From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Rapoport Subject: [PATCH 2/7] of: ignore sub-page memory regions Date: Fri, 3 Aug 2018 22:58:45 +0300 Message-ID: <1533326330-31677-3-git-send-email-rppt@linux.vnet.ibm.com> References: <1533326330-31677-1-git-send-email-rppt@linux.vnet.ibm.com> Return-path: In-Reply-To: <1533326330-31677-1-git-send-email-rppt@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Andrew Morton Cc: Richard Kuo , Ley Foon Tan , Richard Weinberger , Guan Xuetao , Michal Hocko , linux-hexagon@vger.kernel.org, nios2-dev@lists.rocketboards.org, linux-um@lists.infradead.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 Reviewed-by: Rob Herring --- 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