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 Received: from picard.linux.it (picard.linux.it [213.254.12.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5AD20C64ED6 for ; Tue, 28 Feb 2023 10:17:08 +0000 (UTC) Received: from picard.linux.it (localhost [IPv6:::1]) by picard.linux.it (Postfix) with ESMTP id 18D3F3CCE34 for ; Tue, 28 Feb 2023 11:17:06 +0100 (CET) Received: from in-4.smtp.seeweb.it (in-4.smtp.seeweb.it [217.194.8.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384)) (No client certificate requested) by picard.linux.it (Postfix) with ESMTPS id 8B2D53CBA10 for ; Tue, 28 Feb 2023 11:16:55 +0100 (CET) Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by in-4.smtp.seeweb.it (Postfix) with ESMTPS id 621D910005E3 for ; Tue, 28 Feb 2023 11:16:54 +0100 (CET) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 9B5141FDC1; Tue, 28 Feb 2023 10:16:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1677579413; h=from:from:reply-to:reply-to:date:date:message-id:message-id:to:to: cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=LWTw47escqF1YwJ9bNbBTmUbmoCliVCHNgr7viMBPSc=; b=EFIvH8NGzGPw/flVyo+a2iH6GxkQ4P4Xan+q9e9oHarDnOxBy/aQVn/nq7kOzggd9Ad6gm sfEpMCAsSm2oQ6hJjoLhwmwGhLxFaqwl7kxzyGn65hS+3FXpDpTWD7xQXcSfzzulmYxPWM Pq6h14FPZS5bOP6QiB18hpDDtif6uUg= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1677579413; h=from:from:reply-to:reply-to:date:date:message-id:message-id:to:to: cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=LWTw47escqF1YwJ9bNbBTmUbmoCliVCHNgr7viMBPSc=; b=MTQXUQEU/TjFFzTvftHHoDNSfzOpjLmTicj/bt6DClmUlVrd3wkCUjVma9WispQKBHldQG Ai4nACVjuNCFsMBQ== Received: from g78 (unknown [10.163.28.198]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 6CBBF2C141; Tue, 28 Feb 2023 10:16:53 +0000 (UTC) References: <20230215055727.20793-1-xiaoshoukui@gmail.com> User-agent: mu4e 1.8.13; emacs 28.2 From: Richard Palethorpe To: xiaoshoukui Date: Tue, 28 Feb 2023 10:06:54 +0000 Organization: Linux Private Site In-reply-to: <20230215055727.20793-1-xiaoshoukui@gmail.com> Message-ID: <875ybmumb0.fsf@suse.de> MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.102.4 at in-4.smtp.seeweb.it X-Virus-Status: Clean Subject: Re: [LTP] [PATCH v2] Add ioctl_loop08 test for LOOP_GET_STATUS lock imbalance X-BeenThere: ltp@lists.linux.it X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Test Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: rpalethorpe@suse.de Cc: ltp@lists.linux.it Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ltp-bounces+ltp=archiver.kernel.org@lists.linux.it Sender: "ltp" Hello, xiaoshoukui writes: > --- > .../kernel/syscalls/ioctl/ioctl_loop08.c | 147 ++++++++++++++++++ > 1 file changed, 147 insertions(+) > create mode 100644 testcases/kernel/syscalls/ioctl/ioctl_loop08.c > > diff --git a/testcases/kernel/syscalls/ioctl/ioctl_loop08.c b/testcases/kernel/syscalls/ioctl/ioctl_loop08.c > new file mode 100644 > index 000000000..047273576 > --- /dev/null > +++ b/testcases/kernel/syscalls/ioctl/ioctl_loop08.c > @@ -0,0 +1,147 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Copyright (c) 2022 xiaoshoukui > + */ > + > +/*\ > + * [Description] > + * > + * This is a basic ioctl test about loopdevice LOOP_GET_STATUS > + * and LOOP_GET_STATUS64. > + * Commit 2d1d4c1e591f made loop_get_status() drop lo_ctx_mutex before > + * returning, but the loop_get_status_old(), loop_get_status64(), and > + * loop_get_status_compat() wrappers don't call loop_get_status() if the > + * passed argument is NULL. The callers expect that the lock is dropped, so > + * make sure we drop it in that case, too. > + * > + * Fixed by commit: > + * > + * commit bdac616db9bbadb90b7d6a406144571015e138f7 > + * Author: Omar Sandoval > + * Date: Fri Apr 06 09:57:03 2018 -0700 > + * > + * loop: fix LOOP_GET_STATUS lock imbalance > + */ > + > +#include > +#include > +#include > +#include > +#include "lapi/loop.h" > +#include "tst_test.h" > + > +#define MAX_MSGSIZE 4096 > + > +static const char lock_imbalance[] = "lock held when returning to user space"; > + > +static struct tcase { > + int ioctl_flag; > + char *message; > +} tcases[] = { > + { LOOP_GET_STATUS, > + "Testing LOOP_GET_STATUS lock imbalance" }, > + > + { LOOP_GET_STATUS64, > + "Testing LOOP_GET_STATUS64 lock imbalance" }, > +}; > + > +static int find_kmsg(const char *text_to_find) > +{ > + int f, msg_found = 0; > + char msg[MAX_MSGSIZE + 1]; > + > + f = SAFE_OPEN("/dev/kmsg", O_RDONLY | O_NONBLOCK); > + > + while (1) { > + TEST(read(f, msg, MAX_MSGSIZE)); > + if (TST_RET < 0) { > + if (TST_ERR == EAGAIN) > + /* there are no more messages */ > + break; > + else if (TST_ERR == EPIPE) > + /* current message was overwritten */ > + continue; > + else > + tst_brk(TBROK | TTERRNO, > + "err reading /dev/kmsg"); > + } else { > + /* lines from kmsg are not NULL terminated */ > + msg[TST_RET] = '\0'; > + if (strstr(msg, text_to_find) != NULL) { > + msg_found = 1; > + break; > + } > + } > + } > + SAFE_CLOSE(f); > + > + if (msg_found) > + return 0; > + else > + return -1; > +} > + > +static void do_child(void) > +{ > + char dev_path[1024]; > + int dev_num, dev_fd; > + unsigned int i; > + > + for (i = 0; i < ARRAY_SIZE(tcases); i++) { > + tst_res(TINFO, "%s", tcases[i].message); > + dev_num = tst_find_free_loopdev(dev_path, sizeof(dev_path)); > + > + if (dev_num < 0) > + tst_brk(TBROK, "Failed to find free loop device"); > + > + dev_fd = SAFE_OPEN(dev_path, O_RDWR); > + > + if (tcases[i].ioctl_flag == LOOP_GET_STATUS) > + ioctl(dev_fd, LOOP_GET_STATUS, NULL); > + else > + ioctl(dev_fd, LOOP_GET_STATUS64, NULL); > + > + if (dev_fd > 0) > + SAFE_CLOSE(dev_fd); > + > + } > + > + exit(0); > + > +} > + > +static void verify_ioctl_loop(void) > +{ > + int ret, pid; > + > + pid = SAFE_FORK(); > + if (!pid) > + do_child(); > + > + ret = TST_PROCESS_STATE_WAIT(pid, 'D', 5000); > + > + if (!ret && !find_kmsg(lock_imbalance)) > + tst_res(TFAIL, "Trigger ioctl loop lock imbalance"); > + else > + tst_res(TPASS, "Nothing bad happened, probably"); > + > +} > + > +static struct tst_test test = { > + .test_all = verify_ioctl_loop, > + .needs_root = 1, > + .needs_kconfigs = (const char *[]) { > + "CONFIG_LOCKDEP=y", We don't want to rely on a debugging feature unless necessary. Often testing is done on production kernels. If the test is run on a buggy kernel without lockdep then might we get a deadlock? So I think it would be best to run the test, but skip the kmsg check if lockdep is not enabled (using tst_kconfig_get). > + NULL > + }, > + .tags = (const struct tst_tag[]) { > + {"linux-git", "bdac616db9bb "}, > + {} > + }, > + .needs_drivers = (const char *const[]) { > + "loop", > + NULL > + }, > + .forks_child = 1, > + .timeout = 60, > +}; > -- > 2.20.1 -- Thank you, Richard. -- Mailing list info: https://lists.linux.it/listinfo/ltp