Thermal control fixes for 7.2-rc1

- Fix dangling resources on thermal_throttle_online() failure in the
    Intel thermal_throttle driver (Ricardo Neri)
 
  - Eliminate a possibility of running thermal testing module code after
    that module has been removed (Rafael Wysocki)
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Merge tag 'thermal-7.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull thermal control fixes from Rafael Wysocki:
 "These fix a failure path in an Intel thermal driver and prevent
  thermal testing module code from being executed after it has been
  freed:

   - Fix dangling resources on thermal_throttle_online() failure in the
     Intel thermal_throttle driver (Ricardo Neri)

   - Eliminate a possibility of running thermal testing module code
     after that module has been removed (Rafael Wysocki)"

* tag 'thermal-7.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  thermal: testing: zone: Flush work items during cleanup
  thermal: intel: Fix dangling resources on thermal_throttle_online() failure

drivers/thermal/intel/therm_throt.c

@@ -529,8 +529,13 @@ static int thermal_throttle_online(unsigned int cpu)
 {
 	struct thermal_state *state = &per_cpu(thermal_state, cpu);
 	struct device *dev = get_cpu_device(cpu);
+	int err;
 	u32 l;
 
+	err = thermal_throttle_add_dev(dev, cpu);
+	if (err)
+		return err;
+
 	state->package_throttle.level = PACKAGE_LEVEL;
 	state->core_throttle.level = CORE_LEVEL;
 
@@ -548,7 +553,7 @@ static int thermal_throttle_online(unsigned int cpu)
 	l = apic_read(APIC_LVTTHMR);
 	apic_write(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
 
-	return thermal_throttle_add_dev(dev, cpu);
+	return err;
 }
 
 static int thermal_throttle_offline(unsigned int cpu)

drivers/thermal/testing/command.c

@@ -86,7 +86,10 @@
 
 #include "thermal_testing.h"
 
-struct dentry *d_testing;
+struct workqueue_struct *tt_wq __ro_after_init;
+
+struct dentry *d_testing __ro_after_init;
+static struct dentry *d_command __ro_after_init;
 
 #define TT_COMMAND_SIZE		16
 
@@ -203,17 +206,42 @@ static const struct file_operations tt_command_fops = {
 
 static int __init thermal_testing_init(void)
 {
+	int error;
+
+	tt_wq = alloc_workqueue("thermal_testing", WQ_UNBOUND, 0);
+	if (!tt_wq)
+		return -ENOMEM;
+
 	d_testing = debugfs_create_dir("thermal-testing", NULL);
-	if (!IS_ERR(d_testing))
-		debugfs_create_file("command", 0200, d_testing, NULL,
-				    &tt_command_fops);
+	if (IS_ERR(d_testing)) {
+		error = PTR_ERR(d_testing);
+		goto destroy_wq;
+	}
+
+	d_command = debugfs_create_file("command", 0200, d_testing, NULL, &tt_command_fops);
+	if (IS_ERR(d_command)) {
+		error = PTR_ERR(d_command);
+		goto remove_d_testing;
+	}
 
 	return 0;
+
+remove_d_testing:
+	debugfs_remove(d_testing);
+destroy_wq:
+	destroy_workqueue(tt_wq);
+	return error;
 }
 module_init(thermal_testing_init);
 
 static void __exit thermal_testing_exit(void)
 {
+	/* First, prevent new commands from being entered. */
+	debugfs_remove(d_command);
+	/* Flush commands in progress (if any). */
+	flush_workqueue(tt_wq);
+	destroy_workqueue(tt_wq);
+	/* Remove the directory structure and clean up. */
 	debugfs_remove(d_testing);
 	tt_zone_cleanup();
 }

drivers/thermal/testing/thermal_testing.h

@@ -1,4 +1,12 @@
 /* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/workqueue.h>
+
+extern struct workqueue_struct *tt_wq;
+
+static inline void tt_queue_work(struct work_struct *work)
+{
+	queue_work(tt_wq, work);
+}
 
 extern struct dentry *d_testing;
 

drivers/thermal/testing/zone.c

@@ -13,7 +13,6 @@
 #include <linux/idr.h>
 #include <linux/list.h>
 #include <linux/thermal.h>
-#include <linux/workqueue.h>
 
 #include "thermal_testing.h"
 
@@ -207,7 +206,7 @@ int tt_add_tz(void)
 
 	INIT_WORK(&tt_work->work, tt_add_tz_work_fn);
 	tt_work->tt_zone = no_free_ptr(tt_zone);
-	schedule_work(&(no_free_ptr(tt_work)->work));
+	tt_queue_work(&(no_free_ptr(tt_work)->work));
 
 	return 0;
 }
@@ -269,7 +268,7 @@ int tt_del_tz(const char *arg)
 
 	INIT_WORK(&tt_work->work, tt_del_tz_work_fn);
 	tt_work->tt_zone = tt_zone;
-	schedule_work(&(no_free_ptr(tt_work)->work));
+	tt_queue_work(&(no_free_ptr(tt_work)->work));
 
 	return 0;
 }
@@ -358,7 +357,7 @@ int tt_zone_add_trip(const char *arg)
 	INIT_WORK(&tt_work->work, tt_zone_add_trip_work_fn);
 	tt_work->tt_zone = no_free_ptr(tt_zone);
 	tt_work->tt_trip = no_free_ptr(tt_trip);
-	schedule_work(&(no_free_ptr(tt_work)->work));
+	tt_queue_work(&(no_free_ptr(tt_work)->work));
 
 	return 0;
 }