diff options
author | Michael Kelley <mikelley@microsoft.com> | 2020-09-13 22:47:29 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-09-23 13:59:55 +0300 |
commit | b3233e4ae6d36f8c3bb2ff1a872ae5f11589d7b5 (patch) | |
tree | 8a3a32b15b0f8e044f9dc15eff7f575067d3611e /drivers/hv | |
parent | 9065c93d56401f6c28daa7610ca8aaf7a4b0b47c (diff) | |
download | linux-b3233e4ae6d36f8c3bb2ff1a872ae5f11589d7b5.tar.xz |
Drivers: hv: vmbus: Add timeout to vmbus_wait_for_unload
[ Upstream commit 911e1987efc8f3e6445955fbae7f54b428b92bd3 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/hv')
-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 417a95e5094d..af7832e13167 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; |