diff mbox series

[4.19,132/247] IB/umad: Return EPOLLERR in case of when device disassociated

Message ID 20210301161038.129991424@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg Kroah-Hartman March 1, 2021, 4:12 p.m. UTC 
From: Shay Drory <shayd@nvidia.com>

[ Upstream commit def4cd43f522253645b72c97181399c241b54536 ]

Currently, polling a umad device will always works, even if the device was
disassociated. A disassociated device should immediately return EPOLLERR
from poll(). Otherwise userspace is endlessly hung on poll() with no idea
that the device has been removed from the system.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Link: https://lore.kernel.org/r/20210125121339.837518-3-leon@kernel.org
Signed-off-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/infiniband/core/user_mad.c | 10 ++++++++++
 1 file changed, 10 insertions(+)
diff mbox series

Patch

diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
index db2ac5218c371..471a824be86c4 100644
--- a/drivers/infiniband/core/user_mad.c
+++ b/drivers/infiniband/core/user_mad.c
@@ -384,6 +384,11 @@  static ssize_t ib_umad_read(struct file *filp, char __user *buf,
 		mutex_lock(&file->mutex);
 	}
 
+	if (file->agents_dead) {
+		mutex_unlock(&file->mutex);
+		return -EIO;
+	}
+
 	packet = list_entry(file->recv_list.next, struct ib_umad_packet, list);
 	list_del(&packet->list);
 
@@ -642,10 +647,14 @@  static __poll_t ib_umad_poll(struct file *filp, struct poll_table_struct *wait)
 	/* we will always be able to post a MAD send */
 	__poll_t mask = EPOLLOUT | EPOLLWRNORM;
 
+	mutex_lock(&file->mutex);
 	poll_wait(filp, &file->recv_wait, wait);
 
 	if (!list_empty(&file->recv_list))
 		mask |= EPOLLIN | EPOLLRDNORM;
+	if (file->agents_dead)
+		mask = EPOLLERR;
+	mutex_unlock(&file->mutex);
 
 	return mask;
 }
@@ -1262,6 +1271,7 @@  static void ib_umad_kill_port(struct ib_umad_port *port)
 	list_for_each_entry(file, &port->file_list, port_list) {
 		mutex_lock(&file->mutex);
 		file->agents_dead = 1;
+		wake_up_interruptible(&file->recv_wait);
 		mutex_unlock(&file->mutex);
 
 		for (id = 0; id < IB_UMAD_MAX_AGENTS; ++id)