checkpatch: add check for sscanf without return use
Naked use sscanf can be troublesome because the pointed to variables may
not have been set.
Add a warning when the sscanf return value is not used.
For now, do not add __must_check to the sscanf prototype because that will
cause a couple of hundred new warnings when compiling a kernel.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 1eb5d2f..61090e0 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -4019,6 +4019,23 @@
}
}
+# check for naked sscanf
+ if ($^V && $^V ge 5.10.0 &&
+ defined $stat &&
+ $stat =~ /\bsscanf\b/ &&
+ ($stat !~ /$Ident\s*=\s*sscanf\s*$balanced_parens/ &&
+ $stat !~ /\bsscanf\s*$balanced_parens\s*(?:$Compare)/ &&
+ $stat !~ /(?:$Compare)\s*\bsscanf\s*$balanced_parens/)) {
+ my $lc = $stat =~ tr@\n@@;
+ $lc = $lc + $linenr;
+ my $stat_real = raw_line($linenr, 0);
+ for (my $count = $linenr + 1; $count <= $lc; $count++) {
+ $stat_real = $stat_real . "\n" . raw_line($count, 0);
+ }
+ WARN("NAKED_SSCANF",
+ "unchecked sscanf return value\n" . "$here\n$stat_real\n");
+ }
+
# check for new externs in .h files.
if ($realfile =~ /\.h$/ &&
$line =~ /^\+\s*(extern\s+)$Type\s*$Ident\s*\(/s) {