[PATCH V2] checkpatch: Improve the octal permissions tests

[Joe Perches]

The function calls with octal permissions commonly span multiple lines.
The current test is line oriented and fails to find some matches.

Make the test use the $stat variable instead of the $line variable to
span multiple lines.

Also add a few functions to the known functions with permissions list.

Move the SYMBOLIC_PERMS test to a separate section to find all the
S_<FOO> permissions in any form not just those that have specific
function names.

This can now find and fix permissions uses like:
     .mode = S_<FOO> | S_<BAR>;

Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
---

V2: Move the SYMBOLIC_PERMS test.

 scripts/checkpatch.pl | 60 +++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 44 insertions(+), 16 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 0ef3d837f2aa..22055004c56a 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -524,7 +524,11 @@ our @mode_permission_funcs = (
 	["module_param_array_named", 5],
 	["debugfs_create_(?:file|u8|u16|u32|u64|x8|x16|x32|x64|size_t|atomic_t|bool|blob|regset32|u32_array)", 2],
 	["proc_create(?:_data|)", 2],
-	["(?:CLASS|DEVICE|SENSOR)_ATTR", 2],
+	["(?:CLASS|DEVICE|SENSOR|SENSOR_DEVICE|IIO_DEVICE)_ATTR", 2],
+	["IIO_DEV_ATTR_[A-Z_]+", 1],
+	["SENSOR_(?:DEVICE_|)ATTR_2", 2],
+	["SENSOR_TEMPLATE(?:_2|)", 3],
+	["__ATTR", 2],
 );
 
 #Create a search pattern for all these functions to speed up a loop below
@@ -6079,45 +6083,69 @@ sub process {
 # Mode permission misuses where it seems decimal should be octal
 # This uses a shortcut match to avoid unnecessary uses of a slow foreach loop
 		if ($^V && $^V ge 5.10.0 &&
+		    defined $stat &&
 		    $line =~ /$mode_perms_search/) {
 			foreach my $entry (@mode_permission_funcs) {
 				my $func = $entry->[0];
 				my $arg_pos = $entry->[1];
 
+				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);
+				}
+
 				my $skip_args = "";
 				if ($arg_pos > 1) {
 					$arg_pos--;
 					$skip_args = "(?:\\s*$FuncArg\\s*,\\s*){$arg_pos,$arg_pos}";
 				}
 				my $test = "\\b$func\\s*\\(${skip_args}($FuncArg(?:\\|\\s*$FuncArg)*)\\s*[,\\)]";
-				if ($line =~ /$test/) {
+				if ($stat =~ /$test/) {
 					my $val = $1;
 					$val = $6 if ($skip_args ne "");
 					if (($val =~ /^$Int$/ && $val !~ /^$Octal$/) ||
 					    ($val =~ /^$Octal$/ && length($val) ne 4)) {
 						ERROR("NON_OCTAL_PERMISSIONS",
-						      "Use 4 digit octal (0777) not decimal permissions\n" . $herecurr);
+						      "Use 4 digit octal (0777) not decimal permissions\n" . "$here\n" . $stat_real);
 					}
 					if ($val =~ /^$Octal$/ && (oct($val) & 02)) {
 						ERROR("EXPORTED_WORLD_WRITABLE",
-						      "Exporting writable files is usually an error. Consider more restrictive permissions.\n" . $herecurr);
-					}
-					if ($val =~ /\b$mode_perms_string_search\b/) {
-						my $to = 0;
-						while ($val =~ /\b($mode_perms_string_search)\b(?:\s*\|\s*)?\s*/g) {
-							$to |=  $mode_permission_string_types{$1};
-						}
-						my $new = sprintf("%04o", $to);
-						if (WARN("SYMBOLIC_PERMS",
-							 "Symbolic permissions are not preferred. Consider using octal permissions $new.\n" . $herecurr) &&
-						    $fix) {
-							$fixed[$fixlinenr] =~ s/\Q$val\E/$new/;
-						}
+						      "Exporting writable files is usually an error. Consider more restrictive permissions.\n" . "$here\n" . $stat_real);
 					}
 				}
 			}
 		}
 
+# 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", $to);
+			if (WARN("SYMBOLIC_PERMS",
+				 "Symbolic permissions '$oval' are not preferred. Consider using octal permissions '$octal'.\n" . $herecurr) &&
+			    $fix) {
+				$fixed[$fixlinenr] =~ s/$val/$octal/;
+			}
+		}
+
 # validate content of MODULE_LICENSE against list from include/linux/module.h
 		if ($line =~ /\bMODULE_LICENSE\s*\(\s*($String)\s*\)/) {
 			my $extracted_string = get_quoted_string($line, $rawline);
-- 
2.10.0.rc2.1.g053435c