From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pdx-out-009.esa.us-west-2.outbound.mail-perimeter.amazon.com (pdx-out-009.esa.us-west-2.outbound.mail-perimeter.amazon.com [35.155.198.111]) (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 334ED50C2B0; Fri, 25 Sep 2026 23:02:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=35.155.198.111 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790377379; cv=none; b=PPL+1Y0to8dml/64tHxpOZxSP5vewTKUm0fvwwsVdTr1X0dtE9vxu/QIFaVv+jgEUm3lEQ0xjhzTXwsHopusETTtyGPaauBhhHTyN3S8owHWyRrlsCpFgf8rydHilI53Lpr0AlP+snDqtX6wBLEex94qGvM16i5vBt7Cui2hkbo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790377379; c=relaxed/simple; bh=/c5Co9F/am8EjP/vE2uczd6+1rxzpiX4bq+WxQVokQs=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=QhdUZowl+gf0+kcT2xNqj35cF3SOLyojqWV5H483VpHTeR1IT8C07vPqxirtVkuMmD3j+tPkN00EdrdOHltIM0I70y3w7Qa0OJamGQwVFe1z1GzG/3E6rkcSzOeQR8BjIeR9pJvliRg+pmOmEDqJDpNkgNE/6Is06flrEgHXgTA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com; spf=pass smtp.mailfrom=amazon.com; dkim=pass (2048-bit key) header.d=amazon.com header.i=@amazon.com header.b=IUJUYpw5; arc=none smtp.client-ip=35.155.198.111 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=amazon.com header.i=@amazon.com header.b="IUJUYpw5" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazoncorp2; t=1790377373; x=1821913373; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=/nC5Hs6za1TBw6xFElyyI5lgMUaptfWcUfplRQMPLdU=; b=IUJUYpw5i+Si931kCt8RZG29wcvsJHkEde6EE+TeHE6iy6bm6LNGj7M0 gVjRnnAUb5jH+7BWQHWdfYSACvxuTsYaOc/mZuiGNWDhd/FHtD3h+M/Vr l/ZGi+gzq0Hpi5ubFWDgUA+nd7x7JnA3ErbQOH8MJFmIgn/iF9YO3H/9i NX9URxuSp9cqpxJVc69AJqWJerVpWSwLBgybRI/BXhl58Eevu5abzjpG+ U25Y7oPboe/0PqWcPnuOZV/UupR0rMCluQg07DZGcn6ZgaRF7tLDL1eDs ECUJNM/0MY0bHB+X1Hh7OCku+1+BRW6sTNRXSeJTDORVeo0hK8SeQTxu1 Q==; X-CSE-ConnectionGUID: 0e0YVNQNRTC6OhS2S1B8ZQ== X-CSE-MsgGUID: u3vSdn/eT5egbyqJCBrOxw== X-IronPort-AV: E=Sophos;i="6.27,123,1787011200"; d="scan'208";a="29582881" Received: from ip-10-5-0-115.us-west-2.compute.internal (HELO smtpout.naws.us-west-2.prod.farcaster.email.amazon.dev) ([10.5.0.115]) by internal-pdx-out-009.esa.us-west-2.outbound.mail-perimeter.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2026 23:02:53 +0000 Received: from EX19MTAUWC002.ant.amazon.com [205.251.233.111:25894] by smtpin.naws.us-west-2.prod.farcaster.email.amazon.dev [10.0.13.104:2525] with esmtp (Farcaster) id a5162554-736a-4bf5-8a0e-aec9cf76434b; Fri, 25 Sep 2026 23:02:52 +0000 (UTC) X-Farcaster-Flow-ID: a5162554-736a-4bf5-8a0e-aec9cf76434b Received: from EX19D001UWA001.ant.amazon.com (10.13.138.214) by EX19MTAUWC002.ant.amazon.com (10.250.64.143) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.49; Fri, 25 Sep 2026 23:02:52 +0000 Received: from dev-dsk-wanjay-2c-d25651b4.us-west-2.amazon.com (172.19.198.4) by EX19D001UWA001.ant.amazon.com (10.13.138.214) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.49; Fri, 25 Sep 2026 23:02:52 +0000 From: Jay Wang To: CC: , Subject: Re: [PATCH bpf-next v2 9/9] kbuild, bpf: allow building the vmlinux BTF as a module Date: Fri, 25 Sep 2026 23:02:52 +0000 Message-ID: <20260925230252.34602-1-wanjay@amazon.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260925213305.A7C371F000FF@smtp.kernel.org> References: <20260925213305.A7C371F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-modules@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: EX19D040UWA003.ant.amazon.com (10.13.139.6) To EX19D001UWA001.ant.amazon.com (10.13.138.214) For "depends on DEBUG_INFO_BTF" this does not happen: Kconfig turns an m upper bound into y for a bool symbol (scripts/kconfig/symbol.c, sym_calc_visibility()). I checked it with olddefconfig: with SCHED_CLASS_EXT, NET_SCH_BPF, PROBE_EVENTS_BTF_ARGS, BINFMT_MISC_BPF, IO_URING_BPF_OPS and DEBUG_INFO_BTF_MODULES enabled, switching DEBUG_INFO_BTF from y to m changes nothing but BPF_PRELOAD, which the series excludes on purpose. Looking at the other uses turned up the reverse case, though: RUST and GENDWARFKSYMS say "depends on !DEBUG_INFO_BTF", and !m is m, which a bool again takes as y, so with =m those pahole restrictions no longer applied. v3 writes them as DEBUG_INFO_BTF=n (patch 8/9): https://lore.kernel.org/bpf/20260925224229.1850-1-wanjay@amazon.com/ Jay