diff options
| author | Michael Kelley <mikelley@microsoft.com> | 2020-09-13 12:47:29 -0700 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2020-09-14 11:42:33 +0000 |
| commit | 911e1987efc8f3e6445955fbae7f54b428b92bd3 (patch) | |
| tree | f513da7f15a88350919e084894fe41f00b5f3991 | |
| parent | 19873eec7e13fda140a0ebc75d6664e57c00bfb1 (diff) | |
| download | uml-911e1987efc8f3e6445955fbae7f54b428b92bd3.tar.gz | |
Drivers: hv: vmbus: Add timeout to vmbus_wait_for_unload
vmbus_wait_for_unload() looks for a CHANNELMSG_UNLOAD_RESPONSE message
coming from Hyper-V. But if the message isn't found for some reason,
the panic path gets hung forever. Add a timeout of 10 seconds to prevent
this.
Fixes: 415719160de3 ("Drivers: hv: vmbus: avoid scheduling in interrupt context in vmbus_initiate_unload()")
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/1600026449-23651-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
| -rw-r--r-- | drivers/hv/channel_mgmt.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index 417a95e5094dd9..af7832e1316741 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -750,7 +750,7 @@ static void vmbus_wait_for_unload(void) void *page_addr; struct hv_message *msg; struct vmbus_channel_message_header *hdr; - u32 message_type; + u32 message_type, i; /* * CHANNELMSG_UNLOAD_RESPONSE is always delivered to the CPU which was @@ -760,8 +760,11 @@ static void vmbus_wait_for_unload(void) * functional and vmbus_unload_response() will complete * vmbus_connection.unload_event. If not, the last thing we can do is * read message pages for all CPUs directly. + * + * Wait no more than 10 seconds so that the panic path can't get + * hung forever in case the response message isn't seen. */ - while (1) { + for (i = 0; i < 1000; i++) { if (completion_done(&vmbus_connection.unload_event)) break; |