* [PATCH v1 1/1] wwan: core: Avoid returning error pointer from wwan_create_dev()
@ 2021-08-05 18:31 Andy Shevchenko
2021-08-05 19:53 ` Loic Poulain
0 siblings, 1 reply; 4+ messages in thread
From: Andy Shevchenko @ 2021-08-05 18:31 UTC (permalink / raw)
To: David S. Miller, Sergey Ryazanov, Loic Poulain, netdev, linux-kernel
Cc: Johannes Berg, Jakub Kicinski, Andy Shevchenko
wwan_create_dev() is expected to return either valid pointer or NULL,
In some cases it might return the error pointer. Prevent this by converting
it to NULL after wwan_dev_get_by_parent().
Fixes: 9a44c1cc6388 ("net: Add a WWAN subsystem")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
drivers/net/wwan/wwan_core.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wwan/wwan_core.c b/drivers/net/wwan/wwan_core.c
index 674a81d79db3..35e10a98e774 100644
--- a/drivers/net/wwan/wwan_core.c
+++ b/drivers/net/wwan/wwan_core.c
@@ -160,7 +160,9 @@ static struct wwan_device *wwan_create_dev(struct device *parent)
/* If wwandev already exists, return it */
wwandev = wwan_dev_get_by_parent(parent);
- if (!IS_ERR(wwandev))
+ if (IS_ERR(wwandev))
+ wwandev = NULL;
+ else
goto done_unlock;
id = ida_alloc(&wwan_dev_ids, GFP_KERNEL);
--
2.30.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v1 1/1] wwan: core: Avoid returning error pointer from wwan_create_dev()
2021-08-05 18:31 [PATCH v1 1/1] wwan: core: Avoid returning error pointer from wwan_create_dev() Andy Shevchenko
@ 2021-08-05 19:53 ` Loic Poulain
2021-08-06 9:07 ` Andy Shevchenko
0 siblings, 1 reply; 4+ messages in thread
From: Loic Poulain @ 2021-08-05 19:53 UTC (permalink / raw)
To: Andy Shevchenko
Cc: David S. Miller, Sergey Ryazanov, Network Development, open list,
Johannes Berg, Jakub Kicinski
On Thu, 5 Aug 2021 at 20:38, Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> wwan_create_dev() is expected to return either valid pointer or NULL,
> In some cases it might return the error pointer. Prevent this by converting
> it to NULL after wwan_dev_get_by_parent().
wwan_create_dev is called both from wwan_register_ops() and
wwan_create_port(), one using IS_ERR and the other using NULL testing,
they should be aligned as well.
Regards,
Loic
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v1 1/1] wwan: core: Avoid returning error pointer from wwan_create_dev()
2021-08-05 19:53 ` Loic Poulain
@ 2021-08-06 9:07 ` Andy Shevchenko
2021-08-06 9:13 ` Sergey Ryazanov
0 siblings, 1 reply; 4+ messages in thread
From: Andy Shevchenko @ 2021-08-06 9:07 UTC (permalink / raw)
To: Loic Poulain
Cc: David S. Miller, Sergey Ryazanov, Network Development, open list,
Johannes Berg, Jakub Kicinski
On Thu, Aug 05, 2021 at 09:53:57PM +0200, Loic Poulain wrote:
> On Thu, 5 Aug 2021 at 20:38, Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> >
> > wwan_create_dev() is expected to return either valid pointer or NULL,
> > In some cases it might return the error pointer. Prevent this by converting
> > it to NULL after wwan_dev_get_by_parent().
>
> wwan_create_dev is called both from wwan_register_ops() and
> wwan_create_port(), one using IS_ERR and the other using NULL testing,
> they should be aligned as well.
Ah, good catch!
I just sent v2, but eventually I have decided to switch to error pointer since
it seems the most used pattern in the code.
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v1 1/1] wwan: core: Avoid returning error pointer from wwan_create_dev()
2021-08-06 9:07 ` Andy Shevchenko
@ 2021-08-06 9:13 ` Sergey Ryazanov
0 siblings, 0 replies; 4+ messages in thread
From: Sergey Ryazanov @ 2021-08-06 9:13 UTC (permalink / raw)
To: Andy Shevchenko
Cc: Loic Poulain, David S. Miller, Network Development, open list,
Johannes Berg, Jakub Kicinski
Hello Andy,
On Fri, Aug 6, 2021 at 12:08 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
> On Thu, Aug 05, 2021 at 09:53:57PM +0200, Loic Poulain wrote:
>> On Thu, 5 Aug 2021 at 20:38, Andy Shevchenko
>> <andriy.shevchenko@linux.intel.com> wrote:
>>>
>>> wwan_create_dev() is expected to return either valid pointer or NULL,
>>> In some cases it might return the error pointer. Prevent this by converting
>>> it to NULL after wwan_dev_get_by_parent().
>>
>> wwan_create_dev is called both from wwan_register_ops() and
>> wwan_create_port(), one using IS_ERR and the other using NULL testing,
>> they should be aligned as well.
>
> Ah, good catch!
>
> I just sent v2, but eventually I have decided to switch to error pointer since
> it seems the most used pattern in the code.
I agree that returning the error pointer is a good solution here.
Thank you for the fix.
--
Sergey
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-08-06 9:13 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2021-08-05 18:31 [PATCH v1 1/1] wwan: core: Avoid returning error pointer from wwan_create_dev() Andy Shevchenko
2021-08-05 19:53 ` Loic Poulain
2021-08-06 9:07 ` Andy Shevchenko
2021-08-06 9:13 ` Sergey Ryazanov
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