From patchwork Tue Jul 26 03:01:58 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Cooper X-Patchwork-Id: 9247553 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 5E58B607F2 for ; Tue, 26 Jul 2016 03:05:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 513511FF29 for ; Tue, 26 Jul 2016 03:05:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4508426D08; Tue, 26 Jul 2016 03:05:50 +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=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED 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 86EAB1FF29 for ; Tue, 26 Jul 2016 03:05:49 +0000 (UTC) Received: (qmail 17817 invoked by uid 550); 26 Jul 2016 03:05:38 -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: Reply-To: kernel-hardening@lists.openwall.com Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 17614 invoked from network); 26 Jul 2016 03:05:36 -0000 X-MHO-User: f360a4d7-52dd-11e6-8929-8ded99d5e9d7 X-Report-Abuse-To: https://support.duocircle.com/support/solutions/articles/5000540958-duocircle-standard-smtp-abuse-information X-Originating-IP: 74.99.77.15 X-Mail-Handler: DuoCircle Outbound SMTP From: Jason Cooper To: william.c.roberts@intel.com, linux-mm@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com Cc: Jason Cooper , linux@arm.linux.org.uk, akpm@linux-foundation.org, keescook@chromium.org, tytso@mit.edu, arnd@arndb.de, gregkh@linuxfoundation.org, catalin.marinas@arm.com, will.deacon@arm.com, ralf@linux-mips.org, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, davem@davemloft.net, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, viro@zeniv.linux.org.uk, nnk@google.com, jeffv@google.com, alyzyn@android.com, dcashman@android.com Date: Tue, 26 Jul 2016 03:01:58 +0000 Message-Id: <20160726030201.6775-4-jason@lakedaemon.net> X-Mailer: git-send-email 2.9.2 In-Reply-To: <20160726030201.6775-1-jason@lakedaemon.net> References: <1469471141-25669-1-git-send-email-william.c.roberts@intel.com> <20160726030201.6775-1-jason@lakedaemon.net> Subject: [kernel-hardening] [RFC patch 4/6] arm64: Use simpler API for random address requests X-Virus-Scanned: ClamAV using ClamSMTP Currently, all callers to randomize_range() set the length to 0 and calculate end by adding a constant to the start address. We can simplify the API to remove a bunch of needless checks and variables. Use the new randomize_addr(start, range) call to set the requested address. Signed-off-by: Jason Cooper --- arch/arm64/kernel/process.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 6cd2612236dc..11bf454baf86 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -374,12 +374,8 @@ unsigned long arch_align_stack(unsigned long sp) unsigned long arch_randomize_brk(struct mm_struct *mm) { - unsigned long range_end = mm->brk; - if (is_compat_task()) - range_end += 0x02000000; + return randomize_addr(mm->brk, 0x02000000); else - range_end += 0x40000000; - - return randomize_range(mm->brk, range_end, 0) ? : mm->brk; + return randomize_addr(mm->brk, 0x40000000); }