From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-172.mta0.migadu.com (out-172.mta0.migadu.com [91.218.175.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7665042A93 for ; Thu, 24 Oct 2024 02:46:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729737987; cv=none; b=fNELWJrWHDbDlFZw6lSYx7mAG78oymtkFmXevF20iCCpwoLN+qieGhdkiZ+WynL9D56xfhqY0BzU9KgwU2rXQlEL3ZeLMJ2JXA8Q6A1193hqWsu6rWJd3jlGiKIkK70j7LqaJO1HLbugKTG0juOCiSi+bBhAo+vb3va9ht5XnnY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729737987; c=relaxed/simple; bh=gUxpCsx1FJYQ35TxTUCTzSHnfoj11eiYmuwuBfD+S5A=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=RV9/CJqsy4d+J6b+nJM+6xfx2tHln0UKenMFyasLl8r5X/JlptjXbL/7awmgc6hjrHAAD5sl5ktMKuZmjFVnYzIZN6buPKJ+beUB3fGxfekVEwkg+6mYNQrzX1hEse1hglgaBQIfQErjENkZK4tVCJO+WjcojraBGJzUDeVUUSw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=OSgkoW2j; arc=none smtp.client-ip=91.218.175.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="OSgkoW2j" Message-ID: <4f9b0a96-a72c-4977-982b-3da21204b81e@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1729737983; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=gUxpCsx1FJYQ35TxTUCTzSHnfoj11eiYmuwuBfD+S5A=; b=OSgkoW2jfaJ1SdJmzkcmnC+TOG525g3L7eXwHLg0OPXGx5v32FHEBA7BGzPq1t6BWoP28/ LJeeLbam/MRIOWo8hE3jtJNGxiV4mP5MIJkz/+FYuLfap6UT2/riBgW2tx1Bz2TRKbfO7j U+fUqG8JBjRec4LiRXUTaNJDNrZJe68= Date: Wed, 23 Oct 2024 19:46:15 -0700 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next 2/2] bpf, verifier: Check trampoline target is tail_call_reachable subprog Content-Language: en-GB To: Leon Hwang , 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 References: <20241021133929.67782-1-leon.hwang@linux.dev> <20241021133929.67782-3-leon.hwang@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Yonghong Song In-Reply-To: <20241021133929.67782-3-leon.hwang@linux.dev> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT 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 Looks correct to me. Acked-by: Yonghong Song