From 75ff3a8a9168df750b5bd0589e897a6c0517a9f1 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Fri, 26 Feb 2016 15:13:16 -0800 Subject: [PATCH] Drivers: hv: vmbus: avoid wait_for_completion() on crash MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit wait_for_completion() may sleep, it enables interrupts and this is something we really want to avoid on crashes because interrupt handlers can cause other crashes. Switch to the recently introduced vmbus_wait_for_unload() doing busy wait instead. Reported-by: Radim Krcmar Signed-off-by: Vitaly Kuznetsov Reviewed-by: Radim Kr.má Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/channel_mgmt.c | 4 ++-- drivers/hv/connection.c | 2 +- drivers/hv/hyperv_vmbus.h | 2 +- drivers/hv/vmbus_drv.c | 4 ++-- 4 files changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index b40f429aaa13..f70e35278b94 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -641,7 +641,7 @@ static void vmbus_unload_response(struct vmbus_channel_message_header *hdr) complete(&vmbus_connection.unload_event); } -void vmbus_initiate_unload(void) +void vmbus_initiate_unload(bool crash) { struct vmbus_channel_message_header hdr; @@ -658,7 +658,7 @@ void vmbus_initiate_unload(void) * vmbus_initiate_unload() is also called on crash and the crash can be * happening in an interrupt context, where scheduling is impossible. */ - if (!in_interrupt()) + if (!crash) wait_for_completion(&vmbus_connection.unload_event); else vmbus_wait_for_unload(); diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c index fa86b2cb28b8..3b6dc0017269 100644 --- a/drivers/hv/connection.c +++ b/drivers/hv/connection.c @@ -236,7 +236,7 @@ void vmbus_disconnect(void) /* * First send the unload request to the host. */ - vmbus_initiate_unload(); + vmbus_initiate_unload(false); if (vmbus_connection.work_queue) { drain_workqueue(vmbus_connection.work_queue); diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index b9ea7f59036b..b0299da9c2db 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -663,7 +663,7 @@ void hv_vss_onchannelcallback(void *); int hv_fcopy_init(struct hv_util_service *); void hv_fcopy_deinit(void); void hv_fcopy_onchannelcallback(void *); -void vmbus_initiate_unload(void); +void vmbus_initiate_unload(bool crash); static inline void hv_poll_channel(struct vmbus_channel *channel, void (*cb)(void *)) diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 30ea8ad902e2..c8f1671944d5 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1291,7 +1291,7 @@ static void hv_kexec_handler(void) int cpu; hv_synic_clockevents_cleanup(); - vmbus_initiate_unload(); + vmbus_initiate_unload(false); for_each_online_cpu(cpu) smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1); hv_cleanup(); @@ -1299,7 +1299,7 @@ static void hv_kexec_handler(void) static void hv_crash_handler(struct pt_regs *regs) { - vmbus_initiate_unload(); + vmbus_initiate_unload(true); /* * In crash handler we can't schedule synic cleanup for all CPUs, * doing the cleanup for current CPU only. This should be sufficient -- 2.20.1