[PATCH 4.14 063/124] x86/cpu/vmware: Do not trace vmware_sched_clock()

Greg Kroah-Hartman
2018-11-19T16:49:37Z

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

commit 15035388439f892017d38b05214d3cda6578af64 upstream.

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.

Fixes: 80e9a4f21fd7c ("x86/vmware: Add paravirt sched clock")
Reported-by: GwanYeong Kim <gy741.kim@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
CC: Alok Kataria <akataria@vmware.com>
CC: GwanYeong Kim <gy741.kim@gmail.com>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
CC: Thomas Gleixner <tglx@linutronix.de>
CC: virtualization@lists.linux-foundation.org
CC: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/20181109152207.4d3e7d70@gandalf.local.home
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/kernel/cpu/vmware.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- 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(
}
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;