From patchwork Fri Apr 12 03:16:33 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Scott Wood X-Patchwork-Id: 10897157 X-Patchwork-Delegate: atull@kernel.org 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 CD5B517E6 for ; Fri, 12 Apr 2019 03:16:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ABA7428ADD for ; Fri, 12 Apr 2019 03:16:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9E56228DD1; Fri, 12 Apr 2019 03:16:36 +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=-7.9 required=2.0 tests=BAYES_00,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 0DF0C28ADD for ; Fri, 12 Apr 2019 03:16:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726682AbfDLDQf (ORCPT ); Thu, 11 Apr 2019 23:16:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37900 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726640AbfDLDQf (ORCPT ); Thu, 11 Apr 2019 23:16:35 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E35FA3082128; Fri, 12 Apr 2019 03:16:34 +0000 (UTC) Received: from t460p.redhat.com (ovpn-118-18.phx2.redhat.com [10.3.118.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4845C19C7E; Fri, 12 Apr 2019 03:16:34 +0000 (UTC) From: Scott Wood To: Alan Tull , Moritz Fischer Cc: linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org, Wu Hao , Scott Wood Subject: [PATCH v2] fpga: dfl: Add lockdep classes for pdata->lock Date: Thu, 11 Apr 2019 22:16:33 -0500 Message-Id: <20190412031633.9100-1-swood@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Fri, 12 Apr 2019 03:16:34 +0000 (UTC) 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 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 --- v2: Removed incorrect "static" from a local variable 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..56dd39dcdcdf 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