The only legal integer return is 0, anything else
following "return" should be -ERRCODE or a function.
http://lkml.org/lkml/2010/7/23/318
There's lots of "return -1;" statements in this patch - it's obscene
that this is used to indicate "some error occurred" in kernel space
rather than a real errno value - even when an existing function
(eg, request_irq) gave you an error code already.
Signed-off-by: Patrick Pannuto <[email protected]>
Signed-off-by: Stepan Moskovchenko <[email protected]>
Signed-off-by: Prakruthi Deepak Heragu <[email protected]>
---
scripts/checkpatch.pl | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index a9c0550..260d252 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6197,6 +6197,12 @@ sub process {
"switch default: should use break\n" . $herectx);
}
+# check for return codes on error paths
+ if ($line =~ /\breturn\s+-\d+/) {
+ ERROR("NO_ERROR_CODE",
+ "illegal return value, please use an error code");
+ }
+
# check for gcc specific __FUNCTION__
if ($line =~ /\b__FUNCTION__\b/) {
if (WARN("USE_FUNC",
--
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a Linux Foundation Collaborative Project
On Tue, 2018-07-03 at 11:09 -0700, Prakruthi Deepak Heragu wrote:
> The only legal integer return is 0, anything else
> following "return" should be -ERRCODE or a function.
>
> http://lkml.org/lkml/2010/7/23/318
> There's lots of "return -1;" statements in this patch - it's obscene
> that this is used to indicate "some error occurred" in kernel space
> rather than a real errno value - even when an existing function
> (eg, request_irq) gave you an error code already.
>
> Signed-off-by: Patrick Pannuto <[email protected]>
> Signed-off-by: Stepan Moskovchenko <[email protected]>
> Signed-off-by: Prakruthi Deepak Heragu <[email protected]>
> ---
> scripts/checkpatch.pl | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index a9c0550..260d252 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -6197,6 +6197,12 @@ sub process {
> "switch default: should use break\n" . $herectx);
> }
>
> +# check for return codes on error paths
> + if ($line =~ /\breturn\s+-\d+/) {
> + ERROR("NO_ERROR_CODE",
> + "illegal return value, please use an error code");
> + }
> +
Substitute illegal to invalid as this wouldn't be illegal.
It might be invalid and this needs a newline and $herecurr
I'm not sure this is even useful.
There are _way_ too many of these already existing
and simple return identifiers can be OK.
$ git grep -P '\breturn\s*\-(?!0)\d+' | wc -l
10193
and
$ git grep -P '\breturn\s*\-(?!1)\d+' | wc -l
240
On 2018-07-03 11:19, Joe Perches wrote:
> On Tue, 2018-07-03 at 11:09 -0700, Prakruthi Deepak Heragu wrote:
>> The only legal integer return is 0, anything else
>> following "return" should be -ERRCODE or a function.
>>
>> http://lkml.org/lkml/2010/7/23/318
>> There's lots of "return -1;" statements in this patch - it's obscene
>> that this is used to indicate "some error occurred" in kernel space
>> rather than a real errno value - even when an existing function
>> (eg, request_irq) gave you an error code already.
>>
>> Signed-off-by: Patrick Pannuto <[email protected]>
>> Signed-off-by: Stepan Moskovchenko <[email protected]>
>> Signed-off-by: Prakruthi Deepak Heragu <[email protected]>
>> ---
>> scripts/checkpatch.pl | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
>> index a9c0550..260d252 100755
>> --- a/scripts/checkpatch.pl
>> +++ b/scripts/checkpatch.pl
>> @@ -6197,6 +6197,12 @@ sub process {
>> "switch default: should use break\n" . $herectx);
>> }
>>
>> +# check for return codes on error paths
>> + if ($line =~ /\breturn\s+-\d+/) {
>> + ERROR("NO_ERROR_CODE",
>> + "illegal return value, please use an error code");
>> + }
>> +
>
> Substitute illegal to invalid as this wouldn't be illegal.
> It might be invalid and this needs a newline and $herecurr
>
> I'm not sure this is even useful.
>
> There are _way_ too many of these already existing
> and simple return identifiers can be OK.
>
> $ git grep -P '\breturn\s*\-(?!0)\d+' | wc -l
> 10193
>
> and
>
> $ git grep -P '\breturn\s*\-(?!1)\d+' | wc -l
> 240
True. However, this would be helpful to avoid usage of such return
statements in the future.
On Tue, 2018-07-03 at 12:07 -0700, [email protected] wrote:
> On 2018-07-03 11:19, Joe Perches wrote:
> > On Tue, 2018-07-03 at 11:09 -0700, Prakruthi Deepak Heragu wrote:
> > > The only legal integer return is 0, anything else
> > > following "return" should be -ERRCODE or a function.
> > >
> > > http://lkml.org/lkml/2010/7/23/318
> > > There's lots of "return -1;" statements in this patch - it's obscene
> > > that this is used to indicate "some error occurred" in kernel space
> > > rather than a real errno value - even when an existing function
> > > (eg, request_irq) gave you an error code already.
[]
> > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> > @@ -6197,6 +6197,12 @@ sub process {
> > > "switch default: should use break\n" . $herectx);
> > > }
> > >
> > > +# check for return codes on error paths
> > > + if ($line =~ /\breturn\s+-\d+/) {
> > > + ERROR("NO_ERROR_CODE",
> > > + "illegal return value, please use an error code");
> > > + }
> > > +
> >
> > Substitute illegal to invalid as this wouldn't be illegal.
> > It might be invalid and this needs a newline and $herecurr
> >
> > I'm not sure this is even useful.
> >
> > There are _way_ too many of these already existing
> > and simple return identifiers can be OK.
> >
> > $ git grep -P '\breturn\s*\-(?!0)\d+' | wc -l
> > 10193
> >
> > and
> >
> > $ git grep -P '\breturn\s*\-(?!1)\d+' | wc -l
> > 240
>
> True. However, this would be helpful to avoid usage of such return
> statements in the future.
Maybe use CHK and not ERROR and maybe the output message
could be something like "Prefer 'return -<APPROPRIATE_ERRNO>'"