After commit 07919126ecfc ("netfilter: annotate NAT helper hook pointers
with __rcu"), genksyms fails to parse the __rcu annotation when building
with CONFIG_DEBUG_INFO_BTF=y, CONFIG_PAHOLE_HAS_BTF_TAG=y, and a version
of clang that supports btf_type_tag.

  $ clang --version | head -1
  ClangBuiltLinux clang version 22.1.0 (https://github.com/llvm/llvm-project.git 4434dabb69916856b824f68a64b029c67175e532)

  $ cat kernel/configs/repro.config
  CONFIG_BPF_SYSCALL=y
  CONFIG_MODVERSIONS=y
  # CONFIG_DEBUG_INFO_NONE is not set
  CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y
  CONFIG_DEBUG_INFO_BTF=y

  $ make -skj"$(nproc)" ARCH=x86_64 LLVM=1 mrproper defconfig repro.config all
  WARNING: modpost: EXPORT symbol "nf_nat_ftp_hook" [vmlinux] version generation failed, symbol will not be versioned.
  ...
  WARNING: modpost: EXPORT symbol "nf_nat_irc_hook" [vmlinux] version generation failed, symbol will not be versioned.
  ...

genksyms falls over parsing the __rcu attribute in the declarator:

  # Kernel reproducer
  $ make -skj"$(nproc)" ARCH=x86_64 KCFLAGS=-D__GENKSYMS__ LLVM=1 net/netfilter/nf_conntrack_ftp.i

  $ scripts/genksyms/genksyms -w <net/netfilter/nf_conntrack_ftp.i &| rg 'syntax error'
  include/linux/netfilter/nf_conntrack_ftp.h:29: syntax error
  net/netfilter/nf_conntrack_ftp.c:46: syntax error

  # Trivial reproducer
  $ cat test.c
  int (*func)(void *foo, int bar);
  int (__attribute__((btf_type_tag("rcu"))) *func_with_attr)(void *foo, int bar);

  $ scripts/genksyms/genksyms -w <test.c
  <stdin>:2: syntax error

Optionally allow an attribute to precede a declarator to resolve this
error and properly generate symbol versions.

Fixes: 07919126ecfc ("netfilter: annotate NAT helper hook pointers with __rcu")
Link: https://patch.msgid.link/20260225-genksyms-fix-attribute-declarator-v1-1-1b21478663fb@kernel.org
Tested-by: Nicolas Schier <nsc@kernel.org>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Enumeration constants read from a symbol reference file can incorrectly
affect new enumeration constants parsed from an actual input file.

Example:

 $ cat test.c
 enum { E_A, E_B, E_MAX };
 struct bar { int mem[E_MAX]; };
 int foo(struct bar *a) {}
 __GENKSYMS_EXPORT_SYMBOL(foo);

 $ cat test.c | ./scripts/genksyms/genksyms -T test.0.symtypes
 #SYMVER foo 0x070d854d

 $ cat test.0.symtypes
 E#E_MAX 2
 s#bar struct bar { int mem [ E#E_MAX ] ; }
 foo int foo ( s#bar * )

 $ cat test.c | ./scripts/genksyms/genksyms -T test.1.symtypes -r test.0.symtypes
 <stdin>:4: warning: foo: modversion changed because of changes in enum constant E_MAX
 #SYMVER foo 0x9c9dfd81

 $ cat test.1.symtypes
 E#E_MAX ( 2 ) + 3
 s#bar struct bar { int mem [ E#E_MAX ] ; }
 foo int foo ( s#bar * )

The __add_symbol() function includes logic to handle the incrementation of
enumeration values, but this code is also invoked when reading a reference
file. As a result, the variables last_enum_expr and enum_counter might be
incorrectly set after reading the reference file, which later affects
parsing of the actual input.

Fix the problem by splitting the logic for the incrementation of
enumeration values into a separate function process_enum() and call it from
__add_symbol() only when processing non-reference data.

Fixes: e37ddb825003 ("genksyms: Track changes to enum constants")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Handle typeof_unqual, __typeof_unqual and __typeof_unqual__ keywords
using TYPEOF_KEYW token in the same way as typeof keyword.

Also ignore x86 __seg_fs and __seg_gs named address space qualifiers
using X86_SEG_KEYW token in the same way as const, volatile or
restrict qualifiers.

Fixes: ac053946f5c4 ("compiler.h: introduce TYPEOF_UNQUAL() macro")
Closes: https://lore.kernel.org/lkml/81a25a60-de78-43fb-b56a-131151e1c035@molgen.mpg.de/
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Link: https://lore.kernel.org/r/20250413220749.270704-1-ubizjak@gmail.com

For the ST_NORMAL state, APP is called regardless of the token type.
Factor it out.

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

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

For example, genksyms fails to parse the following valid code:

    int x, __attribute__((__section__(".init.data")))y;

Here, only 'y' is annotated by the attribute, although I am not aware
of actual uses of this pattern in the kernel tree.

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.

    $ echo 'int x, __attribute__((__section__(".init.data")))y;' | scripts/genksyms/genksyms -w
    <stdin>:1: syntax error

This commit allows attributes to be placed between a comma and
init_declarator.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Nicolas Schier <n.schier@avm.de>

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, genksyms fails to parse the following code in
arch/arm64/lib/xor-neon.c:

    static inline uint64x2_t eor3(uint64x2_t p, uint64x2_t q, uint64x2_t r)
    {
            [ snip ]
    }

The syntax error occurs because genksyms does not recognize the
uint64x2_t keyword.

This commit adds support for builtin types described in Arm Neon
Intrinsics Reference.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Nicolas Schier <n.schier@avm.de>

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 __packed, which is defined as
__attribute__((__packed__)), immediately after the 'union' keyword.

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

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Nicolas Schier <n.schier@avm.de>

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__ arch/x86/kernel/cpu/mshyperv.i
    $ cat arch/x86/kernel/cpu/mshyperv.i | scripts/genksyms/genksyms -w
        [ snip ]
    ./arch/x86/include/asm/svm.h:122: syntax error

The syntax error occurs in the following code in arch/x86/include/asm/svm.h:

    struct __attribute__ ((__packed__)) vmcb_control_area {
            [ snip ]
    };

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

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

The lexer must be adjusted because dont_want_brace_phase should not be
decremented while processing attributes.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Nicolas Schier <n.schier@avm.de>

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__ kernel/module/main.i
    $ cat kernel/module/main.i | scripts/genksyms/genksyms -w
        [ snip ]
    kernel/module/main.c:97: syntax error

The syntax error occurs in the following code in kernel/module/main.c:

    static void __mod_update_bounds(enum mod_mem_type type __maybe_unused, void *base,
                                    unsigned int size, struct mod_tree_root *tree)
    {
            [ snip ]
    }

The issue arises from __maybe_unused, which is defined as
__attribute__((__unused__)).

This commit allows direct_abstract_declarator to be followed with
attributes.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Nicolas Schier <n.schier@avm.de>

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__ drivers/acpi/prmt.i
    $ cat drivers/acpi/prmt.i | scripts/genksyms/genksyms -w
        [ snip ]
    drivers/acpi/prmt.c:56: syntax error

The syntax error occurs in the following code in drivers/acpi/prmt.c:

    struct prm_handler_info {
            [ snip ]
            efi_status_t (__efiapi *handler_addr)(u64, void *);
            [ snip ]
    };

The issue arises from __efiapi, which is defined as either
__attribute__((ms_abi)) or __attribute__((regparm(0))).

This commit allows nested_declarator to be prefixed with attributes.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Nicolas Schier <n.schier@avm.de>