From patchwork Thu May 9 21:08:28 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alan Tull X-Patchwork-Id: 10937739 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DD2A81390 for ; Thu, 9 May 2019 21:08:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CE53328813 for ; Thu, 9 May 2019 21:08:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C26F328B05; Thu, 9 May 2019 21:08:55 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1EB3A28813 for ; Thu, 9 May 2019 21:08:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727150AbfEIVIr (ORCPT ); Thu, 9 May 2019 17:08:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:43620 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727099AbfEIVIj (ORCPT ); Thu, 9 May 2019 17:08:39 -0400 Received: from localhost.localdomain (user-0ccsrjt.cable.mindspring.com [24.206.110.125]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 222B421851; Thu, 9 May 2019 21:08:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557436117; bh=FumUuo4wYXFTqF7bJmQ9ad+dmc/xsN8zJk7dDGd2wRc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Vrny1cfZVV/7LmT4SJ1ozMbUMRSPp3+tMAH+36YVVZPzeIezsKuubA6C+2gjH3BjO Su55TGZm7sNV6Xga5n6s39ZcfT7JyhwDXjU3DjXegg+BxwL3BcMAidOpzxUrcXSTnn s+I4z84V4jXEEd+VuT/s4j6bpT25x4tlP2nJJSd0= From: Alan Tull To: Greg Kroah-Hartman Cc: Moritz Fischer , Alan Tull , linux-kernel@vger.kernel.org, linux-fpga@vger.kernel.org, Scott Wood , Wu Hao Subject: [PATCH 3/4] fpga: dfl: Add lockdep classes for pdata->lock Date: Thu, 9 May 2019 16:08:28 -0500 Message-Id: <20190509210829.31815-4-atull@kernel.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190509210829.31815-1-atull@kernel.org> References: <20190509210829.31815-1-atull@kernel.org> MIME-Version: 1.0 Sender: linux-fpga-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fpga@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Scott Wood struct dfl_feature_platform_data (and it's mutex) is used by both fme and port devices, and when lockdep is enabled it complains about nesting between these locks. Tell lockdep about the difference so it can track each class separately. Here's the lockdep complaint: [ 409.680668] WARNING: possible recursive locking detected [ 409.685983] 5.1.0-rc3.fpga+ #1 Tainted: G E [ 409.691469] -------------------------------------------- [ 409.696779] fpgaconf/9348 is trying to acquire lock: [ 409.701746] 00000000a443fe2e (&pdata->lock){+.+.}, at: port_enable_set+0x24/0x60 [dfl_afu] [ 409.710006] [ 409.710006] but task is already holding lock: [ 409.715837] 0000000063b78782 (&pdata->lock){+.+.}, at: fme_pr_ioctl+0x21d/0x330 [dfl_fme] [ 409.724012] [ 409.724012] other info that might help us debug this: [ 409.730535] Possible unsafe locking scenario: [ 409.730535] [ 409.736457] CPU0 [ 409.738910] ---- [ 409.741360] lock(&pdata->lock); [ 409.744679] lock(&pdata->lock); [ 409.747999] [ 409.747999] *** DEADLOCK *** [ 409.747999] [ 409.753920] May be due to missing lock nesting notation [ 409.753920] [ 409.760704] 4 locks held by fpgaconf/9348: [ 409.764805] #0: 0000000063b78782 (&pdata->lock){+.+.}, at: fme_pr_ioctl+0x21d/0x330 [dfl_fme] [ 409.773408] #1: 00000000213c8a66 (®ion->mutex){+.+.}, at: fpga_region_program_fpga+0x24/0x200 [fpga_region] [ 409.783489] #2: 00000000fe63afb9 (&mgr->ref_mutex){+.+.}, at: fpga_mgr_lock+0x15/0x40 [fpga_mgr] [ 409.792354] #3: 000000000b2285c5 (&bridge->mutex){+.+.}, at: __fpga_bridge_get+0x26/0xa0 [fpga_bridge] [ 409.801740] [ 409.801740] stack backtrace: [ 409.806102] CPU: 45 PID: 9348 Comm: fpgaconf Kdump: loaded Tainted: G E 5.1.0-rc3.fpga+ #1 [ 409.815658] Hardware name: Intel Corporation S2600BT/S2600BT, BIOS SE5C620.86B.01.00.0763.022420181017 02/24/2018 [ 409.825911] Call Trace: [ 409.828369] dump_stack+0x5e/0x8b [ 409.831686] __lock_acquire+0xf3d/0x10e0 [ 409.835612] ? find_held_lock+0x3c/0xa0 [ 409.839451] lock_acquire+0xbc/0x1d0 [ 409.843030] ? port_enable_set+0x24/0x60 [dfl_afu] [ 409.847823] ? port_enable_set+0x24/0x60 [dfl_afu] [ 409.852616] __mutex_lock+0x86/0x970 [ 409.856195] ? port_enable_set+0x24/0x60 [dfl_afu] [ 409.860989] ? port_enable_set+0x24/0x60 [dfl_afu] [ 409.865777] ? __mutex_unlock_slowpath+0x4b/0x290 [ 409.870486] port_enable_set+0x24/0x60 [dfl_afu] [ 409.875106] fpga_bridges_disable+0x36/0x50 [fpga_bridge] [ 409.880502] fpga_region_program_fpga+0xea/0x200 [fpga_region] [ 409.886338] fme_pr_ioctl+0x13e/0x330 [dfl_fme] [ 409.890870] fme_ioctl+0x66/0xe0 [dfl_fme] [ 409.894973] do_vfs_ioctl+0xa9/0x720 [ 409.898548] ? lockdep_hardirqs_on+0xf0/0x1a0 [ 409.902907] ksys_ioctl+0x60/0x90 [ 409.906225] __x64_sys_ioctl+0x16/0x20 [ 409.909981] do_syscall_64+0x5a/0x220 [ 409.913644] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 409.918698] RIP: 0033:0x7f9d31b9b8d7 [ 409.922276] Code: 44 00 00 48 8b 05 b9 15 2d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 89 15 2d 00 f7 d8 64 89 01 48 [ 409.941020] RSP: 002b:00007ffe4cae0d68 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 409.948588] RAX: ffffffffffffffda RBX: 00007f9d32ade6a0 RCX: 00007f9d31b9b8d7 [ 409.955719] RDX: 00007ffe4cae0df0 RSI: 000000000000b680 RDI: 0000000000000003 [ 409.962852] RBP: 0000000000000003 R08: 00007f9d2b70a177 R09: 00007ffe4cae0e40 [ 409.969984] R10: 00007ffe4cae0160 R11: 0000000000000202 R12: 00007ffe4cae0df0 [ 409.977115] R13: 000000000000b680 R14: 0000000000000000 R15: 00007ffe4cae0f60 Signed-off-by: Scott Wood Acked-by: Wu Hao Acked-by: Alan Tull --- drivers/fpga/dfl.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c index 2c09e502e721..c25217cde5ca 100644 --- a/drivers/fpga/dfl.c +++ b/drivers/fpga/dfl.c @@ -40,6 +40,13 @@ enum dfl_fpga_devt_type { DFL_FPGA_DEVT_MAX, }; +static struct lock_class_key dfl_pdata_keys[DFL_ID_MAX]; + +static const char *dfl_pdata_key_strings[DFL_ID_MAX] = { + "dfl-fme-pdata", + "dfl-port-pdata", +}; + /** * dfl_dev_info - dfl feature device information. * @name: name string of the feature platform device. @@ -443,11 +450,16 @@ static int build_info_commit_dev(struct build_feature_devs_info *binfo) struct platform_device *fdev = binfo->feature_dev; struct dfl_feature_platform_data *pdata; struct dfl_feature_info *finfo, *p; + enum dfl_id_type type; int ret, index = 0; if (!fdev) return 0; + type = feature_dev_id_type(fdev); + if (WARN_ON_ONCE(type >= DFL_ID_MAX)) + return -EINVAL; + /* * we do not need to care for the memory which is associated with * the platform device. After calling platform_device_unregister(), @@ -463,6 +475,8 @@ static int build_info_commit_dev(struct build_feature_devs_info *binfo) pdata->num = binfo->feature_num; pdata->dfl_cdev = binfo->cdev; mutex_init(&pdata->lock); + lockdep_set_class_and_name(&pdata->lock, &dfl_pdata_keys[type], + dfl_pdata_key_strings[type]); /* * the count should be initialized to 0 to make sure @@ -497,7 +511,7 @@ static int build_info_commit_dev(struct build_feature_devs_info *binfo) ret = platform_device_add(binfo->feature_dev); if (!ret) { - if (feature_dev_id_type(binfo->feature_dev) == PORT_ID) + if (type == PORT_ID) dfl_fpga_cdev_add_port_dev(binfo->cdev, binfo->feature_dev); else