On Sun, 2020-05-10 at 11:51 -0700, Jakub Kicinski wrote:
> ENOTSUPP often feels like the right error code to use, but it's
> in fact not a standard Unix error. E.g.:
It is SUSv3 though.
> $ python
> > > > import errno
> > > > errno.errorcode[errno.ENOTSUPP]
> Traceback (most recent call last):
> File "<stdin>", line 1, in <module>
> AttributeError: module 'errno' has no attribute 'ENOTSUPP'
>
> There were numerous commits converting the uses back to EOPNOTSUPP
> but in some cases we are stuck with the high error code for backward
> compatibility reasons.
>
> Let's try prevent more ENOTSUPPs from getting into the kernel.
>
> Suggested-by: Andrew Lunn <and...@lunn.ch>
> Signed-off-by: Jakub Kicinski <k...@kernel.org>
> ---
> Hi Joe, I feel like I already talked to you about this, but I lost
> my email archive, so appologies if you already said no.
Not so far as I can tell.
This seems OK to me, but using checkpatch -f should probably
not show this error.
You might include a link to where Andrew Lunn suggested it
in the commit message. I didn't find it with a trivial search.
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -4199,6 +4199,14 @@ sub process {
> "ENOSYS means 'invalid syscall nr' and nothing
> else\n" . $herecurr);
> }
>
> +# ENOTSUPP is not a standard error code and should be avoided.
> +# Folks usually mean EOPNOTSUPP (also called ENOTSUP), when they type
> ENOTSUPP.
> +# Similarly to ENOSYS warning a small number of false positives is expected.
> + if ($line =~ /\bENOTSUPP\b/) {
So to avoid having newbies and others trying to convert
existing uses in files using checkpatch.pl -f, maybe:
---
scripts/checkpatch.pl | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index e5b6b9aa21d6..f1bc81d4d97c 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -4244,6 +4244,17 @@ sub process {
"ENOSYS means 'invalid syscall nr' and nothing
else\n" . $herecurr);
}
+# ENOTSUPP is not a standard error code and should be avoided in new patches.
+# Folks usually mean EOPNOTSUPP (also called ENOTSUP), when they type ENOTSUPP.
+# Similarly to ENOSYS warning a small number of false positives is expected.
+ if (~$file && $line =~ /\bENOTSUPP\b/) {
+ if (WARN("ENOTSUPP",
+ "ENOTSUPP is not a SUSV4 error code, prefer
EOPNOTSUPP\n" . $herecurr) &&
+ $fix) {
+ $fixed[$fixlinenr] =~
s/\bENOTSUPP\b/EOPNOTSUPP/;
+ }
+ }
+
# function brace can't be on same line, except for #defines of do while,
# or if closed on same line
if ($perl_version_ok &&
