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| author | Masahiro Yamada <masahiroy@kernel.org> | 2025-01-14 00:00:49 +0900 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2025-01-18 09:11:46 +0900 |
| commit | 2966b66c94a2b0d897f8626b8f2c50a0fd4878a9 (patch) | |
| tree | 2e73a2f8fcd7fea339ab955c818e9d656141cbe3 /scripts | |
| parent | ec28bfff83c49b65527f0055e313d9d7c8c04a31 (diff) | |
genksyms: fix syntax error for attribute before abstract_declarator
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__ init/main.i
$ cat init/main.i | scripts/genksyms/genksyms -w
[ snip ]
./include/linux/efi.h:1225: syntax error
The syntax error occurs in the following code in include/linux/efi.h:
efi_status_t
efi_call_acpi_prm_handler(efi_status_t (__efiapi *handler_addr)(u64, void *),
u64 param_buffer_addr, void *context);
The issue arises from __efiapi, which is defined as either
__attribute__((ms_abi)) or __attribute__((regparm(0))).
This commit allows abstract_declarator to be prefixed with attributes.
To avoid conflicts, I tweaked the rule for decl_specifier_seq. Due to
this change, a standalone attribute cannot become decl_specifier_seq.
Otherwise, I do not know how to resolve the conflicts.
The following code, which was previously accepted by genksyms, will now
result in a syntax error:
void my_func(__attribute__((unused))x);
I do not think it is a big deal because GCC also fails to parse it.
$ echo 'void my_func(__attribute__((unused))x);' | gcc -c -x c -
<stdin>:1:37: error: unknown type name 'x'
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Nicolas Schier <n.schier@avm.de>
Diffstat (limited to 'scripts')
| -rw-r--r-- | scripts/genksyms/parse.y | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/scripts/genksyms/parse.y b/scripts/genksyms/parse.y index cd933a95548d..54e16c2e0b4b 100644 --- a/scripts/genksyms/parse.y +++ b/scripts/genksyms/parse.y @@ -203,8 +203,9 @@ decl_specifier_seq_opt: ; decl_specifier_seq: - decl_specifier { decl_spec = *$1; } + attribute_opt decl_specifier { decl_spec = *$2; } | decl_specifier_seq decl_specifier { decl_spec = *$2; } + | decl_specifier_seq ATTRIBUTE_PHRASE { decl_spec = *$2; } ; decl_specifier: @@ -216,7 +217,6 @@ decl_specifier: } | type_specifier { dont_want_type_specifier = true; $$ = $1; } | type_qualifier - | ATTRIBUTE_PHRASE ; storage_class_specifier: @@ -406,8 +406,8 @@ direct_abstract_declarator1: { $$ = $4; } | direct_abstract_declarator1 BRACKET_PHRASE { $$ = $2; } - | open_paren abstract_declarator ')' - { $$ = $3; } + | open_paren attribute_opt abstract_declarator ')' + { $$ = $4; } | open_paren error ')' { $$ = $3; } | BRACKET_PHRASE |