From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 5D0841A0197 for ; Fri, 11 Jul 2014 01:15:37 +1000 (EST) Received: from e28smtp01.in.ibm.com (e28smtp01.in.ibm.com [122.248.162.1]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id A838F140127 for ; Fri, 11 Jul 2014 01:15:36 +1000 (EST) Received: from /spool/local by e28smtp01.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 10 Jul 2014 20:45:34 +0530 Received: from d28relay02.in.ibm.com (d28relay02.in.ibm.com [9.184.220.59]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id 0D114125805F for ; Thu, 10 Jul 2014 20:45:15 +0530 (IST) Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay02.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s6AFGr6h60293238 for ; Thu, 10 Jul 2014 20:46:54 +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 s6AFFIlb031605 for ; Thu, 10 Jul 2014 20:45:19 +0530 Message-ID: <53BEAE01.7000401@linux.vnet.ibm.com> Date: Thu, 10 Jul 2014 20:45:13 +0530 From: Madhusudanan Kandasamy 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 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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