checkpatch: add a --strict check for utf-8 in commit logs

Some find using utf-8 in commit logs inappropriate.

Some patch commit logs contain unintended utf-8 characters when doing
things like copy/pasting compilation output.

Look for the start of any commit log by skipping initial lines that look
like email headers and "From: " lines.

Stop looking for utf-8 at the first signature line.

Signed-off-by: Joe Perches <joe@perches.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 26 insertions, 4 deletions

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 5ba679c8cde6..5e93342d22f9 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -240,9 +240,8 @@ our $NonptrType;
 our $Type;
 our $Declare;
 
-our $UTF8       = qr {
-        [\x09\x0A\x0D\x20-\x7E]              # ASCII
-        | [\xC2-\xDF][\x80-\xBF]             # non-overlong 2-byte
+our $NON_ASCII_UTF8     = qr{
+        [\xC2-\xDF][\x80-\xBF]               # non-overlong 2-byte
         |  \xE0[\xA0-\xBF][\x80-\xBF]        # excluding overlongs
         | [\xE1-\xEC\xEE\xEF][\x80-\xBF]{2}  # straight 3-byte
         |  \xED[\x80-\x9F][\x80-\xBF]        # excluding surrogates
@@ -251,6 +250,11 @@ our $UTF8	= qr {
         |  \xF4[\x80-\x8F][\x80-\xBF]{2}     # plane 16
 }x;
 
+our $UTF8       = qr{
+        [\x09\x0A\x0D\x20-\x7E]              # ASCII
+        | $NON_ASCII_UTF8
+}x;
+
 our $typeTypedefs = qr{(?x:
         (?:__)?(?:u|s|be|le)(?:8|16|32|64)|
         atomic_t
@@ -1330,6 +1334,9 @@ sub process {
         my $signoff = 0;
         my $is_patch = 0;
 
+        my $in_header_lines = 1;
+        my $in_commit_log = 0;          #Scanning lines before patch
+
         our @report = ();
         our $cnt_lines = 0;
         our $cnt_error = 0;
@@ -1497,7 +1504,6 @@ sub process {
                 if ($line =~ /^diff --git.*?(\S+)$/) {
                         $realfile = $1;
                         $realfile =~ s@^([^/]*)/@@;
-
                 } elsif ($line =~ /^\+\+\+\s+(\S+)/) {
                         $realfile = $1;
                         $realfile =~ s@^([^/]*)/@@;
@@ -1536,6 +1542,7 @@ sub process {
 # Check the patch for a signoff:
                 if ($line =~ /^\s*signed-off-by:/i) {
                         $signoff++;
+                        $in_commit_log = 0;
                 }
 
 # Check signature styles
@@ -1613,6 +1620,21 @@ sub process {
                             "Invalid UTF-8, patch and commit message should be encoded in UTF-8\n" . $hereptr);
                 }
 
+# Check if it's the start of a commit log
+# (not a header line and we haven't seen the patch filename)
+                if ($in_header_lines && $realfile =~ /^$/ &&
+                    $rawline !~ /^(commit\b|from\b|\w+:).+$/i) {
+                        $in_header_lines = 0;
+                        $in_commit_log = 1;
+                }
+
+# Still not yet in a patch, check for any UTF-8
+                if ($in_commit_log && $realfile =~ /^$/ &&
+                    $rawline =~ /$NON_ASCII_UTF8/) {
+                        CHK("UTF8_BEFORE_PATCH",
+                            "8-bit UTF-8 used in possible commit log\n" . $herecurr);
+                }
+
 # ignore non-hunk lines and lines being removed
                 next if (!$hunk_line || $line =~ /^-/);