From patchwork Tue Apr 9 12:49:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Magnus Karlsson X-Patchwork-Id: 1082237 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44dnDj3fSwz9sRC for ; Tue, 9 Apr 2019 22:49:41 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727204AbfDIMtl (ORCPT ); Tue, 9 Apr 2019 08:49:41 -0400 Received: from mga18.intel.com ([134.134.136.126]:46478 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726035AbfDIMtl (ORCPT ); Tue, 9 Apr 2019 08:49:41 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Apr 2019 05:49:40 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,329,1549958400"; d="scan'208";a="290023619" Received: from mkarlsso-mobl.ger.corp.intel.com (HELO localhost.localdomain) ([10.249.46.212]) by orsmga004.jf.intel.com with ESMTP; 09 Apr 2019 05:49:38 -0700 From: Magnus Karlsson To: magnus.karlsson@intel.com, bjorn.topel@intel.com, ast@kernel.org, daniel@iogearbox.net, netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH bpf-next] libbpf: fix crash in XDP socket part with new larger BPF_LOG_BUF_SIZE Date: Tue, 9 Apr 2019 14:49:34 +0200 Message-Id: <1554814174-28765-1-git-send-email-magnus.karlsson@intel.com> X-Mailer: git-send-email 2.7.4 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-Id: netdev.vger.kernel.org In commit da11b417583e ("libbpf: teach libbpf about log_level bit 2"), the BPF_LOG_BUF_SIZE was increased to 16M. The XDP socket part of libbpf allocated the log_buf on the stack, but for the new 16M buffer size this is not going to work. Change the code to allocate the log_buf using malloc instead. If the allocation fails, we go ahead and load the program without a log buffer. Signed-off-by: Magnus Karlsson Acked-by: Jonathan Lemon --- tools/lib/bpf/xsk.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index 8d0078b..412531b 100644 --- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -259,7 +259,7 @@ int xsk_umem__create(struct xsk_umem **umem_ptr, void *umem_area, __u64 size, static int xsk_load_xdp_prog(struct xsk_socket *xsk) { - char bpf_log_buf[BPF_LOG_BUF_SIZE]; + char *bpf_log_buf; int err, prog_fd; /* This is the C-program: @@ -307,22 +307,27 @@ static int xsk_load_xdp_prog(struct xsk_socket *xsk) }; size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn); + bpf_log_buf = malloc(BPF_LOG_BUF_SIZE); prog_fd = bpf_load_program(BPF_PROG_TYPE_XDP, prog, insns_cnt, "LGPL-2.1 or BSD-2-Clause", 0, bpf_log_buf, - BPF_LOG_BUF_SIZE); + bpf_log_buf ? BPF_LOG_BUF_SIZE : 0); if (prog_fd < 0) { - pr_warning("BPF log buffer:\n%s", bpf_log_buf); - return prog_fd; + if (bpf_log_buf) + pr_warning("BPF log buffer:\n%s", bpf_log_buf); + err = prog_fd; + goto out; } err = bpf_set_link_xdp_fd(xsk->ifindex, prog_fd, xsk->config.xdp_flags); if (err) { close(prog_fd); - return err; + goto out; } xsk->prog_fd = prog_fd; - return 0; +out: + free(bpf_log_buf); + return err; } static int xsk_get_max_queues(struct xsk_socket *xsk)