A preserve_context kexec returns to the current kernel, which is
unrelated to live update where the state is passed to the next kernel.
Skip liveupdate_reboot() in this case to avoid serialization and prevent
sessions from being left in a frozen state upon return.

Fixes: db8bed8082dc ("kexec: call liveupdate_reboot() before kexec")
Reported-by: Oskar Gerlicz Kowalczuk <oskar@gerlicz.space>
Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org>
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
---
 kernel/kexec_core.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index a43d2da0fe3e..dc770b9a6d05 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -1146,9 +1146,11 @@ int kernel_kexec(void)
 		goto Unlock;
 	}
 
-	error = liveupdate_reboot();
-	if (error)
-		goto Unlock;
+	if (!kexec_image->preserve_context) {
+		error = liveupdate_reboot();
+		if (error)
+			goto Unlock;
+	}
 
 #ifdef CONFIG_KEXEC_JUMP
 	if (kexec_image->preserve_context) {
-- 
2.54.0.545.g6539524ca2-goog