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authorThomas Gleixner <tglx@linutronix.de>2015-10-13 19:00:14 +0200
committerThomas Gleixner <tglx@linutronix.de>2015-10-13 19:00:14 +0200
commite50226b4b86755e65aef2129e94d952fee3df722 (patch)
treed4dd925fc7f5c6fe46b647c8027911190595f014 /kernel/irq/proc.c
parente9849777d0e27cdd2902805be51da73e7c79578c (diff)
parent25cb62b76430a91cc6195f902e61c2cb84ade622 (diff)
downloadlinux-stericsson-e50226b4b86755e65aef2129e94d952fee3df722.tar.gz
Merge branch 'linus' into irq/core
Bring in upstream updates for patches which depend on them
Diffstat (limited to 'kernel/irq/proc.c')
-rw-r--r--kernel/irq/proc.c19
1 files changed, 17 insertions, 2 deletions
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 7d6090519630..a916cf144b65 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -12,6 +12,7 @@
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
+#include <linux/mutex.h>
#include "internals.h"
@@ -323,18 +324,29 @@ void register_handler_proc(unsigned int irq, struct irqaction *action)
void register_irq_proc(unsigned int irq, struct irq_desc *desc)
{
+ static DEFINE_MUTEX(register_lock);
char name [MAX_NAMELEN];
- if (!root_irq_dir || (desc->irq_data.chip == &no_irq_chip) || desc->dir)
+ if (!root_irq_dir || (desc->irq_data.chip == &no_irq_chip))
return;
+ /*
+ * irq directories are registered only when a handler is
+ * added, not when the descriptor is created, so multiple
+ * tasks might try to register at the same time.
+ */
+ mutex_lock(&register_lock);
+
+ if (desc->dir)
+ goto out_unlock;
+
memset(name, 0, MAX_NAMELEN);
sprintf(name, "%d", irq);
/* create /proc/irq/1234 */
desc->dir = proc_mkdir(name, root_irq_dir);
if (!desc->dir)
- return;
+ goto out_unlock;
#ifdef CONFIG_SMP
/* create /proc/irq/<irq>/smp_affinity */
@@ -355,6 +367,9 @@ void register_irq_proc(unsigned int irq, struct irq_desc *desc)
proc_create_data("spurious", 0444, desc->dir,
&irq_spurious_proc_fops, (void *)(long)irq);
+
+out_unlock:
+ mutex_unlock(&register_lock);
}
void unregister_irq_proc(unsigned int irq, struct irq_desc *desc)