kernel/bpf/helpers.c:1905:19: warning: no previous declaration for 'bpf_percpu_obj_new_impl'

From: kernel test robot
Date: Thu Nov 02 2023 - 04:43:48 EST


Hi Yonghong,

FYI, the error/warning still remains.

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 21e80f3841c01aeaf32d7aee7bbc87b3db1aa0c6
commit: 36d8bdf75a93190e5669b9d1d95994e13e15ba1d bpf: Add alloc/xchg/direct_access support for local percpu kptr
date: 8 weeks ago
config: x86_64-buildonly-randconfig-006-20231102 (https://download.01.org/0day-ci/archive/20231102/202311021613.I5dZri9c-lkp@xxxxxxxxx/config)
compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231102/202311021613.I5dZri9c-lkp@xxxxxxxxx/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311021613.I5dZri9c-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

kernel/bpf/helpers.c:1891:19: warning: no previous declaration for 'bpf_obj_new_impl' [-Wmissing-declarations]
__bpf_kfunc void *bpf_obj_new_impl(u64 local_type_id__k, void *meta__ign)
^~~~~~~~~~~~~~~~
>> kernel/bpf/helpers.c:1905:19: warning: no previous declaration for 'bpf_percpu_obj_new_impl' [-Wmissing-declarations]
__bpf_kfunc void *bpf_percpu_obj_new_impl(u64 local_type_id__k, void *meta__ign)
^~~~~~~~~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:1933:18: warning: no previous declaration for 'bpf_obj_drop_impl' [-Wmissing-declarations]
__bpf_kfunc void bpf_obj_drop_impl(void *p__alloc, void *meta__ign)
^~~~~~~~~~~~~~~~~
>> kernel/bpf/helpers.c:1941:18: warning: no previous declaration for 'bpf_percpu_obj_drop_impl' [-Wmissing-declarations]
__bpf_kfunc void bpf_percpu_obj_drop_impl(void *p__alloc, void *meta__ign)
^~~~~~~~~~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:1947:19: warning: no previous declaration for 'bpf_refcount_acquire_impl' [-Wmissing-declarations]
__bpf_kfunc void *bpf_refcount_acquire_impl(void *p__refcounted_kptr, void *meta__ign)
^~~~~~~~~~~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:1992:17: warning: no previous declaration for 'bpf_list_push_front_impl' [-Wmissing-declarations]
__bpf_kfunc int bpf_list_push_front_impl(struct bpf_list_head *head,
^~~~~~~~~~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2002:17: warning: no previous declaration for 'bpf_list_push_back_impl' [-Wmissing-declarations]
__bpf_kfunc int bpf_list_push_back_impl(struct bpf_list_head *head,
^~~~~~~~~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2035:35: warning: no previous declaration for 'bpf_list_pop_front' [-Wmissing-declarations]
__bpf_kfunc struct bpf_list_node *bpf_list_pop_front(struct bpf_list_head *head)
^~~~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2040:35: warning: no previous declaration for 'bpf_list_pop_back' [-Wmissing-declarations]
__bpf_kfunc struct bpf_list_node *bpf_list_pop_back(struct bpf_list_head *head)
^~~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2045:33: warning: no previous declaration for 'bpf_rbtree_remove' [-Wmissing-declarations]
__bpf_kfunc struct bpf_rb_node *bpf_rbtree_remove(struct bpf_rb_root *root,
^~~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2101:17: warning: no previous declaration for 'bpf_rbtree_add_impl' [-Wmissing-declarations]
__bpf_kfunc int bpf_rbtree_add_impl(struct bpf_rb_root *root, struct bpf_rb_node *node,
^~~~~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2111:33: warning: no previous declaration for 'bpf_rbtree_first' [-Wmissing-declarations]
__bpf_kfunc struct bpf_rb_node *bpf_rbtree_first(struct bpf_rb_root *root)
^~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2124:33: warning: no previous declaration for 'bpf_task_acquire' [-Wmissing-declarations]
__bpf_kfunc struct task_struct *bpf_task_acquire(struct task_struct *p)
^~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2135:18: warning: no previous declaration for 'bpf_task_release' [-Wmissing-declarations]
__bpf_kfunc void bpf_task_release(struct task_struct *p)
^~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2224:33: warning: no previous declaration for 'bpf_task_from_pid' [-Wmissing-declarations]
__bpf_kfunc struct task_struct *bpf_task_from_pid(s32 pid)
^~~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2265:19: warning: no previous declaration for 'bpf_dynptr_slice' [-Wmissing-declarations]
__bpf_kfunc void *bpf_dynptr_slice(const struct bpf_dynptr_kern *ptr, u32 offset,
^~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2349:19: warning: no previous declaration for 'bpf_dynptr_slice_rdwr' [-Wmissing-declarations]
__bpf_kfunc void *bpf_dynptr_slice_rdwr(const struct bpf_dynptr_kern *ptr, u32 offset,
^~~~~~~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2380:17: warning: no previous declaration for 'bpf_dynptr_adjust' [-Wmissing-declarations]
__bpf_kfunc int bpf_dynptr_adjust(struct bpf_dynptr_kern *ptr, u32 start, u32 end)
^~~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2398:18: warning: no previous declaration for 'bpf_dynptr_is_null' [-Wmissing-declarations]
__bpf_kfunc bool bpf_dynptr_is_null(struct bpf_dynptr_kern *ptr)
^~~~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2403:18: warning: no previous declaration for 'bpf_dynptr_is_rdonly' [-Wmissing-declarations]
__bpf_kfunc bool bpf_dynptr_is_rdonly(struct bpf_dynptr_kern *ptr)
^~~~~~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2411:19: warning: no previous declaration for 'bpf_dynptr_size' [-Wmissing-declarations]
__bpf_kfunc __u32 bpf_dynptr_size(const struct bpf_dynptr_kern *ptr)
^~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2419:17: warning: no previous declaration for 'bpf_dynptr_clone' [-Wmissing-declarations]
__bpf_kfunc int bpf_dynptr_clone(struct bpf_dynptr_kern *ptr,
^~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2432:19: warning: no previous declaration for 'bpf_cast_to_kern_ctx' [-Wmissing-declarations]
__bpf_kfunc void *bpf_cast_to_kern_ctx(void *obj)
^~~~~~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2437:19: warning: no previous declaration for 'bpf_rdonly_cast' [-Wmissing-declarations]
__bpf_kfunc void *bpf_rdonly_cast(void *obj__ign, u32 btf_id__k)
^~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2442:18: warning: no previous declaration for 'bpf_rcu_read_lock' [-Wmissing-declarations]
__bpf_kfunc void bpf_rcu_read_lock(void)
^~~~~~~~~~~~~~~~~
kernel/bpf/helpers.c:2447:18: warning: no previous declaration for 'bpf_rcu_read_unlock' [-Wmissing-declarations]
__bpf_kfunc void bpf_rcu_read_unlock(void)
^~~~~~~~~~~~~~~~~~~


vim +/bpf_percpu_obj_new_impl +1905 kernel/bpf/helpers.c

1904
> 1905 __bpf_kfunc void *bpf_percpu_obj_new_impl(u64 local_type_id__k, void *meta__ign)
1906 {
1907 u64 size = local_type_id__k;
1908
1909 /* The verifier has ensured that meta__ign must be NULL */
1910 return bpf_mem_alloc(&bpf_global_percpu_ma, size);
1911 }
1912
1913 /* Must be called under migrate_disable(), as required by bpf_mem_free */
1914 void __bpf_obj_drop_impl(void *p, const struct btf_record *rec)
1915 {
1916 if (rec && rec->refcount_off >= 0 &&
1917 !refcount_dec_and_test((refcount_t *)(p + rec->refcount_off))) {
1918 /* Object is refcounted and refcount_dec didn't result in 0
1919 * refcount. Return without freeing the object
1920 */
1921 return;
1922 }
1923
1924 if (rec)
1925 bpf_obj_free_fields(rec, p);
1926
1927 if (rec && rec->refcount_off >= 0)
1928 bpf_mem_free_rcu(&bpf_global_ma, p);
1929 else
1930 bpf_mem_free(&bpf_global_ma, p);
1931 }
1932
1933 __bpf_kfunc void bpf_obj_drop_impl(void *p__alloc, void *meta__ign)
1934 {
1935 struct btf_struct_meta *meta = meta__ign;
1936 void *p = p__alloc;
1937
1938 __bpf_obj_drop_impl(p, meta ? meta->record : NULL);
1939 }
1940
> 1941 __bpf_kfunc void bpf_percpu_obj_drop_impl(void *p__alloc, void *meta__ign)
1942 {
1943 /* The verifier has ensured that meta__ign must be NULL */
1944 bpf_mem_free_rcu(&bpf_global_percpu_ma, p__alloc);
1945 }
1946

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