From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 36247472F71; Fri, 2 Oct 2026 09:14:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790932454; cv=none; b=XL9SUHcSiR2i9lUAUyGiNSE3jqqLoTJwNqOWwT9N7R7Tuy01aiM44zy/k9c6keX/PhX0Mbapw1XPWo7/7+Vb1WpzmsZ7N583VCrD6drR936Yet0T2MbGJfsHEpfhX78y0U33uHhnlgE16LdwwJBPaPbvDiqe9JBCLX/IK2bVb1s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790932454; c=relaxed/simple; bh=VM6MSlVh3jzBQPFjrXdc6pR9ehMicjLJtRznf8HwY3s=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=qsmk1xbJE6WsUMiuPQhvz+1uNVT40FpFJzVALer11QHVIWnCgm7c1892Aj1XbDsE74rbI2iIzLVIO2Z2r2l9XyfXfauSrtimJ+1iOlccY2oiqMmXdbaZI3OtkbtPFH1cGeN4IQfCC5imzCzWlxjApVKxCibtUz1pe+Pq2xYdcJs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=V/MmYVh6; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="V/MmYVh6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9262A1F00893; Fri, 2 Oct 2026 09:14:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790932453; bh=g3xI0ZfRVma0vVgDDAPIVsW/WN8aWz4RHMfiSpVmGKc=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=V/MmYVh66kSQiBhN2eFF9NgP3IJgcLglfXA8Hi9+B/nGjl0T0MqCqWmmDQN6QfNV/ 4txqkbO7x3nZeBnUzacoIqYqMbQRtbwFPb3SkoQRfrb2ukCw1u8yZcC0EwEUrqgk1F pZ/yVAkHWvZS+wKEcCIaJog9+VmyAAcoQ9bqPjydM07UwNR/qei+VlgeIglncZtc+a fAZjCNMJbtJf1q6tt/VDyPbM+xLmvKf0M31pCtbNFROTrXv5u6DoLcK2SkHXXINfPh DDK1HGEcVBcO8lIgDNC3cSIknWS1Ppw8dVPiedOnnv8+Dbv65B+HYj8MI4EiywapZ6 H/Tob9EHzIKDQ== From: sashiko-bot@kernel.org Subject: Re: [PATCH bpf-next v4 07/12] bpf: keep module BTF until the vmlinux BTF is available Reply-To: sashiko-reviews@lists.linux.dev To: "Jay Wang" Cc: sched-ext@lists.linux.dev, linux-perf-users@vger.kernel.org, linux-modules@vger.kernel.org, "Petr Pavlu" , dmitry.torokhov@gmail.com, linux-trace-kernel@vger.kernel.org, linux-input@vger.kernel.org, ojeda@kernel.org, bpf@vger.kernel.org, gary@garyguo.net In-Reply-To: <20261001225214.12351-8-wanjay@amazon.com> References: <20261001225214.12351-1-wanjay@amazon.com> <20261001225214.12351-8-wanjay@amazon.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 02 Oct 2026 09:14:12 +0000 Message-Id: <20261002091412.9262A1F00893@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-input@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > Module BTF is split BTF against the vmlinux BTF and is parsed in the > module notifier. With CONFIG_DEBUG_INFO_BTF=3Dm the vmlinux BTF may not = be > loaded yet when a module loads, and the notifier cannot load btf_vmlinux > (that would nest a module load in a module load). >=20 > So a module loaded before the vmlinux BTF keeps a copy of its .BTF and > .BTF.base and gets a list entry with btf =3D=3D NULL; its kfunc, dtor kfu= nc > and struct_ops registrations wait on that entry. Without a .BTF.base > the data is final and is exposed in /sys/kernel/btf right away (the raw > bytes need no parsing); with one, parsing relocates the data in place, > so its file is created once parsed, as with =3Dy. The next patch creates > that file earlier. >=20 > When the vmlinux BTF arrives, btf_parse_deferred_modules() parses the > kept copies (the copy is the one btf_parse_module() makes anyway, so an > [ ... ] > With =3Dy the BTF is present from boot and the notifier takes the existing > path. Still nothing is reachable until the Kconfig symbol becomes a > tristate. >=20 > Signed-off-by: Jay Wang Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261001225214.1235= 1-1-wanjay@amazon.com?part=3D7