The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 040026df7088c56ccbad28f7042308f67bde63df Mon Sep 17 00:00:00 2001
From: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
Date: Mon, 6 Apr 2020 08:53:30 -0700
Subject: [PATCH] x86/Hyper-V: Report crash register data when
sysctl_record_panic_msg is not set
When sysctl_record_panic_msg is not set, the panic will
not be reported to Hyper-V via hyperv_report_panic_msg().
So the crash should be reported via hyperv_report_panic().
Fixes: 81b18bce48af ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic")
Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
Signed-off-by: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200406155331.2105-6-Tianyu.Lan@xxxxxxxxxxxxx
Signed-off-by: Wei Liu <wei.liu@xxxxxxxxxx>
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 333dad39b1c1..172ceae69abb 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -48,6 +48,18 @@ static int hyperv_cpuhp_online;
static void *hv_panic_page;
+/*
+ * Boolean to control whether to report panic messages over Hyper-V.
+ *
+ * It can be set via /proc/sys/kernel/hyperv/record_panic_msg
+ */
+static int sysctl_record_panic_msg = 1;
+
+static int hyperv_report_reg(void)
+{
+ return !sysctl_record_panic_msg || !hv_panic_page;
+}
+
static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
void *args)
{
@@ -61,7 +73,7 @@ static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
* the notification here.
*/
if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE
- && !hv_panic_page) {
+ && hyperv_report_reg()) {
regs = current_pt_regs();
hyperv_report_panic(regs, val);
}
@@ -79,7 +91,7 @@ static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
* doing hyperv_report_panic_msg() later with kmsg data, don't do
* the notification here.
*/
- if (!hv_panic_page)
+ if (hyperv_report_reg())
hyperv_report_panic(regs, val);
return NOTIFY_DONE;
}
@@ -1267,13 +1279,6 @@ static void vmbus_isr(void)
add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
}
-/*
- * Boolean to control whether to report panic messages over Hyper-V.
- *
- * It can be set via /proc/sys/kernel/hyperv/record_panic_msg
- */
-static int sysctl_record_panic_msg = 1;
-
/*
* Callback from kmsg_dump. Grab as much as possible from the end of the kmsg
* buffer and call into Hyper-V to transfer the data.
