From patchwork Thu Jun 22 18:06:32 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 9805069 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id C9B6260329 for ; Thu, 22 Jun 2017 18:07:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C03E52870B for ; Thu, 22 Jun 2017 18:07:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B43C22870D; Thu, 22 Jun 2017 18:07:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id D38EC2870B for ; Thu, 22 Jun 2017 18:07:24 +0000 (UTC) Received: (qmail 11605 invoked by uid 550); 22 Jun 2017 18:06:56 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 11392 invoked from network); 22 Jun 2017 18:06:54 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=COJafQLePeyG6MzE8Xg6iiTm7M0yyK2qkvVIO1KcABQ=; b=Dgp60xBFFQuEqbBkLczOUYVdl7+gZGNfeF8dp6wWz9xXwHA0tkCpDO4o2lhi6BT+q4 Fu7fuGDRCyweOmb8UXmXlSS1l0XmoLYgK2mYlmUBReFo5maa5de4kVkNcZFXs4fyMpTU YcLF9yUuvHz9DSaSPZUGVo1u5WE0tXqZVvTz4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=COJafQLePeyG6MzE8Xg6iiTm7M0yyK2qkvVIO1KcABQ=; b=X5w8tuTQ9mOb8kQSeF0Wp+02y5J/VhRC7OQo+Kwu+dDoCicMrCRdUKCPmrJCM0izGV c48HDne8Z1me1e/WpMTYj4F+8qxJ+1uaAQE0nbSbUpD/VblwcsOQucIARh+C9/o4V4mE DUpisIqyTnrvsBiWFnpGRS+7/B3oeqxAVQEIdooQJaUgHN8B6VTPm2Hu87+UiZb/rns1 zdU6GXUj0WWvw3ktAXOaGURc/Y9LjdsQFEfj5u+E4kUsOxw3MRv87SHfqw0jcn+0BFV8 xYs+BMNd/+uoYDGnhVhenVskQWLs0kqNq/xXvjE+WUlMOYbZw+rcHcAcDilfotB1Bhnh FyBg== X-Gm-Message-State: AKS2vOwJ2W9bvFULIzrWLr2VcPh/Xj4qEga53KEYjOVio+HbMO0BKh9T g4gRtFzhRcbkqQPy X-Received: by 10.98.36.19 with SMTP id r19mr3989169pfj.162.1498154802133; Thu, 22 Jun 2017 11:06:42 -0700 (PDT) From: Kees Cook To: Andrew Morton Cc: Kees Cook , Russell King , Catalin Marinas , Will Deacon , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Martin Schwidefsky , Heiko Carstens , James Hogan , Pratyush Anand , Ingo Molnar , linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, kernel-hardening@lists.openwall.com Date: Thu, 22 Jun 2017 11:06:32 -0700 Message-Id: <1498154792-49952-5-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1498154792-49952-1-git-send-email-keescook@chromium.org> References: <1498154792-49952-1-git-send-email-keescook@chromium.org> Subject: [kernel-hardening] [PATCH 4/4] s390: Reduce ELF_ET_DYN_BASE X-Virus-Scanned: ClamAV using ClamSMTP Now that explicitly executed loaders are loaded in the mmap region, position PIE binaries lower in the address space to avoid possible collisions with mmap or stack regions. For 64-bit, align to 4GB to allow runtimes to use the entire 32-bit address space for 32-bit pointers. Signed-off-by: Kees Cook --- arch/s390/include/asm/elf.h | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/arch/s390/include/asm/elf.h b/arch/s390/include/asm/elf.h index e8f623041769..7c58d599f91b 100644 --- a/arch/s390/include/asm/elf.h +++ b/arch/s390/include/asm/elf.h @@ -161,14 +161,13 @@ extern unsigned int vdso_enabled; #define CORE_DUMP_USE_REGSET #define ELF_EXEC_PAGESIZE 4096 -/* This is the location that an ET_DYN program is loaded if exec'ed. Typical - use of this is to invoke "./ld.so someprog" to test out a new version of - the loader. We need to make sure that it is out of the way of the program - that it will "exec", and that there is sufficient room for the brk. 64-bit - tasks are aligned to 4GB. */ -#define ELF_ET_DYN_BASE (is_compat_task() ? \ - (STACK_TOP / 3 * 2) : \ - (STACK_TOP / 3 * 2) & ~((1UL << 32) - 1)) +/* + * This is the base location for PIE (ET_DYN with INTERP) loads. On + * 64-bit, this is raised to 4GB to leave the entire 32-bit address + * space open for things that want to use the area for 32-bit pointers. + */ +#define ELF_ET_DYN_BASE (is_compat_task() ? 0x000400000UL : \ + 0x100000000UL) /* This yields a mask that user programs can use to figure out what instruction set this CPU supports. */