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authorDenis Efremov <efremov@linux.com>2019-09-25 16:49:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-09-25 17:51:42 -0700
commitde3f186f87cf15bed8d13fedafb5bcad0167fc6d (patch)
treea3207fcc15d1708ff81182e1cc77e50feb4254b7 /scripts/checkpatch.pl
parentc7cc8d77316b4386622b2dbd29de800df7b05099 (diff)
downloadlinux-stericsson-de3f186f87cf15bed8d13fedafb5bcad0167fc6d.tar.gz
checkpatch: check for nested (un)?likely() calls
IS_ERR(), IS_ERR_OR_NULL(), IS_ERR_VALUE() and WARN*() already contain unlikely() optimization internally. Thus, there is no point in calling these functions and defines 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/ Link: http://lkml.kernel.org/r/20190829165025.15750-1-efremov@linux.com Signed-off-by: Denis Efremov <efremov@linux.com> Cc: Joe Perches <joe@perches.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Anton Altaparmakov <anton@tuxera.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Boris Pismenny <borisp@mellanox.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Denis Efremov <efremov@linux.com> Cc: Dennis Dalessandro <dennis.dalessandro@intel.com> Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> Cc: Juergen Gross <jgross@suse.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: Mike Marciniszyn <mike.marciniszyn@intel.com> Cc: Rob Clark <robdclark@gmail.com> Cc: Saeed Mahameed <saeedm@mellanox.com> Cc: Sean Paul <sean@poorly.run> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'scripts/checkpatch.pl')
-rwxr-xr-xscripts/checkpatch.pl6
1 files changed, 6 insertions, 0 deletions
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 4eb355d8ae73..6fcc66afb088 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6507,6 +6507,12 @@ sub process {
"Using $1 should generally have parentheses around the comparison\n" . $herecurr);
}
+# nested likely/unlikely calls
+ if ($line =~ /\b(?:(?:un)?likely)\s*\(\s*!?\s*(IS_ERR(?:_OR_NULL|_VALUE)?|WARN)/) {
+ WARN("LIKELY_MISUSE",
+ "nested (un)?likely() calls, $1 already uses unlikely() internally\n" . $herecurr);
+ }
+
# whine mightly about in_atomic
if ($line =~ /\bin_atomic\s*\(/) {
if ($realfile =~ m@^drivers/@) {