From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753940AbaGJPPi (ORCPT ); Thu, 10 Jul 2014 11:15:38 -0400 Received: from e28smtp03.in.ibm.com ([122.248.162.3]:38092 "EHLO e28smtp03.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753286AbaGJPPg (ORCPT ); Thu, 10 Jul 2014 11:15:36 -0400 Message-ID: <53BEAE01.7000401@linux.vnet.ibm.com> Date: Thu, 10 Jul 2014 20:45:13 +0530 From: Madhusudanan Kandasamy User-Agent: Mozilla/5.0 (X11; Linux i686; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Benjamin Herrenschmidt , Paul Mackerras , linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org Subject: [PATCH V3] powerpc : Fail remap_4k_pfn() if PFN doesn't fit inside PTE Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14071015-3864-0000-0000-00000F633F81 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org remap_4k_pfn() silently truncates upper bits of input 4K PFN if it cannot be contained in PTE. This leads invalid memory mapping and could result in a system crash when the memory is accessed. This patch fails remap_4k_pfn() and returns -EINVAL if the input 4K PFN cannot be contained in PTE. V3 : Added parentheses to protect 'pfn' and entire macro as suggested by Brian. V2 : Rewritten to avoid helper function as suggested by Stephen Rothwell. Signed-off-by: Madhusudanan Kandasamy --- arch/powerpc/include/asm/pte-hash64-64k.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/pte-hash64-64k.h b/arch/powerpc/include/asm/pte-hash64-64k.h index d836d94..b6d2d42 100644 --- a/arch/powerpc/include/asm/pte-hash64-64k.h +++ b/arch/powerpc/include/asm/pte-hash64-64k.h @@ -75,7 +75,8 @@ (((pte) & _PAGE_COMBO)? MMU_PAGE_4K: MMU_PAGE_64K) #define remap_4k_pfn(vma, addr, pfn, prot) \ - remap_pfn_range((vma), (addr), (pfn), PAGE_SIZE, \ - __pgprot(pgprot_val((prot)) | _PAGE_4K_PFN)) + (WARN_ON(((pfn) >= (1UL << (64 - PTE_RPN_SHIFT)))) ? -EINVAL : \ + remap_pfn_range((vma), (addr), (pfn), PAGE_SIZE, \ + __pgprot(pgprot_val((prot)) | _PAGE_4K_PFN))) #endif /* __ASSEMBLY__ */ -- 2.0.1