Re: [PATCH] bpf, powerpc: fix jit for seccomp_data access

["Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>]

Mark Lord wrote:
> On 18-02-21 07:52 AM, Mark Lord wrote:
>> On 18-02-21 03:35 AM, Naveen N. Rao wrote:
> ..
>>> Looks good to me, but I am not able to apply this patch. There seems to=
 be whitespace damage.
>>=20
>> Here (attached) is a clean copy.
>=20
> Again, this time with the commit message included!

Thanks. However...
I am able to apply this using 'patch', but not with 'git am' since the=20
headers are missing. FWIW, the usual workflow is to make the changes and=20
commit it into your repository using 'git commit' and then use 'git=20
format-patch' to generate a patch file that you can then post.

I'll defer to Michael on whether he is ok to process this as it is.

>=20
> I am using SECCOMP to filter syscalls on a ppc32 platform,
> and noticed that the JIT compiler was failing on the BPF
> even though the interpreter was working fine.
>=20
> The issue was that the compiler was missing one of the instructions
> used by SECCOMP, so here is a patch to enable JIT for that instruction.
>=20
> Signed-Off-By:  Mark Lord <mlord@pobox.com>

Minot nit: The correct (TM) tag to use is:
Signed-off-by:
(note the case)

>=20
> --- old/arch/powerpc/net/bpf_jit_comp.c 2018-02-16 14:07:01.000000000 -05=
00
> +++ linux/arch/powerpc/net/bpf_jit_comp.c       2018-02-20 14:41:20.80522=
7494 -0500
> @@ -329,6 +329,9 @@ static int bpf_jit_build_body(struct bpf
>                         BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) !=
=3D 4);
>                         PPC_LWZ_OFFS(r_A, r_skb, offsetof(struct sk_buff,=
 len));
>                         break;
> +               case BPF_LDX | BPF_W | BPF_ABS: /* A =3D *((u32 *)(seccom=
p_data + K)); */
> +                       PPC_LWZ_OFFS(r_A, r_skb, K);
> +                       break;
>                 case BPF_LDX | BPF_W | BPF_LEN: /* X =3D skb->len; */
>                         PPC_LWZ_OFFS(r_X, r_skb, offsetof(struct sk_buff,=
 len));
>                         break;

Apart from those aspects, for this patch:
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>


- Naveen

=