[patch 15/47] genirq: Prepare proc for real sparse irq support

From: Thomas Gleixner
Date: Thu Sep 30 2010 - 19:16:31 EST


/proc/irq never removes any entries, but when irq descriptors can be
freed for real this is necessary. Otherwise we'd reference a freed
descriptor in /proc/irq/N

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
kernel/irq/internals.h | 2 ++
kernel/irq/irqdesc.c | 2 ++
kernel/irq/proc.c | 18 ++++++++++++++++++
3 files changed, 22 insertions(+)

Index: linux-2.6-tip/kernel/irq/internals.h
===================================================================
--- linux-2.6-tip.orig/kernel/irq/internals.h
+++ linux-2.6-tip/kernel/irq/internals.h
@@ -26,10 +26,12 @@ void replace_irq_desc(unsigned int irq,

#ifdef CONFIG_PROC_FS
extern void register_irq_proc(unsigned int irq, struct irq_desc *desc);
+extern void unregister_irq_proc(unsigned int irq, struct irq_desc *desc);
extern void register_handler_proc(unsigned int irq, struct irqaction *action);
extern void unregister_handler_proc(unsigned int irq, struct irqaction *action);
#else
static inline void register_irq_proc(unsigned int irq, struct irq_desc *desc) { }
+static inline void unregister_irq_proc(unsigned int irq, struct irq_desc *desc); { }
static inline void register_handler_proc(unsigned int irq,
struct irqaction *action) { }
static inline void unregister_handler_proc(unsigned int irq,
Index: linux-2.6-tip/kernel/irq/irqdesc.c
===================================================================
--- linux-2.6-tip.orig/kernel/irq/irqdesc.c
+++ linux-2.6-tip/kernel/irq/irqdesc.c
@@ -210,6 +210,8 @@ static void free_desc(unsigned int irq)
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;

+ unregister_irq_proc(irq, desc);
+
raw_spin_lock_irqsave(&sparse_irq_lock, flags);
delete_irq_desc(irq);
raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
Index: linux-2.6-tip/kernel/irq/proc.c
===================================================================
--- linux-2.6-tip.orig/kernel/irq/proc.c
+++ linux-2.6-tip/kernel/irq/proc.c
@@ -297,6 +297,24 @@ void register_irq_proc(unsigned int irq,
&irq_spurious_proc_fops, (void *)(long)irq);
}

+void unregister_irq_proc(unsigned int irq, struct irq_desc *desc)
+{
+ char name [MAX_NAMELEN];
+
+ if (!root_irq_dir || !desc->dir)
+ return;
+#ifdef CONFIG_SMP
+ remove_proc_entry("smp_affinity", desc->dir);
+ remove_proc_entry("affinity_hint", desc->dir);
+ remove_proc_entry("node", desc->dir);
+#endif
+ remove_proc_entry("spurious", desc->dir);
+
+ memset(name, 0, MAX_NAMELEN);
+ sprintf(name, "%u", irq);
+ remove_proc_entry(name, root_irq_dir);
+}
+
#undef MAX_NAMELEN

void unregister_handler_proc(unsigned int irq, struct irqaction *action)


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