Re: [PATCH 2/3] introduce probe_slab_address()

[Kirill Tkhai <tkhai@yandex.ru>]

On 28.10.2014 20:56, Kirill Tkhai wrote:
> On 28.10.2014 18:01, Peter Zijlstra wrote:
>> On Tue, Oct 28, 2014 at 08:44:51AM +0300, Kirill Tkhai wrote:
>>> В Пн, 27/10/2014 в 20:54 +0100, Oleg Nesterov пишет:
>>
>>>> +#define probe_slab_address(addr, retval)	\
>>>> +	probe_kernel_address(addr, retval)
>>>
>>> probe_kernel_read() was arch-dependent on tree platforms:
>>>
>>> arch/blackfin/mm/maccess.c
>>> arch/parisc/lib/memcpy.c
>>> arch/um/kernel/maccess.c
>>>
>>> But now we skip these arch-dependent implementations. Is there no a problem?
>>
>> Nope, see the first patch, it makes probe_kernel_address use
>> __probe_kernel_read().
>>
> 
> Yes, probe_kernel_read() is in [1/3], but it's not the same as
> __probe_kernel_read() for blackfin, for example.

Vise versa, I mean __probe_kernel_read() is in [1/3].

> It's defined as
> 
> long __weak probe_kernel_read(void *dst, const void *src, size_t size)
>     __attribute__((alias("__probe_kernel_read")));
> 
> But blackfin's probe_kernel_read() redefines this __weak function,
> isn't it? Didn't get_freepointer_safe() use to call architecture's
> probe_kernel_read() before?
> 
> I don't see how it is called now...
>