From patchwork Tue Dec 20 06:39:23 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Leizhen (ThunderTown)" X-Patchwork-Id: 13077523 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 027CBC4332F for ; Tue, 20 Dec 2022 06:42:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230090AbiLTGmN (ORCPT ); Tue, 20 Dec 2022 01:42:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229571AbiLTGmM (ORCPT ); Tue, 20 Dec 2022 01:42:12 -0500 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95816633E; Mon, 19 Dec 2022 22:42:10 -0800 (PST) Received: from dggpemm500006.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4Nbn5j2SxqzRq0Y; Tue, 20 Dec 2022 14:40:57 +0800 (CST) Received: from thunder-town.china.huawei.com (10.174.178.55) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Tue, 20 Dec 2022 14:42:06 +0800 From: Zhen Lei To: Petr Mladek , , Luis Chamberlain , CC: Zhen Lei , Anders Roxell Subject: [PATCH] kallsyms: Fix sleeping function called from invalid context when CONFIG_KALLSYMS_SELFTEST=y Date: Tue, 20 Dec 2022 14:39:23 +0800 Message-ID: <20221220063923.1937-1-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.37.3.windows.1 MIME-Version: 1.0 X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected Precedence: bulk List-ID: [T58] BUG: sleeping function called from invalid context at kernel/kallsyms.c:305 [T58] in_atomic(): 0, irqs_disabled(): 128, non_block: 0, pid: 58, name: kallsyms_test [T58] preempt_count: 0, expected: 0 [T58] RCU nest depth: 0, expected: 0 [T58] no locks held by kallsyms_test/58. [T58] irq event stamp: 18899904 [T58] hardirqs last enabled at (18899903): finish_task_switch.isra.0 (core.c:?) [T58] hardirqs last disabled at (18899904): test_perf_kallsyms_on_each_symbol (kallsyms_selftest.c:?) [T58] softirqs last enabled at (18899886): __do_softirq (??:?) [T58] softirqs last disabled at (18899879): ____do_softirq (irq.c:?) [T58] CPU: 0 PID: 58 Comm: kallsyms_test Tainted: G T 6.1.0-next-20221215 #2 [T58] Hardware name: linux,dummy-virt (DT) [T58] Call trace: [T58] dump_backtrace (??:?) [T58] show_stack (??:?) [T58] dump_stack_lvl (??:?) [T58] dump_stack (??:?) [T58] __might_resched (??:?) [T58] kallsyms_on_each_symbol (??:?) [T58] test_perf_kallsyms_on_each_symbol (kallsyms_selftest.c:?) [T58] test_entry (kallsyms_selftest.c:?) [T58] kthread (kthread.c:?) [T58] ret_from_fork (??:?) [T58] kallsyms_selftest: kallsyms_on_each_symbol() traverse all: 5744310840 ns [T58] kallsyms_selftest: kallsyms_on_each_match_symbol() traverse all: 1164580 ns [T58] kallsyms_selftest: finish Functions kallsyms_on_each_symbol() and kallsyms_on_each_match_symbol() call the user-registered hook function for each symbol that meets the requirements. Because it is uncertain how long that hook function will execute, they call cond_resched() to avoid consuming CPU resources for a long time. However, irqs need to be disabled during the performance test to ensure the accuracy of test data. Because the performance test hook is very clear, very simple function, let's do not call cond_resched() when CONFIG_KALLSYMS_SELFTEST=y. Fixes: 30f3bb09778d ("kallsyms: Add self-test facility") Reported-by: Anders Roxell Signed-off-by: Zhen Lei --- kernel/kallsyms.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 83f499182c9aa31..a49e344a686517b 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -302,7 +302,8 @@ int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, ret = fn(data, namebuf, NULL, kallsyms_sym_address(i)); if (ret != 0) return ret; - cond_resched(); + if (!IS_ENABLED(CONFIG_KALLSYMS_SELFTEST)) + cond_resched(); } return 0; } @@ -319,7 +320,8 @@ int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long), for (i = start; !ret && i <= end; i++) { ret = fn(data, kallsyms_sym_address(get_symbol_seq(i))); - cond_resched(); + if (!IS_ENABLED(CONFIG_KALLSYMS_SELFTEST)) + cond_resched(); } return ret;