| 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
| ||
|
Message-ID: <20220710181458.GA20827@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net>
Date: Sun, 10 Jul 2022 11:14:58 -0700
From: Shradha Gupta <shradhagupta@...ux.microsoft.com>
To: linux-hyperv@...r.kernel.org, linux-kernel@...r.kernel.org
Cc: "K. Y. Srinivasan" <kys@...rosoft.com>,
Haiyang Zhang <haiyangz@...rosoft.com>,
Stephen Hemminger <sthemmin@...rosoft.com>,
Wei Liu <wei.liu@...nel.org>, Dexuan Cui <decui@...rosoft.com>,
Shradha Gupta <shradhagupta@...rosoft.com>,
Praveen Kumar <kumarpraveen@...rosoft.com>
Subject: [PATCH v2] Drivers: hv: vm_bus: Handle vmbus rescind calls after
vmbus is suspended
Add a flag to indicate that the vmbus is suspended so we should ignore
any offer message. Add a new work_queue for rescind msg, so we could drain
it along with other offer work_queues upon suspension.
It was observed that in some hibernation related scenario testing, after
vmbus_bus_suspend() we get rescind offer message for the vmbus. This would
lead to processing of a rescind message for a channel that has already been
suspended.
Signed-off-by: Shradha Gupta <shradhagupta@...ux.microsoft.com>
---
Changes in v2:
* Rename the ignore_offer_rescind_msg flag to ignore_any_offer_msg, to
indicate that the flag can cause any offer message to be dropped.
* Remove redundent tasklet_enable(), tasklet_disable() calls around
ignore_any_offer_msg flag when value is changed from true to false.
* Add comment about tasklet_enable() providing memory barrier.
* In vmbus_bus_suspend() after we drain all workqueues, remove the code
to wait for any offer_in_progress
---
drivers/hv/connection.c | 11 +++++++++++
drivers/hv/hyperv_vmbus.h | 7 +++++++
drivers/hv/vmbus_drv.c | 29 +++++++++++++++++++++--------
3 files changed, 39 insertions(+), 8 deletions(-)
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 6218bbf6863a..eca7afd366d6 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -171,6 +171,14 @@ int vmbus_connect(void)
goto cleanup;
}
+ vmbus_connection.rescind_work_queue =
+ create_workqueue("hv_vmbus_rescind");
+ if (!vmbus_connection.rescind_work_queue) {
+ ret = -ENOMEM;
+ goto cleanup;
+ }
+ vmbus_connection.ignore_any_offer_msg = false;
+
vmbus_connection.handle_primary_chan_wq =
create_workqueue("hv_pri_chan");
if (!vmbus_connection.handle_primary_chan_wq) {
@@ -357,6 +365,9 @@ void vmbus_disconnect(void)
if (vmbus_connection.handle_primary_chan_wq)
destroy_workqueue(vmbus_connection.handle_primary_chan_wq);
+ if (vmbus_connection.rescind_work_queue)
+ destroy_workqueue(vmbus_connection.rescind_work_queue);
+
if (vmbus_connection.work_queue)
destroy_workqueue(vmbus_connection.work_queue);
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 4f5b824b16cf..dc673edf053c 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -261,6 +261,13 @@ struct vmbus_connection {
struct workqueue_struct *work_queue;
struct workqueue_struct *handle_primary_chan_wq;
struct workqueue_struct *handle_sub_chan_wq;
+ struct workqueue_struct *rescind_work_queue;
+
+ /*
+ * On suspension of the vmbus, the accumulated offer messages
+ * must be dropped.
+ */
+ bool ignore_any_offer_msg;
/*
* The number of sub-channels and hv_sock channels that should be
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 547ae334e5cd..4ba0eb2441cf 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1160,7 +1160,9 @@ void vmbus_on_msg_dpc(unsigned long data)
* work queue: the RESCIND handler can not start to
* run before the OFFER handler finishes.
*/
- schedule_work(&ctx->work);
+ if (vmbus_connection.ignore_any_offer_msg)
+ break;
+ queue_work(vmbus_connection.rescind_work_queue, &ctx->work);
break;
case CHANNELMSG_OFFERCHANNEL:
@@ -1186,6 +1188,8 @@ void vmbus_on_msg_dpc(unsigned long data)
* to the CPUs which will execute the offer & rescind
* works by the time these works will start execution.
*/
+ if (vmbus_connection.ignore_any_offer_msg)
+ break;
atomic_inc(&vmbus_connection.offer_in_progress);
fallthrough;
@@ -2446,15 +2450,20 @@ static int vmbus_acpi_add(struct acpi_device *device)
#ifdef CONFIG_PM_SLEEP
static int vmbus_bus_suspend(struct device *dev)
{
+ struct hv_per_cpu_context *hv_cpu = per_cpu_ptr(
+ hv_context.cpu_context, VMBUS_CONNECT_CPU);
struct vmbus_channel *channel, *sc;
- while (atomic_read(&vmbus_connection.offer_in_progress) != 0) {
- /*
- * We wait here until the completion of any channel
- * offers that are currently in progress.
- */
- usleep_range(1000, 2000);
- }
+ tasklet_disable(&hv_cpu->msg_dpc);
+ vmbus_connection.ignore_any_offer_msg = true;
+ /* The tasklet_enable() takes care of providing a memory barrier */
+ tasklet_enable(&hv_cpu->msg_dpc);
+
+ /* Drain all the workqueues as we are in suspend */
+ drain_workqueue(vmbus_connection.rescind_work_queue);
+ drain_workqueue(vmbus_connection.work_queue);
+ drain_workqueue(vmbus_connection.handle_primary_chan_wq);
+ drain_workqueue(vmbus_connection.handle_sub_chan_wq);
mutex_lock(&vmbus_connection.channel_mutex);
list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
@@ -2527,10 +2536,14 @@ static int vmbus_bus_suspend(struct device *dev)
static int vmbus_bus_resume(struct device *dev)
{
+ struct hv_per_cpu_context *hv_cpu = per_cpu_ptr(
+ hv_context.cpu_context, VMBUS_CONNECT_CPU);
struct vmbus_channel_msginfo *msginfo;
size_t msgsize;
int ret;
+ vmbus_connection.ignore_any_offer_msg = false;
+
/*
* We only use the 'vmbus_proto_version', which was in use before
* hibernation, to re-negotiate with the host.
--
2.17.1
Powered by blists - more mailing lists