[PATCH] mfd: 88pm80x: refine irq bit operation

Qiao Zhou
2015-05-15T11:10:17Z

Set_bit/clear_bit for wu_flag may be corrupted if irq > 5(or 6 for
aarch64). The maximum irq number from 88pm80x chip series is 24.
Here we refine the code to protect the potential memory corruption.

Also change wu_flag to wakeup_flag for easier understanding.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Qiao Zhou <zhouqiao@marvell.com>
---
drivers/mfd/88pm80x.c | 4 ++--
include/linux/mfd/88pm80x.h | 19 ++++++++++++++++---
2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/drivers/mfd/88pm80x.c b/drivers/mfd/88pm80x.c
index 5e72f65..e1d803a 100644
--- a/drivers/mfd/88pm80x.c
+++ b/drivers/mfd/88pm80x.c
@@ -136,7 +136,7 @@ static int pm80x_suspend(struct device *dev)
struct i2c_client *client = container_of(dev, struct i2c_client, dev);
struct pm80x_chip *chip = i2c_get_clientdata(client);

- if (chip && chip->wu_flag)
+ if (chip && chip->wakeup_flag)
if (device_may_wakeup(chip->dev))
enable_irq_wake(chip->irq);

@@ -148,7 +148,7 @@ static int pm80x_resume(struct device *dev)
struct i2c_client *client = container_of(dev, struct i2c_client, dev);
struct pm80x_chip *chip = i2c_get_clientdata(client);

- if (chip && chip->wu_flag)
+ if (chip && chip->wakeup_flag)
if (device_may_wakeup(chip->dev))
disable_irq_wake(chip->irq);

diff --git a/include/linux/mfd/88pm80x.h b/include/linux/mfd/88pm80x.h
index 97cb283..1bca7eb 100644
--- a/include/linux/mfd/88pm80x.h
+++ b/include/linux/mfd/88pm80x.h
@@ -276,6 +276,9 @@ enum {
#define PM805_EARPHONE_SETTING (0x29)
#define PM805_AUTO_SEQ_SETTING (0x2A)

+/* supported 24 sub-irq */
+#define PM80x_MAX_IRQ 24
+
struct pm80x_rtc_pdata {
int vrtc;
int rtc_wakeup;
@@ -301,7 +304,7 @@ struct pm80x_chip {
int type;
int irq;
int irq_mode;
- unsigned long wu_flag;
+ unsigned long wakeup_flag;
spinlock_t lock;
};

@@ -348,8 +351,13 @@ static inline int pm80x_dev_suspend(struct device *dev)
struct pm80x_chip *chip = dev_get_drvdata(pdev->dev.parent);
int irq = platform_get_irq(pdev, 0);

+ if (irq < 0 || irq >= PM80x_MAX_IRQ) {
+ dev_err(dev, "Invalid irq %d\n", irq);
+ return 0;
+ }
+
if (device_may_wakeup(dev))
- set_bit((1 << irq), &chip->wu_flag);
+ set_bit(irq, &chip->wakeup_flag);

return 0;
}
@@ -360,8 +368,13 @@ static inline int pm80x_dev_resume(struct device *dev)
struct pm80x_chip *chip = dev_get_drvdata(pdev->dev.parent);
int irq = platform_get_irq(pdev, 0);

+ if (irq < 0 || irq >= PM80x_MAX_IRQ) {
+ dev_err(dev, "Invalid irq %d\n", irq);
+ return 0;
+ }
+
if (device_may_wakeup(dev))
- clear_bit((1 << irq), &chip->wu_flag);
+ clear_bit(irq, &chip->wakeup_flag);

return 0;
}
--
1.7.9.5