From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f71.google.com (mail-wm0-f71.google.com [74.125.82.71]) by kanga.kvack.org (Postfix) with ESMTP id 07C4F6B026F for ; Wed, 4 Jul 2018 09:18:29 -0400 (EDT) Received: by mail-wm0-f71.google.com with SMTP id b203-v6so2083144wme.2 for ; Wed, 04 Jul 2018 06:18:28 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id l1-v6si1660451wre.114.2018.07.04.06.18.27 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 04 Jul 2018 06:18:27 -0700 (PDT) Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w64D9C6V045405 for ; Wed, 4 Jul 2018 09:18:26 -0400 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 2k0wb5mk99-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 04 Jul 2018 09:18:26 -0400 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 4 Jul 2018 14:18:24 +0100 From: Mike Rapoport Subject: [PATCH 1/3] of: ignore sub-page memory regions Date: Wed, 4 Jul 2018 16:18:13 +0300 In-Reply-To: <1530710295-10774-1-git-send-email-rppt@linux.vnet.ibm.com> References: <1530710295-10774-1-git-send-email-rppt@linux.vnet.ibm.com> Message-Id: <1530710295-10774-2-git-send-email-rppt@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Ley Foon Tan Cc: Rob Herring , Frank Rowand , Michal Hocko , nios2-dev@lists.rocketboards.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Mike Rapoport Memory region size is rounded down to page boundary and with sub-page region it becomes 0 and there is no point to add an empty region. Moreover, when the base is less than PAGE_SIZE we get a bogus size as (base + size - 1) evaluates to -1. The commit 8cccffc52694 ("of: check for size < 0 after rounding in early_init_dt_add_memory_arch") introduced a test for wrap around for the case when base is not page aligned, the same test can be used to ignore sub-page region sizes. Signed-off-by: Mike Rapoport --- drivers/of/fdt.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 6da20b9..e866745 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -1134,12 +1134,13 @@ void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size) { const u64 phys_offset = MIN_MEMBLOCK_ADDR; + if (size < PAGE_SIZE - (base & ~PAGE_MASK)) { + pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", + base, base + size); + return; + } + if (!PAGE_ALIGNED(base)) { - if (size < PAGE_SIZE - (base & ~PAGE_MASK)) { - pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", - base, base + size); - return; - } size -= PAGE_SIZE - (base & ~PAGE_MASK); base = PAGE_ALIGN(base); } -- 2.7.4