From patchwork Fri Oct 20 10:42:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Francis Laniel X-Patchwork-Id: 155977 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a05:612c:2010:b0:403:3b70:6f57 with SMTP id fe16csp962633vqb; Fri, 20 Oct 2023 03:43:28 -0700 (PDT) X-Google-Smtp-Source: AGHT+IG4dqesPuFT1xBMUbNYIe+Ma6qAesIkO5SSqskWrIbF2FSR0B0zdPW//DtXPMcFRMD0Fm+/ X-Received: by 2002:a17:90b:2b4d:b0:27d:9b7:cc7 with SMTP id rr13-20020a17090b2b4d00b0027d09b70cc7mr1384380pjb.24.1697798608050; Fri, 20 Oct 2023 03:43:28 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1697798608; cv=none; d=google.com; s=arc-20160816; b=qE+V975onVLKGAAQwRYARlqjhDv3tdFjNThkTzFvMFqierXciOwEBCYyZ3U778KsAE y78d6MgHknxOHPImhJ6DQ6ogzLc6WLjcuL4HF3XNlbw9jSvJ3qlZNfsFOk4WxtNvagBl l+rBzIGf4JV3eC9BCDH/7Lqj+bjbee9XiRlY4vRbSgQW/m06vA3H6nVIBsN7JT0miNCK RsyzZDAKTplmlJft33Ls5pXS4SC71vkg1RjGnwJkS9AhI/nkHTIIVgekQ8iwl5lu3c4A 8C99qFwT3MBhPi2BkpT9gW8RyjsVlQqqayeA9gdsA1fDgX5Kb3Skh2kpeSVkpmbTydkY 6//Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature:dkim-filter; bh=9VCxaeebanUQ/Qf2MXAfmGic0SqHTRKJ/14/HCr2fXM=; fh=eKzZdbva5vlPxC/2sk7ok5HTMakDSIbH6IugOtffm4M=; b=Wn0yLXqAQWY6Y4nrLXns3mwufJyfcYqLK4A7O/7MP4V7QWdw4wuFcKVV/U/FvumHfX GhoZVAm7zUeiChGUG0/Fw5+zMwzZCMrKc3dZhNp4tjES4rKfQRLoWSXLyifKvQZmEbQs CHhD3gK7zmeHWYHYyXHJd3PX1HkF72GNfUhvDlWpLpZdfFCP5l2E8xS9Lw0Sai0uCajl i47vAaXjD7Hq4/IkULJE+zrLyG8Im21t94VOUSl5myD1fT07o9fDQlVKK7vkXjepjnt1 aWu/8rfVj+qyl5pf2LAGrgeJbTKOiwziOVkROedbp/8sLPJM7An65KblrkoVkfIIWr7q Gnzw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linux.microsoft.com header.s=default header.b=dqkKKU5M; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:2 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linux.microsoft.com Received: from agentk.vger.email (agentk.vger.email. [2620:137:e000::3:2]) by mx.google.com with ESMTPS id ms19-20020a17090b235300b00274b23c2867si1604882pjb.58.2023.10.20.03.43.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 20 Oct 2023 03:43:28 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:2 as permitted sender) client-ip=2620:137:e000::3:2; Authentication-Results: mx.google.com; dkim=pass header.i=@linux.microsoft.com header.s=default header.b=dqkKKU5M; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:2 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linux.microsoft.com Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by agentk.vger.email (Postfix) with ESMTP id 36D6E82D2B6A; Fri, 20 Oct 2023 03:43:25 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at agentk.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1376910AbjJTKnT (ORCPT + 25 others); Fri, 20 Oct 2023 06:43:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49266 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376699AbjJTKnS (ORCPT ); Fri, 20 Oct 2023 06:43:18 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 5CD3C114; Fri, 20 Oct 2023 03:43:16 -0700 (PDT) Received: from pwmachine.numericable.fr (unknown [188.24.154.80]) by linux.microsoft.com (Postfix) with ESMTPSA id A88F020B74C1; Fri, 20 Oct 2023 03:43:13 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com A88F020B74C1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1697798595; bh=9VCxaeebanUQ/Qf2MXAfmGic0SqHTRKJ/14/HCr2fXM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dqkKKU5MpbDhpDEo8R7b8r+QLcxwpUm9Sne3TIlfIMKTHnvCpTFFbRWvp0iqUik4d 74Rs/+3i7npIqE7Jz7mSvHSCfD8UV0FtB/pUE+nJsWHmvX0RhA2Hy0Wfps+ukYsnSU Xs6FJuuAPh/empUA36bf1/L7t96s5VhlQMtAtFMw= From: Francis Laniel To: linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Francis Laniel , stable@vger.kernel.org, Steven Rostedt , Ananth N Mavinakayanahalli , Frederic Weisbecker , linux-kernel@vger.kernel.org Subject: [PATCH v6 1/2] tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols Date: Fri, 20 Oct 2023 13:42:49 +0300 Message-Id: <20231020104250.9537-2-flaniel@linux.microsoft.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231020104250.9537-1-flaniel@linux.microsoft.com> References: <20231020104250.9537-1-flaniel@linux.microsoft.com> MIME-Version: 1.0 X-Spam-Status: No, score=-8.3 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on agentk.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (agentk.vger.email [0.0.0.0]); Fri, 20 Oct 2023 03:43:25 -0700 (PDT) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1780270873571411104 X-GMAIL-MSGID: 1780270873571411104 When a kprobe is attached to a function that's name is not unique (is static and shares the name with other functions in the kernel), the kprobe is attached to the first function it finds. This is a bug as the function that it is attaching to is not necessarily the one that the user wants to attach to. Instead of blindly picking a function to attach to what is ambiguous, error with EADDRNOTAVAIL to let the user know that this function is not unique, and that the user must use another unique function with an address offset to get to the function they want to attach to. Cc: stable@vger.kernel.org Fixes: 413d37d1eb69 ("tracing: Add kprobe-based event tracer") Suggested-by: Masami Hiramatsu Signed-off-by: Francis Laniel Link: https://lore.kernel.org/lkml/20230819101105.b0c104ae4494a7d1f2eea742@kernel.org/ --- kernel/trace/trace_kprobe.c | 63 +++++++++++++++++++++++++++++++++++++ kernel/trace/trace_probe.h | 1 + 2 files changed, 64 insertions(+) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 3d7a180a8427..a8fef6ab0872 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -705,6 +705,25 @@ static struct notifier_block trace_kprobe_module_nb = { .priority = 1 /* Invoked after kprobe module callback */ }; +static int count_symbols(void *data, unsigned long unused) +{ + unsigned int *count = data; + + (*count)++; + + return 0; +} + +static unsigned int number_of_same_symbols(char *func_name) +{ + unsigned int count; + + count = 0; + kallsyms_on_each_match_symbol(count_symbols, func_name, &count); + + return count; +} + static int __trace_kprobe_create(int argc, const char *argv[]) { /* @@ -836,6 +855,31 @@ static int __trace_kprobe_create(int argc, const char *argv[]) } } + if (symbol && !strchr(symbol, ':')) { + unsigned int count; + + count = number_of_same_symbols(symbol); + if (count > 1) { + /* + * Users should use ADDR to remove the ambiguity of + * using KSYM only. + */ + trace_probe_log_err(0, NON_UNIQ_SYMBOL); + ret = -EADDRNOTAVAIL; + + goto error; + } else if (count == 0) { + /* + * We can return ENOENT earlier than when register the + * kprobe. + */ + trace_probe_log_err(0, BAD_PROBE_ADDR); + ret = -ENOENT; + + goto error; + } + } + trace_probe_log_set_index(0); if (event) { ret = traceprobe_parse_event_name(&event, &group, gbuf, @@ -1695,6 +1739,7 @@ static int unregister_kprobe_event(struct trace_kprobe *tk) } #ifdef CONFIG_PERF_EVENTS + /* create a trace_kprobe, but don't add it to global lists */ struct trace_event_call * create_local_trace_kprobe(char *func, void *addr, unsigned long offs, @@ -1705,6 +1750,24 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs, int ret; char *event; + if (func) { + unsigned int count; + + count = number_of_same_symbols(func); + if (count > 1) + /* + * Users should use addr to remove the ambiguity of + * using func only. + */ + return ERR_PTR(-EADDRNOTAVAIL); + else if (count == 0) + /* + * We can return ENOENT earlier than when register the + * kprobe. + */ + return ERR_PTR(-ENOENT); + } + /* * local trace_kprobes are not added to dyn_event, so they are never * searched in find_trace_kprobe(). Therefore, there is no concern of diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 02b432ae7513..850d9ecb6765 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -450,6 +450,7 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call, C(BAD_MAXACT, "Invalid maxactive number"), \ C(MAXACT_TOO_BIG, "Maxactive is too big"), \ C(BAD_PROBE_ADDR, "Invalid probed address or symbol"), \ + C(NON_UNIQ_SYMBOL, "The symbol is not unique"), \ C(BAD_RETPROBE, "Retprobe address must be an function entry"), \ C(NO_TRACEPOINT, "Tracepoint is not found"), \ C(BAD_ADDR_SUFFIX, "Invalid probed address suffix"), \ From patchwork Fri Oct 20 10:42:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Francis Laniel X-Patchwork-Id: 155978 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a05:612c:2010:b0:403:3b70:6f57 with SMTP id fe16csp962726vqb; Fri, 20 Oct 2023 03:43:39 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHdpfm6k3wYxzuS416kfE5jGaRqVs/G94sLUibTeadiw3MuHSFEHItrL7aYYUfLwU3YKRCi X-Received: by 2002:a05:6a20:4305:b0:159:f884:4d72 with SMTP id h5-20020a056a20430500b00159f8844d72mr1512417pzk.42.1697798618708; Fri, 20 Oct 2023 03:43:38 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1697798618; cv=none; d=google.com; s=arc-20160816; b=p1MskMaze1aWWdwRw8sQixrOXu0WHE+9oRKmWaAWzxrEZqvdVTqkHvy04fyvWtipDu 8aArE3pIYlEzxxkVqXjrVhL31lFMUOcWekp23rub5TWO5q+23ZQfYLv6PIn4LkHRfETX fH6oOvDImMPCorRb1G68kfMF8qmEjEkuZOQpe5MuxWM2xpo2GPHGPkU1oP8aHE9F8sjb 4J869fhjMQKiTGe9NDe2N5y0i18oR2u1/yGRJTHZ5UhsPKx+YkKp61pWpD3cxgSSJAp1 /iAiMo94zY2cvRnPGodJ7FxVdT2RsHEZN8youSl1FuuxyXwMPSjbgmcsHJCRelvCFakb o88w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature:dkim-filter; bh=jHEMFSWvEcx1czRBXUE2OS96KE3ALvaIroFuMgx4g8g=; fh=hKV3imhyLdLg/YPlbhw3l8jGKba1w7M7ni3k4xpQwNE=; b=GqBXSOXnhrxLMI1Rs5TAF1gWwoT7p2K4XO29CjRGEWgII5byVgq2l3h7HHkp38Dcx1 68JMiaKCPqjqgWcYyVZjz4i2w+TRsjgTlkznRc7AsmJr6/parUdrCrFVBFsAvFIH1Mqo m089j2I3Bqe3uP6dNun/yjRVtaG5kTlPpddayw6R3GeFkDOKL9ym+rbkBtaF7Gjuhfuj skqP4efnmgh7LC/BToDMm+xFLYW7L76i3IHSeBAqYmSGbulDnxSNUQtjvqZS0ETrDnwF mL5rWxIiwAsurjRKVPwjdLkYdfDJTMhVuAk9IB2pwdf77X9M57Sm3tUWkFEY9+eTdQS0 Z/Yg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linux.microsoft.com header.s=default header.b=G4ZwyRGD; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.33 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linux.microsoft.com Received: from lipwig.vger.email (lipwig.vger.email. [23.128.96.33]) by mx.google.com with ESMTPS id d38-20020a631d66000000b00578b37ad24bsi1544774pgm.619.2023.10.20.03.43.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 20 Oct 2023 03:43:38 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.33 as permitted sender) client-ip=23.128.96.33; Authentication-Results: mx.google.com; dkim=pass header.i=@linux.microsoft.com header.s=default header.b=G4ZwyRGD; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.33 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linux.microsoft.com Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by lipwig.vger.email (Postfix) with ESMTP id E213C82A3F50; Fri, 20 Oct 2023 03:43:36 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at lipwig.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1376972AbjJTKnZ (ORCPT + 25 others); Fri, 20 Oct 2023 06:43:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49300 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376699AbjJTKnX (ORCPT ); Fri, 20 Oct 2023 06:43:23 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 5F82EA4; Fri, 20 Oct 2023 03:43:22 -0700 (PDT) Received: from pwmachine.numericable.fr (unknown [188.24.154.80]) by linux.microsoft.com (Postfix) with ESMTPSA id CB9AA20B74C0; Fri, 20 Oct 2023 03:43:19 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com CB9AA20B74C0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1697798601; bh=jHEMFSWvEcx1czRBXUE2OS96KE3ALvaIroFuMgx4g8g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=G4ZwyRGDZ8VV6xRFRRI5YT2sOs4vbJ9C1Ls7T6m8Ll4k+alQa91Ymp65cGpTEHlvM fivLgH/sEdRBx51wFJ5cBYSAa87N3p4rUHYZl3JyELXjwSm+WgCsYP86XHT7wto0Fe 1f9HbJFCI1NfES2mnL2pq6X2moTAjGc68KWZk4qQ= From: Francis Laniel To: linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Francis Laniel , stable@vger.kernel.org, Steven Rostedt , Shuah Khan , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH v6 2/2] selftests/ftrace: Add new test case which checks non unique symbol Date: Fri, 20 Oct 2023 13:42:50 +0300 Message-Id: <20231020104250.9537-3-flaniel@linux.microsoft.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231020104250.9537-1-flaniel@linux.microsoft.com> References: <20231020104250.9537-1-flaniel@linux.microsoft.com> MIME-Version: 1.0 X-Spam-Status: No, score=-8.3 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lipwig.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (lipwig.vger.email [0.0.0.0]); Fri, 20 Oct 2023 03:43:36 -0700 (PDT) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1780270884700320351 X-GMAIL-MSGID: 1780270884700320351 If name_show() is non unique, this test will try to install a kprobe on this function which should fail returning EADDRNOTAVAIL. On kernel where name_show() is not unique, this test is skipped. Cc: stable@vger.kernel.org Signed-off-by: Francis Laniel --- .../ftrace/test.d/kprobe/kprobe_non_uniq_symbol.tc | 13 +++++++++++++ 1 file changed, 13 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_non_uniq_symbol.tc diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_non_uniq_symbol.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_non_uniq_symbol.tc new file mode 100644 index 000000000000..bc9514428dba --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_non_uniq_symbol.tc @@ -0,0 +1,13 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Test failure of registering kprobe on non unique symbol +# requires: kprobe_events + +SYMBOL='name_show' + +# We skip this test on kernel where SYMBOL is unique or does not exist. +if [ "$(grep -c -E "[[:alnum:]]+ t ${SYMBOL}" /proc/kallsyms)" -le '1' ]; then + exit_unsupported +fi + +! echo "p:test_non_unique ${SYMBOL}" > kprobe_events