Re: Fw: [Bug 205469] New: x86_32: bpf: multiple test_bpf failures using eBPF JIT

[Daniel Borkmann <daniel@iogearbox.net>]

On 11/21/19 9:37 PM, Greg KH wrote:
> On Mon, Nov 11, 2019 at 01:56:31PM +0100, Daniel Borkmann wrote:
>> On 11/9/19 7:36 PM, Wang YanQing wrote:
>>> On Sat, Nov 09, 2019 at 12:37:49AM +0100, Daniel Borkmann wrote:
>>>> [ Cc Wang (x86_32 BPF JIT maintainer) ]
>>>>
>>>> On 11/8/19 4:57 PM, Stephen Hemminger wrote:
>>>>>
>>>>> Begin forwarded message:
>>>>>
>>>>> Date: Fri, 08 Nov 2019 07:35:59 +0000
>>>>> From: bugzilla-daemon@bugzilla.kernel.org
>>>>> To: stephen@networkplumber.org
>>>>> Subject: [Bug 205469] New: x86_32: bpf: multiple test_bpf failures using eBPF JIT
>>>>>
>>>>>
>>>>> https://bugzilla.kernel.org/show_bug.cgi?id=205469
>>>>>
>>>>>                Bug ID: 205469
>>>>>               Summary: x86_32: bpf: multiple test_bpf failures using eBPF JIT
>>>>>               Product: Networking
>>>>>               Version: 2.5
>>>>>        Kernel Version: 4.19.81 LTS
>>>>>              Hardware: i386
>>>>>                    OS: Linux
>>>>>                  Tree: Mainline
>>>>>                Status: NEW
>>>>>              Severity: normal
>>>>>              Priority: P1
>>>>>             Component: Other
>>>>>              Assignee: stephen@networkplumber.org
>>>>>              Reporter: itugrok@yahoo.com
>>>>>                    CC: itugrok@yahoo.com
>>>>>            Regression: No
>>>>>
>>>>> Created attachment 285829
>>>>>      --> https://bugzilla.kernel.org/attachment.cgi?id=285829&action=edit
>>>>> test_bpf failures: kernel 4.19.81/x86_32 (OpenWrt)
>>>>>
>>>>> Summary:
>>>>> ========
>>>>>
>>>>> Running the 4.19.81 LTS kernel on QEMU/x86_32, the standard test_bpf.ko
>>>>> testsuite generates multiple errors with the eBPF JIT enabled:
>>>>>
>>>>>      ...
>>>>>      test_bpf: #32 JSET jited:1 40 ret 0 != 20 46 FAIL
>>>>>      test_bpf: #321 LD_IND word positive offset jited:1 ret 0 != -291897430 FAIL
>>>>>      test_bpf: #322 LD_IND word negative offset jited:1 ret 0 != -1437222042 FAIL
>>>>>      test_bpf: #323 LD_IND word unaligned (addr & 3 == 2) jited:1 ret 0 !=
>>>>> -1150890889 FAIL
>>>>>      test_bpf: #326 LD_IND word positive offset, all ff jited:1 ret 0 != -1 FAIL
>>>>>      ...
>>>>>      test_bpf: Summary: 373 PASSED, 5 FAILED, [344/366 JIT'ed]
>>>>>
>>>>> However, with eBPF JIT disabled (net.core.bpf_jit_enable=0) all tests pass.
>>>>>
>>>>>
>>>>> Steps to Reproduce:
>>>>> ===================
>>>>>
>>>>>      # sysctl net.core.bpf_jit_enable=1
>>>>>      # modprobe test_bpf
>>>>>      <Kernel log with failures and test summary>
>>>>>
>>>>>
>>>>> Affected Systems Tested:
>>>>> ========================
>>>>>
>>>>>      OpenWrt master on QEMU/pc-q35(x86_32) [LTS kernel 4.19.81]
>>>>>
>>>>>
>>>>> Kernel Logs:
>>>>> ============
>>>>>
>>>>> Boot log with test results is attached.
>>>>>
>>>
>>> Hi Daniel Borkmann!
>>>
>>> I have tested and verified that the report bug has been fixed by commit
>>> 711aef1bbf88 ("bpf, x32: Fix bug for BPF_JMP | {BPF_JSGT, BPF_JSLE, BPF_JSLT, BPF_JSGE}")
>>>
>>> But that fix hasn't been backport to stable trees, so maybe we should do it:)
>>
>> Yes, given you have access to a x32 setup and are also able to runtime test the backported
>> JIT changes, please submit it to stable with us in Cc. Thanks Wang!
> 
> Backporting this would be nice if someone could do it :)

It landed on the stable list today:

https://lore.kernel.org/stable/20191121074336.GA15326@udknight/
https://lore.kernel.org/stable/20191121074725.GA15476@udknight/
https://lore.kernel.org/stable/20191121074511.GC15326@udknight/
https://lore.kernel.org/stable/20191121074452.GB15326@udknight/

Thanks,
Daniel