Merge tag 'pm-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

torvalds · torvalds · commit 8e377a1c7e24 · 2019-03-30T10:06:09.000-07:00
Pull power management fixes from Rafael Wysocki:
 "These fix CPU base frequency reporting in the intel_pstate driver and
  a use-after-free in the scpi-cpufreq driver.

  Specifics:

   - Fix the ACPI CPPC library to actually follow the specification when
     decoding the guaranteed performance register information and make
     the intel_pstate driver to fall back to the nominal frequency when
     reporting the base frequency if the guaranteed performance register
     information is not there (Srinivas Pandruvada).

   - Fix use-after-free in the exit callback of the scpi-cpufreq left
     after an update during the 5.0 development cycle (Vincent Stehlé)"

* tag 'pm-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: scpi: Fix use after free
  cpufreq: intel_pstate: Also use CPPC nominal_perf for base_frequency
  ACPI / CPPC: Fix guaranteed performance handling
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
@@ -1150,8 +1150,13 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
 	cpc_read(cpunum, nominal_reg, &nom);
 	perf_caps->nominal_perf = nom;
 
-	cpc_read(cpunum, guaranteed_reg, &guaranteed);
-	perf_caps->guaranteed_perf = guaranteed;
+	if (guaranteed_reg->type != ACPI_TYPE_BUFFER  ||
+	    IS_NULL_REG(&guaranteed_reg->cpc_entry.reg)) {
+		perf_caps->guaranteed_perf = 0;
+	} else {
+		cpc_read(cpunum, guaranteed_reg, &guaranteed);
+		perf_caps->guaranteed_perf = guaranteed;
+	}
 
 	cpc_read(cpunum, lowest_non_linear_reg, &min_nonlinear);
 	perf_caps->lowest_nonlinear_perf = min_nonlinear;
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
@@ -385,7 +385,10 @@ static int intel_pstate_get_cppc_guranteed(int cpu)
 	if (ret)
 		return ret;
 
-	return cppc_perf.guaranteed_perf;
+	if (cppc_perf.guaranteed_perf)
+		return cppc_perf.guaranteed_perf;
+
+	return cppc_perf.nominal_perf;
 }
 
 #else /* CONFIG_ACPI_CPPC_LIB */
diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c
@@ -189,8 +189,8 @@ static int scpi_cpufreq_exit(struct cpufreq_policy *policy)
 
 	clk_put(priv->clk);
 	dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
-	kfree(priv);
 	dev_pm_opp_remove_all_dynamic(priv->cpu_dev);
+	kfree(priv);
 
 	return 0;
 }

Original file line number	Diff line number	Diff line change
`@@ -189,8 +189,8 @@ static int scpi_cpufreq_exit(struct cpufreq_policy *policy)`
`189`	`189`
`190`	`190`	`clk_put(priv->clk);`
`191`	`191`	`dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);`
`192`		`- kfree(priv);`
`193`	`192`	`dev_pm_opp_remove_all_dynamic(priv->cpu_dev);`
	`193`	`+ kfree(priv);`
`194`	`194`
`195`	`195`	`return 0;`
`196`	`196`	`}`