[patch 039/123] oprofile/x86: fix msr access to reserved counters

[Greg KH]

2.6.33-stable review patch.  If anyone has any objections, please let me know.

-----------------

From: Robert Richter <robert.richter@xxxxxxx>

commit cfc9c0b450176a077205ef39092f0dc1a04e020a 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@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 arch/x86/oprofile/op_model_amd.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

--- a/arch/x86/oprofile/op_model_amd.c
+++ b/arch/x86/oprofile/op_model_amd.c
@@ -85,7 +85,7 @@ static void op_mux_switch_ctrl(struct op
 	/* 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_
 
 	/* 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_
 	/* 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 */


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