From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 998001A0158 for ; Thu, 10 Jul 2014 18:42:28 +1000 (EST) Received: from e28smtp04.in.ibm.com (e28smtp04.in.ibm.com [122.248.162.4]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 02D86140141 for ; Thu, 10 Jul 2014 18:42:27 +1000 (EST) Received: from /spool/local by e28smtp04.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 10 Jul 2014 14:12:25 +0530 Received: from d28relay03.in.ibm.com (d28relay03.in.ibm.com [9.184.220.60]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id 190FFE0045 for ; Thu, 10 Jul 2014 14:13:49 +0530 (IST) Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay03.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s6A8hrck43974828 for ; Thu, 10 Jul 2014 14:13:53 +0530 Received: from d28av01.in.ibm.com (localhost [127.0.0.1]) by d28av01.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s6A8gLaC024058 for ; Thu, 10 Jul 2014 14:12:21 +0530 Message-ID: <53BE51EB.5090208@linux.vnet.ibm.com> Date: Thu, 10 Jul 2014 14:12:19 +0530 From: Madhusudanan Kandasamy MIME-Version: 1.0 To: Benjamin Herrenschmidt , Paul Mackerras , linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, Stephen Rothwell Subject: [PATCH V2] powerpc: Fail remap_4k_pfn() if PFN doesn't fit inside PTE Content-Type: text/plain; charset=ISO-8859-1 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , V2 : Rewritten to avoid helper function as suggested by Stephen Rothwell. 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. Signed-off-by: Madhusudanan Kandasamy --- arch/powerpc/include/asm/pte-hash64-64k.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/pte-hash64-64k.h b/arch/powerpc/include/asm/pte-hash64-64k.h index d836d94..b5178e4 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, \ + 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