[PATCH] kernel-doc: fix struct_group_tagged() parsing

From: Alexander Lobakin
Date: Thu Apr 11 2024 - 05:34:54 EST


From: Kees Cook <keescook@xxxxxxxxxxxx>

kernel-doc emits a warning on struct_group_tagged() if you describe your
struct group member:

include/net/libeth/rx.h:69: warning: Excess struct member 'fp' description in 'libeth_fq'

The code:

/**
* struct libeth_fq - structure representing a buffer queue
* @fp: hotpath part of the structure
* @pp: &page_pool for buffer management
[...]
*/
struct libeth_fq {
struct_group_tagged(libeth_fq_fp, fp,
struct page_pool *pp;
[...]
);

When a struct_group_tagged() is encountered, we need to build a
`struct TAG NAME;` from it, so that it will be treated as a valid
embedded struct.
Decouple the regex and do the replacement there. As far as I can see,
this doesn't produce any new warnings on the current mainline tree.

Reported-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Closes: https://lore.kernel.org/netdev/20240405212513.0d189968@xxxxxxxxxx
Fixes: 50d7bd38c3aa ("stddef: Introduce struct_group() helper macro")
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Co-developed-by: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx>
---
scripts/kernel-doc | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/scripts/kernel-doc b/scripts/kernel-doc
index 43a30f2de513..01ac8f794b30 100755
--- a/scripts/kernel-doc
+++ b/scripts/kernel-doc
@@ -1152,7 +1152,8 @@ sub dump_struct($$) {
# - first eat non-declaration parameters and rewrite for final match
# - then remove macro, outer parens, and trailing semicolon
$members =~ s/\bstruct_group\s*\(([^,]*,)/STRUCT_GROUP(/gos;
- $members =~ s/\bstruct_group_(attr|tagged)\s*\(([^,]*,){2}/STRUCT_GROUP(/gos;
+ $members =~ s/\bstruct_group_attr\s*\(([^,]*,){2}/STRUCT_GROUP(/gos;
+ $members =~ s/\bstruct_group_tagged\s*\(([^,]*),([^,]*),/struct $1 $2; STRUCT_GROUP(/gos;
$members =~ s/\b__struct_group\s*\(([^,]*,){3}/STRUCT_GROUP(/gos;
$members =~ s/\bSTRUCT_GROUP(\(((?:(?>[^)(]+)|(?1))*)\))[^;]*;/$2/gos;

--
2.44.0