From patchwork Wed May 26 09:30:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 12281093 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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 AD69BC47088 for ; Wed, 26 May 2021 09:31:25 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 26DC76023D for ; Wed, 26 May 2021 09:31:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 26DC76023D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id BBC106B006E; Wed, 26 May 2021 05:31:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B6CDB6B0070; Wed, 26 May 2021 05:31:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9BEDF6B0071; Wed, 26 May 2021 05:31:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0137.hostedemail.com [216.40.44.137]) by kanga.kvack.org (Postfix) with ESMTP id 5F3136B006E for ; Wed, 26 May 2021 05:31:24 -0400 (EDT) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id EBFE9181AF5C4 for ; Wed, 26 May 2021 09:31:23 +0000 (UTC) X-FDA: 78182864046.06.B7A20A9 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf10.hostedemail.com (Postfix) with ESMTP id 25A8240F8C16 for ; Wed, 26 May 2021 09:31:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1622021483; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=CeyyYgXMaIv1KkLK2Mxpk2s8iuflkxKOKdYcMCECEco=; b=LaenYMzBz5H+4qqK8cZzZQE8rJWnVthzpQWRNhUadxI9NMk3Jd+DZuCnfk6mIP/18+oxmA SkOfYvGGmA2ZbZ8UTBp1VgpEvQhE1oFLeeR09tnsR8gFAaz0T1KamAx9FiW/6nrRDAhBwy QpkE0UdgZR/xdjNQtGSiFM8mYL0qSBs= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-394-KMaDda-lNSilAZz1rrmwcg-1; Wed, 26 May 2021 05:31:19 -0400 X-MC-Unique: KMaDda-lNSilAZz1rrmwcg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 083AC180FD65; Wed, 26 May 2021 09:31:17 +0000 (UTC) Received: from t480s.redhat.com (ovpn-113-99.ams2.redhat.com [10.36.113.99]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9CB925D9CC; Wed, 26 May 2021 09:31:01 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: David Hildenbrand , Andrew Morton , "Michael S. Tsirkin" , Jason Wang , Alexey Dobriyan , Mike Rapoport , "Matthew Wilcox (Oracle)" , Oscar Salvador , Michal Hocko , Roman Gushchin , Alex Shi , Steven Price , Mike Kravetz , Aili Yao , Jiri Bohac , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Wei Liu , Naoya Horiguchi , linux-hyperv@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Mike Rapoport Subject: [PATCH v3 2/6] fs/proc/kcore: pfn_is_ram check only applies to KCORE_RAM Date: Wed, 26 May 2021 11:30:37 +0200 Message-Id: <20210526093041.8800-3-david@redhat.com> In-Reply-To: <20210526093041.8800-1-david@redhat.com> References: <20210526093041.8800-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=LaenYMzB; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf10.hostedemail.com: domain of david@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=david@redhat.com X-Stat-Signature: 8qesjdm9gxqbdf9unb3jjq1sfmgd5zho X-Rspamd-Queue-Id: 25A8240F8C16 X-Rspamd-Server: rspam02 X-HE-Tag: 1622021477-247897 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: Let's resturcture the code, using switch-case, and checking pfn_is_ram() only when we are dealing with KCORE_RAM. Reviewed-by: Mike Rapoport Signed-off-by: David Hildenbrand --- fs/proc/kcore.c | 35 +++++++++++++++++++++++++++-------- 1 file changed, 27 insertions(+), 8 deletions(-) diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c index 09f77d3c6e15..ed6fbb3bd50c 100644 --- a/fs/proc/kcore.c +++ b/fs/proc/kcore.c @@ -483,25 +483,36 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) goto out; } m = NULL; /* skip the list anchor */ - } else if (!pfn_is_ram(__pa(start) >> PAGE_SHIFT)) { - if (clear_user(buffer, tsz)) { - ret = -EFAULT; - goto out; - } - } else if (m->type == KCORE_VMALLOC) { + goto skip; + } + + switch (m->type) { + case KCORE_VMALLOC: vread(buf, (char *)start, tsz); /* we have to zero-fill user buffer even if no read */ if (copy_to_user(buffer, buf, tsz)) { ret = -EFAULT; goto out; } - } else if (m->type == KCORE_USER) { + break; + case KCORE_USER: /* User page is handled prior to normal kernel page: */ if (copy_to_user(buffer, (char *)start, tsz)) { ret = -EFAULT; goto out; } - } else { + break; + case KCORE_RAM: + if (!pfn_is_ram(__pa(start) >> PAGE_SHIFT)) { + if (clear_user(buffer, tsz)) { + ret = -EFAULT; + goto out; + } + break; + } + fallthrough; + case KCORE_VMEMMAP: + case KCORE_TEXT: if (kern_addr_valid(start)) { /* * Using bounce buffer to bypass the @@ -525,7 +536,15 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) goto out; } } + break; + default: + pr_warn_once("Unhandled KCORE type: %d\n", m->type); + if (clear_user(buffer, tsz)) { + ret = -EFAULT; + goto out; + } } +skip: buflen -= tsz; *fpos += tsz; buffer += tsz;