From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753256Ab3BUUKs (ORCPT ); Thu, 21 Feb 2013 15:10:48 -0500 Received: from us01smtp2.synopsys.com ([198.182.44.80]:65033 "EHLO kiruna.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752384Ab3BUUKr (ORCPT ); Thu, 21 Feb 2013 15:10:47 -0500 From: Vineet Gupta To: Tejun Heo CC: Vineet Gupta , Andrew Morton , Yinghai Lu , Wanpeng Li , Ingo Molnar , , Subject: [PATCH v2 1/2] memblock: add assertion for zero allocation alignment Date: Fri, 22 Feb 2013 01:40:21 +0530 Message-ID: <1361477421-3964-1-git-send-email-vgupta@synopsys.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <20130221193639.GN3570@htj.dyndns.org> References: <20130221193639.GN3570@htj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.12.197.217] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This came to light when calling memblock allocator from arc port (for copying flattended DT). If a "0" alignment is passed, the allocator round_up() call incorrectly rounds up the size to 0. round_up(num, alignto) => ((num - 1) | (alignto -1)) + 1 While the obvious allocation failure causes kernel to panic, it is better to warn the caller to fix the code. Tejun suggested that instead of BUG_ON(!align) - which might be ineffective due to pending console init and such, it is better to WARN_ON, and continue the boot with a reasonable default align. Caller passing @size need not be handled similarly as the subsequent panic will indicate that anyhow. Signed-off-by: Vineet Gupta Cc: Andrew Morton Cc: Tejun Heo Cc: Yinghai Lu Cc: Wanpeng Li Cc: Ingo Molnar Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org --- mm/memblock.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/mm/memblock.c b/mm/memblock.c index 1bcd9b9..f3804bd 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -824,6 +824,9 @@ static phys_addr_t __init memblock_alloc_base_nid(phys_addr_t size, /* align @size to avoid excessive fragmentation on reserved array */ size = round_up(size, align); + if (WARN_ON(!align)) + align = __alignof__(long long); + found = memblock_find_in_range_node(0, max_addr, size, align, nid); if (found && !memblock_reserve(found, size)) return found; -- 1.7.4.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx176.postini.com [74.125.245.176]) by kanga.kvack.org (Postfix) with SMTP id 923CB6B0011 for ; Thu, 21 Feb 2013 15:10:47 -0500 (EST) From: Vineet Gupta Subject: [PATCH v2 1/2] memblock: add assertion for zero allocation alignment Date: Fri, 22 Feb 2013 01:40:21 +0530 Message-ID: <1361477421-3964-1-git-send-email-vgupta@synopsys.com> In-Reply-To: <20130221193639.GN3570@htj.dyndns.org> References: <20130221193639.GN3570@htj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: Tejun Heo Cc: Vineet Gupta , Andrew Morton , Yinghai Lu , Wanpeng Li , Ingo Molnar , linux-mm@kvack.org, linux-kernel@vger.kernel.org This came to light when calling memblock allocator from arc port (for copying flattended DT). If a "0" alignment is passed, the allocator round_up() call incorrectly rounds up the size to 0. round_up(num, alignto) => ((num - 1) | (alignto -1)) + 1 While the obvious allocation failure causes kernel to panic, it is better to warn the caller to fix the code. Tejun suggested that instead of BUG_ON(!align) - which might be ineffective due to pending console init and such, it is better to WARN_ON, and continue the boot with a reasonable default align. Caller passing @size need not be handled similarly as the subsequent panic will indicate that anyhow. Signed-off-by: Vineet Gupta Cc: Andrew Morton Cc: Tejun Heo Cc: Yinghai Lu Cc: Wanpeng Li Cc: Ingo Molnar Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org --- mm/memblock.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/mm/memblock.c b/mm/memblock.c index 1bcd9b9..f3804bd 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -824,6 +824,9 @@ static phys_addr_t __init memblock_alloc_base_nid(phys_addr_t size, /* align @size to avoid excessive fragmentation on reserved array */ size = round_up(size, align); + if (WARN_ON(!align)) + align = __alignof__(long long); + found = memblock_find_in_range_node(0, max_addr, size, align, nid); if (found && !memblock_reserve(found, size)) return found; -- 1.7.4.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org