From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f197.google.com (mail-pf1-f197.google.com [209.85.210.197]) by kanga.kvack.org (Postfix) with ESMTP id B65FF8E0001 for ; Thu, 10 Jan 2019 16:10:33 -0500 (EST) Received: by mail-pf1-f197.google.com with SMTP id t2so8661081pfj.15 for ; Thu, 10 Jan 2019 13:10:33 -0800 (PST) Received: from userp2130.oracle.com (userp2130.oracle.com. [156.151.31.86]) by mx.google.com with ESMTPS id b89si9544153pfj.207.2019.01.10.13.10.32 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 10 Jan 2019 13:10:32 -0800 (PST) From: Khalid Aziz Subject: [RFC PATCH v7 04/16] swiotlb: Map the buffer if it was unmapped by XPFO Date: Thu, 10 Jan 2019 14:09:36 -0700 Message-Id: <98f9b9be522d694d5a52640dd1dfbdd14ca6f8e5.1547153058.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: Juerg Haefliger , 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, Tycho Andersen , Khalid Aziz From: Juerg Haefliger v6: * guard against lookup_xpfo() returning NULL CC: Konrad Rzeszutek Wilk Signed-off-by: Juerg Haefliger Signed-off-by: Tycho Andersen Signed-off-by: Khalid Aziz --- include/linux/xpfo.h | 4 ++++ kernel/dma/swiotlb.c | 3 ++- mm/xpfo.c | 15 +++++++++++++++ 3 files changed, 21 insertions(+), 1 deletion(-) diff --git a/include/linux/xpfo.h b/include/linux/xpfo.h index a39259ce0174..e38b823f44e3 100644 --- a/include/linux/xpfo.h +++ b/include/linux/xpfo.h @@ -35,6 +35,8 @@ void xpfo_kunmap(void *kaddr, struct page *page); void xpfo_alloc_pages(struct page *page, int order, gfp_t gfp); void xpfo_free_pages(struct page *page, int order); +bool xpfo_page_is_unmapped(struct page *page); + #else /* !CONFIG_XPFO */ static inline void xpfo_kmap(void *kaddr, struct page *page) { } @@ -42,6 +44,8 @@ static inline void xpfo_kunmap(void *kaddr, struct page *page) { } static inline void xpfo_alloc_pages(struct page *page, int order, gfp_t gfp) { } static inline void xpfo_free_pages(struct page *page, int order) { } +static inline bool xpfo_page_is_unmapped(struct page *page) { return false; } + #endif /* CONFIG_XPFO */ #endif /* _LINUX_XPFO_H */ diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 045930e32c0e..820a54b57491 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -396,8 +396,9 @@ static void swiotlb_bounce(phys_addr_t orig_addr, phys_addr_t tlb_addr, { unsigned long pfn = PFN_DOWN(orig_addr); unsigned char *vaddr = phys_to_virt(tlb_addr); + struct page *page = pfn_to_page(pfn); - if (PageHighMem(pfn_to_page(pfn))) { + if (PageHighMem(page) || xpfo_page_is_unmapped(page)) { /* The buffer does not have a mapping. Map it in and copy */ unsigned int offset = orig_addr & ~PAGE_MASK; char *buffer; diff --git a/mm/xpfo.c b/mm/xpfo.c index bff24afcaa2e..cdbcbac582d5 100644 --- a/mm/xpfo.c +++ b/mm/xpfo.c @@ -220,3 +220,18 @@ void xpfo_kunmap(void *kaddr, struct page *page) spin_unlock(&xpfo->maplock); } EXPORT_SYMBOL(xpfo_kunmap); + +bool xpfo_page_is_unmapped(struct page *page) +{ + struct xpfo *xpfo; + + if (!static_branch_unlikely(&xpfo_inited)) + return false; + + xpfo = lookup_xpfo(page); + if (unlikely(!xpfo) && !xpfo->inited) + return false; + + return test_bit(XPFO_PAGE_UNMAPPED, &xpfo->flags); +} +EXPORT_SYMBOL(xpfo_page_is_unmapped); -- 2.17.1