From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA711C433DF for ; Sun, 5 Jul 2020 06:27:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A1A7F207CD for ; Sun, 5 Jul 2020 06:27:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593930437; bh=j/k1+B7wkCi8TSTAT6vwsg8IilF6kwnCgtC2Tyh8esI=; h=From:To:Cc:Subject:Date:List-ID:From; b=IQ5qhE29RLsXSeBd335mzQwZ2pi3EU8RdGwrAx1op1NA9lHV3sQkGtz5e0uB0OCST y/3UX67b5yrLmHXHDrReYQqH9kAIDwkSNRk95GM4SUCBTItP8AlsP11XtUTUrjSbLP 4VXgTN6P3N417CjMJ0mBLptUsfqCoRkmIfm9ADkU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726270AbgGEGZY (ORCPT ); Sun, 5 Jul 2020 02:25:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:46978 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725873AbgGEGZX (ORCPT ); Sun, 5 Jul 2020 02:25:23 -0400 Received: from localhost.localdomain (unknown [89.208.247.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 58031207CD; Sun, 5 Jul 2020 06:25:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593930322; bh=j/k1+B7wkCi8TSTAT6vwsg8IilF6kwnCgtC2Tyh8esI=; h=From:To:Cc:Subject:Date:From; b=IBJqT+/t6RF8oJE4tYJNDhNag1zBFY9YGGFiI1+roc5OKJAHNR5pHc67IMt+86PSL ffzMSMcJL7BhRaBnmK6iWQMIWGEZ6PFlG4cjwTyDRkSKnoE9B9eU5YwUiZ25uVceED BNA61f5ly40MihKlN4cTxwu+idkiuLAZ5hqt36Mc= From: guoren@kernel.org To: palmerdabbelt@google.com, paul.walmsley@sifive.com, anup@brainfault.org, greentime.hu@sifive.com, zong.li@sifive.com, guoren@kernel.org Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-csky@vger.kernel.org, Guo Ren , Albert Ou , Masami Hiramatsu , =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Greentime Hu , Atish Patra Subject: [PATCH] riscv: Add STACKPROTECTOR supported Date: Sun, 5 Jul 2020 06:24:15 +0000 Message-Id: <1593930255-12378-1-git-send-email-guoren@kernel.org> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Guo Ren The -fstack-protector & -fstack-protector-strong features are from gcc. The patch only add basic kernel support to stack-protector feature and some arch could have its own solution such as ARM64_PTR_AUTH. After enabling STACKPROTECTOR and STACKPROTECTOR_STRONG, the .text size is expanded from 0x7de066 to 0x81fb32 (only 5%) to add canary checking code. Signed-off-by: Guo Ren Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Masami Hiramatsu Cc: Björn Töpel Cc: Greentime Hu Cc: Atish Patra --- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/stackprotector.h | 29 +++++++++++++++++++++++++++++ arch/riscv/kernel/process.c | 6 ++++++ 3 files changed, 36 insertions(+) create mode 100644 arch/riscv/include/asm/stackprotector.h diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index f927a91..4b0e308 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -63,6 +63,7 @@ config RISCV select HAVE_PERF_EVENTS select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP + select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS select IRQ_DOMAIN select MODULES_USE_ELF_RELA if MODULES diff --git a/arch/riscv/include/asm/stackprotector.h b/arch/riscv/include/asm/stackprotector.h new file mode 100644 index 00000000..5962f88 --- /dev/null +++ b/arch/riscv/include/asm/stackprotector.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _ASM_RISCV_STACKPROTECTOR_H +#define _ASM_RISCV_STACKPROTECTOR_H + +#include +#include + +extern unsigned long __stack_chk_guard; + +/* + * Initialize the stackprotector canary value. + * + * NOTE: this must only be called from functions that never return, + * and it must always be inlined. + */ +static __always_inline void boot_init_stack_canary(void) +{ + unsigned long canary; + + /* Try to get a semi random initial value. */ + get_random_bytes(&canary, sizeof(canary)); + canary ^= LINUX_VERSION_CODE; + canary &= CANARY_MASK; + + current->stack_canary = canary; + __stack_chk_guard = current->stack_canary; +} +#endif /* _ASM_RISCV_STACKPROTECTOR_H */ diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index 824d117..6548929 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -24,6 +24,12 @@ register unsigned long gp_in_global __asm__("gp"); +#ifdef CONFIG_STACKPROTECTOR +#include +unsigned long __stack_chk_guard __read_mostly; +EXPORT_SYMBOL(__stack_chk_guard); +#endif + extern asmlinkage void ret_from_fork(void); extern asmlinkage void ret_from_kernel_thread(void); -- 2.7.4