From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1AFFEC433E7 for ; Mon, 12 Oct 2020 13:45:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CC61D2237B for ; Mon, 12 Oct 2020 13:45:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602510333; bh=UJHkcwtAMBTTaQj49a9rbFF+vKgSWPKHudMnhOaOilU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=l0sswJcT2+wJ3EHBoCy6TzgmHx1l9OWNBV3T7L5hI0pSPmh0kULCbtvV73y1FCOOh R6NFBCPejQBn09tHaIiAN4pTRy/3kaiWEO14uInVzBe4Jz3lq6C0VT6b2npoSYn5g8 StkPVfiQ79O29PBg/wzkZekCOd0S9xIdWd22O6z4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731413AbgJLNpb (ORCPT ); Mon, 12 Oct 2020 09:45:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:46218 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731329AbgJLNmD (ORCPT ); Mon, 12 Oct 2020 09:42:03 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B720722228; Mon, 12 Oct 2020 13:41:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602510120; bh=UJHkcwtAMBTTaQj49a9rbFF+vKgSWPKHudMnhOaOilU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PF78RTHanPxwp0cH3g3nX0neB7/4SQM0+Z4rEg9A9ViVQqQLB32o0BYKoaCbdwc0c ZK6SB+AmWQzQW6GohRd+E20aQkGwQFQMQmsxJHYwX7WIk+jebsOeqdKG8vHkxKH4Zl FDD0WTlVDxxgxXvQeuMnlth7J1gjDkhHA19ZOQrU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tony Ambardar , Daniel Borkmann , John Fastabend , Andrii Nakryiko Subject: [PATCH 5.4 18/85] bpf: Prevent .BTF section elimination Date: Mon, 12 Oct 2020 15:26:41 +0200 Message-Id: <20201012132633.725047120@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201012132632.846779148@linuxfoundation.org> References: <20201012132632.846779148@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tony Ambardar commit 65c204398928f9c79f1a29912b410439f7052635 upstream. Systems with memory or disk constraints often reduce the kernel footprint by configuring LD_DEAD_CODE_DATA_ELIMINATION. However, this can result in removal of any BTF information. Use the KEEP() macro to preserve the BTF data as done with other important sections, while still allowing for smaller kernels. Fixes: 90ceddcb4950 ("bpf: Support llvm-objcopy for vmlinux BTF") Signed-off-by: Tony Ambardar Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/a635b5d3e2da044e7b51ec1315e8910fbce0083f.1600417359.git.Tony.Ambardar@gmail.com Signed-off-by: Greg Kroah-Hartman --- include/asm-generic/vmlinux.lds.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -599,7 +599,7 @@ #define BTF \ .BTF : AT(ADDR(.BTF) - LOAD_OFFSET) { \ __start_BTF = .; \ - *(.BTF) \ + KEEP(*(.BTF)) \ __stop_BTF = .; \ } #else