Messages in this thread | | | Date | Wed, 22 Jan 2014 21:03:54 +0800 | From | Wang Nan <> | Subject | Re: [PATCH 2/3] ARM: kexec: copying code to ioremapped area |
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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.
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