When CONFIG_DEBUG_INFO_BTF is enabled and CONFIG_BPF_SYSCALL is
disabled, the following compilation error can be seen:
GEN .version
CHK include/generated/compile.h
UPD include/generated/compile.h
CC init/version.o
AR init/built-in.a
LD vmlinux.o
MODPOST vmlinux.symvers
MODINFO modules.builtin.modinfo
GEN modules.builtin
LD .tmp_vmlinux.btf
ld: net/ipv4/tcp_cubic.o: in function `cubictcp_unregister':
net/ipv4/tcp_cubic.c:545: undefined reference to `bpf_tcp_ca_kfunc_list'
ld: net/ipv4/tcp_cubic.c:545: undefined reference to `unregister_kfunc_btf_id_set'
ld: net/ipv4/tcp_cubic.o: in function `cubictcp_register':
net/ipv4/tcp_cubic.c:539: undefined reference to `bpf_tcp_ca_kfunc_list'
ld: net/ipv4/tcp_cubic.c:539: undefined reference to `register_kfunc_btf_id_set'
BTF .btf.vmlinux.bin.o
pahole: .tmp_vmlinux.btf: No such file or directory
LD .tmp_vmlinux.kallsyms1
.btf.vmlinux.bin.o: file not recognized: file format not recognized
make: *** [Makefile:1187: vmlinux] Error 1
'bpf_tcp_ca_kfunc_list', 'register_kfunc_btf_id_set()' and
'unregister_kfunc_btf_id_set()' are only defined when
CONFIG_BPF_SYSCALL is enabled.
Fix that by moving those definitions somewhere that doesn't depend on
the bpf() syscall.
Fixes: 14f267d95fe4 ("bpf: btf: Introduce helpers for dynamic BTF set registration")
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@xxxxxxxxx>
---
This is RFC-ish as I don't know enough about BPF/BTF. I could be missing something.
kernel/bpf/btf.c | 25 -------------------------
kernel/bpf/core.c | 37 +++++++++++++++++++++++++++++++++++++
2 files changed, 37 insertions(+), 25 deletions(-)
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index dbc3ad07e21b..69dd2efd518f 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -6344,33 +6344,8 @@ const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = {
BTF_ID_LIST_GLOBAL_SINGLE(btf_task_struct_ids, struct, task_struct)
-/* BTF ID set registration API for modules */
-
-struct kfunc_btf_id_list {
- struct list_head list;
- struct mutex mutex;
-};
-
#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
-void register_kfunc_btf_id_set(struct kfunc_btf_id_list *l,
- struct kfunc_btf_id_set *s)
-{
- mutex_lock(&l->mutex);
- list_add(&s->list, &l->list);
- mutex_unlock(&l->mutex);
-}
-EXPORT_SYMBOL_GPL(register_kfunc_btf_id_set);
-
-void unregister_kfunc_btf_id_set(struct kfunc_btf_id_list *l,
- struct kfunc_btf_id_set *s)
-{
- mutex_lock(&l->mutex);
- list_del_init(&s->list);
- mutex_unlock(&l->mutex);
-}
-EXPORT_SYMBOL_GPL(unregister_kfunc_btf_id_set);
-
bool bpf_check_mod_kfunc_call(struct kfunc_btf_id_list *klist, u32 kfunc_id,
struct module *owner)
{
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 327e3996eadb..4b2ad0fa0a4f 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -2449,6 +2449,43 @@ int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
EXPORT_SYMBOL(bpf_stats_enabled_key);
+/* BTF ID set registration API for modules */
+
+struct kfunc_btf_id_list {
+ struct list_head list;
+ struct mutex mutex;
+};
+
+#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
+
+void register_kfunc_btf_id_set(struct kfunc_btf_id_list *l,
+ struct kfunc_btf_id_set *s)
+{
+ mutex_lock(&l->mutex);
+ list_add(&s->list, &l->list);
+ mutex_unlock(&l->mutex);
+}
+EXPORT_SYMBOL_GPL(register_kfunc_btf_id_set);
+
+void unregister_kfunc_btf_id_set(struct kfunc_btf_id_list *l,
+ struct kfunc_btf_id_set *s)
+{
+ mutex_lock(&l->mutex);
+ list_del_init(&s->list);
+ mutex_unlock(&l->mutex);
+}
+EXPORT_SYMBOL_GPL(unregister_kfunc_btf_id_set);
+
+#endif
+
+#define DEFINE_KFUNC_BTF_ID_LIST(name) \
+ struct kfunc_btf_id_list name = { LIST_HEAD_INIT(name.list), \
+ __MUTEX_INITIALIZER(name.mutex) }; \
+ EXPORT_SYMBOL_GPL(name)
+
+DEFINE_KFUNC_BTF_ID_LIST(bpf_tcp_ca_kfunc_list);
+DEFINE_KFUNC_BTF_ID_LIST(prog_test_kfunc_list);
+
/* All definitions of tracepoints related to BPF. */
#define CREATE_TRACE_POINTS
#include <linux/bpf_trace.h>
--
2.33.1
