Re: [PATCH 18/20] objtool: Add UACCESS validation

[Andrey Ryabinin]

On 3/7/19 11:33 PM, Peter Zijlstra wrote:
> On Thu, Mar 07, 2019 at 11:15:42PM +0300, Andrey Ryabinin wrote:
>>
>>
>> On 3/7/19 8:41 PM, Peter Zijlstra wrote:
>>> On Thu, Mar 07, 2019 at 08:33:26AM -0800, Linus Torvalds wrote:
>>>> On Thu, Mar 7, 2019 at 3:52 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>>>>>
>>>>> XXX: are we sure we want __memset marked AC-safe?
>>>>
>>>> It's certainly one of the safer functions to call with AC set, but it
>>>> sounds wrong anyway. It's not like it's likely to leak kernel data
>>>> (most memset's are with 0, and even the non-zero ones I can't imagine
>>>> are sensitive - more like poison values etc).
>>>>
>>>> What's the call site that made you go "just add __memset() to the list"?
>>>
>>> __asan_{,un}poinson_stack_memory()
>>
>> These two can be called only with CONFIG_KASAN_EXTRA=y which 
>> was removed very recently, so it should be safe to delete these functions.
> 
> Ooh shiny. Clearly my tree still has them; what commit do I need to look
> for?
> 


commit 7771bdbbfd3d6f204631b6fd9e1bbc30cd15918e