From f90774e1fd2700de4a6e0d62866d34a26c544bd0 Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Tue, 11 Oct 2016 13:51:47 -0700 Subject: [PATCH] checkpatch: look for symbolic permissions and suggest octal instead S_ 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: Joe Perches Cc: Linus Torvalds Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- scripts/checkpatch.pl | 49 +++++++++++++++++++++++++++++++++++++------ 1 file changed, 43 insertions(+), 6 deletions(-) diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 34b445574011..1c82b01d581a 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -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/; + } + } } } }