Re: [PATCH] parisc: fix kernel crash when unwinding a userspace process

[Helge Deller <deller@gmx.de>]

Randolph Chung wrote:
> Helge Deller wrote:
>> Any user on existing parisc 32- and 64bit-kernels can easily crash
>> the kernel and as such enforce a DSO.
>> A simple testcase is available here: 
>>     http://gsyprf10.external.hp.com/~deller/crash.tgz
>>
>> The problem is introduced by the fact, that the handle_interruption()
>> crash handler calls the show_regs() function, which in turn tries
>> to unwind the stack by calling parisc_show_stack().
>> Since the stack contains userspace addresses, a try to unwind the 
>> stack is dangerous and useless and leads to the crash.
> 
> Helge,
> 
> I think this is ok, but can you preserve the printing of IAOQ/RP even 
> for user processes?

Thanks Randolph,

You are probably right. It's better to stay consistent for debugging and 
you'll see the important registers at once.
I'll respin a new patch.

Helge