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: Joe Perches <joe@perches.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Joe Perches 2016-10-11 13:51:47 -07:00 committed by Linus Torvalds
parent 85b0ee18bb
commit f90774e1fd
1 changed files with 43 additions and 6 deletions

View File

@ -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/;
}
}
}
}
}