diff mbox series

power: supply: cpcap-battery: fix invalid usage of list cursor

Message ID 20210414064724.27068-1-zhuguangqing83@gmail.com
State Superseded
Headers show
Series power: supply: cpcap-battery: fix invalid usage of list cursor | expand

Commit Message

zhuguangqing83@gmail.com April 14, 2021, 6:47 a.m. UTC
From: Guangqing Zhu <zhuguangqing83@gmail.com>

Fix invalid usage of a list_for_each_entry in cpcap_battery_irq_thread().
When list is empty or if the list is completely traversed (without breaking
from the loop on one of the entries) then the list cursor does not point
to a valid entry and therefore should not be used. "if (!d)" will never
happen, maybe we should use "if (&d->node == &ddata->irq_list)".

Fixes: 874b2adbed125 ("power: supply: cpcap-battery: Add a battery driver")
Signed-off-by: Guangqing Zhu <zhuguangqing83@gmail.com>
---
 drivers/power/supply/cpcap-battery.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Sebastian Reichel April 20, 2021, 2:13 p.m. UTC | #1
[+Cc Tony]

Hi,

On Wed, Apr 14, 2021 at 02:47:24PM +0800, zhuguangqing83@gmail.com wrote:
> From: Guangqing Zhu <zhuguangqing83@gmail.com>

>

> Fix invalid usage of a list_for_each_entry in cpcap_battery_irq_thread().

> When list is empty or if the list is completely traversed (without breaking

> from the loop on one of the entries) then the list cursor does not point

> to a valid entry and therefore should not be used. "if (!d)" will never

> happen, maybe we should use "if (&d->node == &ddata->irq_list)".


Commit message does not make sense. I think you meant to say:

Empty list or fully traversed list points to list head, which is not
NULL (and before the first element containing real data).

> Fixes: 874b2adbed125 ("power: supply: cpcap-battery: Add a battery driver")

> Signed-off-by: Guangqing Zhu <zhuguangqing83@gmail.com>

> ---

>  drivers/power/supply/cpcap-battery.c | 2 +-

>  1 file changed, 1 insertion(+), 1 deletion(-)

> 

> diff --git a/drivers/power/supply/cpcap-battery.c b/drivers/power/supply/cpcap-battery.c

> index 6d5bcdb9f45d..8169dc71a786 100644

> --- a/drivers/power/supply/cpcap-battery.c

> +++ b/drivers/power/supply/cpcap-battery.c

> @@ -786,7 +786,7 @@ static irqreturn_t cpcap_battery_irq_thread(int irq, void *data)

>  			break;

>  	}

>  

> -	if (!d)

> +	if (&d->node == &ddata->irq_list)

>  		return IRQ_NONE;


Please use list_entry_is_head() instead of open coding it.

>  	latest = cpcap_battery_latest(ddata);


Thanks,

-- Sebastian
diff mbox series

Patch

diff --git a/drivers/power/supply/cpcap-battery.c b/drivers/power/supply/cpcap-battery.c
index 6d5bcdb9f45d..8169dc71a786 100644
--- a/drivers/power/supply/cpcap-battery.c
+++ b/drivers/power/supply/cpcap-battery.c
@@ -786,7 +786,7 @@  static irqreturn_t cpcap_battery_irq_thread(int irq, void *data)
 			break;
 	}
 
-	if (!d)
+	if (&d->node == &ddata->irq_list)
 		return IRQ_NONE;
 
 	latest = cpcap_battery_latest(ddata);