lkml.org 
[lkml]   [2014]   [Jan]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 2/3] ARM: kexec: copying code to ioremapped area
On 2014/1/22 20:56, Vaibhav Bedia wrote:
> On Wed, Jan 22, 2014 at 6:25 AM, Wang Nan <wangnan0@huawei.com <mailto: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)?

This patch is depend on the previous one:

ARM: Premit ioremap() to map reserved pages

However, Russell is opposed to it.




\
 
 \ /
  Last update: 2014-01-22 14:41    [W:0.082 / U:2.204 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site