netdev - Re: [PATCH bpf-next 0/3] bpf: cleanups on managing subprog information

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Date:   Wed, 2 May 2018 17:59:50 +0100
From:   Jiong Wang <jiong.wang@...ronome.com>
To:     Alexei Starovoitov <alexei.starovoitov@...il.com>
Cc:     borkmann@...earbox.net, ecree@...arflare.com,
        netdev@...r.kernel.org, oss-drivers@...ronome.com
Subject: Re: [PATCH bpf-next 0/3] bpf: cleanups on managing subprog
 information

On 01/05/2018 23:22, Alexei Starovoitov wrote:
...
> [   27.784931]  ? bpf_int_jit_compile+0x7ac/0xab0
> [   27.785475]  bpf_int_jit_compile+0x2b6/0xab0
> [   27.786001]  ? do_jit+0x6020/0x6020
> [   27.786428]  ? kasan_kmalloc+0xa0/0xd0
> [   27.786885]  bpf_check+0x2c05/0x4c40
> [   27.787346]  ? fixup_bpf_calls+0x1140/0x1140
> [   27.787865]  ? kasan_unpoison_shadow+0x30/0x40
> [   27.788406]  ? kasan_kmalloc+0xa0/0xd0
> [   27.788865]  ? memset+0x1f/0x40
> [   27.789255]  ? bpf_obj_name_cpy+0x2d/0x200
> [   27.789750]  bpf_prog_load+0xb07/0xeb0
>
> simply running test_verifier with JIT and kasan on.

Ah, sorry, I should add "sysctl net/core/bpf_jit_enable=1" to my test
script, error reproduced.

convert_ctx_accesses and fixup_bpf_calls might insert ebpf insns that
prog->len would change.

The new fake "exit" subprog whose .start offset is prog->len should be
updated as well.

The "for" condition in adjust_subprog_starts:

   for (i = 0; i < env->subprog_cnt; i++) {

need to be changed into:

   for (i = 0; i <= env->subprog_cnt; i++) {

Will respin the patch set.

Thanks.

Regards,
Jiong