From patchwork Thu May 5 11:19:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: xiujianfeng X-Patchwork-Id: 1626909 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4KvBW44Wqnz9sBB for ; Thu, 5 May 2022 21:37:04 +1000 (AEST) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4KvBW36sq0z3byF for ; Thu, 5 May 2022 21:37:03 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=huawei.com (client-ip=45.249.212.189; helo=szxga03-in.huawei.com; envelope-from=xiujianfeng@huawei.com; receiver=) X-Greylist: delayed 949 seconds by postgrey-1.36 at boromir; Thu, 05 May 2022 21:36:51 AEST Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4KvBVq2ymbz3bft for ; Thu, 5 May 2022 21:36:47 +1000 (AEST) Received: from dggpeml500023.china.huawei.com (unknown [172.30.72.55]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4KvB2x6FckzHnV5; Thu, 5 May 2022 19:16:09 +0800 (CST) Received: from ubuntu1804.huawei.com (10.67.174.58) by dggpeml500023.china.huawei.com (7.185.36.114) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 5 May 2022 19:20:51 +0800 From: Xiu Jianfeng To: , , , , , , Subject: [PATCH -next] powerpc: add support for syscall stack randomization Date: Thu, 5 May 2022 19:19:32 +0800 Message-ID: <20220505111932.228814-1-xiujianfeng@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.67.174.58] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpeml500023.china.huawei.com (7.185.36.114) X-CFilter-Loop: Reflected X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Add support for adding a random offset to the stack while handling syscalls. This patch uses mftb() instead of get_random_int() for better performance. Signed-off-by: Xiu Jianfeng --- arch/powerpc/Kconfig | 1 + arch/powerpc/kernel/interrupt.c | 3 +++ 2 files changed, 4 insertions(+) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 5fc9153927ac..7e04c9f80cbc 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -192,6 +192,7 @@ config PPC select HAVE_ARCH_KASAN if PPC32 && PPC_PAGE_SHIFT <= 14 select HAVE_ARCH_KASAN_VMALLOC if PPC32 && PPC_PAGE_SHIFT <= 14 select HAVE_ARCH_KFENCE if PPC_BOOK3S_32 || PPC_8xx || 40x + select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET select HAVE_ARCH_KGDB select HAVE_ARCH_MMAP_RND_BITS select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c index 784ea3289c84..459385769721 100644 --- a/arch/powerpc/kernel/interrupt.c +++ b/arch/powerpc/kernel/interrupt.c @@ -4,6 +4,7 @@ #include #include #include /* for show_regs */ +#include #include #include @@ -82,6 +83,7 @@ notrace long system_call_exception(long r3, long r4, long r5, kuap_lock(); + add_random_kstack_offset(); regs->orig_gpr3 = r3; if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) @@ -405,6 +407,7 @@ interrupt_exit_user_prepare_main(unsigned long ret, struct pt_regs *regs) /* Restore user access locks last */ kuap_user_restore(regs); + choose_random_kstack_offset(mftb() & 0xFF); return ret; }