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=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 03110C433E5 for ; Tue, 19 May 2020 13:46:02 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BAD6520825 for ; Tue, 19 May 2020 13:46:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="etRLBJXU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BAD6520825 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0DF6C900003; Tue, 19 May 2020 09:46:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 01BAC80006; Tue, 19 May 2020 09:45:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E71C6900004; Tue, 19 May 2020 09:45:59 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0146.hostedemail.com [216.40.44.146]) by kanga.kvack.org (Postfix) with ESMTP id CCD52900003 for ; Tue, 19 May 2020 09:45:59 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id E111A181AEF1E for ; Tue, 19 May 2020 13:45:58 +0000 (UTC) X-FDA: 76833591996.23.front26_8b81395323005 X-HE-Tag: front26_8b81395323005 X-Filterd-Recvd-Size: 3680 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf27.hostedemail.com (Postfix) with ESMTP for ; Tue, 19 May 2020 13:45:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=qCsBvrh+KJD94OzZIg2wzK8eCwrltTUzrmGt8F6Hn0Y=; b=etRLBJXUk51bBqKHOncqZVvZyI vQtqk4TEib0NYj8DZbaJYTWVbFti0S1FOQTd8OOvMAOvvG0eS2z886Ra8KdtsaBczmwJT/lYKIa/q kPbCLDNzaKZGTVer4rnsbXu/5PQUPlqefb96nX8OiUKS3OzpI5MRZsEbjFpAp9JFwupLVwCSfFMHu O/RNnLpEedx5Un+x3Exl18c0pjdk1wEN197kzQh2dzmpruxazCfrkrQCb7pLl19MmtTUEoxexHmud ejW4iRE3Hxs5MV+slCZgYSzYLpYgDBm5mDmm10BLqkixlob6lKEkc0PntbPpD71QC5GQzubFsF2Vn Np5UHAWA==; Received: from [2001:4bb8:188:1506:c70:4a89:bc61:2] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jb2ZA-0003wy-0R; Tue, 19 May 2020 13:45:56 +0000 From: Christoph Hellwig To: x86@kernel.org, Alexei Starovoitov , Daniel Borkmann , Masami Hiramatsu , Linus Torvalds , Andrew Morton Cc: linux-parisc@vger.kernel.org, linux-um@lists.infradead.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 20/20] maccess: return -ERANGE when copy_from_kernel_nofault_allowed fails Date: Tue, 19 May 2020 15:44:49 +0200 Message-Id: <20200519134449.1466624-21-hch@lst.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200519134449.1466624-1-hch@lst.de> References: <20200519134449.1466624-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Allow the callers to distinguish a real unmapped address vs a range that can't be probed. Suggested-by: Masami Hiramatsu Signed-off-by: Christoph Hellwig --- mm/maccess.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/mm/maccess.c b/mm/maccess.c index 1e7d77656c596..4010d64189d21 100644 --- a/mm/maccess.c +++ b/mm/maccess.c @@ -25,7 +25,7 @@ bool __weak copy_from_kernel_nofault_allowed(void *dst,= const void *unsafe_src, long copy_from_kernel_nofault(void *dst, const void *src, size_t size) { if (!copy_from_kernel_nofault_allowed(dst, src, size)) - return -EFAULT; + return -ERANGE; =20 pagefault_disable(); copy_from_kernel_nofault_loop(dst, src, size, u64, Efault); @@ -69,7 +69,7 @@ long strncpy_from_kernel_nofault(char *dst, const void = *unsafe_addr, long count) if (unlikely(count <=3D 0)) return 0; if (!copy_from_kernel_nofault_allowed(dst, unsafe_addr, count)) - return -EFAULT; + return -ERANGE; =20 pagefault_disable(); do { @@ -107,7 +107,7 @@ long copy_from_kernel_nofault(void *dst, const void *= src, size_t size) mm_segment_t old_fs =3D get_fs(); =20 if (!copy_from_kernel_nofault_allowed(dst, src, size)) - return -EFAULT; + return -ERANGE; =20 set_fs(KERNEL_DS); pagefault_disable(); @@ -174,7 +174,7 @@ long strncpy_from_kernel_nofault(char *dst, const voi= d *unsafe_addr, long count) if (unlikely(count <=3D 0)) return 0; if (!copy_from_kernel_nofault_allowed(dst, unsafe_addr, count)) - return -EFAULT; + return -ERANGE; =20 set_fs(KERNEL_DS); pagefault_disable(); --=20 2.26.2