From patchwork Thu Jun 22 18:06:31 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 9805059 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 2787C60329 for ; Thu, 22 Jun 2017 18:07:06 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1FA2B2870B for ; Thu, 22 Jun 2017 18:07:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 12EEE2870D; Thu, 22 Jun 2017 18:07:06 +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 206322870B for ; Thu, 22 Jun 2017 18:07:04 +0000 (UTC) Received: (qmail 11371 invoked by uid 550); 22 Jun 2017 18:06:53 -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 11348 invoked from network); 22 Jun 2017 18:06:52 -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=4H66ulum5JhXcHImf4hi47X04RBDTt2zRkkQ2a5Gf8g=; b=GwAXbfqhmIA1sbkE7bAYGpk/tM6SVr7tLQlg46c44CEvc5EOufuUqB6d+02ZRcctyp WwcYvdEeNJyMjmjz76o+JFhPRSAAev9UveEeMZm7VDN3vXZBHRUyQyvxcoqiFjmlHAFl GZeSx2rE1+xI+EvZJEazd9J94ZU4qbvYmOYMI= 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=4H66ulum5JhXcHImf4hi47X04RBDTt2zRkkQ2a5Gf8g=; b=lE5mzK/r/WWR+a2d+4HcDNE80USHkbg+stIhaJdsK2q5O8V8IrPfBnxEzePxLEQyLN h9jNSl2K8GMUxFBB911tKf4Tkw4vjYVJzv+7S0t46FBpnpFreUBDXuH4rUPsbd7zpOKz m9GEFPWcmmCruYXwVFVa3dauFFLYQdSu3OOTiI/a3kSiDJeArr9RTdMSMWEFQKxF0xo5 Ym8nYgA9TVwt7MkyV2kEvdEbNSl0TF/fbWm3ov3cd86XjZqy7wa9c+MatEnzY7XBGyHB F3aMiBENZcKIRoBHpIlAqpsgb/F53J8tO1v6ZXCBjBKRRNshwEkRZQQgz4l+BSCUrVBe ZuTA== X-Gm-Message-State: AKS2vOwYXMqMCQTWc024H7JTmYswGX1ErmQdke2+s51AApxTYlB0KRFP FZb/WbUQQjSyIcAN X-Received: by 10.84.214.22 with SMTP id h22mr4367667pli.127.1498154800838; Thu, 22 Jun 2017 11:06:40 -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 11:06:31 -0700 Message-Id: <1498154792-49952-4-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 3/4] powerpc: 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 Acked-by: Michael Ellerman --- arch/powerpc/include/asm/elf.h | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h index 09bde6e34f5d..548d9a411a0d 100644 --- a/arch/powerpc/include/asm/elf.h +++ b/arch/powerpc/include/asm/elf.h @@ -23,12 +23,13 @@ #define CORE_DUMP_USE_REGSET #define ELF_EXEC_PAGESIZE PAGE_SIZE -/* 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. */ - -#define ELF_ET_DYN_BASE 0x20000000 +/* + * 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_32bit_task() ? 0x000400000UL : \ + 0x100000000UL) #define ELF_CORE_EFLAGS (is_elf2_task() ? 2 : 0)