lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <1499670369-44143-8-git-send-email-wangyijing@huawei.com>
Date:   Mon, 10 Jul 2017 15:06:09 +0800
From:   Yijing Wang <wangyijing@...wei.com>
To:     <jejb@...ux.vnet.ibm.com>, <martin.petersen@...cle.com>
CC:     <chenqilin2@...wei.com>, <hare@...e.com>,
        <linux-scsi@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <chenxiang66@...ilicon.com>, <huangdaode@...ilicon.com>,
        <wangkefeng.wang@...wei.com>, <zhaohongjiang@...wei.com>,
        <dingtianhong@...wei.com>, <guohanjun@...wei.com>,
        <yanaijie@...wei.com>, <hch@....de>, <dan.j.williams@...el.com>,
        <emilne@...hat.com>, <thenzl@...hat.com>, <wefu@...hat.com>,
        <charles.chenxin@...wei.com>, <chenweilong@...wei.com>,
        <john.garry@...wei.com>, Yijing Wang <wangyijing@...wei.com>,
        "Johannes Thumshirn" <jthumshirn@...e.de>
Subject: [PATCH v3 7/7] libsas: release disco mutex during waiting in sas_ex_discover_end_dev

Disco mutex was introudced to prevent domain rediscovery competing
with ata error handling(87c8331). If we have already hold the lock
in sas_revalidate_domain and sync executing probe, deadlock caused,
because, sas_probe_sata() also need hold disco_mutex. Since disco mutex
use to prevent revalidata domain happen during ata error handler,
it should be safe to release disco mutex when sync probe, because
no new revalidate domain event would be process until the sync return,
and the current sas revalidate domain finish.

Signed-off-by: Yijing Wang <wangyijing@...wei.com>
CC: John Garry <john.garry@...wei.com>
CC: Johannes Thumshirn <jthumshirn@...e.de>
CC: Ewan Milne <emilne@...hat.com>
CC: Christoph Hellwig <hch@....de>
CC: Tomas Henzl <thenzl@...hat.com>
CC: Dan Williams <dan.j.williams@...el.com>
---
 drivers/scsi/libsas/sas_expander.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 9d26c28..077024e 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -776,6 +776,7 @@ static struct domain_device *sas_ex_discover_end_dev(
 	struct ex_phy *phy = &parent_ex->ex_phy[phy_id];
 	struct domain_device *child = NULL;
 	struct sas_rphy *rphy;
+	bool prev_lock;
 	int res;
 
 	if (phy->attached_sata_host || phy->attached_sata_ps)
@@ -803,6 +804,7 @@ static struct domain_device *sas_ex_discover_end_dev(
 	sas_ex_get_linkrate(parent, child, phy);
 	sas_device_set_phy(child, phy->port);
 
+	prev_lock = mutex_is_locked(&child->port->ha->disco_mutex);
 #ifdef CONFIG_SCSI_SAS_ATA
 	if ((phy->attached_tproto & SAS_PROTOCOL_STP) || phy->attached_sata_dev) {
 		res = sas_get_ata_info(child, phy);
@@ -832,7 +834,11 @@ static struct domain_device *sas_ex_discover_end_dev(
 				    SAS_ADDR(parent->sas_addr), phy_id, res);
 			goto out_list_del;
 		}
+		if (prev_lock)
+			mutex_unlock(&child->port->ha->disco_mutex);
 		sas_disc_wait_completion(child->port, DISCE_PROBE);
+		if (prev_lock)
+			mutex_lock(&child->port->ha->disco_mutex);
 
 	} else
 #endif
@@ -861,7 +867,11 @@ static struct domain_device *sas_ex_discover_end_dev(
 				    SAS_ADDR(parent->sas_addr), phy_id, res);
 			goto out_list_del;
 		}
+		if (prev_lock)
+			mutex_unlock(&child->port->ha->disco_mutex);
 		sas_disc_wait_completion(child->port, DISCE_PROBE);
+		if (prev_lock)
+			mutex_lock(&child->port->ha->disco_mutex);
 	} else {
 		SAS_DPRINTK("target proto 0x%x at %016llx:0x%x not handled\n",
 			    phy->attached_tproto, SAS_ADDR(parent->sas_addr),
-- 
2.5.0

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ