[PATCH] ARM: kernel: Detect DTB overwrite and error out

[swarren@wwwdotorg.org (Stephen Warren)]

On 11/21/2013 12:48 PM, Joel Fernandes wrote:
> On 11/21/2013 10:48 AM, Stephen Warren wrote:
>> On 11/20/2013 09:04 PM, Joel Fernandes wrote:
>>> Kernel can silenty fail for DT-boot after the decompression stage, if DTB is
>>> overwritten. Instead of simply failing, we detect the condition and print an
>>> error.
>>>
>>> One may think that it is sufficient for the bootloader to place the DTB away
>>> from kernel, but this is not the right fix because: (1) We add more dependence
>>> to the bootloader's stupidity (2) the decompressed kernel end address is not
>>> known to the loader. Also, we shouldn't depend on bootloader for silently
>>> failing us, so we detect the condition and error out.
>>
>> If this problem happens, is there any guarantee that the kernel will
>> still execute far enough to actually print this error message? Can the
> 
> Yes, because till this point we don't depend on DTB yet. We're still just about
> to parse it. The problem detected here is the kernel overwriting the DTB, not
> the other way.

Ah yes, that makes sense. Thanks.