[PATCH v2] checkpatch: Do not complain about positive return values starting with EPOLL

From: Guenter Roeck
Date: Mon Jun 21 2021 - 20:43:42 EST


checkpatch complains about positive return values of poll functions.
Example:

WARNING: return of an errno should typically be negative (ie: return -EPOLLIN)
+ return EPOLLIN;

Poll functions return positive values. The defines for the return values
of poll functions all start with EPOLL, resulting in a number of false
positives. An often used workaround is to assign poll function return
values to variables and returning that variable, but that is a less than
perfect solution.

There is no error definition which starts with EPOLL, so it is safe to omit
the warning for return values starting with EPOLL.

Cc: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
v2: Replaced 'rindex($name, 'EPOLL', 0) != 0' with '$name !~ /^EPOLL/'

scripts/checkpatch.pl | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 23697a6b1eaa..9ab006df01fe 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -5458,7 +5458,7 @@ sub process {
# Return of what appears to be an errno should normally be negative
if ($sline =~ /\breturn(?:\s*\(+\s*|\s+)(E[A-Z]+)(?:\s*\)+\s*|\s*)[;:,]/) {
my $name = $1;
- if ($name ne 'EOF' && $name ne 'ERROR') {
+ if ($name ne 'EOF' && $name ne 'ERROR' && $name !~ /^EPOLL/) {
WARN("USE_NEGATIVE_ERRNO",
"return of an errno should typically be negative (ie: return -$1)\n" . $herecurr);
}
--
2.25.1