linux-kernel - [PATCH V3 4/5] arch_topology: Localize cap_parsing_failed to topology_parse_cpu

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 23 Jun 2017 14:55:33 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Juri Lelli <juri.lelli@....com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     Viresh Kumar <viresh.kumar@...aro.org>,
        linux-arm-kernel@...ts.infradead.org,
        Catalin Marinas <catalin.marinas@....com>,
        linux@....linux.org.uk, Will Deacon <will.deacon@....com>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        arnd.bergmann@...aro.org, linux-kernel@...r.kernel.org
Subject: [PATCH V3 4/5] arch_topology: Localize cap_parsing_failed to topology_parse_cpu_capacity()

cap_parsing_failed is only required in topology_parse_cpu_capacity() to
know if we have already tried to allocate raw_capacity and failed, or if
at least one of the cpu_node didn't had the required
"capacity-dmips-mhz" property.

All other users can use raw_capacity instead of cap_parsing_failed.

Make sure we set raw_capacity to NULL after we free it.

Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
 drivers/base/arch_topology.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 5728e2fbb765..9e4d2107f4fa 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -95,14 +95,21 @@ subsys_initcall(register_cpu_capacity_sysctl);
 
 static u32 capacity_scale;
 static u32 *raw_capacity;
-static bool cap_parsing_failed;
+
+static int __init free_raw_capacity(void)
+{
+	kfree(raw_capacity);
+	raw_capacity = NULL;
+
+	return 0;
+}
 
 void topology_normalize_cpu_scale(void)
 {
 	u64 capacity;
 	int cpu;
 
-	if (!raw_capacity || cap_parsing_failed)
+	if (!raw_capacity)
 		return;
 
 	pr_debug("cpu_capacity: capacity_scale=%u\n", capacity_scale);
@@ -121,6 +128,7 @@ void topology_normalize_cpu_scale(void)
 
 bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
 {
+	static bool cap_parsing_failed;
 	int ret;
 	u32 cpu_capacity;
 
@@ -151,7 +159,7 @@ bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
 			pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
 		}
 		cap_parsing_failed = true;
-		kfree(raw_capacity);
+		free_raw_capacity();
 	}
 
 	return !ret;
@@ -171,7 +179,7 @@ init_cpu_capacity_callback(struct notifier_block *nb,
 	struct cpufreq_policy *policy = data;
 	int cpu;
 
-	if (cap_parsing_failed || cap_parsing_done)
+	if (!raw_capacity || cap_parsing_done)
 		return 0;
 
 	if (val != CPUFREQ_NOTIFY)
@@ -191,7 +199,7 @@ init_cpu_capacity_callback(struct notifier_block *nb,
 
 	if (cpumask_empty(cpus_to_visit)) {
 		topology_normalize_cpu_scale();
-		kfree(raw_capacity);
+		free_raw_capacity();
 		pr_debug("cpu_capacity: parsing done\n");
 		cap_parsing_done = true;
 		schedule_work(&parsing_done_work);
@@ -233,11 +241,5 @@ static void parsing_done_workfn(struct work_struct *work)
 }
 
 #else
-static int __init free_raw_capacity(void)
-{
-	kfree(raw_capacity);
-
-	return 0;
-}
 core_initcall(free_raw_capacity);
 #endif
-- 
2.13.0.71.gd7076ec9c9cb