From patchwork Thu Jan 10 21:09:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Khalid Aziz X-Patchwork-Id: 10756915 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 71D9113B5 for ; Thu, 10 Jan 2019 21:11:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 617A129B9C for ; Thu, 10 Jan 2019 21:11:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 558F229BF7; Thu, 10 Jan 2019 21:11:22 +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=-5.3 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 6E35E29B9C for ; Thu, 10 Jan 2019 21:11:21 +0000 (UTC) Received: (qmail 10057 invoked by uid 550); 10 Jan 2019 21:10:58 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 9950 invoked from network); 10 Jan 2019 21:10:56 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : in-reply-to : references; s=corp-2018-07-02; bh=igejgCvAio6u1Ussld9AuQC3Ul6s8euovTImu0aEjD4=; b=1RiH7Ayttgl67HmBUpj9Zdch6LCLPksWDKHZCY0c3O4g6K6f5lB+hFkquaMWY/CeqG2c WA3MN5u8IJiO8Q9EgRsR9weHv6aPXsg7lHvl6yVYGrFoAElAl/Qtxo/16weY5EyApWJw ZcUENEhCipmYwEhouhHCKcEms6inTWl5F8KMuKzhwQTrjTOoEAagowAB7i5Bu3g6vsTO g6DsIP3fE09F4sXWS4Bh+elRfQKiEMVnQyVSwOrGHEEUPs0EeBDb01Zp18Asj2eNwi1g Wr2MJ/rH5TiF9nQr2d44cNyQBMa8MVknWh6/vaIjGPPQMqxLcxhzgvfyKlQJRmStxkM5 KA== From: Khalid Aziz To: juergh@gmail.com, tycho@tycho.ws, jsteckli@amazon.de, ak@linux.intel.com, torvalds@linux-foundation.org, liran.alon@oracle.com, keescook@google.com, konrad.wilk@oracle.com Cc: Tycho Andersen , deepa.srinivasan@oracle.com, chris.hyser@oracle.com, tyhicks@canonical.com, dwmw@amazon.co.uk, andrew.cooper3@citrix.com, jcm@redhat.com, boris.ostrovsky@oracle.com, kanth.ghatraju@oracle.com, joao.m.martins@oracle.com, jmattson@google.com, pradeep.vincent@oracle.com, john.haxby@oracle.com, tglx@linutronix.de, kirill.shutemov@linux.intel.com, hch@lst.de, steven.sistare@oracle.com, kernel-hardening@lists.openwall.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Khalid Aziz Subject: [RFC PATCH v7 06/16] xpfo: add primitives for mapping underlying memory Date: Thu, 10 Jan 2019 14:09:38 -0700 Message-Id: <5deed7a1eb65fc6c66acb8a00d46d63e7f0fd22f.1547153058.git.khalid.aziz@oracle.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9132 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=2 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=972 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1901100164 X-Virus-Scanned: ClamAV using ClamSMTP From: Tycho Andersen In some cases (on arm64 DMA and data cache flushes) we may have unmapped the underlying pages needed for something via XPFO. Here are some primitives useful for ensuring the underlying memory is mapped/unmapped in the face of xpfo. Signed-off-by: Tycho Andersen Signed-off-by: Khalid Aziz --- include/linux/xpfo.h | 22 ++++++++++++++++++++++ mm/xpfo.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 52 insertions(+) diff --git a/include/linux/xpfo.h b/include/linux/xpfo.h index e38b823f44e3..2682a00ebbcb 100644 --- a/include/linux/xpfo.h +++ b/include/linux/xpfo.h @@ -37,6 +37,15 @@ void xpfo_free_pages(struct page *page, int order); bool xpfo_page_is_unmapped(struct page *page); +#define XPFO_NUM_PAGES(addr, size) \ + (PFN_UP((unsigned long) (addr) + (size)) - \ + PFN_DOWN((unsigned long) (addr))) + +void xpfo_temp_map(const void *addr, size_t size, void **mapping, + size_t mapping_len); +void xpfo_temp_unmap(const void *addr, size_t size, void **mapping, + size_t mapping_len); + #else /* !CONFIG_XPFO */ static inline void xpfo_kmap(void *kaddr, struct page *page) { } @@ -46,6 +55,19 @@ static inline void xpfo_free_pages(struct page *page, int order) { } static inline bool xpfo_page_is_unmapped(struct page *page) { return false; } +#define XPFO_NUM_PAGES(addr, size) 0 + +static inline void xpfo_temp_map(const void *addr, size_t size, void **mapping, + size_t mapping_len) +{ +} + +static inline void xpfo_temp_unmap(const void *addr, size_t size, + void **mapping, size_t mapping_len) +{ +} + + #endif /* CONFIG_XPFO */ #endif /* _LINUX_XPFO_H */ diff --git a/mm/xpfo.c b/mm/xpfo.c index cdbcbac582d5..f79075bf7d65 100644 --- a/mm/xpfo.c +++ b/mm/xpfo.c @@ -13,6 +13,7 @@ * the Free Software Foundation. */ +#include #include #include #include @@ -235,3 +236,32 @@ bool xpfo_page_is_unmapped(struct page *page) return test_bit(XPFO_PAGE_UNMAPPED, &xpfo->flags); } EXPORT_SYMBOL(xpfo_page_is_unmapped); + +void xpfo_temp_map(const void *addr, size_t size, void **mapping, + size_t mapping_len) +{ + struct page *page = virt_to_page(addr); + int i, num_pages = mapping_len / sizeof(mapping[0]); + + memset(mapping, 0, mapping_len); + + for (i = 0; i < num_pages; i++) { + if (page_to_virt(page + i) >= addr + size) + break; + + if (xpfo_page_is_unmapped(page + i)) + mapping[i] = kmap_atomic(page + i); + } +} +EXPORT_SYMBOL(xpfo_temp_map); + +void xpfo_temp_unmap(const void *addr, size_t size, void **mapping, + size_t mapping_len) +{ + int i, num_pages = mapping_len / sizeof(mapping[0]); + + for (i = 0; i < num_pages; i++) + if (mapping[i]) + kunmap_atomic(mapping[i]); +} +EXPORT_SYMBOL(xpfo_temp_unmap);