Re: debugctl msr

From: stephane eranian
Date: Wed Nov 19 2008 - 15:59:48 EST


Markus,


On Wed, Nov 19, 2008 at 8:20 PM, stephane eranian
<eranian@xxxxxxxxxxxxxx> wrote:
>
>> For a single ds_release() call matching a corresponding successful
>> ds_request() call, the buffer is freed if and only if it had been
>> allocated by ds.c.
>>
>> Kfree() itself handles NULL pointers and scripts/checkpatch.pl warns on
>> a check for NULL around a kfree() call.
>>
> Yes, I have narrowed this down to the following lines:
> current->mm->total_vm -= context->pages[qual];
> current->mm->locked_vm -= context->pages[qual];

To follow-up on this, the other issue with this code is that you
should not decrease
those two mm fields if the buffer was not allocated by ds.c. So I
think, the modification
I sent you in my patch is actually valid (just for another reason).
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/