[PATCH v3] checkpatch: ignore warning designated initializers using NR_CPUS

From: Peng Wang
Date: Wed Dec 30 2020 - 07:30:53 EST


Some max_length wants to hold as large room as possible to
ensure enough size to tackle with the biggest NR_CPUS.
An example below:

kernel/cgroup/cpuset.c:
static struct cftype legacy_files[] = {
{
.name = "cpus",
.seq_show = cpuset_common_seq_show,
.write = cpuset_write_resmask,
.max_write_len = (100U + 6 * NR_CPUS),
.private = FILE_CPULIST,
},
...
}

Signed-off-by: Peng Wang <rocking@xxxxxxxxxxxxxxxxx>
---
scripts/checkpatch.pl | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 92e888e..6f112fb 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -7028,12 +7028,14 @@ sub process {

# use of NR_CPUS is usually wrong
# ignore definitions of NR_CPUS and usage to define arrays as likely right
+# ignore designated initializers using NR_CPUS
if ($line =~ /\bNR_CPUS\b/ &&
$line !~ /^.\s*\s*#\s*if\b.*\bNR_CPUS\b/ &&
$line !~ /^.\s*\s*#\s*define\b.*\bNR_CPUS\b/ &&
$line !~ /^.\s*$Declare\s.*\[[^\]]*NR_CPUS[^\]]*\]/ &&
$line !~ /\[[^\]]*\.\.\.[^\]]*NR_CPUS[^\]]*\]/ &&
- $line !~ /\[[^\]]*NR_CPUS[^\]]*\.\.\.[^\]]*\]/)
+ $line !~ /\[[^\]]*NR_CPUS[^\]]*\.\.\.[^\]]*\]/ &&
+ $line !~ /^.\s*\.\w+\s*=\s*.*\bNR_CPUS\b/)
{
WARN("NR_CPUS",
"usage of NR_CPUS is often wrong - consider using cpu_possible(), num_possible_cpus(), for_each_possible_cpu(), etc\n" . $herecurr);
--
2.9.5