Commit f90774e1 authored by Joe Perches's avatar Joe Perches Committed by Linus Torvalds
Browse files

checkpatch: look for symbolic permissions and suggest octal instead 

S_<FOO> uses should be avoided where octal is more intelligible.

Linus didst say:

: It's *much* easier to parse and understand the octal numbers, while the
: symbolic macro names are just random line noise and hard as hell to
: understand.  You really have to think about it.
:
: So we should rather go the other way: convert existing bad symbolic
: permission bit macro use to just use the octal numbers.
:
: The symbolic names are good for the *other* bits (ie sticky bit, and the
: inode mode _type_ numbers etc), but for the permission bits, the symbolic
: names are just insane crap.  Nobody sane should ever use them.  Not in the
: kernel, not in user space.
(http://lkml.kernel.org/r/CA+55aFw5v23T-zvDZp-MmD_EYxF8WbafwwB59934FV7g21uMGQ@mail.gmail.com)

Link: http://lkml.kernel.org/r/7232ef011d05a92f4caa86a5e9830d87966a2eaf.1470180926.git.joe@perches.com


Signed-off-by: default avatarJoe Perches <joe@perches.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 85b0ee18

scripts/checkpatch.pl

+43 −6
Original line number Diff line number Diff line
@@ -541,6 +541,32 @@ our $mode_perms_world_writable = qr{ 
	0[0-7][0-7][2367]

}x;



our %mode_permission_string_types = (

	"S_IRWXU" => 0700,

	"S_IRUSR" => 0400,

	"S_IWUSR" => 0200,

	"S_IXUSR" => 0100,

	"S_IRWXG" => 0070,

	"S_IRGRP" => 0040,

	"S_IWGRP" => 0020,

	"S_IXGRP" => 0010,

	"S_IRWXO" => 0007,

	"S_IROTH" => 0004,

	"S_IWOTH" => 0002,

	"S_IXOTH" => 0001,

	"S_IRWXUGO" => 0777,

	"S_IRUGO" => 0444,

	"S_IWUGO" => 0222,

	"S_IXUGO" => 0111,

);



#Create a search pattern for all these strings to speed up a loop below

our $mode_perms_string_search = "";

foreach my $entry (keys %mode_permission_string_types) {

	$mode_perms_string_search .= '|' if ($mode_perms_string_search ne "");

	$mode_perms_string_search .= $entry;

}



our $allowed_asm_includes = qr{(?x:

	irq|

	memory|
@@ -6003,20 +6029,31 @@ sub process { 
					$arg_pos--;

					$skip_args = "(?:\\s*$FuncArg\\s*,\\s*){$arg_pos,$arg_pos}";

				}

				my $test = "\\b$func\\s*\\(${skip_args}([\\d]+)\\s*[,\\)]";

				my $test = "\\b$func\\s*\\(${skip_args}($FuncArg(?:\\|\\s*$FuncArg)*)\\s*[,\\)]";

				if ($line =~ /$test/) {

					my $val = $1;

					$val = $6 if ($skip_args ne "");



					if ($val !~ /^0$/ &&

					    (($val =~ /^$Int$/ && $val !~ /^$Octal$/) ||

					     length($val) ne 4)) {

					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);

					} elsif ($val =~ /^$Octal$/ && (oct($val) & 02)) {

					}

					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/;

						}

					}

				}

			}

		}

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