linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Vaibhav Bedia <vaibhav.bedia@gmail.com>
To: Wang Nan <wangnan0@huawei.com>
Cc: kexec@lists.infradead.org, stable@vger.kernel.org,
	linux-kernel@vger.kernel.org, Geng Hui <hui.geng@huawei.com>,
	linux-mm@kvack.org, Eric Biederman <ebiederm@xmission.com>,
	Russell King <rmk+kernel@arm.linux.org.uk>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linux ARM Kernel List <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 2/3] ARM: kexec: copying code to ioremapped area
Date: Wed, 22 Jan 2014 07:56:52 -0500	[thread overview]
Message-ID: <CANacCWz2DdLvns9htszpwWnASrYGXQt+tHMsw4aBbjoyw-DmeQ@mail.gmail.com> (raw)
In-Reply-To: <1390389916-8711-3-git-send-email-wangnan0@huawei.com>

[-- Attachment #1: Type: text/plain, Size: 700 bytes --]

On Wed, Jan 22, 2014 at 6:25 AM, Wang Nan <wangnan0@huawei.com> 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)?

[-- Attachment #2: Type: text/html, Size: 1067 bytes --]

  reply	other threads:[~2014-01-22 12:56 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-01-22 11:25 [PATCH 0/3] Bugfix for kdump on arm Wang Nan
2014-01-22 11:25 ` [PATCH 1/3] ARM: Premit ioremap() to map reserved pages Wang Nan
2014-01-22 11:38   ` Will Deacon
2014-01-22 11:42   ` Russell King - ARM Linux
2014-01-22 11:55     ` Wang Nan
2014-01-22 11:25 ` [PATCH 2/3] ARM: kexec: copying code to ioremapped area Wang Nan
2014-01-22 12:56   ` Vaibhav Bedia [this message]
2014-01-22 13:03     ` Wang Nan
2014-01-22 13:27   ` Russell King - ARM Linux
2014-01-23  2:16     ` Wang Nan
2014-01-22 11:25 ` [PATCH 3/3] ARM: allow kernel to be loaded in middle of phymem Wang Nan
2014-01-23 19:15   ` Nicolas Pitre
2014-01-23 19:31     ` Russell King - ARM Linux
2014-01-23 20:01       ` Nicolas Pitre

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CANacCWz2DdLvns9htszpwWnASrYGXQt+tHMsw4aBbjoyw-DmeQ@mail.gmail.com \
    --to=vaibhav.bedia@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=ebiederm@xmission.com \
    --cc=hui.geng@huawei.com \
    --cc=kexec@lists.infradead.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=rmk+kernel@arm.linux.org.uk \
    --cc=stable@vger.kernel.org \
    --cc=wangnan0@huawei.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox