Merge tag 'pm-5.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These fix two cpufreq issues, one in the intel_pstate driver and one
  in the core.

  Specifics:

   - Prevent intel_pstate from avoiding to use HWP, even if instructed
     to do so via the kernel command line, when HWP has been enabled
     already by the platform firmware (Doug Smythies).

   - Prevent use-after-free from occurring in the schedutil cpufreq
     governor on exit by fixing a core helper function that attempts to
     access memory associated with a kobject after calling kobject_put()
     on it (James Morse)"

* tag 'pm-5.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: schedutil: Destroy mutex before kobject_put() frees the memory
  cpufreq: intel_pstate: Override parameters if HWP forced by BIOS

2 files changed, 15 insertions, 9 deletions

diff --git a/drivers/cpufreq/cpufreq_governor_attr_set.c b/drivers/cpufreq/cpufreq_governor_attr_set.c
index 66b05a326910..a6f365b9cc1a 100644
--- a/drivers/cpufreq/cpufreq_governor_attr_set.c
+++ b/drivers/cpufreq/cpufreq_governor_attr_set.c
@@ -74,8 +74,8 @@ unsigned int gov_attr_set_put(struct gov_attr_set *attr_set, struct list_head *l
 	if (count)
 		return count;
 
-	kobject_put(&attr_set->kobj);
 	mutex_destroy(&attr_set->update_lock);
+	kobject_put(&attr_set->kobj);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(gov_attr_set_put);
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 1097f826ad70..8c176b7dae41 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -3205,11 +3205,15 @@ static int __init intel_pstate_init(void)
 	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
 		return -ENODEV;
 
-	if (no_load)
-		return -ENODEV;
-
 	id = x86_match_cpu(hwp_support_ids);
 	if (id) {
+		bool hwp_forced = intel_pstate_hwp_is_enabled();
+
+		if (hwp_forced)
+			pr_info("HWP enabled by BIOS\n");
+		else if (no_load)
+			return -ENODEV;
+
 		copy_cpu_funcs(&core_funcs);
 		/*
 		 * Avoid enabling HWP for processors without EPP support,
@@ -3219,8 +3223,7 @@ static int __init intel_pstate_init(void)
 		 * If HWP is enabled already, though, there is no choice but to
 		 * deal with it.
 		 */
-		if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
-		    intel_pstate_hwp_is_enabled()) {
+		if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || hwp_forced) {
 			hwp_active++;
 			hwp_mode_bdw = id->driver_data;
 			intel_pstate.attr = hwp_cpufreq_attrs;
@@ -3235,7 +3238,11 @@ static int __init intel_pstate_init(void)
 
 			goto hwp_cpu_matched;
 		}
+		pr_info("HWP not enabled\n");
 	} else {
+		if (no_load)
+			return -ENODEV;
+
 		id = x86_match_cpu(intel_pstate_cpu_ids);
 		if (!id) {
 			pr_info("CPU model not supported\n");
@@ -3314,10 +3321,9 @@ static int __init intel_pstate_setup(char *str)
 	else if (!strcmp(str, "passive"))
 		default_driver = &intel_cpufreq;
 
-	if (!strcmp(str, "no_hwp")) {
-		pr_info("HWP disabled\n");
+	if (!strcmp(str, "no_hwp"))
 		no_hwp = 1;
-	}
+
 	if (!strcmp(str, "force"))
 		force_load = 1;
 	if (!strcmp(str, "hwp_only"))