[PATCH 85/98] ACPI: Avoid wiping out pr->performance during preregistering

Len Brown
2009-03-28T04:33:47Z

From: Stanislaw Gruszka <sgruszka@redhat.com>

When cpufreq driver call acpi_processor_preregister_performance() , function
will clean up pr->performance even if there is possibly already registered
other cpufreq driver. The patch fix this potential problem. It also remove
double checks in P domain basic validity code and move these checks to function
where _PSD data is captured.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
---
drivers/acpi/processor_perflib.c | 46 +++++++++++++++++--------------------
1 files changed, 21 insertions(+), 25 deletions(-)

diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index 9cc769b..215f1bf 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -479,6 +479,13 @@ static int acpi_processor_get_psd(struct acpi_processor *pr)
goto end;
}

+ if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
+ pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
+ pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
+ printk(KERN_ERR PREFIX "Invalid _PSD:coord_type\n");
+ result = -EFAULT;
+ goto end;
+ }
end:
kfree(buffer.pointer);
return result;
@@ -501,9 +508,10 @@ int acpi_processor_preregister_performance(

mutex_lock(&performance_mutex);

- retval = 0;
-
- /* Call _PSD for all CPUs */
+ /*
+ * Check if another driver has already registered, and abort before
+ * changing pr->performance if it has. Check input data as well.
+ */
for_each_possible_cpu(i) {
pr = per_cpu(processors, i);
if (!pr) {
@@ -513,13 +521,20 @@ int acpi_processor_preregister_performance(

if (pr->performance) {
retval = -EBUSY;
- continue;
+ goto err_out;
}

if (!performance || !percpu_ptr(performance, i)) {
retval = -EINVAL;
- continue;
+ goto err_out;
}
+ }
+
+ /* Call _PSD for all CPUs */
+ for_each_possible_cpu(i) {
+ pr = per_cpu(processors, i);
+ if (!pr)
+ continue;

pr->performance = percpu_ptr(performance, i);
cpumask_set_cpu(i, pr->performance->shared_cpu_map);
@@ -535,26 +550,6 @@ int acpi_processor_preregister_performance(
* Now that we have _PSD data from all CPUs, lets setup P-state
* domain info.
*/
- for_each_possible_cpu(i) {
- pr = per_cpu(processors, i);
- if (!pr)
- continue;
-
- /* Basic validity check for domain info */
- pdomain = &(pr->performance->domain_info);
- if ((pdomain->revision != ACPI_PSD_REV0_REVISION) ||
- (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES)) {
- retval = -EINVAL;
- goto err_ret;
- }
- if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
- pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
- pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
- retval = -EINVAL;
- goto err_ret;
- }
- }
-
cpumask_clear(covered_cpus);
for_each_possible_cpu(i) {
pr = per_cpu(processors, i);
@@ -643,6 +638,7 @@ err_ret:
pr->performance = NULL; /* Will be set for real in register */
}

+err_out:
mutex_unlock(&performance_mutex);
free_cpumask_var(covered_cpus);
return retval;
--
1.6.0.6