From patchwork Thu Feb 2 22:28:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brian King X-Patchwork-Id: 649940 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 E236DC61DA4 for ; Thu, 2 Feb 2023 22:29:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232908AbjBBW2q (ORCPT ); Thu, 2 Feb 2023 17:28:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232866AbjBBW22 (ORCPT ); Thu, 2 Feb 2023 17:28:28 -0500 Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1914A1EBD3 for ; Thu, 2 Feb 2023 14:28:26 -0800 (PST) Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 312Lfxil015159; Thu, 2 Feb 2023 22:28:22 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=JMLDYZJGOfsxpi3oilVM4Bp0wb4SQR9TLpUeJcrDszQ=; b=tZs9vPN+gPAbYtx27ZthPPJ5XqIRBR6um1BN8OipO46eKJkNgE91O3qZ8in3Fo756RUf rIMKbRrW8mHy9ZwlU92Yh/bR+ANEaoCREOOEXr6aKIsg/dX/6VT1hSkju6yV2i3kaax1 VpipO/+PQeMLmvhlK/G/INSTp0qZa34AYXRzW0xwfiWWqZI1PdBgoK4WfAAvlFwaU617 WTOvXEzQnqNqNI425+DNvcDVNZDa6F6QCTXP+UhyGVY8IkwJEd+f3mVQfEXesY9dyDmz euKp85/1OJo6t42CKIjCDz6QjGVmO9ppL3F34id7c+I49hVSOm/KOAenCeSyfKjdNnYA Ug== Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com (PPS) with ESMTPS id 3ngmy41ars-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 02 Feb 2023 22:28:22 +0000 Received: from m0098416.ppops.net (m0098416.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 312MIbXb001502; Thu, 2 Feb 2023 22:28:21 GMT Received: from ppma05wdc.us.ibm.com (1b.90.2fa9.ip4.static.sl-reverse.com [169.47.144.27]) by mx0b-001b2d01.pphosted.com (PPS) with ESMTPS id 3ngmy41arb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 02 Feb 2023 22:28:21 +0000 Received: from pps.filterd (ppma05wdc.us.ibm.com [127.0.0.1]) by ppma05wdc.us.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 312Ie0rO012329; Thu, 2 Feb 2023 22:28:21 GMT Received: from smtprelay04.dal12v.mail.ibm.com ([9.208.130.102]) by ppma05wdc.us.ibm.com (PPS) with ESMTPS id 3ncvvdwqus-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 02 Feb 2023 22:28:21 +0000 Received: from smtpav01.wdc07v.mail.ibm.com (smtpav01.wdc07v.mail.ibm.com [10.39.53.228]) by smtprelay04.dal12v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 312MSKjf4850368 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 2 Feb 2023 22:28:20 GMT Received: from smtpav01.wdc07v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id F1FBD58063; Thu, 2 Feb 2023 22:28:19 +0000 (GMT) Received: from smtpav01.wdc07v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 446A758059; Thu, 2 Feb 2023 22:28:19 +0000 (GMT) Received: from li-6bf4d4cc-31f5-11b2-a85c-838e9310af65.ibm.com.com (unknown [9.211.158.218]) by smtpav01.wdc07v.mail.ibm.com (Postfix) with ESMTP; Thu, 2 Feb 2023 22:28:19 +0000 (GMT) From: Brian King To: gregkh@linuxfoundation.org Cc: linuxppc-dev@lists.ozlabs.org, brking@pobox.com, mmc@linux.vnet.ibm.com, linux-serial@vger.kernel.org, Brian King Subject: [PATCH v2 6/6] hvcs: Synchronize hotplug remove with port free Date: Thu, 2 Feb 2023 16:28:04 -0600 Message-Id: <20230202222804.383229-7-brking@linux.vnet.ibm.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20230202222804.383229-1-brking@linux.vnet.ibm.com> References: <20230202222804.383229-1-brking@linux.vnet.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: oIlUNwsazyijjNosx2ldOIl886jdG4On X-Proofpoint-GUID: FcaJBeLK3YKY1y4fA48L7eKmrfD3Bs31 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.930,Hydra:6.0.562,FMLib:17.11.122.1 definitions=2023-02-02_14,2023-02-02_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 adultscore=0 mlxscore=0 malwarescore=0 clxscore=1015 phishscore=0 bulkscore=0 mlxlogscore=999 lowpriorityscore=0 impostorscore=0 suspectscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2302020196 Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Synchronizes hotplug remove with the freeing of the port. This ensures we have freed all the memory associated with this port and are not leaking memory. Signed-off-by: Brian King --- drivers/tty/hvc/hvcs.c | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c index 2e9e45f06916..c360965e9c1b 100644 --- a/drivers/tty/hvc/hvcs.c +++ b/drivers/tty/hvc/hvcs.c @@ -52,6 +52,7 @@ #include #include +#include #include #include #include @@ -285,6 +286,7 @@ struct hvcs_struct { char p_location_code[HVCS_CLC_LENGTH + 1]; /* CLC + Null Term */ struct list_head next; /* list management */ struct vio_dev *vdev; + struct completion *destroyed; }; static LIST_HEAD(hvcs_structs); @@ -677,11 +679,13 @@ static void hvcs_destruct_port(struct tty_port *p) { struct hvcs_struct *hvcsd = container_of(p, struct hvcs_struct, port); struct vio_dev *vdev; + struct completion *comp; unsigned long flags; spin_lock(&hvcs_structs_lock); spin_lock_irqsave(&hvcsd->lock, flags); + comp = hvcsd->destroyed; /* the list_del poisons the pointers */ list_del(&(hvcsd->next)); @@ -701,6 +705,7 @@ static void hvcs_destruct_port(struct tty_port *p) hvcsd->p_unit_address = 0; hvcsd->p_partition_ID = 0; + hvcsd->destroyed = NULL; hvcs_return_index(hvcsd->index); memset(&hvcsd->p_location_code[0], 0x00, HVCS_CLC_LENGTH + 1); @@ -708,6 +713,8 @@ static void hvcs_destruct_port(struct tty_port *p) spin_unlock(&hvcs_structs_lock); kfree(hvcsd); + if (comp) + complete(comp); } static const struct tty_port_operations hvcs_port_ops = { @@ -806,6 +813,7 @@ static int hvcs_probe( static void hvcs_remove(struct vio_dev *dev) { struct hvcs_struct *hvcsd = dev_get_drvdata(&dev->dev); + DECLARE_COMPLETION_ONSTACK(comp); unsigned long flags; struct tty_struct *tty; @@ -813,16 +821,11 @@ static void hvcs_remove(struct vio_dev *dev) spin_lock_irqsave(&hvcsd->lock, flags); + hvcsd->destroyed = ∁ tty = tty_port_tty_get(&hvcsd->port); spin_unlock_irqrestore(&hvcsd->lock, flags); - /* - * Let the last holder of this object cause it to be removed, which - * would probably be tty_hangup below. - */ - tty_port_put(&hvcsd->port); - /* * The tty should always be valid at this time unless a * simultaneous tty close already cleaned up the hvcs_struct. @@ -832,6 +835,8 @@ static void hvcs_remove(struct vio_dev *dev) tty_kref_put(tty); } + tty_port_put(&hvcsd->port); + wait_for_completion(&comp); printk(KERN_INFO "HVCS: vty-server@%X removed from the" " vio bus.\n", dev->unit_address); }; @@ -1185,7 +1190,10 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp) hvcsd = tty->driver_data; spin_lock_irqsave(&hvcsd->lock, flags); - if (--hvcsd->port.count == 0) { + if (hvcsd->port.count == 0) { + spin_unlock_irqrestore(&hvcsd->lock, flags); + return; + } else if (--hvcsd->port.count == 0) { vio_disable_interrupts(hvcsd->vdev); @@ -1241,11 +1249,7 @@ static void hvcs_hangup(struct tty_struct * tty) vio_disable_interrupts(hvcsd->vdev); hvcsd->todo_mask = 0; - - /* I don't think the tty needs the hvcs_struct pointer after a hangup */ - tty->driver_data = NULL; hvcsd->port.tty = NULL; - hvcsd->port.count = 0; /* This will drop any buffered data on the floor which is OK in a hangup