From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
To: Thadeu Lima de Souza Cascardo <cascardo@redhat.com>,
Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
netdev@vger.kernel.org, Matt Evans <matt@ozlabs.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Alexei Starovoitov <ast@fb.com>,
Denis Kirjanov <kda@linux-powerpc.org>,
Paul Mackerras <paulus@samba.org>,
"David S. Miller" <davem@davemloft.net>,
Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Subject: Re: [PATCH] ppc: Fix BPF JIT for ABIv2
Date: Tue, 21 Jun 2016 14:28:07 +0530 [thread overview]
Message-ID: <20160621085807.GE8886@naverao1-tp.localdomain> (raw)
In-Reply-To: <20160620185620.GD3516@indiana.gru.redhat.com>
On 2016/06/20 03:56PM, Thadeu Lima de Souza Cascardo wrote:
> On Sun, Jun 19, 2016 at 11:19:14PM +0530, Naveen N. Rao wrote:
> > On 2016/06/17 10:00AM, Thadeu Lima de Souza Cascardo wrote:
> > >
> > > Hi, Michael and Naveen.
> > >
> > > I noticed independently that there is a problem with BPF JIT and ABIv2, and
> > > worked out the patch below before I noticed Naveen's patchset and the latest
> > > changes in ppc tree for a better way to check for ABI versions.
> > >
> > > However, since the issue described below affect mainline and stable kernels,
> > > would you consider applying it before merging your two patchsets, so that we can
> > > more easily backport the fix?
> >
> > Hi Cascardo,
> > Given that this has been broken on ABIv2 since forever, I didn't bother
> > fixing it. But, I can see why this would be a good thing to have for
> > -stable and existing distros. However, while your patch below may fix
> > the crash you're seeing on ppc64le, it is not sufficient -- you'll need
> > changes in bpf_jit_asm.S as well.
>
> Hi, Naveen.
>
> Any tips on how to exercise possible issues there? Or what changes you think
> would be sufficient?
The calling convention is different with ABIv2 and so we'll need changes
in bpf_slow_path_common() and sk_negative_common().
However, rather than enabling classic JIT for ppc64le, are we better off
just disabling it?
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -128,7 +128,7 @@ config PPC
select IRQ_FORCED_THREADING
select HAVE_RCU_TABLE_FREE if SMP
select HAVE_SYSCALL_TRACEPOINTS
- select HAVE_CBPF_JIT
+ select HAVE_CBPF_JIT if CPU_BIG_ENDIAN
select HAVE_ARCH_JUMP_LABEL
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select ARCH_HAS_GCOV_PROFILE_ALL
Michael,
Let me know your thoughts on whether you intend to take this patch or
Cascardo's patch for -stable before the eBPF patches. I can redo my
patches accordingly.
- Naveen
next prev parent reply other threads:[~2016-06-21 10:36 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-07 13:32 [PATCH 0/6] eBPF JIT for PPC64 Naveen N. Rao
2016-06-07 13:32 ` [PATCH 1/6] ppc: bpf/jit: Fix/enhance 32-bit Load Immediate implementation Naveen N. Rao
2016-06-07 13:32 ` [PATCH 2/6] ppc: bpf/jit: Optimize 64-bit Immediate loads Naveen N. Rao
2016-06-07 13:32 ` [PATCH 3/6] ppc: bpf/jit: Introduce rotate immediate instructions Naveen N. Rao
2016-06-07 13:32 ` [PATCH 4/6] ppc: bpf/jit: A few cleanups Naveen N. Rao
2016-06-07 13:32 ` [PATCH 5/6] ppc: bpf/jit: Isolate classic BPF JIT specifics into a separate header Naveen N. Rao
2016-06-07 13:32 ` [PATCH 6/6] ppc: ebpf/jit: Implement JIT compiler for extended BPF Naveen N. Rao
2016-06-07 22:56 ` Alexei Starovoitov
2016-06-08 17:17 ` Naveen N. Rao
2016-06-09 3:19 ` Nilay Vaish
2016-06-09 6:07 ` Naveen N. Rao
2016-06-17 12:53 ` [6/6] " Michael Ellerman
2016-06-17 13:00 ` [PATCH] ppc: Fix BPF JIT for ABIv2 Thadeu Lima de Souza Cascardo
2016-06-19 17:49 ` Naveen N. Rao
2016-06-20 18:56 ` Thadeu Lima de Souza Cascardo
2016-06-21 8:58 ` Naveen N. Rao [this message]
2016-06-21 11:15 ` Michael Ellerman
2016-06-21 14:47 ` Thadeu Lima de Souza Cascardo
2016-06-21 15:45 ` Alexei Starovoitov
2016-06-22 4:06 ` Michael Ellerman
2016-06-22 7:12 ` Naveen N. Rao
2016-06-22 14:57 ` Naveen N. Rao
2016-06-22 5:20 ` Michael Ellerman
2016-06-22 5:18 ` Michael Ellerman
2016-06-19 17:36 ` [6/6] ppc: ebpf/jit: Implement JIT compiler for extended BPF Naveen N. Rao
2016-06-20 23:38 ` Michael Ellerman
2016-06-21 6:58 ` Naveen N. Rao
2016-06-21 11:04 ` Michael Ellerman
2016-06-22 7:06 ` Naveen N. Rao
2016-06-22 10:37 ` [PATCH 6/6] " Michael Ellerman
2016-06-22 12:32 ` Naveen N. Rao
2016-06-11 5:47 ` [PATCH 0/6] eBPF JIT for PPC64 David Miller
2016-06-13 5:40 ` Naveen N. Rao
2016-06-18 4:57 ` mpe
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