On Wed, 4 Mar 2026 at 15:51, Chengkaitao <[email protected]> wrote: > > From: Kaitao Cheng <[email protected]> > > Extend the refcounted_kptr test: add a node to both an rbtree and a > list, retrieve the node from the rbtree to obtain the node pointer, > then add a new node after the first in the list, and finally use > bpf_list_del to remove both nodes. > > The test asserts that the list is non-empty after insert, asserts the > first and last nodes after bpf_list_add, and asserts that the list is > empty after removing both nodes. > > To verify the validity of bpf_list_del/add, the test also expects the > verifier to reject calls to bpf_list_del/add made without holding the > spin_lock. > > Signed-off-by: Kaitao Cheng <[email protected]> > ---
No reply to or feedback addressed from https://lore.kernel.org/all/[email protected]. Please don't respin without acting on it, or explaining why you chose to skip it. > .../testing/selftests/bpf/bpf_experimental.h | 39 ++++ > .../selftests/bpf/progs/refcounted_kptr.c | 182 ++++++++++++++++++ > 2 files changed, 221 insertions(+) > > diff --git a/tools/testing/selftests/bpf/bpf_experimental.h > b/tools/testing/selftests/bpf/bpf_experimental.h > index 4b7210c318dd..d5f42ed69166 100644 > --- a/tools/testing/selftests/bpf/bpf_experimental.h > +++ b/tools/testing/selftests/bpf/bpf_experimental.h > @@ -99,6 +99,45 @@ extern struct bpf_list_node *bpf_list_pop_front(struct > bpf_list_head *head) __ks > */ > extern struct bpf_list_node *bpf_list_pop_back(struct bpf_list_head *head) > __ksym; > > +/* Description > + * Remove 'node' from the BPF linked list with head 'head'. > + * The node must be in the list. Caller receives ownership of the > + * removed node and must release it with bpf_obj_drop. > + * Returns > + * Pointer to the removed bpf_list_node, or NULL if 'node' is NULL > + * or not in the list. > + */ > +extern struct bpf_list_node *bpf_list_del(struct bpf_list_head *head, > + struct bpf_list_node *node) __ksym; > + > +/* Description > + * Insert 'new' after 'prev' in the BPF linked list with head 'head'. > + * The bpf_spin_lock protecting the list must be held. 'prev' must > already > + * be in that list; 'new' must not be in any list. The 'meta' and 'off' > + * parameters are rewritten by the verifier, no need for BPF programs to > + * set them. > + * Returns > + * 0 on success, -EINVAL if head is NULL, prev is not in the list with > head, > + * or new is already in a list. > + */ > +extern int bpf_list_add_impl(struct bpf_list_head *head, struct > bpf_list_node *new, > + struct bpf_list_node *prev, void *meta, __u64 > off) __ksym; > + > +/* Convenience macro to wrap over bpf_list_add_impl */ > +#define bpf_list_add(head, new, prev) bpf_list_add_impl(head, new, prev, > NULL, 0) > + > +/* Description > + * Return true if 'node' is the first (when 'is_first' is true) or the > last > + * (when 'is_first' is false) node in the list with head 'head'. > + */ > +extern bool bpf_list_node_is_edge(struct bpf_list_head *head, > + struct bpf_list_node *node, bool is_first) > __ksym; > + > +/* Description > + * Return true if the list with head 'head' has no entries. > + */ > +extern bool bpf_list_empty(struct bpf_list_head *head) __ksym; > + Except the macro, the rest can come from vmlinux.h. > /* Description > * Remove 'node' from rbtree with root 'root' > * Returns > diff --git a/tools/testing/selftests/bpf/progs/refcounted_kptr.c > b/tools/testing/selftests/bpf/progs/refcounted_kptr.c > index 1aca85d86aeb..aca201f9fb56 100644 > --- a/tools/testing/selftests/bpf/progs/refcounted_kptr.c > +++ b/tools/testing/selftests/bpf/progs/refcounted_kptr.c > @@ -367,6 +367,188 @@ long insert_rbtree_and_stash__del_tree_##rem_tree(void > *ctx) \ > INSERT_STASH_READ(true, "insert_stash_read: remove from tree"); > INSERT_STASH_READ(false, "insert_stash_read: don't remove from tree"); > > +/* Insert one node in tree and list, remove it from tree, add a second node > + * after it with bpf_list_add, check bpf_list_node_is_edge/empty, then > + * remove both nodes from list via bpf_list_del. > + */ Incorrect comment style. > +[...] >
