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authorVitaly Kuznetsov <vkuznets@redhat.com>2015-08-01 16:08:09 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-08-04 22:28:38 -0700
commitb4370df2b1f5158de028e167974263c5757b34a6 (patch)
tree4a8733a8b1ae446e1b1a3df70f7c180f8bc15ecf /arch
parentd7646eaa7678fe5adc42247b4bdfbe9d9db8c253 (diff)
downloadlinux-b4370df2b1f5158de028e167974263c5757b34a6.tar.bz2
Drivers: hv: vmbus: add special crash handler
Full kernel hang is observed when kdump kernel starts after a crash. This hang happens in vmbus_negotiate_version() function on wait_for_completion() as Hyper-V host (Win2012R2 in my testing) never responds to CHANNELMSG_INITIATE_CONTACT as it thinks the connection is already established. We need to perform some mandatory minimalistic cleanup before we start new kernel. Reported-by: K. Y. Srinivasan <kys@microsoft.com> 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 'arch')
-rw-r--r--arch/x86/include/asm/mshyperv.h2
-rw-r--r--arch/x86/kernel/cpu/mshyperv.c22
2 files changed, 24 insertions, 0 deletions
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index d3db9108346b..d02f9c9a6592 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -22,4 +22,6 @@ void hv_remove_vmbus_irq(void);
void hv_setup_kexec_handler(void (*handler)(void));
void hv_remove_kexec_handler(void);
+void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
+void hv_remove_crash_handler(void);
#endif
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index fa483ed4756e..5ea5bbcc85b3 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -35,6 +35,7 @@ struct ms_hyperv_info ms_hyperv;
EXPORT_SYMBOL_GPL(ms_hyperv);
static void (*hv_kexec_handler)(void);
+static void (*hv_crash_handler)(struct pt_regs *regs);
#if IS_ENABLED(CONFIG_HYPERV)
static void (*vmbus_handler)(void);
@@ -83,6 +84,18 @@ void hv_remove_kexec_handler(void)
hv_kexec_handler = NULL;
}
EXPORT_SYMBOL_GPL(hv_remove_kexec_handler);
+
+void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs))
+{
+ hv_crash_handler = handler;
+}
+EXPORT_SYMBOL_GPL(hv_setup_crash_handler);
+
+void hv_remove_crash_handler(void)
+{
+ hv_crash_handler = NULL;
+}
+EXPORT_SYMBOL_GPL(hv_remove_crash_handler);
#endif
static void hv_machine_shutdown(void)
@@ -92,6 +105,14 @@ static void hv_machine_shutdown(void)
native_machine_shutdown();
}
+static void hv_machine_crash_shutdown(struct pt_regs *regs)
+{
+ if (hv_crash_handler)
+ hv_crash_handler(regs);
+ native_machine_crash_shutdown(regs);
+}
+
+
static uint32_t __init ms_hyperv_platform(void)
{
u32 eax;
@@ -165,6 +186,7 @@ static void __init ms_hyperv_init_platform(void)
#endif
machine_ops.shutdown = hv_machine_shutdown;
+ machine_ops.crash_shutdown = hv_machine_crash_shutdown;
}
const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {