Re: [stable] [PATCH 1/2] coresight: etb10: Do not call smp_processor_id from preemptible

[Suzuki Kuruppassery Poulose <suzuki.poulose@arm.com>]

Hi Greg,

On 15/01/2020 15:11, Greg KH wrote:
> On Thu, Jan 09, 2020 at 02:36:17PM +0000, Suzuki Kuruppassery Poulose wrote:
>> On 09/01/2020 14:35, Sasha Levin wrote:
>>> On Wed, Jan 08, 2020 at 11:05:40AM +0000, Suzuki K Poulose wrote:
>>>> [ Upstream commit 730766bae3280a25d40ea76a53dc6342e84e6513 ]
>>>>
>>>> During a perf session we try to allocate buffers on the "node" associated
>>>> with the CPU the event is bound to. If it is not bound to a CPU, we
>>>> use the current CPU node, using smp_processor_id(). However this is
>>>> unsafe
>>>> in a pre-emptible context and could generate the splats as below :
>>>>
>>>> BUG: using smp_processor_id() in preemptible [00000000] code: perf/2544
>>>>
>>>> Use NUMA_NO_NODE hint instead of using the current node for events
>>>> not bound to CPUs.
>>>>
>>>> Fixes: 2997aa4063d97fdb39 ("coresight: etb10: implementing AUX API")
>>>> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
>>>> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
>>>> Cc: stable <stable@vger.kernel.org> # v4.9 to v4.19
>>>> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
>>>> Link: https://lore.kernel.org/r/20190620221237.3536-5-mathieu.poirier@linaro.org
>>>>
>>>
>>> I've queued this for 4.9-4.19. There was a simple conflict on 4.9 which
>>> also had to be resolved.
>>>
>>
>>
>> Thanks Sasha !
> 
> Note, these had to all be dropped as they broke the build :(
> 
> So can you please send us patches that at least build?  :)
> 

Do you have a build failure log ? I did build test it before sending it 
over. I tried it again on 4.9, 4.14 and 4.19. I don't hit any build
failures here.

Please could you share the log if you have it handy ?

Suzuki