Re: [PATCH v2 0/5] MIPS: BPF: JIT fixes and improvements.

[David Daney]

On 03/14/2017 03:49 PM, Alexei Starovoitov wrote:
> On Tue, Mar 14, 2017 at 02:21:39PM -0700, David Daney wrote:
> > Changes from v1:
> >
> >   - Use unsigned access for SKF_AD_HATYPE
> >
> >   - Added three more patches for other problems found.
> >
> >
> > Testing the BPF JIT on Cavium OCTEON (mips64) with the test-bpf module
> > identified some failures and unimplemented features.
> >
> > With this patch set we get:
> >
> >      test_bpf: Summary: 305 PASSED, 0 FAILED, [85/297 JIT'ed]
> >
> > Both big and little endian tested.
> >
> > We still lack eBPF support, but this is better than nothing.
> >
> > David Daney (5):
> >   MIPS: uasm:  Add support for LHU.
> >   MIPS: BPF: Add JIT support for SKF_AD_HATYPE.
> >   MIPS: BPF: Use unsigned access for unsigned SKB fields.
> >   MIPS: BPF: Quit clobbering callee saved registers in JIT code.
> >   MIPS: BPF: Fix multiple problems in JIT skb access helpers.
>
> Thanks. Nice set of fixes. Especially patch 4.
> Did you see crashes because of it?

Only when running the test-bpf module.

The "JMP_JA: Jump, gap, jump, ..." test doesn't actually use any 
registers, which I think is somewhat uncommon in BPF code.  The system 
would either crash or have weird behavior after running this test.




> Acked-by: Alexei Starovoitov <ast@xxxxxxxxxx>