From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3vnfwH3ctXzDq7c for ; Wed, 22 Mar 2017 04:30:23 +1100 (AEDT) Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v2LHTMfZ143859 for ; Tue, 21 Mar 2017 13:30:16 -0400 Received: from e18.ny.us.ibm.com (e18.ny.us.ibm.com [129.33.205.208]) by mx0b-001b2d01.pphosted.com with ESMTP id 29amb3q3an-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 21 Mar 2017 13:30:16 -0400 Received: from localhost by e18.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 21 Mar 2017 13:30:16 -0400 From: "Aneesh Kumar K.V" To: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au Cc: linuxppc-dev@lists.ozlabs.org, "Aneesh Kumar K.V" Subject: [PATCH V3 02/10] powerpc/mm/slice: Fix off-by-1 error when computing slice mask Date: Tue, 21 Mar 2017 22:59:52 +0530 In-Reply-To: <1490117400-9891-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1490117400-9891-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Message-Id: <1490117400-9891-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , For low slice, max addr should be less than 4G. Without limiting this correctly we will end up with a low slice mask which has 17th bit set. This is not a problem with the current code because our low slice mask is of type u16. But in later patch I am switching low slice mask to u64 type and having the 17bit set result in wrong slice mask which in turn results in mmap failures. Reviewed-by: Paul Mackerras Signed-off-by: Aneesh Kumar K.V --- arch/powerpc/mm/slice.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c index 2b27458902ee..bf150557dba8 100644 --- a/arch/powerpc/mm/slice.c +++ b/arch/powerpc/mm/slice.c @@ -83,11 +83,10 @@ static struct slice_mask slice_range_to_mask(unsigned long start, struct slice_mask ret = { 0, 0 }; if (start < SLICE_LOW_TOP) { - unsigned long mend = min(end, SLICE_LOW_TOP); - unsigned long mstart = min(start, SLICE_LOW_TOP); + unsigned long mend = min(end, (SLICE_LOW_TOP - 1)); ret.low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1)) - - (1u << GET_LOW_SLICE_INDEX(mstart)); + - (1u << GET_LOW_SLICE_INDEX(start)); } if ((start + len) > SLICE_LOW_TOP) -- 2.7.4