diff options
author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2015-02-27 11:25:54 -0800 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-03-01 19:29:05 -0800 |
commit | 09a196288ec4617a920e051af6651ce03968c8b9 (patch) | |
tree | 40fb660a649ccd7e12f850138dd82d8b0c75a087 /drivers/hv | |
parent | adcde069a85cb6674bdcf5f49f434d18b2db6e58 (diff) | |
download | lwn-09a196288ec4617a920e051af6651ce03968c8b9.tar.gz lwn-09a196288ec4617a920e051af6651ce03968c8b9.zip |
Drivers: hv: vmbus: teardown hv_vmbus_con workqueue and vmbus_connection pages on shutdown
We need to destroy hv_vmbus_con on module shutdown, otherwise the following
crash is sometimes observed:
[ 76.569845] hv_vmbus: Hyper-V Host Build:9600-6.3-17-0.17039; Vmbus version:3.0
[ 82.598859] BUG: unable to handle kernel paging request at ffffffffa0003480
[ 82.599287] IP: [<ffffffffa0003480>] 0xffffffffa0003480
[ 82.599287] PGD 1f34067 PUD 1f35063 PMD 3f72d067 PTE 0
[ 82.599287] Oops: 0010 [#1] SMP
[ 82.599287] Modules linked in: [last unloaded: hv_vmbus]
[ 82.599287] CPU: 0 PID: 26 Comm: kworker/0:1 Not tainted 3.19.0-rc5_bug923184+ #488
[ 82.599287] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v1.0 11/26/2012
[ 82.599287] Workqueue: hv_vmbus_con 0xffffffffa0003480
[ 82.599287] task: ffff88007b6ddfa0 ti: ffff88007f8f8000 task.ti: ffff88007f8f8000
[ 82.599287] RIP: 0010:[<ffffffffa0003480>] [<ffffffffa0003480>] 0xffffffffa0003480
[ 82.599287] RSP: 0018:ffff88007f8fbe00 EFLAGS: 00010202
...
To avoid memory leaks we need to free monitor_pages and int_page for
vmbus_connection. Implement vmbus_disconnect() function by separating cleanup
path from vmbus_connect().
As we use hv_vmbus_con to release channels (see free_channel() in channel_mgmt.c)
we need to make sure the work was done before we remove the queue, do that with
drain_workqueue(). We also need to avoid handling messages which can (potentially)
create new channels, so set vmbus_connection.conn_state = DISCONNECTED at the very
beginning of vmbus_exit() and check for that in vmbus_onmessage_work().
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv')
-rw-r--r-- | drivers/hv/connection.c | 17 | ||||
-rw-r--r-- | drivers/hv/hyperv_vmbus.h | 1 | ||||
-rw-r--r-- | drivers/hv/vmbus_drv.c | 6 |
3 files changed, 19 insertions, 5 deletions
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c index a63a795300b9..c4acd1ce7c0c 100644 --- a/drivers/hv/connection.c +++ b/drivers/hv/connection.c @@ -216,10 +216,21 @@ int vmbus_connect(void) cleanup: pr_err("Unable to connect to host\n"); + vmbus_connection.conn_state = DISCONNECTED; + vmbus_disconnect(); + + kfree(msginfo); + + return ret; +} - if (vmbus_connection.work_queue) +void vmbus_disconnect(void) +{ + if (vmbus_connection.work_queue) { + drain_workqueue(vmbus_connection.work_queue); destroy_workqueue(vmbus_connection.work_queue); + } if (vmbus_connection.int_page) { free_pages((unsigned long)vmbus_connection.int_page, 0); @@ -230,10 +241,6 @@ cleanup: free_pages((unsigned long)vmbus_connection.monitor_pages[1], 0); vmbus_connection.monitor_pages[0] = NULL; vmbus_connection.monitor_pages[1] = NULL; - - kfree(msginfo); - - return ret; } /* diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 44b1c9424712..6cf2de9f487a 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -692,6 +692,7 @@ void vmbus_free_channels(void); /* Connection interface */ int vmbus_connect(void); +void vmbus_disconnect(void); int vmbus_post_msg(void *buffer, size_t buflen); diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index e334ccc70582..76db97de09fd 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -574,6 +574,10 @@ static void vmbus_onmessage_work(struct work_struct *work) { struct onmessage_work_context *ctx; + /* Do not process messages if we're in DISCONNECTED state */ + if (vmbus_connection.conn_state == DISCONNECTED) + return; + ctx = container_of(work, struct onmessage_work_context, work); vmbus_onmessage(&ctx->msg); @@ -1025,12 +1029,14 @@ cleanup: static void __exit vmbus_exit(void) { + vmbus_connection.conn_state = DISCONNECTED; hv_remove_vmbus_irq(); vmbus_free_channels(); bus_unregister(&hv_bus); hv_cleanup(); acpi_bus_unregister_driver(&vmbus_acpi_driver); hv_cpu_hotplug_quirk(false); + vmbus_disconnect(); } |