Re: [PATCH] x86/process: Silence KASAN warnings in get_wchan()

[Andrey Ryabinin]

2015-10-07 19:27 GMT+03:00 Andi Kleen <ak@xxxxxxxxxxxxxxx>:
> On Wed, Oct 07, 2015 at 11:54:42AM +0300, Andrey Ryabinin wrote:
>> On 10/06/2015 09:11 PM, Andy Lutomirski wrote:
>> >
>> > But what's wrong with the GCC attribute mechanism?  Surely GCC ought
>> > to be able to generate the code, at least in the simple cases, and the
>> > attribute already exists.  The attribute and READ_ONCE_NOCHECK seem
>> > like the least messy in the C code.
>>
>> The problem with 'no_sanitize_address' attribute is incompatibility with inlining.
>> GCC can't inline function with that attribute into function without it.
>> And the contrary is also true - GCC can't inline function without attribute into function with such attribute.
>>
>> Failure to inline always_inline function leads to build failure.
>
> So just don't do that?  Don't set the attribute on functions marked inline.
> Where do you see this anyways?

Besides that we can't set the attribute on functions that *call*
inline functions.
So we can't set it on get_wchan() because it calls __read_once_size().



>
> -Andi
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