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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 10E43C433ED for ; Thu, 29 Apr 2021 07:34:31 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3C24F6143E for ; Thu, 29 Apr 2021 07:34:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3C24F6143E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bluescreens.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4FW6hN50LDz3dY9 for ; Thu, 29 Apr 2021 17:34:28 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=bluescreens.de (client-ip=91.198.250.236; helo=mout-y-111.mailbox.org; envelope-from=cmr@bluescreens.de; receiver=) Received: from mout-y-111.mailbox.org (mout-y-111.mailbox.org [91.198.250.236]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4FW6ch479gz3046 for ; Thu, 29 Apr 2021 17:31:16 +1000 (AEST) Received: from smtp2.mailbox.org (smtp2.mailbox.org [IPv6:2001:67c:2050:105:465:1:2:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-y-111.mailbox.org (Postfix) with ESMTPS id 4FW6PQ2cNrzQjn5; Thu, 29 Apr 2021 09:21:30 +0200 (CEST) X-Virus-Scanned: amavisd-new at heinlein-support.de Received: from smtp2.mailbox.org ([80.241.60.241]) by spamfilter01.heinlein-hosting.de (spamfilter01.heinlein-hosting.de [80.241.56.115]) (amavisd-new, port 10030) with ESMTP id vXW0DGaQY74F; Thu, 29 Apr 2021 09:21:27 +0200 (CEST) From: "Christopher M. Riedl" To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH v4 03/11] x86_64: Add LKDTM accessor for patching addr Date: Thu, 29 Apr 2021 02:20:49 -0500 Message-Id: <20210429072057.8870-4-cmr@bluescreens.de> In-Reply-To: <20210429072057.8870-1-cmr@bluescreens.de> References: <20210429072057.8870-1-cmr@bluescreens.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-MBO-SPAM-Probability: ** X-Rspamd-Score: 1.59 / 15.00 / 15.00 X-Rspamd-Queue-Id: 6FA3117F3 X-Rspamd-UID: cf277a 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: tglx@linutronix.de, x86@kernel.org, linux-hardening@vger.kernel.org, keescook@chromium.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" When live patching with STRICT_KERNEL_RWX 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/x86/include/asm/text-patching.h | 4 ++++ arch/x86/kernel/alternative.c | 7 +++++++ 2 files changed, 11 insertions(+) diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h index b7421780e4e92..f0caf9ee13bd8 100644 --- a/arch/x86/include/asm/text-patching.h +++ b/arch/x86/include/asm/text-patching.h @@ -167,4 +167,8 @@ void int3_emulate_ret(struct pt_regs *regs) } #endif /* !CONFIG_UML_X86 */ +#if IS_BUILTIN(CONFIG_LKDTM) +unsigned long read_cpu_patching_addr(unsigned int cpu); +#endif + #endif /* _ASM_X86_TEXT_PATCHING_H */ diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 8d778e46725d2..4c95fdd9b1965 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -852,6 +852,13 @@ static inline void unuse_temporary_mm(temp_mm_state_t prev_state) __ro_after_init struct mm_struct *poking_mm; __ro_after_init unsigned long poking_addr; +#if IS_BUILTIN(CONFIG_LKDTM) +unsigned long read_cpu_patching_addr(unsigned int cpu) +{ + return poking_addr; +} +#endif + static void *__text_poke(void *addr, const void *opcode, size_t len) { bool cross_page_boundary = offset_in_page(addr) + len > PAGE_SIZE; -- 2.26.1