Re: ioctl get_info: Bad address

[Carl K. <ca...@pe...>]

On Wed, Aug 10, 2011 at 12:05 PM, Clemens Ladisch <cl...@la...> wrote:
> Stefan Richter wrote:
>> On Aug 10 Clemens Ladisch wrote:
>> > So I'd guess the actual cost (.code section) is not nearly that high.
>>
>> FWIW, this is from one of the six u64_to_uptr call sites,
>> ioctl_get_info():
>>       ...
>>       mov     %eax, %r13d     # D.30771, D.30771
>>       movq %gs:kernel_stack,%rdx      #, pfo_ret__
>>       testb   $2, -8132(%rdx) #, <variable>.status
>>       cmove   %rax, %r13      # D.30771,, D.30771, D.33010
>
> Bah, the bytes of these few commands are not worth counting.  :-)
>
>> And this appear to be the two uptr_to_u64 call sites: ...
>
> Where current_thread_info() was _already_ being used.
>
>> > > Is it worthwhile?
>
> Definitely.
>
>
> Carl, if you're still reading this: Stefan's kernel patch will fix your
> problem, but you could just as well replace (u64)&something with
> (unsigned long)&something in async-test.c.
>

This one, right?

313     get_info.bus_reset = (u64)&bus_reset;


-- 
Carl K