From: Daniel Borkmann <daniel@iogearbox.net>
To: Maciej Fijalkowski <maciej.fijalkowski@intel.com>, ast@kernel.org
Cc: bpf@vger.kernel.org, netdev@vger.kernel.org,
bjorn.topel@intel.com, magnus.karlsson@intel.com
Subject: Re: [PATCH v5 bpf-next 4/6] bpf, x64: rework pro/epilogue and tailcall handling in JIT
Date: Tue, 28 Jul 2020 23:33:12 +0200 [thread overview]
Message-ID: <38407b6c-12a2-671f-9929-2ef39be62542@iogearbox.net> (raw)
In-Reply-To: <20200724173557.5764-5-maciej.fijalkowski@intel.com>
On 7/24/20 7:35 PM, Maciej Fijalkowski wrote:
> This commit serves two things:
> 1) it optimizes BPF prologue/epilogue generation
> 2) it makes possible to have tailcalls within BPF subprogram
[...]
[...]
> diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> index 7be02e555ab9..d86a35474d7b 100644
> --- a/kernel/bpf/core.c
> +++ b/kernel/bpf/core.c
> @@ -773,7 +773,8 @@ int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
>
> if (size > poke_tab_max)
> return -ENOSPC;
> - if (poke->ip || poke->ip_stable || poke->adj_off)
> + if (poke->tailcall_target || poke->tailcall_target_stable ||
> + poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
> return -EINVAL;
Hmm, I thought we've been through this from prior review rounds, but these sort of changes
break bisectability. You've already renamed the whole thing in patch 3/6 (poke->ip and the
poke->ip_stable). So if you've applied up to patch 3, then build breaks right here.
> switch (poke->reason) {
>
next prev parent reply other threads:[~2020-07-28 21:33 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-24 17:35 [PATCH v5 bpf-next 0/6] bpf: tailcalls in BPF subprograms Maciej Fijalkowski
2020-07-24 17:35 ` [PATCH v5 bpf-next 1/6] bpf, x64: use %rcx instead of %rax for tail call retpolines Maciej Fijalkowski
2020-07-24 17:35 ` [PATCH v5 bpf-next 2/6] bpf: propagate poke descriptors to subprograms Maciej Fijalkowski
2020-07-24 17:35 ` [PATCH v5 bpf-next 3/6] bpf: rename poke descriptor's 'ip' member to 'tailcall_target' Maciej Fijalkowski
2020-07-24 17:35 ` [PATCH v5 bpf-next 4/6] bpf, x64: rework pro/epilogue and tailcall handling in JIT Maciej Fijalkowski
2020-07-28 21:33 ` Daniel Borkmann [this message]
2020-07-28 22:07 ` Daniel Borkmann
2020-07-29 16:10 ` Maciej Fijalkowski
2020-07-29 21:10 ` Maciej Fijalkowski
2020-07-30 20:16 ` Daniel Borkmann
2020-07-30 22:58 ` Maciej Fijalkowski
2020-07-24 17:35 ` [PATCH v5 bpf-next 5/6] bpf: allow for tailcalls in BPF subprograms for x64 JIT Maciej Fijalkowski
2020-07-24 17:35 ` [PATCH v5 bpf-next 6/6] selftests: bpf: add dummy prog for bpf2bpf with tailcall Maciej Fijalkowski
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