From: Kaitao Cheng <[email protected]> In BPF, a list can only be used to implement a stack structure. Due to an incomplete API set, only FIFO or LIFO operations are supported. The patches enhance the BPF list API, making it more list-like.
Five new kfuncs have been added: bpf_list_del: remove a node from the list bpf_list_add_impl: insert a node after a given list node bpf_list_is_first: check if a node is the first in the list bpf_list_is_last: check if a node is the last in the list bpf_list_empty: check if the list is empty refactor kfunc checks to table-driven approach, and add test cases for the aforementioned kfuncs. Changes in v8: - Use [patch v7 5/5] as the start of the patch series - Introduce double pointer prev_ptr in __bpf_list_del - Extract refactored __bpf_list_del/add into separate patches - Allow bpf_list_front/back result as the prev argument of bpf_list_add - Split test cases Changes in v7: - Replace bpf_list_node_is_edge with bpf_list_is_first/is_last - Reimplement __bpf_list_del and __bpf_list_add - Simplify test cases Changes in v6: - Merge [patch v5 (2,4,6)/6] into [patch v6 4/5] - If list_head was 0-initialized, init it - refactor kfunc checks to table-driven approach Changes in v5: - Fix bpf_obj leak on bpf_list_add_impl error Changes in v4: - [patch v3 1/6] Revert to version v1 - Change the parameters of bpf_list_add_impl to (head, new, prev, ...) Changes in v3: - Add a new lock_rec member to struct bpf_reference_state for lock holding detection. - Add test cases to verify that the verifier correctly restricts calls to bpf_list_del when the spin_lock is not held. Changes in v2: - Remove the head parameter from bpf_list_del - Add bpf_list_add/is_first/is_last/empty to API and test cases Link to v7: https://lore.kernel.org/all/[email protected]/ Link to v6: https://lore.kernel.org/all/[email protected]/ Link to v5: https://lore.kernel.org/all/[email protected]/ Link to v4: https://lore.kernel.org/all/[email protected]/ Link to v3: https://lore.kernel.org/all/[email protected]/ Link to v2: https://lore.kernel.org/all/[email protected]/ Link to v1: https://lore.kernel.org/all/[email protected]/ Kaitao Cheng (8): bpf: refactor kfunc checks using table-driven approach in verifier bpf: refactor __bpf_list_del to take list node pointer bpf: Introduce the bpf_list_del kfunc. bpf: refactor __bpf_list_add to take insertion point via **prev_ptr bpf: Add bpf_list_add_impl to insert node after a given list node bpf: allow bpf_list_front/back result as the prev argument of bpf_list_add_impl bpf: add bpf_list_is_first/last/empty kfuncs selftests/bpf: Add test cases for bpf_list_del/add/is_first/is_last/empty kernel/bpf/helpers.c | 121 +++++-- kernel/bpf/verifier.c | 116 +++++-- .../testing/selftests/bpf/bpf_experimental.h | 16 + .../selftests/bpf/progs/refcounted_kptr.c | 311 ++++++++++++++++++ 4 files changed, 519 insertions(+), 45 deletions(-) -- 2.50.1 (Apple Git-155)
