From patchwork Mon Dec 7 10:26:16 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jon Hunter X-Patchwork-Id: 7781801 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id BD3DFBEEE1 for ; Mon, 7 Dec 2015 10:29:16 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 368E2203B7 for ; Mon, 7 Dec 2015 10:29:12 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 44F28203AB for ; Mon, 7 Dec 2015 10:29:11 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1a5t0K-0003pV-4j; Mon, 07 Dec 2015 10:26:48 +0000 Received: from hqemgate15.nvidia.com ([216.228.121.64]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1a5t0G-0003mB-06 for linux-arm-kernel@lists.infradead.org; Mon, 07 Dec 2015 10:26:44 +0000 Received: from hqnvupgp07.nvidia.com (Not Verified[216.228.121.13]) by hqemgate15.nvidia.com id ; Mon, 07 Dec 2015 02:26:29 -0800 Received: from HQMAIL105.nvidia.com ([172.20.12.94]) by hqnvupgp07.nvidia.com (PGP Universal service); Mon, 07 Dec 2015 02:12:45 -0800 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Mon, 07 Dec 2015 02:12:45 -0800 Received: from UKMAIL101.nvidia.com (10.26.138.13) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1104.5; Mon, 7 Dec 2015 10:26:21 +0000 Received: from [10.21.132.159] (10.21.132.159) by UKMAIL101.nvidia.com (10.26.138.13) with Microsoft SMTP Server (TLS) id 15.0.1104.5; Mon, 7 Dec 2015 10:26:16 +0000 Subject: Re: [PATCH v5 3/4] arm64: mm: support ARCH_MMAP_RND_BITS. To: Daniel Cashman , References: <1449000658-11475-1-git-send-email-dcashman@android.com> <1449000658-11475-2-git-send-email-dcashman@android.com> <1449000658-11475-3-git-send-email-dcashman@android.com> <1449000658-11475-4-git-send-email-dcashman@android.com> From: Jon Hunter Message-ID: <56655EC8.6030905@nvidia.com> Date: Mon, 7 Dec 2015 10:26:16 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <1449000658-11475-4-git-send-email-dcashman@android.com> X-Originating-IP: [10.21.132.159] X-ClientProxiedBy: UKMAIL101.nvidia.com (10.26.138.13) To UKMAIL101.nvidia.com (10.26.138.13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20151207_022644_065284_9622FA03 X-CRM114-Status: GOOD ( 12.33 ) X-Spam-Score: -6.9 (------) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-doc@vger.kernel.org, catalin.marinas@arm.com, will.deacon@arm.com, linux-mm@kvack.org, hpa@zytor.com, mingo@kernel.org, aarcange@redhat.com, linux@arm.linux.org.uk, kirill.shutemov@linux.intel.com, corbet@lwn.net, xypron.glpk@gmx.de, x86@kernel.org, hecmargi@upv.es, mgorman@suse.de, rientjes@google.com, bp@suse.de, nnk@google.com, dzickus@redhat.com, keescook@chromium.org, arnd@arndb.de, jpoimboe@redhat.com, tglx@linutronix.de, akpm@linux-foundation.org, linux-arm-kernel@lists.infradead.org, salyzyn@android.com, ebiederm@xmission.com, jeffv@google.com, n-horiguchi@ah.jp.nec.com, dcashman@google.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On 01/12/15 20:10, Daniel Cashman wrote: > From: dcashman > > arm64: arch_mmap_rnd() uses STACK_RND_MASK to generate the > random offset for the mmap base address. This value represents a > compromise between increased ASLR effectiveness and avoiding > address-space fragmentation. Replace it with a Kconfig option, which > is sensibly bounded, so that platform developers may choose where to > place this compromise. Keep default values as new minimums. > > Signed-off-by: Daniel Cashman > --- > arch/arm64/Kconfig | 31 +++++++++++++++++++++++++++++++ > arch/arm64/mm/mmap.c | 8 ++++++-- > 2 files changed, 37 insertions(+), 2 deletions(-) [snip] > diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c > index ed17747..af461b9 100644 > --- a/arch/arm64/mm/mmap.c > +++ b/arch/arm64/mm/mmap.c > @@ -51,8 +51,12 @@ unsigned long arch_mmap_rnd(void) > { > unsigned long rnd; > > - rnd = (unsigned long)get_random_int() & STACK_RND_MASK; > - > +ifdef CONFIG_COMPAT > + if (test_thread_flag(TIF_32BIT)) > + rnd = (unsigned long)get_random_int() % (1 << mmap_rnd_compat_bits); > + else > +#endif > + rnd = (unsigned long)get_random_int() % (1 << mmap_rnd_bits); > return rnd << PAGE_SHIFT; > } The above is causing a build failure on -next today. commit 42a6c8953112a9856dd09148c3d6a2cc106b6003 Author: Jon Hunter Date: Mon Dec 7 10:15:47 2015 +0000 ARM64: mm: Fix build failure caused by invalid ifdef statement Commit 2e4614190421 ("arm64-mm-support-arch_mmap_rnd_bits-v4") caused the following build failure due to a missing "#". Fix this. arch/arm64/mm/mmap.c: In function ‘arch_mmap_rnd’: arch/arm64/mm/mmap.c:54:1: error: ‘ifdef’ undeclared (first use in this function) ifdef CONFIG_COMPAT ^ Signed-off-by: Jon Hunter Cheers Jon diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index af461b935137..e59a75a308bc 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -51,7 +51,7 @@ unsigned long arch_mmap_rnd(void) { unsigned long rnd; -ifdef CONFIG_COMPAT +#ifdef CONFIG_COMPAT if (test_thread_flag(TIF_32BIT)) rnd = (unsigned long)get_random_int() % (1 << mmap_rnd_compat_bits); else