irq: Use a common macro to go through the actions list

Message ID 1452765253-31148-1-git-send-email-daniel.lezcano@linaro.org
State Accepted
Commit f944b5a7aff05a244a6c8cac297819af09a199e4
Headers show

Commit Message

Daniel Lezcano Jan. 14, 2016, 9:54 a.m.
The irq code browses the list of actions differently to inspect the element
one by one. Even if it is not a problem, for the sake of lisibility and
to unification of the code, provide a macro similar to for_each_irq_desc in
order to have the same loop to go through the actions list and use it in the
code.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

---
 kernel/irq/handle.c    | 7 +++----
 kernel/irq/internals.h | 3 +++
 kernel/irq/manage.c    | 8 +++-----
 kernel/irq/proc.c      | 2 +-
 kernel/irq/spurious.c  | 4 +---
 5 files changed, 11 insertions(+), 13 deletions(-)

-- 
1.9.1

Comments

Daniel Lezcano Feb. 8, 2016, 3:26 p.m. | #1
On 02/08/2016 11:48 AM, tip-bot for Daniel Lezcano wrote:
> Commit-ID:  aff62cf66ad6065ce04fc3454a11ec19714537fb

> Gitweb:     http://git.kernel.org/tip/aff62cf66ad6065ce04fc3454a11ec19714537fb

> Author:     Daniel Lezcano <daniel.lezcano@linaro.org>

> AuthorDate: Thu, 14 Jan 2016 10:54:13 +0100

> Committer:  Thomas Gleixner <tglx@linutronix.de>

> CommitDate: Mon, 8 Feb 2016 11:45:21 +0100

>

> genirq: Use a common macro to go through the actions list

>

> The irq code browses the list of actions differently to inspect the element

> one by one. Even if it is not a problem, for the sake of consistent code,

> provide a macro similar to for_each_irq_desc in order to have the same loop to

> go through the actions list and use it in the code.

>

> [ tglx: Renamed the macro ]

>

> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

> Link: http://lkml.kernel.org/r/1452765253-31148-1-git-send-email-daniel.lezcano@linaro.org

> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

> ---

>   kernel/irq/handle.c    | 5 ++---

>   kernel/irq/internals.h | 3 +++

>   kernel/irq/manage.c    | 8 +++-----

>   kernel/irq/proc.c      | 2 +-

>   kernel/irq/spurious.c  | 4 +---

>   5 files changed, 10 insertions(+), 12 deletions(-)

>

> diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c

> index 57bff78..67534d0 100644

> --- a/kernel/irq/handle.c

> +++ b/kernel/irq/handle.c

> @@ -136,10 +136,9 @@ irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)

>   {

>   	irqreturn_t retval = IRQ_NONE;

>   	unsigned int flags = 0, irq = desc->irq_data.irq;

> -	struct irqaction *action = desc->action;

> +	struct irqaction *action;

>

> -	/* action might have become NULL since we dropped the lock */

> -	while (action) {

> +	for_each_action_of_desc(desc, action) {

>   		irqreturn_t res;

>

>   		trace_irq_handler_entry(irq, action);


The merge lost the removal of:

action = action->next;

resulting to the NULL pointer dereference bug spotted by 01.org.

Do you want me to resend a new patch ?

   -- Daniel


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Patch

diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index a302cf9..d881858 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -136,9 +136,9 @@  irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)
 {
 	irqreturn_t retval = IRQ_NONE;
 	unsigned int flags = 0, irq = desc->irq_data.irq;
-	struct irqaction *action = desc->action;
+	struct irqaction *action;
 
-	do {
+	for_each_desc_action(desc, action) {
 		irqreturn_t res;
 
 		trace_irq_handler_entry(irq, action);
@@ -172,8 +172,7 @@  irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)
 		}
 
 		retval |= res;
-		action = action->next;
-	} while (action);
+	}
 
 	add_interrupt_randomness(irq, flags);
 
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index fcab63c..5ea67df 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -131,6 +131,9 @@  static inline void chip_bus_sync_unlock(struct irq_desc *desc)
 #define IRQ_GET_DESC_CHECK_GLOBAL	(_IRQ_DESC_CHECK)
 #define IRQ_GET_DESC_CHECK_PERCPU	(_IRQ_DESC_CHECK | _IRQ_DESC_PERCPU)
 
+#define for_each_desc_action(desc, act)			\
+	for (act = desc->act; act; act = act->next)
+
 struct irq_desc *
 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 		    unsigned int check);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index c84670c..db54a87 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -144,13 +144,11 @@  int irq_can_set_affinity(unsigned int irq)
  */
 void irq_set_thread_affinity(struct irq_desc *desc)
 {
-	struct irqaction *action = desc->action;
+	struct irqaction *action;
 
-	while (action) {
+	for_each_desc_action(desc, action)
 		if (action->thread)
 			set_bit(IRQTF_AFFINITY, &action->thread_flags);
-		action = action->next;
-	}
 }
 
 #ifdef CONFIG_GENERIC_PENDING_IRQ
@@ -994,7 +992,7 @@  void irq_wake_thread(unsigned int irq, void *dev_id)
 		return;
 
 	raw_spin_lock_irqsave(&desc->lock, flags);
-	for (action = desc->action; action; action = action->next) {
+	for_each_desc_action(desc, action) {
 		if (action->dev_id == dev_id) {
 			if (action->thread)
 				__irq_wake_thread(desc, action);
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index a2c02fd..24ec6ad 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -291,7 +291,7 @@  static int name_unique(unsigned int irq, struct irqaction *new_action)
 	int ret = 1;
 
 	raw_spin_lock_irqsave(&desc->lock, flags);
-	for (action = desc->action ; action; action = action->next) {
+	for_each_desc_action(desc, action) {
 		if ((action != new_action) && action->name &&
 				!strcmp(new_action->name, action->name)) {
 			ret = 0;
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 3214417..3910b0a 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -211,14 +211,12 @@  static void __report_bad_irq(struct irq_desc *desc, irqreturn_t action_ret)
 	 * desc->lock here. See synchronize_irq().
 	 */
 	raw_spin_lock_irqsave(&desc->lock, flags);
-	action = desc->action;
-	while (action) {
+	for_each_desc_action(desc, action) {
 		printk(KERN_ERR "[<%p>] %pf", action->handler, action->handler);
 		if (action->thread_fn)
 			printk(KERN_CONT " threaded [<%p>] %pf",
 					action->thread_fn, action->thread_fn);
 		printk(KERN_CONT "\n");
-		action = action->next;
 	}
 	raw_spin_unlock_irqrestore(&desc->lock, flags);
 }