Documentation/dev-tools/checkpatch.rst | 5 ++ scripts/checkpatch.pl | 112 ++++++++++++++++++++++----------- 2 files changed, 82 insertions(+), 35 deletions(-)
checkpatch validates the Signed-off-by trailers against the patch's
author, but misses the opportunity to also validate the committer when
run with --git. Maintainers therefor need third-party scripts for the
final Signed-off-by check.
git format-patch provides the author and patch content, but not the
committer. Extend the existing git log extraction to record the
committer identity.
Extract the author sign-off comparison logic into a shared helper, and
use it to apply the same heuristics to the final Signed-off-by trailer
and committer.
Emit COMMITTER_SIGN_OFF_MISMATCH when the final trailer does not match
the committer.
Assisted-by: OpenCode:GPT-5.5
Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
---
Documentation/dev-tools/checkpatch.rst | 5 ++
scripts/checkpatch.pl | 112 ++++++++++++++++++++++-----------
2 files changed, 82 insertions(+), 35 deletions(-)
diff --git a/Documentation/dev-tools/checkpatch.rst b/Documentation/dev-tools/checkpatch.rst
index 6139a08c34cd..7726c3863bcc 100644
--- a/Documentation/dev-tools/checkpatch.rst
+++ b/Documentation/dev-tools/checkpatch.rst
@@ -562,6 +562,11 @@ Commit message
- The email subaddresses do not match.
- The email comments do not match.
+ **COMMITTER_SIGN_OFF_MISMATCH**
+ When checking a Git commit, the final Signed-off-by: line does not match
+ the commit's committer. The person committing a patch should add their
+ own Signed-off-by: line last.
+
**MISSING_SIGN_OFF**
The patch is missing a Signed-off-by line. A signed-off-by
line should be added according to Developer's certificate of
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 7a846a3ea127..0e1bff241597 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -37,6 +37,7 @@ my $showfile = 0;
my $file = 0;
my $git = 0;
my %git_commits = ();
+my %git_committers = ();
my $check = 0;
my $check_orig = 0;
my $summary = 1;
@@ -1317,14 +1318,16 @@ if ($git) {
} else {
$git_range = "-1 $commit_expr";
}
- my $lines = `${git_command} log --no-color --no-merges --pretty=format:'%H %s' $git_range`;
+ my $lines = `${git_command} log --no-color --no-merges --pretty=format:'%cn <%ce> %H %s' $git_range`;
foreach my $line (split(/\n/, $lines)) {
- $line =~ /^([0-9a-fA-F]{40,40}) (.*)$/;
- next if (!defined($1) || !defined($2));
- my $sha1 = $1;
- my $subject = $2;
+ $line =~ /^(.* <[^>]+>) ([0-9a-fA-F]{40,40}) (.*)$/;
+ next if (!defined($1) || !defined($2) || !defined($3));
+ my $committer = $1;
+ my $sha1 = $2;
+ my $subject = $3;
unshift(@commits, $sha1);
$git_commits{$sha1} = $subject;
+ $git_committers{$sha1} = $committer;
}
}
die "$P: no git commits after extraction!\n" if (@commits == 0);
@@ -1530,6 +1533,43 @@ sub same_email_addresses {
$comment1 eq $comment2;
}
+sub signoff_match_status {
+ my ($signoff, $identity) = @_;
+ my $authorsignoff = 0;
+
+ if (same_email_addresses($signoff, $identity)) {
+ $authorsignoff = 1;
+ } else {
+ my ($signoff_name, $signoff_comment, $signoff_address, $comment1) = parse_email($signoff);
+ my ($identity_name, $identity_comment, $identity_address, $comment2) = parse_email($identity);
+
+ if (lc $signoff_address eq lc $identity_address &&
+ $signoff_name eq $identity_name) {
+ $authorsignoff = 2;
+ } elsif (lc $signoff_address eq lc $identity_address) {
+ $authorsignoff = 3;
+ } elsif ($signoff_name eq $identity_name) {
+ $authorsignoff = 4;
+
+ my $address1 = $signoff_address;
+ my $address2 = $identity_address;
+
+ if ($address1 =~ /(\S+)\+\S+(\@.*)/) {
+ $address1 = "$1$2";
+ }
+ if ($address2 =~ /(\S+)\+\S+(\@.*)/) {
+ $address2 = "$1$2";
+ }
+
+ if ($address1 eq $address2) {
+ $authorsignoff = 5;
+ }
+ }
+ }
+
+ return $authorsignoff;
+}
+
sub which {
my ($bin) = @_;
@@ -2690,6 +2730,9 @@ sub process {
my $author = '';
my $authorsignoff = 0;
my $author_sob = '';
+ my $last_signoff = '';
+ my $committer = $git_committers{$filename} // '';
+ my $committersignoff = 0;
my $is_patch = 0;
my $is_binding_patch = -1;
my $in_header_lines = $file ? 0 : 1;
@@ -3018,40 +3061,16 @@ sub process {
# Check the patch for a signoff:
if ($line =~ /^\s*signed-off-by:\s*(.*)/i) {
$signoff++;
+ $last_signoff = $1;
$in_commit_log = 0;
if ($author ne '' && $authorsignoff != 1) {
- if (same_email_addresses($1, $author)) {
- $authorsignoff = 1;
- } else {
- my $ctx = $1;
- my ($email_name, $email_comment, $email_address, $comment1) = parse_email($ctx);
- my ($author_name, $author_comment, $author_address, $comment2) = parse_email($author);
-
- if (lc $email_address eq lc $author_address && $email_name eq $author_name) {
- $author_sob = $ctx;
- $authorsignoff = 2;
- } elsif (lc $email_address eq lc $author_address) {
- $author_sob = $ctx;
- $authorsignoff = 3;
- } elsif ($email_name eq $author_name) {
- $author_sob = $ctx;
- $authorsignoff = 4;
-
- my $address1 = $email_address;
- my $address2 = $author_address;
-
- if ($address1 =~ /(\S+)\+\S+(\@.*)/) {
- $address1 = "$1$2";
- }
- if ($address2 =~ /(\S+)\+\S+(\@.*)/) {
- $address2 = "$1$2";
- }
- if ($address1 eq $address2) {
- $authorsignoff = 5;
- }
- }
+ my $signoff_status = signoff_match_status($1, $author);
+ if ($signoff_status != 0) {
+ $authorsignoff = $signoff_status;
+ $author_sob = $1 if ($signoff_status != 1);
}
}
+ $committersignoff = signoff_match_status($1, $committer) if ($committer ne '');
}
# Check for invalid patch separator
@@ -7901,6 +7920,29 @@ sub process {
}
}
}
+ if ($is_patch && $has_commit_log && $chk_signoff &&
+ $committer ne '' &&
+ $last_signoff ne '' &&
+ $committersignoff != 1) {
+ my $sob_msg = "'Committer: $committer' != 'Signed-off-by: $last_signoff'";
+
+ if ($committersignoff == 2) {
+ CHK("COMMITTER_SIGN_OFF_MISMATCH",
+ "Committer:/Signed-off-by: email comments mismatch: $sob_msg\n");
+ } elsif ($committersignoff == 3) {
+ WARN("COMMITTER_SIGN_OFF_MISMATCH",
+ "Committer:/Signed-off-by: email name mismatch: $sob_msg\n");
+ } elsif ($committersignoff == 4) {
+ WARN("COMMITTER_SIGN_OFF_MISMATCH",
+ "Committer:/Signed-off-by: email address mismatch: $sob_msg\n");
+ } elsif ($committersignoff == 5) {
+ WARN("COMMITTER_SIGN_OFF_MISMATCH",
+ "Committer:/Signed-off-by: email subaddress mismatch: $sob_msg\n");
+ } else {
+ WARN("COMMITTER_SIGN_OFF_MISMATCH",
+ "Last Signed-off-by: '$last_signoff' != commit committer '$committer'\n");
+ }
+ }
print report_dump();
if ($summary && !($clean == 1 && $quiet == 1)) {
---
base-commit: 290aaf24a551d5a0dce037e3fab30820f9113a10
change-id: 20260723-checkpatch-committer-sob-10fcbd636d43
Best regards,
--
Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>© 2016 - 2026 Red Hat, Inc.