From patchwork Mon Apr 15 09:49:36 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vincenzo Frascino X-Patchwork-Id: 10900419 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 75D82139A for ; Mon, 15 Apr 2019 09:50:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 52B0828924 for ; Mon, 15 Apr 2019 09:50:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 50DB228925; Mon, 15 Apr 2019 09:50:49 +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=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id E3D1628924 for ; Mon, 15 Apr 2019 09:50:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=g35XZGH7kvd1medy/oSQ6XYOgfeCcheUw0Uv9NJqr3Q=; b=WPTuSuHH0D0nAr JROKFn8UoifJ9+TeNOK/EgrahWhV9rAxTO7bvC024wm7zxREgbTbkDRwIyguZlw9nJfI+prEoecof BerQoyDY1u7mY0ja7Au+Pw3UuqO/qgDA1jwmNfy31WO0QNNRSc6fPnS2v+NZ9FqZuCMNmr4NUzi6M WtO32ynQxgMnxN7inOAjrdhBW34gECFx2zzSn7LhUYfsEJ8iR3ZvDzcj71UstUHeYV3IQfvmwCkAZ acYKqIIHkGTVaDndPeFhA99uoOufUUAPND4n7aYDmoi422TABknTfnLXi9l97nKc9Nc28lObTNF1H YI33xGLXbJj3OgZZgIgQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hFyFm-0004ZL-E7; Mon, 15 Apr 2019 09:50:18 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hFyFN-000323-TT for linux-arm-kernel@lists.infradead.org; Mon, 15 Apr 2019 09:49:55 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 51F4F1688; Mon, 15 Apr 2019 02:49:53 -0700 (PDT) Received: from e119884-lin.cambridge.arm.com (e119884-lin.cambridge.arm.com [10.1.196.72]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 65AAB3F557; Mon, 15 Apr 2019 02:49:52 -0700 (PDT) From: Vincenzo Frascino To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v4 3/4] arm64: compat: Refactor aarch32_alloc_vdso_pages() Date: Mon, 15 Apr 2019 10:49:36 +0100 Message-Id: <20190415094937.13518-4-vincenzo.frascino@arm.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190415094937.13518-1-vincenzo.frascino@arm.com> References: <20190415094937.13518-1-vincenzo.frascino@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190415_024953_996558_3D56C456 X-CRM114-Status: GOOD ( 15.64 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Catalin Marinas , Will Deacon Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP aarch32_alloc_vdso_pages() needs to be refactored to make it easier to disable kuser helpers. Divide the function in aarch32_alloc_kuser_vdso_page() and aarch32_alloc_sigreturn_vdso_page(). Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Vincenzo Frascino Reviewed-by: Catalin Marinas --- arch/arm64/kernel/vdso.c | 73 ++++++++++++++++++++++++++-------------- 1 file changed, 48 insertions(+), 25 deletions(-) diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 79fd7a65ae55..22e8b039cfe6 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -77,46 +77,69 @@ static const struct vm_special_mapping aarch32_vdso_spec[C_PAGES] = { }, }; -static int __init aarch32_alloc_vdso_pages(void) +static int aarch32_alloc_kuser_vdso_page(void) { extern char __kuser_helper_start[], __kuser_helper_end[]; - extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[]; - int kuser_sz = __kuser_helper_end - __kuser_helper_start; - int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start; - unsigned long vdso_pages[C_PAGES]; + unsigned long vdso_page; - vdso_pages[C_VECTORS] = get_zeroed_page(GFP_ATOMIC); - if (!vdso_pages[C_VECTORS]) + vdso_page = get_zeroed_page(GFP_ATOMIC); + if (!vdso_page) return -ENOMEM; - vdso_pages[C_SIGPAGE] = get_zeroed_page(GFP_ATOMIC); - if (!vdso_pages[C_SIGPAGE]) { - /* - * free_page() it is required to avoid to leak the vectors page - * if the allocation of sigpage fails. - */ - free_page(vdso_pages[C_VECTORS]); - return -ENOMEM; - } - /* kuser helpers */ - memcpy((void *)(vdso_pages[C_VECTORS] + 0x1000 - kuser_sz), + memcpy((void *)(vdso_page + 0x1000 - kuser_sz), __kuser_helper_start, kuser_sz); + aarch32_vdso_pages[C_VECTORS] = virt_to_page(vdso_page); + + flush_dcache_page(aarch32_vdso_pages[C_VECTORS]); + + return 0; +} + +static int aarch32_alloc_sigreturn_vdso_page(void) +{ + extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[]; + int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start; + unsigned long vdso_page; + + vdso_page = get_zeroed_page(GFP_ATOMIC); + if (!vdso_page) + return -ENOMEM; + /* sigreturn code */ - memcpy((void *)vdso_pages[C_SIGPAGE], + memcpy((void *)vdso_page, __aarch32_sigret_code_start, sigret_sz); - flush_icache_range(vdso_pages[C_VECTORS], - vdso_pages[C_VECTORS] + PAGE_SIZE); - flush_icache_range(vdso_pages[C_SIGPAGE], - vdso_pages[C_SIGPAGE] + PAGE_SIZE); + aarch32_vdso_pages[C_SIGPAGE] = virt_to_page(vdso_page); + + flush_dcache_page(aarch32_vdso_pages[C_SIGPAGE]); + + return 0; +} + +static int __init aarch32_alloc_vdso_pages(void) +{ + int ret; + + ret = aarch32_alloc_kuser_vdso_page(); + if (ret) + return ret; - aarch32_vdso_pages[C_VECTORS] = virt_to_page(vdso_pages[C_VECTORS]); - aarch32_vdso_pages[C_SIGPAGE] = virt_to_page(vdso_pages[C_SIGPAGE]); + ret = aarch32_alloc_sigreturn_vdso_page(); + if (ret) { + unsigned long vectors_addr = (unsigned long)page_to_virt( + aarch32_vdso_pages[C_VECTORS]); + /* + * free_page() it is required to avoid to leak the vectors page + * if the allocation of sigpage fails. + */ + free_page(vectors_addr); + return ret; + } return 0; }