From: Dwaipayan Ray <dwaipayanray1@xxxxxxxxx> Subject: checkpatch: extend author Signed-off-by check for split From: header Checkpatch did not handle cases where the author From: header was split into multiple lines. The author identity could not be resolved and checkpatch generated a false NO_AUTHOR_SIGN_OFF warning. A typical example is commit e33bcbab16d1 ("tee: add support for session's client UUID generation"). When checkpatch was run on this commit, it displayed: "WARNING:NO_AUTHOR_SIGN_OFF: Missing Signed-off-by: line by nominal patch author ''" This was due to split header lines not being handled properly and the author himself wrote in commit cd2614967d8b ("checkpatch: warn if missing author Signed-off-by"): "Split From: headers are not fully handled: only the first part is compared." Support split From: headers by correctly parsing the header extension lines. RFC 5322, Section-2.2.3 stated that each extended line must start with a WSP character (a space or htab). The solution was therefore to concatenate the lines which start with a WSP to get the correct long header. Link: https://lore.kernel.org/linux-kernel-mentees/f5d8124e54a50480b0a9fa638787bc29b6e09854.camel@xxxxxxxxxxx/ Link: https://lkml.kernel.org/r/20200921085436.63003-1-dwaipayanray1@xxxxxxxxx Signed-off-by: Dwaipayan Ray <dwaipayanray1@xxxxxxxxx> Suggested-by: Joe Perches <joe@xxxxxxxxxxx> Reviewed-by: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx> Tested-by: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx> Acked-by: Joe Perches <joe@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- scripts/checkpatch.pl | 4 ++++ 1 file changed, 4 insertions(+) --- a/scripts/checkpatch.pl~checkpatch-extend-author-signed-off-by-check-for-split-from-header +++ a/scripts/checkpatch.pl @@ -2679,6 +2679,10 @@ sub process { # Check the patch for a From: if (decode("MIME-Header", $line) =~ /^From:\s*(.*)/) { $author = $1; + my $curline = $linenr; + while(defined($rawlines[$curline]) && ($rawlines[$curline++] =~ /^[ \t]\s*(.*)/)) { + $author .= $1; + } $author = encode("utf8", $author) if ($line =~ /=\?utf-8\?/i); $author =~ s/"//g; $author = reformat_email($author); _