Re: [PATCH] Consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECK
From: H. Peter Anvin
Date: Wed Feb 27 2013 - 18:21:49 EST
On 02/27/2013 03:19 PM, Stephen Boyd wrote:
> On 02/27/13 14:55, H. Peter Anvin wrote:
>> On 02/27/2013 02:52 PM, Stephen Boyd wrote:
>>> On 02/27/13 14:19, H. Peter Anvin wrote:
>>>> On 02/27/2013 12:42 PM, Stephen Boyd wrote:
>>>>>> It's fine to do your patch as a first step though, which would not
>>>>>> change the behavior.
>>>>> A lot of arches seem to not want to enable it because false positives
>>>>> are everywhere. It really depends on how good the compiler is at doing
>>>>> constant propagation and dead code removal.
>>>>>
>>>> Although some of the cases I have seen being flagged as "false
>>>> positives" have been real bugs.
>>> There were so many false-positives on x86_64 that Andrew eventually
>>> dropped my patch to add support for this option to the copy_from_user()
>>> function there.
>>>
>> I would probably have taken it, especially if it came with more x86-64
>> to i386 unification.
>>
>> It's an option, though.
>
> You acked the patch[1]. Will you pick it up?
>
> [1] https://patchwork.kernel.org/patch/833192/
>
I can, although I would prefer if it came with the uaccess/usercopy
unification.
-hpa
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