From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1525BC43331 for ; Fri, 27 Mar 2020 23:31:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E50DC2076B for ; Fri, 27 Mar 2020 23:31:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727175AbgC0XbT (ORCPT ); Fri, 27 Mar 2020 19:31:19 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:35894 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726212AbgC0XbT (ORCPT ); Fri, 27 Mar 2020 19:31:19 -0400 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jHyRa-004KK5-69; Fri, 27 Mar 2020 23:31:18 +0000 From: Al Viro To: Linus Torvalds Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC][PATCH 02/14] x86_64: csum_..._copy_..._user(): switch to unsafe_..._user() Date: Fri, 27 Mar 2020 23:31:05 +0000 Message-Id: <20200327233117.1031393-2-viro@ZenIV.linux.org.uk> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200327233117.1031393-1-viro@ZenIV.linux.org.uk> References: <20200327233006.GW23230@ZenIV.linux.org.uk> <20200327233117.1031393-1-viro@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Al Viro We already have stac/clac pair around the calls of csum_partial_copy_generic(). Stretch that area back, so that it covers the preceding loop (and convert the loop body from __{get,put}_user() to unsafe_{get,put}_user()). That brings the beginning of the areas to the earlier access_ok(), which allows to convert them into user_access_{begin,end}() ones. Signed-off-by: Al Viro --- arch/x86/lib/csum-wrappers_64.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/arch/x86/lib/csum-wrappers_64.c b/arch/x86/lib/csum-wrappers_64.c index 875c2f5968a0..90d02c82bb7a 100644 --- a/arch/x86/lib/csum-wrappers_64.c +++ b/arch/x86/lib/csum-wrappers_64.c @@ -27,7 +27,7 @@ csum_partial_copy_from_user(const void __user *src, void *dst, might_sleep(); *errp = 0; - if (!likely(access_ok(src, len))) + if (!likely(user_access_begin(src, len))) goto out_err; /* @@ -42,8 +42,7 @@ csum_partial_copy_from_user(const void __user *src, void *dst, while (((unsigned long)src & 6) && len >= 2) { __u16 val16; - if (__get_user(val16, (const __u16 __user *)src)) - goto out_err; + unsafe_get_user(val16, (const __u16 __user *)src, out); *(__u16 *)dst = val16; isum = (__force __wsum)add32_with_carry( @@ -53,15 +52,16 @@ csum_partial_copy_from_user(const void __user *src, void *dst, len -= 2; } } - stac(); isum = csum_partial_copy_generic((__force const void *)src, dst, len, isum, errp, NULL); - clac(); + user_access_end(); if (unlikely(*errp)) goto out_err; return isum; +out: + user_access_end(); out_err: *errp = -EFAULT; memset(dst, 0, len); @@ -89,7 +89,7 @@ csum_and_copy_to_user(const void *src, void __user *dst, might_sleep(); - if (unlikely(!access_ok(dst, len))) { + if (unlikely(!user_access_begin(dst, len))) { *errp = -EFAULT; return 0; } @@ -100,9 +100,7 @@ csum_and_copy_to_user(const void *src, void __user *dst, isum = (__force __wsum)add32_with_carry( (__force unsigned)isum, val16); - *errp = __put_user(val16, (__u16 __user *)dst); - if (*errp) - return isum; + unsafe_put_user(val16, (__u16 __user *)dst, out); src += 2; dst += 2; len -= 2; @@ -110,11 +108,14 @@ csum_and_copy_to_user(const void *src, void __user *dst, } *errp = 0; - stac(); ret = csum_partial_copy_generic(src, (void __force *)dst, len, isum, NULL, errp); - clac(); + user_access_end(); return ret; +out: + user_access_end(); + *errp = -EFAULT; + return isum; } EXPORT_SYMBOL(csum_and_copy_to_user); -- 2.11.0