Re: [linux-next:master] [bpf, x64] f663a03c8e: test-bpf.Tail_call_count_preserved_across_function_calls.fail

[Leon Hwang <hffilwlqm@gmail.com>]

On 26/6/24 10:19, Oliver Sang wrote:
> hi, Leon Hwang,
> 
> On Tue, Jun 25, 2024 at 04:25:00PM +0800, Leon Hwang wrote:
>>
>>
>> On 25/6/24 14:55, kernel test robot wrote:
>>>
>>>
>>> Hello,
>>>
>>> kernel test robot noticed "test-bpf.Tail_call_count_preserved_across_function_calls.fail" on:
>>>
>>> commit: f663a03c8e35c5156bad073a4a8f5e673d656e3f ("bpf, x64: Remove tail call detection")
>>> https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master
>>>
>>> [test failed on linux-next/master 62c97045b8f720c2eac807a5f38e26c9ed512371]
>>>
>>> in testcase: test-bpf
>>> version: 
>>> with following parameters:
>>>
>>> 	test: non-jit
>>>
>>>
>>>
>>> compiler: gcc-13
>>> test machine: 36 threads 1 sockets Intel(R) Core(TM) i9-10980XE CPU @ 3.00GHz (Cascade Lake) with 32G memory
>>>
>>> (please refer to attached dmesg/kmsg for entire log/backtrace)
>>>
>>>
>>>
>>>
>>> If you fix the issue in a separate patch/commit (i.e. not just a new version of
>>> the same patch/commit), kindly add following tags
>>> | Reported-by: kernel test robot <oliver.sang@intel.com>
>>> | Closes: https://lore.kernel.org/oe-lkp/202406251415.c51865bc-oliver.sang@intel.com
>>>
>>>
>>>
>>> [   43.913560] test_bpf: #0 Tail call leaf jited:1 5 PASS
>>> [   43.913572] test_bpf: #1 Tail call 2 jited:1 ret -1 != 3 FAIL
>>> [   43.914138] test_bpf: #2 Tail call 3 jited:1 ret -1 != 6 FAIL
>>> [   43.914756] test_bpf: #3 Tail call 4 jited:1 ret -1 != 10 FAIL
>>> [   43.915374] test_bpf: #4 Tail call load/store leaf jited:1 5 PASS
>>> [   43.915993] test_bpf: #5 Tail call load/store jited:1 ret -1 != 0 FAIL
>>> [   43.916636] test_bpf: #6 Tail call error path, max count reached jited:1 ret 1000 != 34000 FAIL
>>> [   43.917319] test_bpf: #7 Tail call count preserved across function calls jited:1 ret 1000 != 34000 FAIL
>>> [   43.918799] test_bpf: #8 Tail call error path, NULL target jited:1 5 PASS
>>> [   43.919720] test_bpf: #9 Tail call error path, index out of range jited:1 5 PASS
>>> [   43.920474] test_bpf: test_tail_calls: Summary: 4 PASSED, 6 FAILED, [10/10 JIT'ed]
>>>
>>
>> Hi,
>>
>> May I request the source code of these test cases?
>> I do not find them in lkp-tests.
> 
> test-bpf doesn't have source code.
> 
> you could refer to
> https://github.com/intel/lkp-tests/blob/master/programs/test-bpf/run
> to see how it runs.
> 
> then
> https://github.com/intel/lkp-tests/blob/master/programs/test-bpf/parse
> to see how the results are parsed.
> 

I found their source code. Then I fixed it by "bpf: Fix tailcall cases
in test_bpf"[0].

[0] https://lore.kernel.org/bpf/20240625145351.40072-1-hffilwlqm@gmail.com/

Thanks,
Leon