blob: 08108270e6c69d32e79f47cb1ec26290bce54592 [file] [log] [blame]
From 03a0c7ecd1f598aba83fb8490c857f56e2585f6a Mon Sep 17 00:00:00 2001
From: Tianyu Lan <>
Date: Mon, 6 Apr 2020 08:53:31 -0700
Subject: [PATCH] x86/Hyper-V: Report crash data in die() when panic_on_oops is
commit f3a99e761efa616028b255b4de58e9b5b87c5545 upstream.
When oops happens with panic_on_oops unset, the oops
thread is killed by die() and system continues to run.
In such case, guest should not report crash register
data to host since system still runs. Check panic_on_oops
and return directly in hyperv_report_panic() when the function
is called in the die() and panic_on_oops is unset. Fix it.
Fixes: 7ed4325a44ea ("Drivers: hv: vmbus: Make panic reporting to be more useful")
Signed-off-by: Tianyu Lan <>
Reviewed-by: Michael Kelley <>
Signed-off-by: Wei Liu <>
Signed-off-by: Paul Gortmaker <>
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index dd92d8b438d4..18c3c2bb17b0 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -20,6 +20,7 @@
#include <linux/clockchips.h>
#include <linux/hyperv.h>
#include <linux/slab.h>
+#include <linux/kernel.h>
#include <linux/cpuhotplug.h>
@@ -427,11 +428,14 @@ void hyperv_cleanup(void)
-void hyperv_report_panic(struct pt_regs *regs, long err)
+void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die)
static bool panic_reported;
u64 guest_id;
+ if (in_die && !panic_on_oops)
+ return;
* We prefer to report panic on 'die' chain as we have proper
* registers to report, but if we miss it (e.g. on BUG()) we need
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index cc60e617931c..ae44aa1f8a80 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -343,7 +343,7 @@ static inline int cpumask_to_vpset(struct hv_vpset *vpset,
void __init hyperv_init(void);
void hyperv_setup_mmu_ops(void);
-void hyperv_report_panic(struct pt_regs *regs, long err);
+void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die);
void hyperv_report_panic_msg(phys_addr_t pa, size_t size);
bool hv_is_hyperv_initialized(void);
void hyperv_cleanup(void);
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 3406d6e9b125..dfecbbb21608 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -15,6 +15,7 @@
#include <linux/interrupt.h>
#include <linux/sysctl.h>
#include <linux/slab.h>
+#include <linux/kernel.h>
#include <linux/acpi.h>
#include <linux/completion.h>
#include <linux/hyperv.h>
@@ -72,7 +73,7 @@ static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE
&& hyperv_report_reg()) {
regs = current_pt_regs();
- hyperv_report_panic(regs, val);
+ hyperv_report_panic(regs, val, false);
@@ -89,7 +90,7 @@ static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
* the notification here.
if (hyperv_report_reg())
- hyperv_report_panic(regs, val);
+ hyperv_report_panic(regs, val, true);