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From: Yonghong Song <yonghong.song@linux.dev>
To: Leon Hwang <leon.hwang@linux.dev>, bpf@vger.kernel.org
Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
	jolsa@kernel.org, eddyz87@gmail.com, kernel-patches-bot@fb.com
Subject: Re: [PATCH bpf-next 2/2] bpf, verifier: Check trampoline target is tail_call_reachable subprog
Date: Wed, 23 Oct 2024 19:46:15 -0700	[thread overview]
Message-ID: <4f9b0a96-a72c-4977-982b-3da21204b81e@linux.dev> (raw)
In-Reply-To: <20241021133929.67782-3-leon.hwang@linux.dev>


On 10/21/24 6:39 AM, Leon Hwang wrote:
> In the x86_64 JIT, tailcall info is propagated through the trampoline when
> the target program is tail_call_reachable. However, this propagation is
> unnecessary if the target is a main prog, or a subprog that is not
> tail_call_reachable.
>
> Since the verifier can determine if a subprog is tail_call_reachable, it
> should only propagate tailcall info when the target is subprog and the
> subprog is actually tail_call_reachable.
>
> Signed-off-by: Leon Hwang <leon.hwang@linux.dev>

Looks correct to me.

Acked-by: Yonghong Song <yonghong.song@linux.dev>


  reply	other threads:[~2024-10-24  2:46 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-10-21 13:39 [PATCH bpf-next 0/2] bpf, x64: Introduce two tailcall enhancements Leon Hwang
2024-10-21 13:39 ` [PATCH bpf-next 1/2] bpf, x64: Propagate tailcall info only for tail_call_reachable subprogs Leon Hwang
2024-10-21 17:49   ` Yonghong Song
2024-10-22  1:46     ` Leon Hwang
2024-10-24  2:29       ` Yonghong Song
2024-10-24  3:33         ` Leon Hwang
2024-10-24 16:38           ` Yonghong Song
2024-10-24 16:56             ` Yonghong Song
2024-10-24 17:01   ` Yonghong Song
2024-10-24 22:09   ` Alexei Starovoitov
2024-10-25  2:37     ` Leon Hwang
2024-10-21 13:39 ` [PATCH bpf-next 2/2] bpf, verifier: Check trampoline target is tail_call_reachable subprog Leon Hwang
2024-10-24  2:46   ` Yonghong Song [this message]
  -- strict thread matches above, loose matches on Subject: below --
2024-10-28 13:40 [PATCH bpf-next 0/2] bpf, x64: Introduce two tailcall enhancements Leon Hwang
2024-10-28 13:40 ` [PATCH bpf-next 2/2] bpf, verifier: Check trampoline target is tail_call_reachable subprog Leon Hwang

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