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 And add test cases for the aforementioned kfuncs. Changes in v10: - Remove the table-driven approach (Ihor Solodrai) - Use the __nonown_allowed suffix for bpf_list_del/front/back - Add test cases for __nonown_allowed Changes in v9: - Expand table-driven approach coverage (Emil Tsalapatis) - Clear list node owner and unlink before drop (Emil Tsalapatis) - Remove warnings caused by WARN_ON_ONCE() (Emil Tsalapatis) - Introduce the __nonown_allowed suffix (Alexei Starovoitov) Changes in v8: - Use [patch v7 5/5] as the start of the patch series (Leon Hwang) - Introduce double pointer prev_ptr in __bpf_list_del (Kumar Kartikeya Dwivedi) - Extract refactored __bpf_list_del/add into separate patches (Leon Hwang) - Allow bpf_list_front/back result as the prev argument of bpf_list_add - Split test cases (Leon Hwang) Changes in v7: - Replace bpf_list_node_is_edge with bpf_list_is_first/is_last - Reimplement __bpf_list_del and __bpf_list_add (Kumar Kartikeya Dwivedi) - Simplify test cases (Mykyta Yatsenko) Changes in v6: - Merge [patch v5 (2,4,6)/6] into [patch v6 4/5] (Leon Hwang) - If list_head was 0-initialized, init it - refactor kfunc checks to table-driven approach (Leon Hwang) Changes in v5: - Fix bpf_obj leak on bpf_list_add_impl error Changes in v4: - [patch v3 1/6] Revert to version v1 (Alexei Starovoitov) - 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 (Alexei Starovoitov) - Add bpf_list_add/is_first/is_last/empty to API and test cases (Alexei Starovoitov) Link to v9: https://lore.kernel.org/all/[email protected]/ Link to v8: https://lore.kernel.org/all/[email protected]/ 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 __bpf_list_del to take list node pointer bpf: clear list node owner and unlink before drop bpf: Introduce the bpf_list_del kfunc. bpf: refactor __bpf_list_add to take insertion point via **prev_ptr bpf: Add bpf_list_add to insert node after a given list node bpf: add bpf_list_is_first/last/empty kfuncs bpf: allow non-owning list-node args via __nonown_allowed selftests/bpf: Add test cases for bpf_list_del/add/is_first/is_last/empty Documentation/bpf/kfuncs.rst | 22 +- kernel/bpf/helpers.c | 139 ++++-- kernel/bpf/verifier.c | 44 +- .../selftests/bpf/progs/refcounted_kptr.c | 421 ++++++++++++++++++ 4 files changed, 593 insertions(+), 33 deletions(-) -- 2.50.1 (Apple Git-155)
