Merge tag 'v5.4-rc4' into docs-next

I need to pick up the independent changes made to
Documentation/core-api/memory-allocation.rst to be able to merge further
work without creating a total mess.

1 files changed, 25 insertions, 3 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 750f46ad018a..205b1176084f 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -269,19 +269,41 @@ void xen_reboot(int reason)
 		BUG();
 }
 
+static int reboot_reason = SHUTDOWN_reboot;
+static bool xen_legacy_crash;
 void xen_emergency_restart(void)
 {
-	xen_reboot(SHUTDOWN_reboot);
+	xen_reboot(reboot_reason);
 }
 
 static int
 xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
 {
-	if (!kexec_crash_loaded())
-		xen_reboot(SHUTDOWN_crash);
+	if (!kexec_crash_loaded()) {
+		if (xen_legacy_crash)
+			xen_reboot(SHUTDOWN_crash);
+
+		reboot_reason = SHUTDOWN_crash;
+
+		/*
+		 * If panic_timeout==0 then we are supposed to wait forever.
+		 * However, to preserve original dom0 behavior we have to drop
+		 * into hypervisor. (domU behavior is controlled by its
+		 * config file)
+		 */
+		if (panic_timeout == 0)
+			panic_timeout = -1;
+	}
 	return NOTIFY_DONE;
 }
 
+static int __init parse_xen_legacy_crash(char *arg)
+{
+	xen_legacy_crash = true;
+	return 0;
+}
+early_param("xen_legacy_crash", parse_xen_legacy_crash);
+
 static struct notifier_block xen_panic_block = {
 	.notifier_call = xen_panic_event,
 	.priority = INT_MIN