oprofile/x86: fix msr access to reserved counters

commit cfc9c0b4 upstream.

During switching virtual counters there is access to perfctr msrs. If
the counter is not available this fails due to an invalid
address. This patch fixes this.
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

arch/x86/oprofile/op_model_amd.c

@@ -85,7 +85,7 @@ static void op_mux_switch_ctrl(struct op_x86_model_spec const *model,
 	/* enable active counters */
 	for (i = 0; i < NUM_COUNTERS; ++i) {
 		int virt = op_x86_phys_to_virt(i);
-		if (!counter_config[virt].enabled)
+		if (!reset_value[virt])
 			continue;
 		rdmsrl(msrs->controls[i].addr, val);
 		val &= model->reserved;
@@ -121,7 +121,8 @@ static void op_amd_setup_ctrs(struct op_x86_model_spec const *model,
 
 	/* setup reset_value */
 	for (i = 0; i < NUM_VIRT_COUNTERS; ++i) {
-		if (counter_config[i].enabled)
+		if (counter_config[i].enabled
+		    && msrs->counters[op_x86_virt_to_phys(i)].addr)
 			reset_value[i] = counter_config[i].count;
 		else
 			reset_value[i] = 0;
@@ -146,9 +147,7 @@ static void op_amd_setup_ctrs(struct op_x86_model_spec const *model,
 	/* enable active counters */
 	for (i = 0; i < NUM_COUNTERS; ++i) {
 		int virt = op_x86_phys_to_virt(i);
-		if (!counter_config[virt].enabled)
-			continue;
-		if (!msrs->counters[i].addr)
+		if (!reset_value[virt])
 			continue;
 
 		/* setup counter registers */