* [PATCH] watchdog: ftwdt010_wdt: fix test for platform_get_irq() failure
@ 2022-08-11 10:56 Dan Carpenter
2022-08-11 14:56 ` Guenter Roeck
2022-08-11 20:52 ` Christophe JAILLET
0 siblings, 2 replies; 6+ messages in thread
From: Dan Carpenter @ 2022-08-11 10:56 UTC (permalink / raw)
To: Wim Van Sebroeck, Linus Walleij
Cc: Guenter Roeck, linux-watchdog, kernel-janitors
This code assumes that platform_get_irq() function returns zero on
failure. In fact, platform_get_irq() never returns zero. It returns
negative error codes or positive non-zero values on success.
Fixes: eca10ae6000d ("watchdog: add driver for Cortina Gemini watchdog")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
drivers/watchdog/ftwdt010_wdt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/watchdog/ftwdt010_wdt.c b/drivers/watchdog/ftwdt010_wdt.c
index 21dcc7765688..02112fc264bd 100644
--- a/drivers/watchdog/ftwdt010_wdt.c
+++ b/drivers/watchdog/ftwdt010_wdt.c
@@ -156,7 +156,7 @@ static int ftwdt010_wdt_probe(struct platform_device *pdev)
}
irq = platform_get_irq(pdev, 0);
- if (irq) {
+ if (irq > 0) {
ret = devm_request_irq(dev, irq, ftwdt010_wdt_interrupt, 0,
"watchdog bark", gwdt);
if (ret)
--
2.35.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] watchdog: ftwdt010_wdt: fix test for platform_get_irq() failure
2022-08-11 10:56 [PATCH] watchdog: ftwdt010_wdt: fix test for platform_get_irq() failure Dan Carpenter
@ 2022-08-11 14:56 ` Guenter Roeck
2022-08-11 20:52 ` Christophe JAILLET
1 sibling, 0 replies; 6+ messages in thread
From: Guenter Roeck @ 2022-08-11 14:56 UTC (permalink / raw)
To: Dan Carpenter, Wim Van Sebroeck, Linus Walleij
Cc: linux-watchdog, kernel-janitors
On 8/11/22 03:56, Dan Carpenter wrote:
> This code assumes that platform_get_irq() function returns zero on
> failure. In fact, platform_get_irq() never returns zero. It returns
> negative error codes or positive non-zero values on success.
>
> Fixes: eca10ae6000d ("watchdog: add driver for Cortina Gemini watchdog")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> ---
> drivers/watchdog/ftwdt010_wdt.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/watchdog/ftwdt010_wdt.c b/drivers/watchdog/ftwdt010_wdt.c
> index 21dcc7765688..02112fc264bd 100644
> --- a/drivers/watchdog/ftwdt010_wdt.c
> +++ b/drivers/watchdog/ftwdt010_wdt.c
> @@ -156,7 +156,7 @@ static int ftwdt010_wdt_probe(struct platform_device *pdev)
> }
>
> irq = platform_get_irq(pdev, 0);
> - if (irq) {
> + if (irq > 0) {
> ret = devm_request_irq(dev, irq, ftwdt010_wdt_interrupt, 0,
> "watchdog bark", gwdt);
> if (ret)
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] watchdog: ftwdt010_wdt: fix test for platform_get_irq() failure
2022-08-11 10:56 [PATCH] watchdog: ftwdt010_wdt: fix test for platform_get_irq() failure Dan Carpenter
2022-08-11 14:56 ` Guenter Roeck
@ 2022-08-11 20:52 ` Christophe JAILLET
2022-08-11 21:49 ` Guenter Roeck
2022-08-12 6:07 ` Dan Carpenter
1 sibling, 2 replies; 6+ messages in thread
From: Christophe JAILLET @ 2022-08-11 20:52 UTC (permalink / raw)
To: Dan Carpenter, Wim Van Sebroeck, Linus Walleij
Cc: Guenter Roeck, linux-watchdog, kernel-janitors
Le 11/08/2022 à 12:56, Dan Carpenter a écrit :
> This code assumes that platform_get_irq() function returns zero on
> failure. In fact, platform_get_irq() never returns zero. It returns
> negative error codes or positive non-zero values on success.
>
> Fixes: eca10ae6000d ("watchdog: add driver for Cortina Gemini watchdog")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> drivers/watchdog/ftwdt010_wdt.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/watchdog/ftwdt010_wdt.c b/drivers/watchdog/ftwdt010_wdt.c
> index 21dcc7765688..02112fc264bd 100644
> --- a/drivers/watchdog/ftwdt010_wdt.c
> +++ b/drivers/watchdog/ftwdt010_wdt.c
> @@ -156,7 +156,7 @@ static int ftwdt010_wdt_probe(struct platform_device *pdev)
> }
>
> irq = platform_get_irq(pdev, 0);
> - if (irq) {
> + if (irq > 0) {
> ret = devm_request_irq(dev, irq, ftwdt010_wdt_interrupt, 0,
> "watchdog bark", gwdt);
> if (ret)
Hi,
can't platform_get_irq() return 0?
All the paths in platform_get_irq() look like 0 is a valid value.
The other patches you just sent are "< 0 ==> error", so ">= 0 ==> valid"
Any reason here for >0?
CJ
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] watchdog: ftwdt010_wdt: fix test for platform_get_irq() failure
2022-08-11 20:52 ` Christophe JAILLET
@ 2022-08-11 21:49 ` Guenter Roeck
2022-08-12 6:07 ` Dan Carpenter
1 sibling, 0 replies; 6+ messages in thread
From: Guenter Roeck @ 2022-08-11 21:49 UTC (permalink / raw)
To: Christophe JAILLET
Cc: Dan Carpenter, Wim Van Sebroeck, Linus Walleij, linux-watchdog,
kernel-janitors
On Thu, Aug 11, 2022 at 10:52:13PM +0200, Christophe JAILLET wrote:
> Le 11/08/2022 à 12:56, Dan Carpenter a écrit :
> > This code assumes that platform_get_irq() function returns zero on
> > failure. In fact, platform_get_irq() never returns zero. It returns
> > negative error codes or positive non-zero values on success.
> >
> > Fixes: eca10ae6000d ("watchdog: add driver for Cortina Gemini watchdog")
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > ---
> > drivers/watchdog/ftwdt010_wdt.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/watchdog/ftwdt010_wdt.c b/drivers/watchdog/ftwdt010_wdt.c
> > index 21dcc7765688..02112fc264bd 100644
> > --- a/drivers/watchdog/ftwdt010_wdt.c
> > +++ b/drivers/watchdog/ftwdt010_wdt.c
> > @@ -156,7 +156,7 @@ static int ftwdt010_wdt_probe(struct platform_device *pdev)
> > }
> > irq = platform_get_irq(pdev, 0);
> > - if (irq) {
> > + if (irq > 0) {
> > ret = devm_request_irq(dev, irq, ftwdt010_wdt_interrupt, 0,
> > "watchdog bark", gwdt);
> > if (ret)
>
> Hi,
> can't platform_get_irq() return 0?
> All the paths in platform_get_irq() look like 0 is a valid value.
>
> The other patches you just sent are "< 0 ==> error", so ">= 0 ==> valid"
>
> Any reason here for >0?
API documentation says:
* Return: non-zero IRQ number on success, negative error number on failure.
Also, 0 is not a valid interrupt number.
Guenter
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] watchdog: ftwdt010_wdt: fix test for platform_get_irq() failure
2022-08-11 20:52 ` Christophe JAILLET
2022-08-11 21:49 ` Guenter Roeck
@ 2022-08-12 6:07 ` Dan Carpenter
2022-08-12 7:22 ` Christophe JAILLET
1 sibling, 1 reply; 6+ messages in thread
From: Dan Carpenter @ 2022-08-12 6:07 UTC (permalink / raw)
To: Christophe JAILLET
Cc: Wim Van Sebroeck, Linus Walleij, Guenter Roeck, linux-watchdog,
kernel-janitors
On Thu, Aug 11, 2022 at 10:52:13PM +0200, Christophe JAILLET wrote:
> Le 11/08/2022 à 12:56, Dan Carpenter a écrit :
> > This code assumes that platform_get_irq() function returns zero on
> > failure. In fact, platform_get_irq() never returns zero. It returns
> > negative error codes or positive non-zero values on success.
> >
> > Fixes: eca10ae6000d ("watchdog: add driver for Cortina Gemini watchdog")
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > ---
> > drivers/watchdog/ftwdt010_wdt.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/watchdog/ftwdt010_wdt.c b/drivers/watchdog/ftwdt010_wdt.c
> > index 21dcc7765688..02112fc264bd 100644
> > --- a/drivers/watchdog/ftwdt010_wdt.c
> > +++ b/drivers/watchdog/ftwdt010_wdt.c
> > @@ -156,7 +156,7 @@ static int ftwdt010_wdt_probe(struct platform_device *pdev)
> > }
> > irq = platform_get_irq(pdev, 0);
> > - if (irq) {
> > + if (irq > 0) {
> > ret = devm_request_irq(dev, irq, ftwdt010_wdt_interrupt, 0,
> > "watchdog bark", gwdt);
> > if (ret)
>
> Hi,
> can't platform_get_irq() return 0?
> All the paths in platform_get_irq() look like 0 is a valid value.
>
> The other patches you just sent are "< 0 ==> error", so ">= 0 ==> valid"
>
> Any reason here for >0?
It can't really be zero. On some of the other patches there was a tests
failure and success. So if we're testing for < 0 then a test for >= 0
felt more complete.
But here it was like, testing for > 0 won't break anything that isn't
already broken. It's easier to review.
Somebody has a Coccinelle test for:
irq = platform_get_irq(pdev, 0);
if (!irq)
return -ENODEV;
But I implemented it in Smatch just for fun. It turns out people had
introduced a couple new bugs recently. Also the it appears that their
Coccinelle test does not warn about for success tests like this one.
And there are still a bunch of test that do:
if (irq <= 0)
return irq ?: -ENODEV;
But testing for zero is dead code so I didn't bother cleaning it up.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] watchdog: ftwdt010_wdt: fix test for platform_get_irq() failure
2022-08-12 6:07 ` Dan Carpenter
@ 2022-08-12 7:22 ` Christophe JAILLET
0 siblings, 0 replies; 6+ messages in thread
From: Christophe JAILLET @ 2022-08-12 7:22 UTC (permalink / raw)
To: Dan Carpenter
Cc: Guenter Roeck, linux-watchdog, kernel-janitors, Wim Van Sebroeck,
Linus Walleij
Le 12/08/2022 à 08:07, Dan Carpenter a écrit :
> On Thu, Aug 11, 2022 at 10:52:13PM +0200, Christophe JAILLET wrote:
>> Le 11/08/2022 à 12:56, Dan Carpenter a écrit :
>>> This code assumes that platform_get_irq() function returns zero on
>>> failure. In fact, platform_get_irq() never returns zero. It returns
>>> negative error codes or positive non-zero values on success.
>>>
>>> Fixes: eca10ae6000d ("watchdog: add driver for Cortina Gemini watchdog")
>>> Signed-off-by: Dan Carpenter <dan.carpenter-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
>>> ---
>>> drivers/watchdog/ftwdt010_wdt.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/watchdog/ftwdt010_wdt.c b/drivers/watchdog/ftwdt010_wdt.c
>>> index 21dcc7765688..02112fc264bd 100644
>>> --- a/drivers/watchdog/ftwdt010_wdt.c
>>> +++ b/drivers/watchdog/ftwdt010_wdt.c
>>> @@ -156,7 +156,7 @@ static int ftwdt010_wdt_probe(struct platform_device *pdev)
>>> }
>>> irq = platform_get_irq(pdev, 0);
>>> - if (irq) {
>>> + if (irq > 0) {
>>> ret = devm_request_irq(dev, irq, ftwdt010_wdt_interrupt, 0,
>>> "watchdog bark", gwdt);
>>> if (ret)
>>
>> Hi,
>> can't platform_get_irq() return 0?
>> All the paths in platform_get_irq() look like 0 is a valid value.
>>
>> The other patches you just sent are "< 0 ==> error", so ">= 0 ==> valid"
>>
>> Any reason here for >0?
>
> It can't really be zero. On some of the other patches there was a tests
> failure and success. So if we're testing for < 0 then a test for >= 0
> felt more complete.
>
> But here it was like, testing for > 0 won't break anything that isn't
> already broken. It's easier to review.
>
> Somebody has a Coccinelle test for:
>
> irq = platform_get_irq(pdev, 0);
> if (!irq)
> return -ENODEV;
>
> But I implemented it in Smatch just for fun. It turns out people had
> introduced a couple new bugs recently. Also the it appears that their
> Coccinelle test does not warn about for success tests like this one.
> And there are still a bunch of test that do:
>
> if (irq <= 0)
> return irq ?: -ENODEV;
>
> But testing for zero is dead code so I didn't bother cleaning it up.
>
> regards,
> dan carpenter
>
Got it, thanks.
CJ
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-08-12 7:22 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-08-11 10:56 [PATCH] watchdog: ftwdt010_wdt: fix test for platform_get_irq() failure Dan Carpenter
2022-08-11 14:56 ` Guenter Roeck
2022-08-11 20:52 ` Christophe JAILLET
2022-08-11 21:49 ` Guenter Roeck
2022-08-12 6:07 ` Dan Carpenter
2022-08-12 7:22 ` Christophe JAILLET
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.