiko@sntech.de, Guo Ren Subject: [PATCH V10 15/20] riscv: compat: Add hw capability check for elf Date: Sat, 2 Apr 2022 21:35:39 +0800 Message-Id: <20220402133544.2690231-16-guoren@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220402133544.2690231-1-guoren@kernel.org> References: <20220402133544.2690231-1-guoren@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org From: Guo Ren Detect hardware COMPAT (32bit U-mode) capability in rv64. If not support COMPAT mode in hw, compat_elf_check_arch would return false by compat_binfmt_elf.c Add CLASS to enhance (compat_)elf_check_arch to distinguish 32BIT/64BIT elf. Signed-off-by: Guo Ren Signed-off-by: Guo Ren Tested-by: Heiko Stuebner Cc: Arnd Bergmann Cc: Christoph Hellwig --- arch/riscv/include/asm/elf.h | 6 ++++-- arch/riscv/kernel/process.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 32 insertions(+), 2 deletions(-) diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h index a234656cfb5d..754fdb8cee96 100644 --- a/arch/riscv/include/asm/elf.h +++ b/arch/riscv/include/asm/elf.h @@ -33,9 +33,11 @@ /* * This is used to ensure we don't load something for the wrong architecture. */ -#define elf_check_arch(x) ((x)->e_machine == EM_RISCV) +#define elf_check_arch(x) (((x)->e_machine == EM_RISCV) && \ + ((x)->e_ident[EI_CLASS] == ELF_CLASS)) -#define compat_elf_check_arch(x) ((x)->e_machine == EM_RISCV) +extern bool compat_elf_check_arch(Elf32_Ehdr *hdr); +#define compat_elf_check_arch compat_elf_check_arch #define CORE_DUMP_USE_REGSET #define ELF_EXEC_PAGESIZE (PAGE_SIZE) diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index 8c7665481a9f..203fdaa3f9e2 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -83,6 +83,34 @@ void show_regs(struct pt_regs *regs) dump_backtrace(regs, NULL, KERN_DEFAULT); } +#ifdef CONFIG_COMPAT +static bool compat_mode_supported __read_mostly; + +bool compat_elf_check_arch(Elf32_Ehdr *hdr) +{ + return compat_mode_supported && + hdr->e_machine == EM_RISCV && + hdr->e_ident[EI_CLASS] == ELFCLASS32; +} + +static int __init compat_mode_detect(void) +{ + unsigned long tmp = csr_read(CSR_STATUS); + + csr_write(CSR_STATUS, (tmp & ~SR_UXL) | SR_UXL_32); + compat_mode_supported = + (csr_read(CSR_STATUS) & SR_UXL) == SR_UXL_32; + + csr_write(CSR_STATUS, tmp); + + pr_info("riscv: ELF compat mode %s", + compat_mode_supported ? "supported" : "failed"); + + return 0; +} +early_initcall(compat_mode_detect); +#endif + void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp) {