From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932818AbcBYIUH (ORCPT ); Thu, 25 Feb 2016 03:20:07 -0500 Received: from p3plsmtps2ded03.prod.phx3.secureserver.net ([208.109.80.60]:55913 "EHLO p3plsmtps2ded03.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760076AbcBYIUC (ORCPT ); Thu, 25 Feb 2016 03:20:02 -0500 x-originating-ip: 72.167.245.219 From: Dexuan Cui To: gregkh@linuxfoundation.org, toshi.kani@hpe.com, akpm@linux-foundation.org, tglx@linutronix.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org, driverdev-devel@linuxdriverproject.org, jasowang@redhat.com Cc: olaf@aepfle.de, apw@canonical.com, kys@microsoft.com, haiyangz@microsoft.com Subject: [PATCH] x86/mm: fix slow_virt_to_phys() for X86_PAE again Date: Thu, 25 Feb 2016 01:58:12 -0800 Message-Id: <1456394292-9030-1-git-send-email-decui@microsoft.com> X-Mailer: git-send-email 1.7.4.1 X-CMAE-Envelope: MS4wfLCy/6VWtrMSX4tSIRhNWMofMlQZxL1ZO/UR2aWEoe81JTra354Z7vjYCCQnv85P7XobfjeMrYpY+UcMrRTy/82myAG9fHRqM8McJF8V5YFUwQlJyc9q /YuWVUu6ujqvrcfRM41k5FLIaBQssVQeOt96C+5WsesGNduJzXvEHjJg8Fj5CfYBgcMP5RPL37K9N150C50LKKWrIyplkQPCNWDhY6bihQ0mb1GOR5rdeoe9 pWsKtLxvK0VJCAJLLR87QnlkzIWI/HsxH+PxepCtmvzepuU4pAyMd7/EiecHo138R7NR3aIaoW57Ky/d9tmHigwDldIJL5L9VHJQPelMaw8VNyqXCqwuDF8g zQQnCRyX2h+lZql/+YzwP0RUKLrOjiaAqGerQyqZg/eCS5jdUgdUgp5Vav7H6w27vNfuFlCUqlfvWCkAIiCorOxnCnfbhNTI/XK5AmSJSxKvC6hJMKtTHt2X B4SAtxcaumEe8n9mW5JndmAZeWhkIMYsKX8RI69V4hpNrVVldpWg+IAOqtEy2IH9m0snDxeEZ2JNl1mK7zcq96hX2JtScq/gTZxSog== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "d1cd12108346: x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE" was unintentionally removed by the recent "34437e67a672: x86/mm: Fix slow_virt_to_phys() to handle large PAT bit". And, the variable 'phys_addr' was defined as "unsigned long" by mistake -- it should be "phys_addr_t". As a result, Hyper-V network driver in 32-PAE Linux guest can't work again. Fixes: "commmit 34437e67a672: x86/mm: Fix slow_virt_to_phys() to handle large PAT bit" Signed-off-by: Dexuan Cui Cc: Toshi Kani Cc: Andrew Morton Cc: Thomas Gleixner Cc: K. Y. Srinivasan Cc: Haiyang Zhang Cc: gregkh@linuxfoundation.org Cc: linux-mm@kvack.org Cc: olaf@aepfle.de Cc: apw@canonical.com Cc: jasowang@redhat.com Cc: stable@vger.kernel.org --- arch/x86/mm/pageattr.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 2440814..9cf96d8 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -419,24 +419,30 @@ pmd_t *lookup_pmd_address(unsigned long address) phys_addr_t slow_virt_to_phys(void *__virt_addr) { unsigned long virt_addr = (unsigned long)__virt_addr; - unsigned long phys_addr, offset; + phys_addr_t phys_addr; + unsigned long offset; enum pg_level level; pte_t *pte; pte = lookup_address(virt_addr, &level); BUG_ON(!pte); + /* + * pXX_pfn() returns unsigned long, which must be cast to phys_addr_t + * before being left-shifted PAGE_SHIFT bits -- this trick is to + * make 32-PAE kernel work correctly. + */ switch (level) { case PG_LEVEL_1G: - phys_addr = pud_pfn(*(pud_t *)pte) << PAGE_SHIFT; + phys_addr = (phys_addr_t)pud_pfn(*(pud_t *)pte) << PAGE_SHIFT; offset = virt_addr & ~PUD_PAGE_MASK; break; case PG_LEVEL_2M: - phys_addr = pmd_pfn(*(pmd_t *)pte) << PAGE_SHIFT; + phys_addr = (phys_addr_t)pmd_pfn(*(pmd_t *)pte) << PAGE_SHIFT; offset = virt_addr & ~PMD_PAGE_MASK; break; default: - phys_addr = pte_pfn(*pte) << PAGE_SHIFT; + phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT; offset = virt_addr & ~PAGE_MASK; } -- 1.9.1