From patchwork Fri Aug 22 21:52:26 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Lynch X-Patchwork-Id: 4767311 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 [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id C5DA2C0338 for ; Fri, 22 Aug 2014 21:55:17 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 018F52013A for ; Fri, 22 Aug 2014 21:55:17 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 546B320158 for ; Fri, 22 Aug 2014 21:55:15 +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 1XKwlW-0000nC-Tr; Fri, 22 Aug 2014 21:52:58 +0000 Received: from relay1.mentorg.com ([192.94.38.131]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XKwlT-0000lX-Sl for linux-arm-kernel@lists.infradead.org; Fri, 22 Aug 2014 21:52:56 +0000 Received: from svr-orw-fem-01.mgc.mentorg.com ([147.34.98.93]) by relay1.mentorg.com with esmtp id 1XKwl9-0007Ri-Qf from Nathan_Lynch@mentor.com ; Fri, 22 Aug 2014 14:52:35 -0700 Received: from SVR-ORW-FEM-06.mgc.mentorg.com ([147.34.97.120]) by svr-orw-fem-01.mgc.mentorg.com over TLS secured channel with Microsoft SMTPSVC(6.0.3790.4675); Fri, 22 Aug 2014 14:52:35 -0700 Received: from localhost (147.34.91.1) by svr-orw-fem-06.mgc.mentorg.com (147.34.97.120) with Microsoft SMTP Server (TLS) id 14.2.247.3; Fri, 22 Aug 2014 14:52:34 -0700 From: Nathan Lynch To: Russell King Subject: [PATCH v9 1/6] ARM: use _install_special_mapping for sigpage Date: Fri, 22 Aug 2014 16:52:26 -0500 Message-ID: <1408744351-7814-2-git-send-email-nathan_lynch@mentor.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1408744351-7814-1-git-send-email-nathan_lynch@mentor.com> References: <1408744351-7814-1-git-send-email-nathan_lynch@mentor.com> MIME-Version: 1.0 X-OriginalArrivalTime: 22 Aug 2014 21:52:35.0696 (UTC) FILETIME=[62400700:01CFBE53] X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140822_145255_973378_30B5D890 X-CRM114-Status: GOOD ( 11.89 ) X-Spam-Score: -0.0 (/) Cc: Steve Capper , Kees Cook , Ard Biesheuvel , Will Deacon , Andy Lutomirski , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, 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 _install_special_mapping allows the VMA to be identifed in /proc/pid/maps without the use of arch_vma_name, providing a slight net reduction in object size: text data bss dec hex filename 2996 96 144 3236 ca4 arch/arm/kernel/process.o (before) 2956 104 144 3204 c84 arch/arm/kernel/process.o (after) Signed-off-by: Nathan Lynch Reviewed-by: Kees Cook --- arch/arm/kernel/process.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 81ef686a91ca..46fbbb3701a0 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -472,19 +472,23 @@ int in_gate_area_no_mm(unsigned long addr) const char *arch_vma_name(struct vm_area_struct *vma) { - return is_gate_vma(vma) ? "[vectors]" : - (vma->vm_mm && vma->vm_start == vma->vm_mm->context.sigpage) ? - "[sigpage]" : NULL; + return is_gate_vma(vma) ? "[vectors]" : NULL; } static struct page *signal_page; extern struct page *get_signal_page(void); +static const struct vm_special_mapping sigpage_mapping = { + .name = "[sigpage]", + .pages = &signal_page, +}; + int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) { struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; unsigned long addr; - int ret; + int ret = 0; if (!signal_page) signal_page = get_signal_page(); @@ -498,12 +502,16 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) goto up_fail; } - ret = install_special_mapping(mm, addr, PAGE_SIZE, + vma = _install_special_mapping(mm, addr, PAGE_SIZE, VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, - &signal_page); + &sigpage_mapping); + + if (IS_ERR(vma)) { + ret = PTR_ERR(vma); + goto up_fail; + } - if (ret == 0) - mm->context.sigpage = addr; + mm->context.sigpage = addr; up_fail: up_write(&mm->mmap_sem);