Linux Virtualization - Nov 2018 - [PATCH] x86/vmware: Do not trace vmware_sched_clock()

From: Steven Rostedt (VMware) <rostedt at goodmis.org>

When running function tracing on a Linux guest running on VMware
Workstation, the guest would crash. This is due to tracing of the
sched_clock internal call of the VMware vmware_sched_clock(), which
causes an infinite recursion within the tracing code (clock calls must
not be traced).

Make vmware_sched_clock() not traced by ftrace.

Cc: stable at vger.kernel.org
Fixes: 80e9a4f21fd7c ("x86/vmware: Add paravirt sched clock")
Reported-by: GwanYeong Kim <gy741.kim at gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt at goodmis.org>
---
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index d9ab49bed8af..0eda91f8eeac 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -77,7 +77,7 @@ static __init int setup_vmw_sched_clock(char *s)
 }
 early_param("no-vmw-sched-clock", setup_vmw_sched_clock);
 
-static unsigned long long vmware_sched_clock(void)
+static unsigned long long notrace vmware_sched_clock(void)
 {
 	unsigned long long ns;