linux-kernel - [PATCH 15/17] genksyms: fix syntax error for attribute after 'union'

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250113150253.3097820-16-masahiroy@kernel.org>
Date: Tue, 14 Jan 2025 00:00:53 +0900
From: Masahiro Yamada <masahiroy@...nel.org>
To: linux-kbuild@...r.kernel.org
Cc: linux-kernel@...r.kernel.org,
	Masahiro Yamada <masahiroy@...nel.org>
Subject: [PATCH 15/17] genksyms: fix syntax error for attribute after 'union'

A longstanding issue with genksyms is that it has hidden syntax errors.

When a syntax error occurs, yyerror() is called. However,
error_with_pos() is a no-op unless the -w option is provided.

You can observe syntax errors by manually passing the -w option.

For example, with CONFIG_MODVERSIONS=y on v6.13-rc1:

    $ make -s KCFLAGS=-D__GENKSYMS__ fs/lockd/svc.i
    $ cat fs/lockd/svc.i | scripts/genksyms/genksyms -w
        [ snip ]
    ./include/net/addrconf.h:35: syntax error

The syntax error occurs in the following code in include/net/addrconf.h:

    union __packed {
            [ snip ]
    };

The issue arises from __attribute__ immediately after the 'union'
keyword.

This commit allows the 'union' keyword to be followed by attributes.

Signed-off-by: Masahiro Yamada <masahiroy@...nel.org>
---

 scripts/genksyms/parse.y | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/scripts/genksyms/parse.y b/scripts/genksyms/parse.y
index 33639232a709..a2cd035a78c9 100644
--- a/scripts/genksyms/parse.y
+++ b/scripts/genksyms/parse.y
@@ -236,16 +236,16 @@ type_specifier:
 	   so that it is easier to expand the definition fully later.  */
 	| STRUCT_KEYW attribute_opt IDENT
 		{ remove_node($1); (*$3)->tag = SYM_STRUCT; $$ = $3; }
-	| UNION_KEYW IDENT
-		{ remove_node($1); (*$2)->tag = SYM_UNION; $$ = $2; }
+	| UNION_KEYW attribute_opt IDENT
+		{ remove_node($1); (*$3)->tag = SYM_UNION; $$ = $3; }
 	| ENUM_KEYW IDENT
 		{ remove_node($1); (*$2)->tag = SYM_ENUM; $$ = $2; }
 
 	/* Full definitions of an s/u/e.  Record it.  */
 	| STRUCT_KEYW attribute_opt IDENT class_body
 		{ record_compound($1, $3, $4, SYM_STRUCT); $$ = $4; }
-	| UNION_KEYW IDENT class_body
-		{ record_compound($1, $2, $3, SYM_UNION); $$ = $3; }
+	| UNION_KEYW attribute_opt IDENT class_body
+		{ record_compound($1, $3, $4, SYM_UNION); $$ = $4; }
 	| ENUM_KEYW IDENT enum_body
 		{ record_compound($1, $2, $3, SYM_ENUM); $$ = $3; }
 	/*
@@ -255,7 +255,7 @@ type_specifier:
 		{ add_symbol(NULL, SYM_ENUM, NULL, 0); $$ = $2; }
 	/* Anonymous s/u definitions.  Nothing needs doing.  */
 	| STRUCT_KEYW attribute_opt class_body		{ $$ = $3; }
-	| UNION_KEYW class_body				{ $$ = $2; }
+	| UNION_KEYW attribute_opt class_body		{ $$ = $3; }
 	;
 
 simple_type_specifier:
-- 
2.43.0