From patchwork Tue Nov 2 10:15:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 12598395 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2A961C43217 for ; Tue, 2 Nov 2021 10:00:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 13EA861078 for ; Tue, 2 Nov 2021 10:00:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230321AbhKBKC4 (ORCPT ); Tue, 2 Nov 2021 06:02:56 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:14697 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229612AbhKBKCz (ORCPT ); Tue, 2 Nov 2021 06:02:55 -0400 Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4Hk51y5qHqzZcTn; Tue, 2 Nov 2021 17:58:14 +0800 (CST) Received: from dggpeml500025.china.huawei.com (7.185.36.35) by dggemv703-chm.china.huawei.com (10.3.19.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.15; Tue, 2 Nov 2021 18:00:18 +0800 Received: from huawei.com (10.175.124.27) by dggpeml500025.china.huawei.com (7.185.36.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.15; Tue, 2 Nov 2021 18:00:17 +0800 From: Hou Tao To: Alexei Starovoitov CC: Martin KaFai Lau , Yonghong Song , "Daniel Borkmann" , Andrii Nakryiko , , , Subject: [PATCH bpf-next v3 1/2] bpf: clean-up bpf_verifier_vlog() for BPF_LOG_KERNEL log level Date: Tue, 2 Nov 2021 18:15:35 +0800 Message-ID: <20211102101536.2958763-2-houtao1@huawei.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20211102101536.2958763-1-houtao1@huawei.com> References: <20211102101536.2958763-1-houtao1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpeml500025.china.huawei.com (7.185.36.35) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net An extra newline will output for bpf_log() with BPF_LOG_KERNEL level as shown below: [ 52.095704] BPF:The function test_3 has 12 arguments. Too many. [ 52.095704] [ 52.096896] Error in parsing func ptr test_3 in struct bpf_dummy_ops Now all bpf_log() are ended by newline, but not all btf_verifier_log() are ended by newline, so checking whether or not the log message has the trailing newline and adding a newline if not. Also there is no need to calculate the left userspace buffer size for kernel log output and to truncate the output by '\0' which has already been done by vscnprintf(), so only do these for userspace log output. Signed-off-by: Hou Tao Acked-by: Yonghong Song --- kernel/bpf/verifier.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index a4b48bd4e3ca..77beaa46329a 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -299,13 +299,15 @@ void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt, WARN_ONCE(n >= BPF_VERIFIER_TMP_LOG_SIZE - 1, "verifier log line truncated - local buffer too short\n"); - n = min(log->len_total - log->len_used - 1, n); - log->kbuf[n] = '\0'; - if (log->level == BPF_LOG_KERNEL) { - pr_err("BPF:%s\n", log->kbuf); + bool newline = n > 0 && log->kbuf[n - 1] == '\n'; + + pr_err("BPF: %s%s", log->kbuf, newline ? "" : "\n"); return; } + + n = min(log->len_total - log->len_used - 1, n); + log->kbuf[n] = '\0'; if (!copy_to_user(log->ubuf + log->len_used, log->kbuf, n + 1)) log->len_used += n; else