lkml.org 
[lkml]   [2019]   [Aug]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2] checkpatch: check for nested unlikely calls
Date
IS_ERR, IS_ERR_OR_NULL, IS_ERR_VALUE already contain unlikely optimization
internally. Thus, there is no point in calling these functions under
likely/unlikely.

This check is based on the coccinelle rule developed by Enrico Weigelt
https://lore.kernel.org/lkml/1559767582-11081-1-git-send-email-info@metux.net/

Signed-off-by: Denis Efremov <efremov@linux.com>
---
scripts/checkpatch.pl | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 93a7edfe0f05..55b90e1334d2 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6480,6 +6480,12 @@ sub process {
"Using $1 should generally have parentheses around the comparison\n" . $herecurr);
}

+# nested likely/unlikely calls
+ if ($line =~ /\b(?:(?:un)?likely)\s*\(!?\s*(IS_ERR(?:_OR_NULL|_VALUE)?)/) {
+ WARN("LIKELY_MISUSE",
+ "nested (un)?likely calls, unlikely already used in $1 internally\n" . $herecurr);
+ }
+
# whine mightly about in_atomic
if ($line =~ /\bin_atomic\s*\(/) {
if ($realfile =~ m@^drivers/@) {
--
2.21.0
\
 
 \ /
  Last update: 2019-08-28 15:34    [W:0.061 / U:3.496 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site