From patchwork Thu Sep 6 11:09:56 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Thierry X-Patchwork-Id: 10590453 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 ACCFA14E0 for ; Thu, 6 Sep 2018 11:11:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9D4762A6E9 for ; Thu, 6 Sep 2018 11:11:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 917F42A6EF; Thu, 6 Sep 2018 11:11:46 +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=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE 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 4592B2A6F0 for ; Thu, 6 Sep 2018 11:11:45 +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:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: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:In-Reply-To: References:List-Owner; bh=6XQfHN/8Re/8elmP3dTvaFZZ9ttXjEekqC8YuLjGRWE=; b=nTR h8kHDrFoN0rnE2hnJpyM9hrijyY+XRw+a8FPYlXIs2XSATwZNq6SeLTto4psUYeJ7DPVm3EeYVxSG HBtqJvfR3srDsST+5cViHoIEjwEXkLBZaaM22L0jwrTHj2gBOXhkgnxC9gokv/37D9PyH76sw5d50 LdRbSVeKarIOhkISLgo6bO4hcmUJGVNCeH0CpePB/lmPkl4/gUPRKPQ88vTXO+p1vFW4XfHRazUEZ N1Eo5q41xVQMPzbAu3Sbwr0JSwJ7loeZ2G+B7s0ftYKnaJVgGgoYgJ9z+sxaHvzNULQ5fxsXC5irE bbs8RzPUVCSfJBU0GdPUFVr8LEpzIGA==; 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 1fxsCF-00085N-9d; Thu, 06 Sep 2018 11:11:35 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fxsAv-0006JT-5r for linux-arm-kernel@lists.infradead.org; Thu, 06 Sep 2018 11:10:15 +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 664D27A9; Thu, 6 Sep 2018 04:10:08 -0700 (PDT) Received: from e112298-lin.Emea.Arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 7BEB43F557; Thu, 6 Sep 2018 04:10:07 -0700 (PDT) From: Julien Thierry To: linux-arm-kernel@lists.infradead.org Subject: [PATCH] arm64: uaccess: implement unsafe accessors Date: Thu, 6 Sep 2018 12:09:56 +0100 Message-Id: <1536232196-55027-1-git-send-email-julien.thierry@arm.com> X-Mailer: git-send-email 1.9.1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180906_041013_359878_FF51B344 X-CRM114-Status: GOOD ( 12.77 ) 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: Catalin Marinas , Will Deacon , Julien Thierry MIME-Version: 1.0 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 Current implementation of get/put_user_unsafe default to get/put_user which toggle PAN before each access, despite having been told by the caller that multiple accesses to user memory were about to happen. Provide implementations for user_access_begin/end to turn PAN off/on and implement unsafe accessors that assume PAN was already turned off. Signed-off-by: Julien Thierry Cc: Catalin Marinas Cc: Will Deacon Tested-by: Will Deacon --- arch/arm64/include/asm/uaccess.h | 61 ++++++++++++++++++++++++++++++---------- 1 file changed, 46 insertions(+), 15 deletions(-) -- 1.9.1 diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index e66b0fc..c4528dd 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -277,11 +277,9 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr) : "+r" (err), "=&r" (x) \ : "r" (addr), "i" (-EFAULT)) -#define __get_user_err(x, ptr, err) \ +#define __get_user_err_unsafe(x, ptr, err) \ do { \ unsigned long __gu_val; \ - __chk_user_ptr(ptr); \ - uaccess_enable_not_uao(); \ switch (sizeof(*(ptr))) { \ case 1: \ __get_user_asm("ldrb", "ldtrb", "%w", __gu_val, (ptr), \ @@ -302,17 +300,24 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr) default: \ BUILD_BUG(); \ } \ - uaccess_disable_not_uao(); \ (x) = (__force __typeof__(*(ptr)))__gu_val; \ } while (0) -#define __get_user_check(x, ptr, err) \ +#define __get_user_err_check(x, ptr, err) \ +do { \ + __chk_user_ptr(ptr); \ + uaccess_enable_not_uao(); \ + __get_user_err_unsafe((x), (ptr), (err)); \ + uaccess_disable_not_uao(); \ +} while (0) + +#define __get_user_err(x, ptr, err, accessor) \ ({ \ __typeof__(*(ptr)) __user *__p = (ptr); \ might_fault(); \ if (access_ok(VERIFY_READ, __p, sizeof(*__p))) { \ __p = uaccess_mask_ptr(__p); \ - __get_user_err((x), __p, (err)); \ + accessor((x), __p, (err)); \ } else { \ (x) = 0; (err) = -EFAULT; \ } \ @@ -320,14 +325,14 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr) #define __get_user_error(x, ptr, err) \ ({ \ - __get_user_check((x), (ptr), (err)); \ + __get_user_err((x), (ptr), (err), __get_user_err_check); \ (void)0; \ }) #define __get_user(x, ptr) \ ({ \ int __gu_err = 0; \ - __get_user_check((x), (ptr), __gu_err); \ + __get_user_err((x), (ptr), __gu_err, __get_user_err_check); \ __gu_err; \ }) @@ -347,11 +352,9 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr) : "+r" (err) \ : "r" (x), "r" (addr), "i" (-EFAULT)) -#define __put_user_err(x, ptr, err) \ +#define __put_user_err_unsafe(x, ptr, err) \ do { \ __typeof__(*(ptr)) __pu_val = (x); \ - __chk_user_ptr(ptr); \ - uaccess_enable_not_uao(); \ switch (sizeof(*(ptr))) { \ case 1: \ __put_user_asm("strb", "sttrb", "%w", __pu_val, (ptr), \ @@ -372,16 +375,24 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr) default: \ BUILD_BUG(); \ } \ +} while (0) + + +#define __put_user_err_check(x, ptr, err) \ +do { \ + __chk_user_ptr(ptr); \ + uaccess_enable_not_uao(); \ + __put_user_err_unsafe((x), (ptr), (err)); \ uaccess_disable_not_uao(); \ } while (0) -#define __put_user_check(x, ptr, err) \ +#define __put_user_err(x, ptr, err, accessor) \ ({ \ __typeof__(*(ptr)) __user *__p = (ptr); \ might_fault(); \ if (access_ok(VERIFY_WRITE, __p, sizeof(*__p))) { \ __p = uaccess_mask_ptr(__p); \ - __put_user_err((x), __p, (err)); \ + accessor((x), __p, (err)); \ } else { \ (err) = -EFAULT; \ } \ @@ -389,19 +400,39 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr) #define __put_user_error(x, ptr, err) \ ({ \ - __put_user_check((x), (ptr), (err)); \ + __put_user_err((x), (ptr), (err), __put_user_err_check); \ (void)0; \ }) #define __put_user(x, ptr) \ ({ \ int __pu_err = 0; \ - __put_user_check((x), (ptr), __pu_err); \ + __put_user_err((x), (ptr), __pu_err, __put_user_err_check); \ __pu_err; \ }) #define put_user __put_user + +#define user_access_begin() uaccess_enable_not_uao() +#define user_access_end() uaccess_disable_not_uao() + +#define unsafe_get_user(x, ptr, err) \ +do { \ + int __gu_err = 0; \ + __get_user_err((x), (ptr), __gu_err, __get_user_err_unsafe); \ + if (__gu_err != 0) \ + goto err; \ +} while (0) + +#define unsafe_put_user(x, ptr, err) \ +do { \ + int __pu_err = 0; \ + __put_user_err((x), (ptr), __pu_err, __put_user_err_unsafe); \ + if (__pu_err != 0) \ + goto err; \ +} while (0) + extern unsigned long __must_check __arch_copy_from_user(void *to, const void __user *from, unsigned long n); #define raw_copy_from_user(to, from, n) \ ({ \