Re: [PATCH] ppc: Fix BPF JIT for ABIv2

From	Michael Ellerman <mpe@ellerman.id.au>
Newsgroups	linux.kernel
Subject	Re: [PATCH] ppc: Fix BPF JIT for ABIv2
Date	2016-06-22 06:10 +0200
Message-ID	<rMHEd-6TC-5@gated-at.bofh.it> (permalink)
References	(4 earlier) <rMcTM-3R8-7@gated-at.bofh.it> <rMrg6-4Cx-25@gated-at.bofh.it> <rMsca-5dO-35@gated-at.bofh.it> <rMvjI-797-31@gated-at.bofh.it> <rMHEd-6TC-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Tue, 2016-06-21 at 08:45 -0700, Alexei Starovoitov wrote:
> On 6/21/16 7:47 AM, Thadeu Lima de Souza Cascardo wrote:
> > > > 
> > > > The calling convention is different with ABIv2 and so we'll need changes
> > > > in bpf_slow_path_common() and sk_negative_common().
> > > 
> > > How big would those changes be? Do we know?
> > > 
> > > How come no one reported this was broken previously? This is the first I've
> > > heard of it being broken.
> > > 
> > 
> > I just heard of it less than two weeks ago, and only could investigate it last
> > week, when I realized mainline was also affected.
> > 
> > It looks like the little-endian support for classic JIT were done before the
> > conversion to ABIv2. And as JIT is disabled by default, no one seems to have
> > exercised it.
> 
> it's not a surprise unfortunately. The JITs that were written before
> test_bpf.ko was developed were missing corner cases. Typical tcpdump
> would be fine, but fragmented packets, negative offsets and
> out-out-bounds wouldn't be handled correctly.
> I'd suggest to validate the stable backport with test_bpf as well.
 
OK thanks.

I have been running seltests/net/test_bpf, but I realise now it doesn't enable
the JIT.

cheers

Thread

Re: [6/6] ppc: ebpf/jit: Implement JIT compiler for extended BPF Michael Ellerman <mpe@ellerman.id.au> - 2016-06-17 15:00 +0200
  [PATCH] ppc: Fix BPF JIT for ABIv2 Thadeu Lima de Souza Cascardo <cascardo@redhat.com> - 2016-06-17 15:10 +0200
    Re: [PATCH] ppc: Fix BPF JIT for ABIv2 "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> - 2016-06-19 20:00 +0200
      Re: [PATCH] ppc: Fix BPF JIT for ABIv2 Thadeu Lima de Souza Cascardo <cascardo@redhat.com> - 2016-06-20 21:20 +0200
        Re: [PATCH] ppc: Fix BPF JIT for ABIv2 "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> - 2016-06-21 12:40 +0200
          Re: [PATCH] ppc: Fix BPF JIT for ABIv2 Michael Ellerman <mpe@ellerman.id.au> - 2016-06-21 13:40 +0200
            Re: [PATCH] ppc: Fix BPF JIT for ABIv2 Thadeu Lima de Souza Cascardo <cascardo@redhat.com> - 2016-06-21 17:00 +0200
              Re: [PATCH] ppc: Fix BPF JIT for ABIv2 Michael Ellerman <mpe@ellerman.id.au> - 2016-06-22 06:10 +0200
              Re: [PATCH] ppc: Fix BPF JIT for ABIv2 "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> - 2016-06-22 09:20 +0200
                Re: [PATCH] ppc: Fix BPF JIT for ABIv2 "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> - 2016-06-22 17:00 +0200
          Re: [PATCH] ppc: Fix BPF JIT for ABIv2 Michael Ellerman <mpe@ellerman.id.au> - 2016-06-22 07:30 +0200
    Re: [PATCH] ppc: Fix BPF JIT for ABIv2 Michael Ellerman <mpe@ellerman.id.au> - 2016-06-22 07:20 +0200
  Re: [6/6] ppc: ebpf/jit: Implement JIT compiler for extended BPF "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> - 2016-06-19 19:40 +0200
    Re: [6/6] ppc: ebpf/jit: Implement JIT compiler for extended BPF Michael Ellerman <mpe@ellerman.id.au> - 2016-06-21 01:50 +0200
      Re: [6/6] ppc: ebpf/jit: Implement JIT compiler for extended BPF "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> - 2016-06-21 09:10 +0200
        Re: [6/6] ppc: ebpf/jit: Implement JIT compiler for extended BPF Michael Ellerman <mpe@ellerman.id.au> - 2016-06-21 13:20 +0200
          Re: [6/6] ppc: ebpf/jit: Implement JIT compiler for extended BPF "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> - 2016-06-22 09:10 +0200

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