From patchwork Sun Feb 27 16:28:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guo Ren X-Patchwork-Id: 12761959 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 91640C433FE for ; Sun, 27 Feb 2022 16:30:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231252AbiB0Qb1 (ORCPT ); Sun, 27 Feb 2022 11:31:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59212 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231820AbiB0QbA (ORCPT ); Sun, 27 Feb 2022 11:31:00 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 121D55C35D; Sun, 27 Feb 2022 08:30:23 -0800 (PST) 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 B85E0B80CE4; Sun, 27 Feb 2022 16:30:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 939ACC36AE5; Sun, 27 Feb 2022 16:30:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1645979420; bh=YHBMf6oiN7AKyDQcRFQG6drB0b2sg1GEQLG12pVdvWw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GUC/ztJbtzLNu8llpuROUVaZ3E8NyrDFD8yGwy4K8tYgwlx9qdXJqpr8G1CUuJLuL SQs9N9tJ6CzjqSEvgs9Q+TmAF2tzmIMQd1dQI3B3UPxULabUxNCkqiYJ/czct+Gq8k KuRJjLlgK7fwONb/BsASgTeV3DEsjRYmt6jxDwb7SNswxhumCHq3u385kgUhioQ0Dd GHagwTVSEYjk9hyTY2I+qdz6jk0jJtZtezgxQZil86wm9jjug9Y0MLcB7luMCIyN4l 1F5iB1y8UdGZ0BymhjWAqVsaqnV10+qDR2K6/0tp1NrDeZSHAwDHvotDFZ6/eNGZ9t VccjUEfu+whlw== From: guoren@kernel.org To: guoren@kernel.org, palmer@dabbelt.com, arnd@arndb.de, anup@brainfault.org, gregkh@linuxfoundation.org, liush@allwinnertech.com, wefu@redhat.com, drew@beagleboard.org, wangjunqiang@iscas.ac.cn, 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, Guo Ren Subject: [PATCH V7 15/20] riscv: compat: Add hw capability check for elf Date: Mon, 28 Feb 2022 00:28:26 +0800 Message-Id: <20220227162831.674483-16-guoren@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220227162831.674483-1-guoren@kernel.org> References: <20220227162831.674483-1-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 Signed-off-by: Guo Ren Signed-off-by: Guo Ren Cc: Arnd Bergmann Cc: Christoph Hellwig --- arch/riscv/include/asm/elf.h | 3 ++- arch/riscv/kernel/process.c | 26 ++++++++++++++++++++++++++ 2 files changed, 28 insertions(+), 1 deletion(-) diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h index aee40040917b..3a4293dc7229 100644 --- a/arch/riscv/include/asm/elf.h +++ b/arch/riscv/include/asm/elf.h @@ -40,7 +40,8 @@ * elf64_hdr e_machine's offset are different. The checker is * a little bit simple compare to other architectures. */ -#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 54787ca9806a..7bbe4dd95e85 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -83,6 +83,32 @@ 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; +} + +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) {