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Commit 00180468 authored by Joe Perches's avatar Joe Perches Committed by Linus Torvalds
Browse files

checkpatch: add a few DEVICE_ATTR style tests 

DEVICE_ATTR is a declaration macro that has a few alternate and
preferred forms like DEVICE_ATTR_RW, DEVICE_ATTR_RO, and DEVICE_ATTR.

As well, many uses of DEVICE_ATTR could use the preferred forms when the
show or store functions are also named in a regular form.

Suggest the preferred forms when appropriate.

Also emit a permissions warning if the the permissions are not the
typical 0644, 0444, or 0200.

Link: http://lkml.kernel.org/r/725864f363d91d1e1e6894a39fb57662eabd6d65.1513803306.git.joe@perches.com


Signed-off-by: default avatarJoe Perches <joe@perches.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3f7f335d

scripts/checkpatch.pl

+93 −21
Original line number Diff line number Diff line
@@ -566,6 +566,7 @@ foreach my $entry (@mode_permission_funcs) { 
	$mode_perms_search .= '|' if ($mode_perms_search ne "");

	$mode_perms_search .= $entry->[0];

}

$mode_perms_search = "(?:${mode_perms_search})";



our $mode_perms_world_writable = qr{

	S_IWUGO		|
@@ -600,6 +601,37 @@ foreach my $entry (keys %mode_permission_string_types) { 
	$mode_perms_string_search .= '|' if ($mode_perms_string_search ne "");

	$mode_perms_string_search .= $entry;

}

our $single_mode_perms_string_search = "(?:${mode_perms_string_search})";

our $multi_mode_perms_string_search = qr{

	${single_mode_perms_string_search}

	(?:\s*\|\s*${single_mode_perms_string_search})*

}x;



sub perms_to_octal {

	my ($string) = @_;



	return trim($string) if ($string =~ /^\s*0[0-7]{3,3}\s*$/);



	my $val = "";

	my $oval = "";

	my $to = 0;

	my $curpos = 0;

	my $lastpos = 0;

	while ($string =~ /\b(($single_mode_perms_string_search)\b(?:\s*\|\s*)?\s*)/g) {

		$curpos = pos($string);

		my $match = $2;

		my $omatch = $1;

		last if ($lastpos > 0 && ($curpos - length($omatch) != $lastpos));

		$lastpos = $curpos;

		$to |= $mode_permission_string_types{$match};

		$val .= '\s*\|\s*' if ($val ne "");

		$val .= $match;

		$oval .= $omatch;

	}

	$oval =~ s/^\s*\|\s*//;

	$oval =~ s/\s*\|\s*$//;

	return sprintf("%04o", $to);

}



our $allowed_asm_includes = qr{(?x:

	irq|
@@ -6274,6 +6306,63 @@ sub process { 
			     "Exporting world writable files is usually an error. Consider more restrictive permissions.\n" . $herecurr);

		}



# check for DEVICE_ATTR uses that could be DEVICE_ATTR_<FOO>

# and whether or not function naming is typical and if

# DEVICE_ATTR permissions uses are unusual too

		if ($^V && $^V ge 5.10.0 &&

		    defined $stat &&

		    $stat =~ /\bDEVICE_ATTR\s*\(\s*(\w+)\s*,\s*\(?\s*(\s*(?:${multi_mode_perms_string_search}|0[0-7]{3,3})\s*)\s*\)?\s*,\s*(\w+)\s*,\s*(\w+)\s*\)/) {

			my $var = $1;

			my $perms = $2;

			my $show = $3;

			my $store = $4;

			my $octal_perms = perms_to_octal($perms);

			if ($show =~ /^${var}_show$/ &&

			    $store =~ /^${var}_store$/ &&

			    $octal_perms eq "0644") {

				if (WARN("DEVICE_ATTR_RW",

					 "Use DEVICE_ATTR_RW\n" . $herecurr) &&

				    $fix) {

					$fixed[$fixlinenr] =~ s/\bDEVICE_ATTR\s*\(\s*$var\s*,\s*\Q$perms\E\s*,\s*$show\s*,\s*$store\s*\)/DEVICE_ATTR_RW(${var})/;

				}

			} elsif ($show =~ /^${var}_show$/ &&

				 $store =~ /^NULL$/ &&

				 $octal_perms eq "0444") {

				if (WARN("DEVICE_ATTR_RO",

					 "Use DEVICE_ATTR_RO\n" . $herecurr) &&

				    $fix) {

					$fixed[$fixlinenr] =~ s/\bDEVICE_ATTR\s*\(\s*$var\s*,\s*\Q$perms\E\s*,\s*$show\s*,\s*NULL\s*\)/DEVICE_ATTR_RO(${var})/;

				}

			} elsif ($show =~ /^NULL$/ &&

				 $store =~ /^${var}_store$/ &&

				 $octal_perms eq "0200") {

				if (WARN("DEVICE_ATTR_WO",

					 "Use DEVICE_ATTR_WO\n" . $herecurr) &&

				    $fix) {

					$fixed[$fixlinenr] =~ s/\bDEVICE_ATTR\s*\(\s*$var\s*,\s*\Q$perms\E\s*,\s*NULL\s*,\s*$store\s*\)/DEVICE_ATTR_WO(${var})/;

				}

			} elsif ($octal_perms eq "0644" ||

				 $octal_perms eq "0444" ||

				 $octal_perms eq "0200") {

				my $newshow = "$show";

				$newshow = "${var}_show" if ($show ne "NULL" && $show ne "${var}_show");

				my $newstore = $store;

				$newstore = "${var}_store" if ($store ne "NULL" && $store ne "${var}_store");

				my $rename = "";

				if ($show ne $newshow) {

					$rename .= " '$show' to '$newshow'";

				}

				if ($store ne $newstore) {

					$rename .= " '$store' to '$newstore'";

				}

				WARN("DEVICE_ATTR_FUNCTIONS",

				     "Consider renaming function(s)$rename\n" . $herecurr);

			} else {

				WARN("DEVICE_ATTR_PERMS",

				     "DEVICE_ATTR unusual permissions '$perms' used\n" . $herecurr);

			}

		}



# Mode permission misuses where it seems decimal should be octal

# This uses a shortcut match to avoid unnecessary uses of a slow foreach loop

# o Ignore module_param*(...) uses with a decimal 0 permission as that has a
@@ -6318,30 +6407,13 @@ sub process { 
		}



# check for uses of S_<PERMS> that could be octal for readability

		if ($line =~ /\b$mode_perms_string_search\b/) {

			my $val = "";

			my $oval = "";

			my $to = 0;

			my $curpos = 0;

			my $lastpos = 0;

			while ($line =~ /\b(($mode_perms_string_search)\b(?:\s*\|\s*)?\s*)/g) {

				$curpos = pos($line);

				my $match = $2;

				my $omatch = $1;

				last if ($lastpos > 0 && ($curpos - length($omatch) != $lastpos));

				$lastpos = $curpos;

				$to |= $mode_permission_string_types{$match};

				$val .= '\s*\|\s*' if ($val ne "");

				$val .= $match;

				$oval .= $omatch;

			}

			$oval =~ s/^\s*\|\s*//;

			$oval =~ s/\s*\|\s*$//;

			my $octal = sprintf("%04o", $to);

		if ($line =~ /\b($multi_mode_perms_string_search)\b/) {

			my $oval = $1;

			my $octal = perms_to_octal($oval);

			if (WARN("SYMBOLIC_PERMS",

				 "Symbolic permissions '$oval' are not preferred. Consider using octal permissions '$octal'.\n" . $herecurr) &&

			    $fix) {

				$fixed[$fixlinenr] =~ s/$val/$octal/;

				$fixed[$fixlinenr] =~ s/\Q$oval\E/$octal/;

			}

		}