From patchwork Fri Oct 18 10:34:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 1179284 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 (no SPF record) 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=kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 46vj7h1CxHz9sPV for ; Fri, 18 Oct 2019 21:34:08 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2408227AbfJRKeH (ORCPT ); Fri, 18 Oct 2019 06:34:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52858 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2408220AbfJRKeH (ORCPT ); Fri, 18 Oct 2019 06:34:07 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1A91B18C4276; Fri, 18 Oct 2019 10:34:07 +0000 (UTC) Received: from krava.brq.redhat.com (unknown [10.43.17.61]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4C935600C1; Fri, 18 Oct 2019 10:34:05 +0000 (UTC) From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, Andrii Nakryiko , Yonghong Song , Martin KaFai Lau Subject: [PATCH] bpftool: Try to read btf as raw data if elf read fails Date: Fri, 18 Oct 2019 12:34:04 +0200 Message-Id: <20191018103404.12999-1-jolsa@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.62]); Fri, 18 Oct 2019 10:34:07 +0000 (UTC) Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org The bpftool interface stays the same, but now it's possible to run it over BTF raw data, like: $ bpftool btf dump file /sys/kernel/btf/vmlinux libbpf: failed to get EHDR from /sys/kernel/btf/vmlinux [1] INT '(anon)' size=4 bits_offset=0 nr_bits=32 encoding=(none) [2] INT 'long unsigned int' size=8 bits_offset=0 nr_bits=64 encoding=(none) [3] CONST '(anon)' type_id=2 I'm also adding err init to 0 because I was getting uninitialized warnings from gcc. Signed-off-by: Jiri Olsa --- tools/bpf/bpftool/btf.c | 47 ++++++++++++++++++++++++++++++++++++----- 1 file changed, 42 insertions(+), 5 deletions(-) diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c index 9a9376d1d3df..100fb7e02329 100644 --- a/tools/bpf/bpftool/btf.c +++ b/tools/bpf/bpftool/btf.c @@ -12,6 +12,9 @@ #include #include #include +#include +#include +#include #include "btf.h" #include "json_writer.h" @@ -388,6 +391,35 @@ static int dump_btf_c(const struct btf *btf, return err; } +static struct btf *btf__parse_raw(const char *file) +{ + struct btf *btf = ERR_PTR(-EINVAL); + __u8 *buf = NULL; + struct stat st; + FILE *f; + + if (stat(file, &st)) + return btf; + + f = fopen(file, "rb"); + if (!f) + return btf; + + buf = malloc(st.st_size); + if (!buf) + goto err; + + if ((size_t) st.st_size != fread(buf, 1, st.st_size, f)) + goto err; + + btf = btf__new(buf, st.st_size); + +err: + free(buf); + fclose(f); + return btf; +} + static int do_dump(int argc, char **argv) { struct btf *btf = NULL; @@ -397,7 +429,7 @@ static int do_dump(int argc, char **argv) __u32 btf_id = -1; const char *src; int fd = -1; - int err; + int err = 0; if (!REQ_ARGS(2)) { usage(); @@ -468,10 +500,15 @@ static int do_dump(int argc, char **argv) btf = btf__parse_elf(*argv, NULL); if (IS_ERR(btf)) { err = PTR_ERR(btf); - btf = NULL; - p_err("failed to load BTF from %s: %s", - *argv, strerror(err)); - goto done; + if (err == -LIBBPF_ERRNO__FORMAT) + btf = btf__parse_raw(*argv); + if (IS_ERR(btf)) { + btf = NULL; + /* Display the original error value. */ + p_err("failed to load BTF from %s: %s", + *argv, strerror(err)); + goto done; + } } NEXT_ARG(); } else {