[PATCH 12/15] oprofile/x86: fix msr access to reserved counters

[Robert Richter <robert.richter@amd.com>]

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.

Cc: stable@kernel.org
Signed-off-by: Robert Richter <robert.richter@amd.com>
---
 arch/x86/oprofile/op_model_amd.c |    9 ++++-----
 1 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/x86/oprofile/op_model_amd.c b/arch/x86/oprofile/op_model_amd.c
index f4ebc45..6a58256 100644
--- a/arch/x86/oprofile/op_model_amd.c
+++ b/arch/x86/oprofile/op_model_amd.c
@@ -127,7 +127,7 @@ 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;
@@ -163,7 +163,8 @@ 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;
@@ -197,9 +198,7 @@ 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 */
-- 
1.6.6