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=-8.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham 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 39C49C43381 for ; Fri, 15 Mar 2019 06:42:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 080722184C for ; Fri, 15 Mar 2019 06:42:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="XDrGtFMf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728289AbfCOGmU (ORCPT ); Fri, 15 Mar 2019 02:42:20 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:43170 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727151AbfCOGmU (ORCPT ); Fri, 15 Mar 2019 02:42:20 -0400 Received: by mail-pg1-f196.google.com with SMTP id l11so5717448pgq.10 for ; Thu, 14 Mar 2019 23:42:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=z41OO3Ga/cyVJPQRMmKoCQauxHxIQlpyVF8DAQI9hZ8=; b=XDrGtFMfUY/CetGvITDaMLEuwIkaUboOG46AXpofWVld5clT5xqPtkMZfipY6Jzb9B pFUEJocDQ7pNizSPyGNevObeCWZ0L/sVy6GRpBIxVUC80+noQATqYFJJ5FPPvzH20BPA EA0SpBRhwCoycj/o6scoA866hqZlxUzG2ZMv1C35866yIUrZdFfzqzV20Y3hS05aR3Tq Qyvzn1ysQYadTmGKBfeMphbQ1OVkhCXmD3jg10N+qQFjSyPUy+G9zh7YN+MxfXJrPbom qRa7R9TqxSU001iBvRUvzjbxxS4OK7vIKxu6LewqJL3s+yaEmV6RxNPG961QttSmiWPI fLKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=z41OO3Ga/cyVJPQRMmKoCQauxHxIQlpyVF8DAQI9hZ8=; b=s0zzZZOC5yHCFKvOszf2+KcliK6yzS26qQ3c0pq1cBm4hysW55lfInNLX1/NOSBqcB e40WL1nrqrzS9YBNLXSZhQNJjjwmfipumk/W+O3hmBB0zUlGq+MNVOYEDXwNuU5mBoI8 e9A0+fD0W9VBSSLq6DIrKjx2XrT76r60g8yAqm+Y8YoTpw9/kJgUbBjaOOHjvrdq5BqA w53ht9Uj+nNm6tzawyYV/2pWkTD8heUEDtRR2Mv+7StS5t4P4rpVmLn1o28A3VH7YE+k xABCtRFN4EF7PurRORU5wbWjvGK/b1vn/QImHny7lSINRnqqcD9/L1fUqEtoSlsstGIO k6bA== X-Gm-Message-State: APjAAAWLV4S7PsELgSZS9edlelE+ZLn01IkBXVFjEAlm9lzboC1B9Zid 9ZLbsc3kvYqYo842UbXx/Q== X-Google-Smtp-Source: APXvYqx1dJ0r2iSXMYra3AlZwlu8Zbqznpy5N+nB7rSZIO7UI9EjExuicKpibuYD1oVXERf854aE9g== X-Received: by 2002:a17:902:b493:: with SMTP id y19mr2550527plr.9.1552632138661; Thu, 14 Mar 2019 23:42:18 -0700 (PDT) Received: from localhost.localdomain ([182.209.58.45]) by smtp.gmail.com with ESMTPSA id a4sm1418825pga.52.2019.03.14.23.42.17 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 14 Mar 2019 23:42:18 -0700 (PDT) From: "Daniel T. Lee" To: Daniel Borkmann , Alexei Starovoitov Cc: netdev@vger.kernel.org Subject: [PATCH 2/2] samples/bpf: add NULL check for ksym_search Date: Fri, 15 Mar 2019 15:42:10 +0900 Message-Id: <20190315064210.18735-2-danieltimlee@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190315064210.18735-1-danieltimlee@gmail.com> References: <20190315064210.18735-1-danieltimlee@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Since, ksym_search added with verification logic for symbols existence, it could return NULL when the kernel symbols are not loaded. This commit will add NULL check logic after ksym_search. Signed-off-by: Daniel T. Lee --- samples/bpf/offwaketime_user.c | 5 +++++ samples/bpf/sampleip_user.c | 5 +++++ samples/bpf/trace_event_user.c | 5 +++++ 3 files changed, 15 insertions(+) diff --git a/samples/bpf/offwaketime_user.c b/samples/bpf/offwaketime_user.c index f06063af9fcb..52e29467a509 100644 --- a/samples/bpf/offwaketime_user.c +++ b/samples/bpf/offwaketime_user.c @@ -28,6 +28,11 @@ static void print_ksym(__u64 addr) if (!addr) return; sym = ksym_search(addr); + if (!sym){ + printf("ksym not found. Is kallsyms loaded?\n"); + return; + } + if (PRINT_RAW_ADDR) printf("%s/%llx;", sym->name, addr); else diff --git a/samples/bpf/sampleip_user.c b/samples/bpf/sampleip_user.c index 216c7ecbbbe9..23b90a45c802 100644 --- a/samples/bpf/sampleip_user.c +++ b/samples/bpf/sampleip_user.c @@ -109,6 +109,11 @@ static void print_ip_map(int fd) for (i = 0; i < max; i++) { if (counts[i].ip > PAGE_OFFSET) { sym = ksym_search(counts[i].ip); + if (!sym) { + printf("ksym not found. Is kallsyms loaded?\n"); + continue; + } + printf("0x%-17llx %-32s %u\n", counts[i].ip, sym->name, counts[i].count); } else { diff --git a/samples/bpf/trace_event_user.c b/samples/bpf/trace_event_user.c index d08046ab81f0..bc8e6afdae6d 100644 --- a/samples/bpf/trace_event_user.c +++ b/samples/bpf/trace_event_user.c @@ -34,6 +34,11 @@ static void print_ksym(__u64 addr) if (!addr) return; sym = ksym_search(addr); + if (!sym){ + printf("ksym not found. Is kallsyms loaded?\n"); + return; + } + printf("%s;", sym->name); if (!strcmp(sym->name, "sys_read")) sys_read_seen = true; -- 2.17.1