[tip:x86/urgent] x86/cpu/vmware: Do not trace vmware_sched_clock()

[tip-bot for Steven Rostedt (VMware)]

Commit-ID:  15035388439f892017d38b05214d3cda6578af64
Gitweb:     https://git.kernel.org/tip/15035388439f892017d38b05214d3cda6578af64
Author:     Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
AuthorDate: Fri, 9 Nov 2018 15:22:07 -0500
Committer:  Borislav Petkov <bp@xxxxxxx>
CommitDate: Fri, 9 Nov 2018 21:39:14 +0100

x86/cpu/vmware: Do not trace vmware_sched_clock()

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@xxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
CC: Alok Kataria <akataria@xxxxxxxxxx>
CC: GwanYeong Kim <gy741.kim@xxxxxxxxx>
CC: "H. Peter Anvin" <hpa@xxxxxxxxx>
CC: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CC: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
CC: x86-ml <x86@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/20181109152207.4d3e7d70@xxxxxxxxxxxxxxxxxx
---
 arch/x86/kernel/cpu/vmware.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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;