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

rostedt · suryasaimadhu · commit 15035388439f · 2018-11-09T21:39:14.000+01:00
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: 80e9a4f ("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
diff --git 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;
 

Original file line number	Diff line number	Diff line change
`@@ -77,7 +77,7 @@ static __init int setup_vmw_sched_clock(char *s)`
`77`	`77`	`}`
`78`	`78`	`early_param("no-vmw-sched-clock", setup_vmw_sched_clock);`
`79`	`79`
`80`		`-static unsigned long long vmware_sched_clock(void)`
	`80`	`+static unsigned long long notrace vmware_sched_clock(void)`
`81`	`81`	`{`
`82`	`82`	`unsigned long long ns;`
`83`	`83`