From patchwork Wed Apr 29 02:05:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Christopher M. Riedl" X-Patchwork-Id: 1278867 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 49BhrF2N8mz9sRf for ; Wed, 29 Apr 2020 12:13:17 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=informatik.wtf Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 49BhrF19MLzDqwy for ; Wed, 29 Apr 2020 12:13:17 +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=informatik.wtf (client-ip=131.153.2.42; helo=h1.fbrelay.privateemail.com; envelope-from=cmr@informatik.wtf; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=informatik.wtf Received: from h1.fbrelay.privateemail.com (h1.fbrelay.privateemail.com [131.153.2.42]) (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 49Bhdy2ng0zDqyf for ; Wed, 29 Apr 2020 12:04:22 +1000 (AEST) Received: from MTA-14-4.privateemail.com (mta-14.privateemail.com [198.54.118.205]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by h1.fbrelay.privateemail.com (Postfix) with ESMTPS id 33B6880A6D for ; Tue, 28 Apr 2020 22:04:18 -0400 (EDT) Received: from mta-14.privateemail.com (localhost [127.0.0.1]) by mta-14.privateemail.com (Postfix) with ESMTP id B562180061; Tue, 28 Apr 2020 22:04:14 -0400 (EDT) Received: from geist.attlocal.net (unknown [10.20.151.249]) by mta-14.privateemail.com (Postfix) with ESMTPA id 6FCD580063; Wed, 29 Apr 2020 02:04:14 +0000 (UTC) From: "Christopher M. Riedl" To: linuxppc-dev@lists.ozlabs.org, kernel-hardening@lists.openwall.com Subject: [RFC PATCH v2 4/5] powerpc/lib: Add LKDTM accessor for patching addr Date: Tue, 28 Apr 2020 21:05:30 -0500 Message-Id: <20200429020531.20684-5-cmr@informatik.wtf> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200429020531.20684-1-cmr@informatik.wtf> References: <20200429020531.20684-1-cmr@informatik.wtf> MIME-Version: 1.0 X-Virus-Scanned: ClamAV using ClamSMTP 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: , Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" When live patching a STRICT_RWX kernel, a mapping is installed at a "patching address" with temporary write permissions. Provide a LKDTM-only accessor function for this address in preparation for a LKDTM test which attempts to "hijack" this mapping by writing to it from another CPU. Signed-off-by: Christopher M. Riedl --- arch/powerpc/lib/code-patching.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c index 26f06cdb5d7e..cfbdef90384e 100644 --- a/arch/powerpc/lib/code-patching.c +++ b/arch/powerpc/lib/code-patching.c @@ -46,6 +46,13 @@ int raw_patch_instruction(unsigned int *addr, unsigned int instr) static struct mm_struct *patching_mm __ro_after_init; static unsigned long patching_addr __ro_after_init; +#ifdef CONFIG_LKDTM +unsigned long read_cpu_patching_addr(unsigned int cpu) +{ + return patching_addr; +} +#endif + void __init poking_init(void) { spinlock_t *ptl; /* for protecting pte table */