From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751760AbcBLPnA (ORCPT ); Fri, 12 Feb 2016 10:43:00 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44788 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751730AbcBLPm6 (ORCPT ); Fri, 12 Feb 2016 10:42:58 -0500 From: Vitaly Kuznetsov To: devel@linuxdriverproject.org Cc: linux-kernel@vger.kernel.org, "K. Y. Srinivasan" , Haiyang Zhang , Radim Krcmar , Cathy Avery Subject: [PATCH 2/4] Drivers: hv: vmbus: avoid wait_for_completion() on crash Date: Fri, 12 Feb 2016 16:42:48 +0100 Message-Id: <1455291770-15672-3-git-send-email-vkuznets@redhat.com> In-Reply-To: <1455291770-15672-1-git-send-email-vkuznets@redhat.com> References: <1455291770-15672-1-git-send-email-vkuznets@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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 763d0c1..bd60207 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -556,7 +556,7 @@ 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; @@ -573,7 +573,7 @@ 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 3dc5a9c..fb63d30 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 4ebc796..e6160a0 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -665,7 +665,7 @@ 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 895eeed..08f98a1 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1266,7 +1266,7 @@ 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(); @@ -1274,7 +1274,7 @@ 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 -- 2.5.0