From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f199.google.com (mail-pl1-f199.google.com [209.85.214.199]) by kanga.kvack.org (Postfix) with ESMTP id D24A98E0007 for ; Thu, 10 Jan 2019 16:10:34 -0500 (EST) Received: by mail-pl1-f199.google.com with SMTP id l9so6905845plt.7 for ; Thu, 10 Jan 2019 13:10:34 -0800 (PST) Received: from aserp2130.oracle.com (aserp2130.oracle.com. [141.146.126.79]) by mx.google.com with ESMTPS id g8si23341095pgo.166.2019.01.10.13.10.33 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 10 Jan 2019 13:10:33 -0800 (PST) From: 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> In-Reply-To: References: In-Reply-To: References: Sender: owner-linux-mm@kvack.org List-ID: 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 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); -- 2.17.1