diff options
| author | Nathan Chancellor <nathan@kernel.org> | 2026-02-26 01:07:17 +0300 |
|---|---|---|
| committer | Nathan Chancellor <nathan@kernel.org> | 2026-02-26 21:53:05 +0300 |
| commit | d2395bb194ef212b36521ec4fa85e38b45675acb (patch) | |
| tree | 3e6deb0d9f9e8d90ab3e2e480e8e853dc25bd22e | |
| parent | 8678591b47469fe16357234efef9b260317b8be4 (diff) | |
| download | linux-d2395bb194ef212b36521ec4fa85e38b45675acb.tar.xz | |
genksyms: Fix parsing a declarator with a preceding attribute
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>
| -rw-r--r-- | scripts/genksyms/parse.y | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/scripts/genksyms/parse.y b/scripts/genksyms/parse.y index efdcf07c4eb6..cabcd146f3aa 100644 --- a/scripts/genksyms/parse.y +++ b/scripts/genksyms/parse.y @@ -325,8 +325,8 @@ direct_declarator: { $$ = $4; } | direct_declarator BRACKET_PHRASE { $$ = $2; } - | '(' declarator ')' - { $$ = $3; } + | '(' attribute_opt declarator ')' + { $$ = $4; } ; /* Nested declarators differ from regular declarators in that they do |