From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Message-ID: <52DFC1BA.8030001@huawei.com> Date: Wed, 22 Jan 2014 21:03:54 +0800 From: Wang Nan MIME-Version: 1.0 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: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=twosheds.infradead.org@lists.infradead.org To: Vaibhav Bedia Cc: kexec@lists.infradead.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux-mm@kvack.org, Eric Biederman , Geng Hui , Russell King , Andrew Morton , Linux ARM Kernel List 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. _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec