Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755622AbaAVNFF (ORCPT ); Wed, 22 Jan 2014 08:05:05 -0500 Received: from szxga01-in.huawei.com ([119.145.14.64]:25324 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755153AbaAVNFC (ORCPT ); Wed, 22 Jan 2014 08:05:02 -0500 Message-ID: <52DFC1BA.8030001@huawei.com> Date: Wed, 22 Jan 2014 21:03:54 +0800 From: Wang Nan User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 MIME-Version: 1.0 To: Vaibhav Bedia CC: , , , Geng Hui , , Eric Biederman , Russell King , Andrew Morton , Linux ARM Kernel List Subject: Re: [PATCH 2/3] ARM: kexec: copying code to ioremapped area References: <1390389916-8711-1-git-send-email-wangnan0@huawei.com> <1390389916-8711-3-git-send-email-wangnan0@huawei.com> In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.111.69.90] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014/1/22 20:56, Vaibhav Bedia wrote: > On Wed, Jan 22, 2014 at 6:25 AM, Wang Nan > wrote: > > ARM's kdump is actually corrupted (at least for omap4460), mainly because of > cache problem: flush_icache_range can't reliably ensure the copied data > correctly goes into RAM. After mmu turned off and jump to the trampoline, kexec > always failed due to random undef instructions. > > This patch use ioremap to make sure the destnation of all memcpy() is > uncachable memory, including copying of target kernel and trampoline. > > > AFAIK ioremap on RAM in forbidden in ARM and device memory that ioremap() > ends up creating is not meant for executable code. > > Doesn't this trigger the WARN_ON() in _arm_ioremap_pfn_caller)? This patch is depend on the previous one: ARM: Premit ioremap() to map reserved pages However, Russell is opposed to it. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/