scripts: get_abi.pl: Check for missing symbols at the ABI specs

Check for the symbols that exists under /sys but aren't
defined at Documentation/ABI.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/958e4f3a319148af6d847c0df95e35426f9c4c5f.1631957565.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/scripts/get_abi.pl b/scripts/get_abi.pl
index cfc107df59f4a04c4ea364042f71aa90134f34a4..78364c4c496748fc0d2fb68712442d69fe04457e 100755 (executable)
--- a/scripts/get_abi.pl
+++ b/scripts/get_abi.pl
@@ -13,7 +13,9 @@ my $help = 0;
 my $man = 0;
 my $debug = 0;
 my $enable_lineno = 0;
+my $show_warnings = 1;
 my $prefix="Documentation/ABI";
+my $sysfs_prefix="/sys";
 
 #
 # If true, assumes that the description is formatted with ReST
@@ -36,7 +38,7 @@ pod2usage(2) if (scalar @ARGV < 1 || @ARGV > 2);
 
 my ($cmd, $arg) = @ARGV;
 
-pod2usage(2) if ($cmd ne "search" && $cmd ne "rest" && $cmd ne "validate");
+pod2usage(2) if ($cmd ne "search" && $cmd ne "rest" && $cmd ne "validate" && $cmd ne "undefined");
 pod2usage(2) if ($cmd eq "search" && !$arg);
 
 require Data::Dumper if ($debug);
@@ -50,6 +52,8 @@ my %symbols;
 sub parse_error($$$$) {
        my ($file, $ln, $msg, $data) = @_;
 
+       return if (!$show_warnings);
+
        $data =~ s/\s+$/\n/;
 
        print STDERR "Warning: file $file#$ln:\n\t$msg";
@@ -521,11 +525,88 @@ sub search_symbols {
        }
 }
 
+# Exclude /sys/kernel/debug and /sys/kernel/tracing from the search path
+sub skip_debugfs {
+       if (($File::Find::dir =~ m,^/sys/kernel,)) {
+               return grep {!/(debug|tracing)/ } @_;
+       }
+
+       if (($File::Find::dir =~ m,^/sys/fs,)) {
+               return grep {!/(pstore|bpf|fuse)/ } @_;
+       }
+
+       return @_
+}
+
+my %leaf;
+
+my $escape_symbols = qr { ([\x01-\x08\x0e-\x1f\x21-\x29\x2b-\x2d\x3a-\x40\x7b-\xff]) }x;
+sub parse_existing_sysfs {
+       my $file = $File::Find::name;
+
+       my $mode = (stat($file))[2];
+       return if ($mode & S_IFDIR);
+
+       my $leave = $file;
+       $leave =~ s,.*/,,;
+
+       if (defined($leaf{$leave})) {
+               # FIXME: need to check if the path makes sense
+               my $what = $leaf{$leave};
+
+               $what =~ s/,/ /g;
+
+               $what =~ s/\<[^\>]+\>/.*/g;
+               $what =~ s/\{[^\}]+\}/.*/g;
+               $what =~ s/\[[^\]]+\]/.*/g;
+               $what =~ s,/\.\.\./,/.*/,g;
+               $what =~ s,/\*/,/.*/,g;
+
+               $what =~ s/\s+/ /g;
+
+               # Escape all other symbols
+               $what =~ s/$escape_symbols/\\$1/g;
+
+               foreach my $i (split / /,$what) {
+                       if ($file =~ m#^$i$#) {
+#                              print "$file: $i: OK!\n";
+                               return;
+                       }
+               }
+
+               print "$file: $leave is defined at $what\n";
+
+               return;
+       }
+
+       print "$file not found.\n";
+}
+
+sub undefined_symbols {
+       foreach my $w (sort keys %data) {
+               foreach my $what (split /\xac /,$w) {
+                       my $leave = $what;
+                       $leave =~ s,.*/,,;
+
+                       if (defined($leaf{$leave})) {
+                               $leaf{$leave} .= " " . $what;
+                       } else {
+                               $leaf{$leave} = $what;
+                       }
+               }
+       }
+
+       find({wanted =>\&parse_existing_sysfs, preprocess =>\&skip_debugfs, no_chdir => 1}, $sysfs_prefix);
+}
+
 # Ensure that the prefix will always end with a slash
 # While this is not needed for find, it makes the patch nicer
 # with --enable-lineno
 $prefix =~ s,/?$,/,;
 
+if ($cmd eq "undefined" || $cmd eq "search") {
+       $show_warnings = 0;
+}
 #
 # Parses all ABI files located at $prefix dir
 #
@@ -536,7 +617,9 @@ print STDERR Data::Dumper->Dump([\%data], [qw(*data)]) if ($debug);
 #
 # Handles the command
 #
-if ($cmd eq "search") {
+if ($cmd eq "undefined") {
+       undefined_symbols;
+} elsif ($cmd eq "search") {
        search_symbols;
 } else {
        if ($cmd eq "rest") {
@@ -575,6 +658,9 @@ B<rest>                  - output the ABI in ReST markup language
 
 B<validate>              - validate the ABI contents
 
+B<undefined>             - existing symbols at the system that aren't
+                           defined at Documentation/ABI
+
 =back
 
 =head1 OPTIONS