From patchwork Tue Apr 5 07:13:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guo Ren X-Patchwork-Id: 12801080 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 6608BC433EF for ; Tue, 5 Apr 2022 07:15:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231549AbiDEHRL (ORCPT ); Tue, 5 Apr 2022 03:17:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59024 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231436AbiDEHQ6 (ORCPT ); Tue, 5 Apr 2022 03:16:58 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BCCD91140; Tue, 5 Apr 2022 00:14:59 -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 ams.source.kernel.org (Postfix) with ESMTPS id 66684B81B75; Tue, 5 Apr 2022 07:14:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3B5F3C34113; Tue, 5 Apr 2022 07:14:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649142897; bh=ggDDZ4KrMuZa/FnH1iFuGJ/npHtqKAOwj6Ie6vczNw4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fBi4/1UQ8TYPu3HtKyxz7E7vs+XesHh9mqlNAGCCPu7pAqmdCSklUU49E5HTtRTRK J6T69wDNoEPicEALGu2Xw/qiuktVFvAY0ZuDycQ1/Pmcr6H/4HMyWZa409DCqiLvZb s6J3VkTwDyyGyZ3eu9EkAwlc+143LU2cGd1vc1zdgpQ0ZAU2oF3Ih9V8Ec2YmTCED5 SsKGhQ0J5paJUebgWmUFlD4DHHntwyFz4i38LX5Bco9HkbrZtkMpCsZkKeChunvTSM C4x4Gaqwnjgyyps53h1iVUo+JBRfl2xwK/1cH62Pfpt2fUSfFGWk7oOPxYlhjfBb25 g9Itk8RHqE/1A== From: guoren@kernel.org To: guoren@kernel.org, palmer@dabbelt.com, arnd@arndb.de, gregkh@linuxfoundation.org, hch@lst.de, nathan@kernel.org, naresh.kamboju@linaro.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.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 V12 15/20] riscv: compat: Add hw capability check for elf Date: Tue, 5 Apr 2022 15:13:09 +0800 Message-Id: <20220405071314.3225832-16-guoren@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220405071314.3225832-1-guoren@kernel.org> References: <20220405071314.3225832-1-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 b4421c16198c..1c7be865ab31 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -84,6 +84,34 @@ 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) {