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authorJoe Perches <joe@perches.com>2016-05-20 17:04:08 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-20 17:58:30 -0700
commit481aea5c59a57123b66d5850be1be79f9f230c0e (patch)
tree5343816c79009d7c9427c3fbe27e7f6a24a402a9 /scripts
parenta91e8994f242a500bf05b9ee96fcd7ab0228f05f (diff)
checkpatch: whine about ACCESS_ONCE
Add a test for use of ACCESS_ONCE that could be written using READ_ONCE or WRITE_ONCE. --fix it too if desired. The WRITE_ONCE fixes are less correct than the coccinelle script below as checkpatch cannot have a completely correct "expression" mechanism because checkpatch works on patches and not complete files. $ cat access_once.cocci @@ expression e1; expression e2; @@ - ACCESS_ONCE(e1) = e2 + WRITE_ONCE(e1, e2) @@ expression e1; @@ - ACCESS_ONCE(e1) + READ_ONCE(e1) Signed-off-by: Joe Perches <joe@perches.com> Cc: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'scripts')
-rwxr-xr-xscripts/checkpatch.pl22
1 files changed, 22 insertions, 0 deletions
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 6c1213cb32c4..1048672c22ee 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -5850,6 +5850,28 @@ sub process {
}
}
+# whine about ACCESS_ONCE
+ if ($^V && $^V ge 5.10.0 &&
+ $line =~ /\bACCESS_ONCE\s*$balanced_parens\s*(=(?!=))?\s*($FuncArg)?/) {
+ my $par = $1;
+ my $eq = $2;
+ my $fun = $3;
+ $par =~ s/^\(\s*(.*)\s*\)$/$1/;
+ if (defined($eq)) {
+ if (WARN("PREFER_WRITE_ONCE",
+ "Prefer WRITE_ONCE(<FOO>, <BAR>) over ACCESS_ONCE(<FOO>) = <BAR>\n" . $herecurr) &&
+ $fix) {
+ $fixed[$fixlinenr] =~ s/\bACCESS_ONCE\s*\(\s*\Q$par\E\s*\)\s*$eq\s*\Q$fun\E/WRITE_ONCE($par, $fun)/;
+ }
+ } else {
+ if (WARN("PREFER_READ_ONCE",
+ "Prefer READ_ONCE(<FOO>) over ACCESS_ONCE(<FOO>)\n" . $herecurr) &&
+ $fix) {
+ $fixed[$fixlinenr] =~ s/\bACCESS_ONCE\s*\(\s*\Q$par\E\s*\)/READ_ONCE($par)/;
+ }
+ }
+ }
+
# check for lockdep_set_novalidate_class
if ($line =~ /^.\s*lockdep_set_novalidate_class\s*\(/ ||
$line =~ /__lockdep_no_validate__\s*\)/ ) {